Vibration Specifications Standards Setup Criteria

Instrumentation Requirements

Vibration measurements will be made with an FFT analyzer. The type, model, serial number(s) and latest certified calibration date of all equipment used in the measurement of vibration levels for machine certification, shall be recorded and made available upon request.

FFT Analyzer

• The FFT Analyzer shall be capable of a line resolution bandwidth Df = 150 CPM for the frequency range specified for machine certification unless this restriction would result in less than 800 lines of resolution, in which case the requirement defaults to 800 lines of resolution. (Higher resolution may be required to resolve "Side Bands," or in Band 1 to resolve machine vibration between 0.3X and 0.8X Running Speed.)

• The Dynamic Range shall be a minimum of 90 dB.

• The FFT analyzer shall be capable of applying a Hanning window.

• The FFT analyzer shall be capable of linear non-overlap averaging.

• The FFT analyzer shall have anti-aliasing filters.

MEASUREMENT SYSTEM ACCURACY

The measurement system (FFT analyzer, cables, transducer and mounting) used to take vibration measurements for machine certification and acceptance shall have a measurement system. Amplitude accuracy over the selected frequency range as follows:

   • For displacement and velocity measurements ±l0% or ±1 dB.   • For acceleration measurements ±20% or ±1.5 dB.

Figure 1 Measurement System Frequency Response

MEASUREMENT SYSTEM CALIBRATION

Vibration equipment (transducer, preamplifier, FFT analyzer, recorder and connecting cable) used to take vibration measurements for machine certification and acceptance must be calibrated by a qualified instrumentation laboratory in accordance with Sections 5.1 and 5.2 of ANSI S2.17-1980 "Technique of Machinery Vibration Measurement" within one (1) year prior to the date of machine certification.

Calibration shall be traceable to the National Institute of Standards and Technology (NIST) in accordance with MIL-STD45662 "Military Standard Calibration Systems Requirements" (10 June 1980) or latest revision.

VIBRATION TRANSDUCERS

An accelerometer shall be used in the collection of data for machine certification and acceptance. The accelerometer must be selected and attached to the machine in such a way that the minimum frequency (Fmin) and maximum frequency (Fmax) as specified in Section 9 or specified otherwise by the purchaser, are within the usable frequency range of the transducer and can be accurately measured (reference recommendations of pickup manufacturer and/or Section 6.3, ANSI S2.17-1980).

The mass of the accelerometer and its mounting shall have minimal influence on the frequency response of the system over the selected measurement range. (Typical mass of accelerometer and mounting should not exceed 10 % of the dynamic mass of the structure upon which the accelerometer is mounted.) Reference Appendix for Dynamic Mass definition and Procedure to Determine Mass Effect

Integration is acceptable as a means of converting acceleration measurements to velocity or displacement, or for converting velocity measurements to displacement.

VIBRATION MEASUREMENT AXES DIRECTIONS

Axial direction (A) shall be parallel to the rotational axis of the machine.

Radial directions (R) shall be:   • at 90° (perpendicular) relative to the shaft (rotor) centerline.

Vertical shall be in a radial direction:   • on a machine surface opposite the machine mounting plate.

For motors or pumps that are end mounted, vertical readings shall be taken in a radial direction relative to axial readings on a surface opposite the machine to which the motor or pump is attached (reference Figure 2-b).

Horizontal shall be in a radial direction:   • at a right angle (90°) from the vertical readings:   • In the direction of the shaft (rotor) rotation (Reference Figure 2a and 2b).   • For electric motors, the Electrical Connection Box (Pot Head) may be used as the horizontal location relative   to vertical (reference Figure 3).

Other:   • Any radial direction other than Horizontal or Vertical

(A) FOOT-MOUNTEDFigure 2 Vibration Measurement Axes Directions

(B) END-MOUNTEDFigure 3 Vibration Measurement Axes Directions

VIBRATION MEASUREMENT LOCATIONS

Required measurement positions and orientations on a machine's surface at which vibration measurements are to be taken shall be determined by mutual agreement of the purchaser and the machine builder, and shall meet the following requirements:

Follow the convention specified, unless specified otherwise by the purchaser.

If an obstruction or safety prevents locating a transducer as specified, locate as close as possible to the standardized position.

Measurement locations used for machine certification and acceptance shall be identified on the machine layout drawing and/or machine as mutually agreed upon by the purchaser and the machine builder.

Vibration measurement locations shall be on a rigid member of the machine, as close to each bearing as feasible. Bearing housings, bearing pedestals, machine casings or permanently mounted pickup mounting blocks are examples of suitable mounting locations.

Vibration measurement location shall NOT be on a flexible cover or shield such as the fan cover on an electric motor or a sheet-metal belt guard.

Guarding must be designed to allow accessibility to all measurement locations

In the event that vibration monitoring points will be rendered inaccessible after the machine is built or access to the measurement points would present a safety problem during measurement, the purchaser shall be contacted to determine if Permanently mounted transducers are to be installed.

Measurement locations shall be numbered consecutively from 1 to N in the direction of power flow per the following:

Position 1 designates the "out-board" Starting Power Point bearing location of the driver unit of the machine. Position N designates the bearing location at the "terminating" Power Point bearing location of the driven machine. (Reference Figure 3A and Figure 4)

When a machine station consists of multiple components, such as two or more spindles, consecutive numbering of components shall be in the direction of process flow. (Reference Figures 3A and 3B).

Figure 3A Order and Consecutive Numbering Sequence

Figure 3B Order and Consecutive Numbering Sequence

Measurement locations documented for certification and acceptance on the machine layout drawing and on any vibration data submitted shall follow the following convention:

   • Station or Machine   • Component   • Position   • Orientation

Reference Figure 3C

Figure 3C Measurement Location Documentation Convention

Other Component Symbols not listed above should be agreed upon by the machine tool builder and the purchaser on an as-needed basis.

TRANSDUCER & MACHINE MOUNTING CONDITIONS

VIBRATION TRANSDUCER MOUNTING At the designated measurement positions, suitable surfaces shall be provided such that the mounted transducer will attach securely.

Hand-held pickups are not acceptable for measurement by this specification.

For a magnetic base mounted transducer the location on a machine's surface at which vibration measurements are to be taken shall be machined, if necessary, such that the magnet base can be attached firmly without "rocking."

For a stud mounted transducer the machine's surface at which vibration measurements are to be taken shall be in accordance with that specified by the transducer manufacturer (torque, grease, etc.) Designated transducer type to be specified by the purchaser.

If an adhesive is used to attach either the transducer or a magnetic mounting pad, the upper frequency limit of the transducer shall be reduced by 20% of the manufacturer's stated resonance for "hard" adhesives and by 50% of the manufacturer's stated resonance for "soft" adhesives. Transducer manufacturer's specifications should be consulted.

The vibration transducer as mounted must be such that the measurement system Amplitude accuracy over the selected frequency range equals or exceeds the requirements specified

MACHINE MOUNTING

Where a machine can be tested as an individual unit (e.g. motor, spindle, etc.) the machine must be mounted as specified

Where an individual machine can be tested only as an assembled unit (e.g. motor/pump, motor/fan, etc.), the machine mounting conditions shall be as equivalent as possible/feasible to those to be encountered upon installation at the purchaser's site.

Figure 4 Vibration Measurement Locations

Motor - Gear Box Spindle System (e)Figure 4 Vibration Measurement Locations Continued

TECHNICAL REQUIREMENTS

VIBRATION MEASUREMENT UNITS

Vibration data for machine certification and acceptance shall be expressed in the following measurement units:

The "Peak" and "Peak-to-Peak" Vibration Amplitude Measurements will be a Calculated Peak not a True Peak. The Calculated Peak will be derived from the RMS level based on the following equations:

Peak (P) = 1.414 x RMSPeak-to-Peak (P-to-P) = 2 x (P) = 2 x 1.414 x RMS

If a "True Peak" is required, the units of vibration measurement will be designated by the words "True Peak".

FREQUENCY BANDS

The frequency range of measurement shall be divided into sub-groups called bands. The Fmin and Fmax for each band will be defined in units of frequency or orders of running speed of the machine.(Ref. Figure 5)

Mandatory Bands Band 1 shall be (0.3 - 0.8) X Running Order Band 2 shall be (0.8 - 1.2) X Running Order Band 3 shall be (1.2 - 3.5) X Running Order

Other Bands

Bands 4 through N shall be defined by the specific machine tool application.

Figure 5 Frequency Bands

LINE AMPLITUDE ACCEPTANCE LIMITS

For vibration level limits specified in terms of "LINE AMPLITUDE ACCEPTANCE LIMITS":   • A line of resolution will have a band width Df = 150 CPM unless specified otherwise, or unless the Df = 1500 CPM restriction would result in less than 800 lines of resolution over the frequency range specified for certification, in which case the resolution requirement will default to 800 lines. (Greater resolution may be required to resolve "Side Bands," or in Band 1 to resolve machine vibration between 0.3X and 0.8X Running Speed.

   • The maximum amplitude of any line of resolution contained within a band shall not exceed the Line Amplitude Acceptance Limit     for the Band.

BAND-LIMITED OVERALL AMPLITUDE ACCEPTANCE LIMITS

For vibration level limits specified in terms of "BAND-LIMITED OVERALL AMPLITUDE ACCEPTANCE LIMITS" the Total vibration level "A" in a band, as

defined by the following equation, shall not exceed the Overall Amplitude Acceptance Limit specified for the Band

A = Overall vibration level in the BandAi = Amplitude in the ith line of resolution in the Band(I=1) =The first line of resolution in the Band(i=N) = The last line of resolution in the BandN = The number of lines of resolution in the Band

If the total energy in a peak is to be measured, a minimum of 5 lines of resolution must be used and the peak must be centered in the band.

If a line of resolution is coincidental with the Fmin/Fmax Of two adjacent bands, that line of resolution will be included in the band having the lowest acceptance level limit.

The amplitude range sensitivity of the FFT Analyzer shall be set to the maximum input sensitivity possible without overloading such that the actual measurement uses at least 80 dB of the Dynamic Range.

Certification will be based on:• Hanning Window.• Four (4) averages (Linear non-overlapping).

The transducer mounting shall be such that the measurement system Amplitude accuracy over the selected frequency range equals or exceeds the requirements. This may require the use of more than one accelerometer where potentially high frequencies might occur (such as gear mesh or harmonics of gear mesh) along with lower frequencies (such as due to unbalance, misalignment, looseness, etc.)

ALIGNMENT

All coupled rotating machines consisting of consecutive shafts connected through a coupling (whether rigid or flexible) shall be aligned within the tolerances specified by the purchaser in the "Request for Quote." If the Purchaser does not specify an alignment tolerance, the requirements of this Standard defaults to the tolerance limits specified in Alignment Specification

Consideration shall be given to any "thermal growth" that may occur during the normal operation of the machine that would cause the machine to "grow out of alignment" to the extent that the alignment tolerances of this specification would not be met.

BALANCING

STANDARD KEY

For rotating machines and machine components with a keyed shaft, balancing will achieved using a standard one-half key in the key seat in accordance with ISO 8821-1989. If a "full key", corresponding to the half key used for balancing, is not provided with the rotating machine, a tag, as shown below, will be attached to the machine indicating the dimension of the key used to perform the balance test.

Figure 6 Balance Test Key Dimension

The use of solder or similar deposits to achieve rotor balance is not acceptable. Any parent metal removed to achieve dynamic or static balance shall be drilled out in a manner which will maintain the structural integrity of the rotor.

MACHINE QUOTATION, CERTIFICATION, AND ACCEPTANCE

QUOTATION

The Quotation shall specify that the equipment will meet the applicable vibration level limits in Section 9 of this Specification - or the vibration level limits specified by the purchaser in the "Request for Quote."

The Quotation shall state the applicable specification vibration level limits being quoted.

Any additional costs required to meet the specification limits shall be grouped in a separate section of the Quotation and titled "VIBRATION LIMITS." Costs must be itemized and sufficiently detailed to permit a complete evaluation by the Purchaser.

MEASUREMENT REQUIREMENTS FOR MACHINE CERTIFICATION

Vibration measurements shall:

Be the responsibility of the supplier unless specified otherwise by the purchaser.

Be performed by technically qualified person who is trained and experienced in vibration measurement. The technical qualifications of the person doing the vibration certification shall be submitted as a part of the machine vibration certification data.

Be taken with the machine operating as specified in Section 9 Where "no load" is specified, no actual machining such as cutting, grinding, etc. is to be taking place during collection of machine vibration data. Where "rated load" is specified, rated operating load--either actual or simulated--will be applied during collection of machine vibration data.

Prior to taking vibration measurements, the machine will be "run-in" until it reaches speed and thermal stability.

Vibration data for machine certification shall be measured during "run-off' at the vendor's facility. Where it is impractical to set-up and test a complete machine at the vendor's facility, arrangements shall be made to perform the test at the purchaser's facility. Under this circumstance, shipment of the equipment does not relieve the vendor of the responsibility for meeting the specified vibration level limits.

The purchaser shall have the option to verify vibration data of equipment during machine "run-off' at the vendor's test site prior to shipment

The machine layout drawing shall be submitted as a part of the Machine Vibration Certification. Vibration measurement locations on the machine's surface at which vibration measurements are taken shall be designated on the drawing. At the option of the purchaser, Shaft speeds (RPM), gear type and number of gear teeth, gear mesh frequencies (CPM), bearing manufacturer's name, bearing type number and class, shall be identified on the machine layout drawing. Where gearboxes are involved, an insert such as illustrated in Figure 4-e shall be included on the machine layout drawing.

ACCEPTANCE

Authorization for machine/equipment acceptance based on the vibration limits of this specification requires signature by the purchaser's authorized representative. A copy of the acceptance must be sent to the plant's purchasing department before final acceptance is authorized.

 

Vibration Specifications Standards Electrical Motors With Alarm Limits

Electrical Motor Requirements

Motors will be defined by four (4) categories:Standard motor.......Utility OperationsSpecial motor..........Semi-Finish OperationsPrecision motor.......Finish OperationsOther motor............Per agreement by vendor and Lockheed Martin

The frequency range for motor certification will be from Fmin = 0.3 X Running Speed (synchronous speed) to Fmax = 120,000 CPM (2,000 Hertz)

Alternating current motors will be tested at rated voltage and frequency, and no load. Single speed alternating current motors will be tested at synchronous speed. A multi-

speed alternating current motor will be tested at all its rated synchronous speeds. Direct current motors will be tested at their highest rated speed. Series and universal motors will

be tested at operating speed.

Note: The required deflection is inversely proportional to the speed squared.

MOTOR ISOLATION

Method of Motor Isolation for Measuring Vibration Place the motor on an elastic mounting so proportioned that the up and down natural frequency shall be at least as low as 25 percent of the test speed of the motor. To accomplish this it is required that the elastic mounting be deflected downwards at least by the amounts shown in the Following table due to the weight of the motor. When a flexible pad is used the compression shall in no case be more than 50 percent of the original thickness of the flexible pad; otherwise the supports may be too stiff.

MOTOR SYNCHRONOUS SPEED(RPM) ISOLATION PAD COMPRESSION(INCHES)900 11200 9/161800 1/43600 1/167200 1/64

Note: The required deflection is inversely proportional to the speed squared.

MOTOR ISOLATION

Method of Motor Isolation for Measuring Vibration

All new and rebuilt motors shall conform to the vibration limits specified when tested in accordance with this specification.

CRITICAL SPEED

Completely assembled motors shall have a percentage separation between the rotor shaft first actual critical speed and the rated motor speed as specified:

ROTOR DESIGN FIRST ACTUALCRITICAL SPEED LOCATIONRigid Shaft At least 25% Above Rated Motor SpeedFlexible Shaft Maximum of 85% of Motor Speed

LIMITS

All electrical motors defined by NEMA Standard MG-1-1993 Section I "Classification . According to Size,” Small (fractional), Medium (integral) and Large Machines, shall meet the following requirements:

The Velocity Amplitude (Inch/sec-Peak) of any line of resolution, measured at bearing locations in any direction shall not exceed the Line-Amplitude Band Limit values specified in and graphed when determined in accordance with using the frequency range defined

The Acceleration Overall Amplitude (g's Peak) at bearing locations in any direction (ref. Section 4) shall not exceed the Band-Limited Overall Amplitude Acceptance Limit values specified and graphed when determined in accordance with Section using the frequency range defined.

ELECTRICAL MOTOR CERTIFICATION

The amplitude of vibration at bearing locations in any direction shall not exceed the values listed.

Vibration signatures of velocity and acceleration, and a listing of the maximum peak velocity in each band for vibration measurements taken at position 1 horizontal, position 2 vertical, and position 3 axial shall be submitted as part of the motor certification. The data shall be identified with the Motor Serial Number, Frame Number, Model Number, Horsepower and Synchronous speed.

The motor nameplate shall carry the following designation:

Vibration data and signatures must be submitted with the motor to the Maintenance Engineering Department or other authorized representative before acceptance of the motor will be authorized.

Motors not meeting the certification shall be rejected.

Figure 1 Maximum Allowable Vibration Limits for Electric Motors

Vibration Specifications Standards For Fans With Alarm Limits

Fans are defined as:

All non-positive displacement air handling units including Induced Draft (ID) Fans, Forced Draft (FD) Fans, Overhung Fans, Centerhung Fans, Centrifugal, Vaneaxial, Tubeaxial, Blowers, etc.

BALANCING

Permanently attached balancing weighs must be secured by welding, bolting, pop-riveted, or of a "clip-on" design.• If bolted, a hardened bolt must be used in conjunction with a mechanical locking device (e.g. lock washer or lock nut).

• Clip-on" balancing weights can only be used on centrifugal type fans and must be located and attached on the ID pitch of the blades such that the rotational motion of the fan creates a positive seating of the "clip-on" weight against the fan blade.

• Balancing weights and method of attachment must be stable at fan operating temperature, and of a material compatible with the parent material of the fan to which the balancing weight is attached.

NOTE: THE USE OF STICK ON LEAD WEIGHTS IS NOT ACCEPTABLE

Any parent metal removed to achieve dynamic or static balance shall be drilled out in a manner which will maintain the structural integrity of the rotor or sheave.

Access to the fan rotor for field balancing shall be designed in to the system.

NOTE: It is recommended that components (rotor, shafts sheave) be balanced individually and then trimbalanced as a total assembly.

SHAFT TOLERANCEFan shaft diameter shall meet bearing manufacturer specifications for shaft tolerances.

RESONANCENatural frequencies of the completely assembled fan unit shall not be excited at the operating speed. (Running speed should be at least 25% removed from a natural frequency of the system.)

LIMITSNew and Rebuilt/Repaired Fans shall conform to the vibration limits specified when operating at specified system CFM and Fan Static Pressure.

The frequency range for fan certification shall be from Fmin = 0.3 X Running Speed of Fan to 60,000 cpm for velocity and to 120,000 cpm for acceleration.

For fan speeds up to 3600 RPM, the maximum velocity amplitude (inch/sec-Peak) of vibration at bearing locations in any direction shall not exceed the Line Amplitude Band Limit values specified and graphed. When determined in accordance using the frequency range defined

For fan speeds up to 3600 RPM, the Band-Limited Overall vibration level of acceleration (g's Peak) at bearing locations in any direction (as defined in Section 4) shall not exceed the Band-Limited Overall Amplitude Acceptance Limit values specified and graphed, when determined in accordance using the frequency range defined.

Acceptance limits for fans running over 3600 RPM shall be specified by the purchaser.

Figure 1 Line Amplitude Acceptance Limits for Fans

Figure 2 Band Limited Overall Amplitude Acceptance Limits for Fans

OTHER REQUIREMENTS

Variable speed or adjustable sheaves shall not be used in the final installation.

Drive sheave and driven sheave should differ in size by 20 % or more to avoid "beat" vibration

 

Vibration Specifications Standards Gearboxes With Alarm Limits

Gearboxes shall not exceed the Vibration Limits specified

Figure 1 Line Amplitude Acceptance Limits for Gearboxes

Figure 2 Band-Limited Overall Amplitude Acceptance Limits for Gearboxes

Vibration Specifications Standards For Machine Tool Spindles And Heads With Alarm Limits

Spindle And Head Requirements

All single spindle and multi-spindle units will be (where possible) mounted on a test stand in their normal operating attitude, properly secured in a STRESS FREE CONDITION and be either direct coupled or belt driven. Integral motor spindles (motorized spindles) will be tested as a self-powered unit.

The Spindle or Head will be run-in until it reaches temperature stability at operating speed.

Measurement Locations

Vibration measurement locations shall be;· at a point as close to the spindle bearing as possible and in line with the spindle center line

Figure 1 (a) Measurement Locations for Single Precision Spindle

Figure 1 (b) Measusrement Locations for Spindle Cluster

Figure 1 (c) Measurement Locations for Multi-Spindle Gear-type Head

Operating Speed:

If a spindle unit is designed to operate at one speed, the unit is to be tested at that speed.

If a spindle unit is designed to operate at multiple speeds, the unit is to be tested at the each rated speed.

If a spindle unit is designed to operate at all speeds in a given speed range, the unit must be tested at its' maximum rated speed, unless this coincides with a resonance or resonance-like condition. In this case, the test speed shall be the maximum speed possible without encountering the resonance or resonance-like condition.

VIBRATION LIMITS

LIMITS FOR BOX AND CARTRIDGE-TYPE SPINDLES

The maximum velocity amplitude (Inch/sec-Peak) of vibration at bearing locations in any direction shall not exceed the Line Amplitude Band Limit values specified and graphed when determined in accordance

The maximum acceleration amplitude (g's Peak) of vibration at bearing locations in any direction shall not exceed the Band-Limited Overall Amplitude Acceptance Limits specified and graphed when determined in accordance

TABLE 1 MAXIMUM ALLOWABLE VIBRATION LEVELS FOR GEARLESS TYPESPINDLES 600 to 12,000 RPM (<= 400,000 DN)LINE-AMPLITUDE BAND LIMITSBAND FREQUENCYRANGE (CPM) VELOCITY(INCH/SEC - PEAK)1 0.3 x RPM0.8 x RPM 0.012 0.8 x RPM1.2 x RPM 0.01

3 1.2 x RPM3.5 x RPM 0.014 3.5 x RPM120,000 CPM 0.005 - Angular Contact Bearings0.0075 - Roller Bearings

BAND-LIMITED OVERALL AMPLITUDE LIMITSBAND FREQUENCYRANGE (CPM) ACCELERATION(g’s PEAK)1 0.3 x RPM - 120K CPM 0.5 - Angular Contact Bearings1.0 - <= 1000 RPM - Roller Bearings1.5 - > 1000 RPM - Roller Bearings

Figure 2 Line Amplitude Acceptance Limits for Gear less Type Spindles 600 to 12,000 RPM

Figure 3 Band-Limited Overall Amplitude Acceptance Limits for Gear less Type Spindles 600 to 12,000 RPM

TABLE 2 MAXIMUM ALLOWABLE VIBRATION LEVELS FOR GEARLESS TYPE SPINDLES <600 RPMLINE-AMPLITUDE BAND LIMITSBAND FREQUENCYRANGE (CPM) DISPLACEMENT(MILS - PEAK-TO-PEAK)1 0.3 x RPM0.8 x RPM 0.12 0.8 x RPM1.2 x RPM 0.1VELOCITY(INCH/SEC - PEAK)3 1.2 x RPM3.5 x RPM 0.014 3.5 x RPM30,000 CPM 0.005 - Angular Contact Bearings0.0075 - Roller Bearings

BAND-LIMITED OVERALL AMPLITUDE LIMITSBAND FREQUENCYRANGE (CPM) ACCELERATION(g’s PEAK)1 0.3 x RPM - 60K CPM 0.5 - Angular Contact Bearings0.75 - Roller Bearings

Figure 4 Line Amplitude Acceptance Limits for Gear less Type Spindles <600 RPM

Figure 5 Band-Limited Overall Amplitude Acceptance Limits for Gear less Type Spindles <600 RPM

LIMITS FOR INTEGRAL MOTOR (MOTORIZED) SPINDLES

Integral Motor (Motorized) Spindles shall be tested as a complete assembly (motor & spindle).

The complete assembly must meet the vibration limits specified "LIMITS FOR BOX AND CARTRIDGE-TYPE SPINDLES."

LIMITS FOR MULTI-SPINDLE (CLUSTERS) NON-GEAR TYPE ASSEMBLIES

Belt driven Multi-Spindle Clusters shall be tested as a complete assembly.

The complete assembly must meet the vibration limits specified "LIMITS FOR BOX AND CARTRIDGE-TYPE SPINDLES."

LIMITS FOR GEAR-DRIVEN SPINDLE ASSEMBLIES

For gear driven spindle assemblies the number of lines of resolution from 0.3 x Lowest Shaft Running Speed to 3.5 x Highest gear mesh frequency (GMF) or otherwise specified Fmax shall be sufficient to resolve the 1st Order Gear Mesh Sideband frequency (e.g. + 1 x Shaft RPM).

In the Velocity Spectra and the Acceleration Spectra, the line amplitude of the Gear Mesh Frequency Sidebands must be less than (<) 0.5 times the line amplitude of the Gear Mesh Frequency. The line amplitude of sidebands of Harmonics of the Gear Mesh Frequency must also be <.5 X the line amplitude of the GMF Harmonics.

In the Velocity Spectra and the Acceleration spectra, the line amplitude of GMF Harmonics must not exceed 0.2 x GMF line amplitude.

The maximum velocity band-limited overall amplitude (Inch/sec - Peak) of vibration at locations specified and illustrated, in any direction (as defined) shall not exceed the Band-Limited Overall Amplitude Acceptance Limits specified

TABLE 3 MAXIMUM ALLOWABLE VIBRATION LEVELS FORGEAR-DRIVEN SPINDLE ASSEMBLIESBAND-LIMITED OVERALL AMPLITUDE LIMITSBAND FREQUENCYRANGE (CPM) VELOCITY(Inch/sec - Peak)1 0.3 x Lowest Shaft RPMto3.5 x Highest GMF 0.08

Figure 6 Band-Limited Overall Amplitude Acceptance Limits for Gear-Driven Spindle Assemblies

Where the number of machining components or high speeds cause a head to exceed acceptable limits, a decision to correct or accept shall be mutually agreed upon by purchaser and machine builder.

PRECISION MACHINE TOOLS

Precision Machine Tools shall not exceed the Vibration Limits specified and graphically illustrated

TABLE 4 MAXIMUM ALLOWABLE VIBRATION LEVELS FORPRECISION MACHINE TOOLSLINE-AMPLITUDE BAND LIMITSBAND FREQUENCYRANGE (CPM) VELOCITY(INCH/SEC - PEAK)1 0.3 x RPM0.8 x RPM 0.022 0.8 x RPM1.2 x RPM 0.02

3 1.2 x RPM3.5 x RPM 0.014 3.5 x RPM120,000 CPM 0.005 - Angular Contact Bearings0.0075 - Roller Bearings

BAND-LIMITED OVERALL AMPLITUDE LIMITSBAND FREQUENCYRANGE (CPM) ACCELERATION(g’s PEAK)1 0.3 x RPM - 120K CPM 0.5 - Angular Contact Bearings1.0 - <=1000 RPM - roller Bearings1.5 - >=1000 RPM - Roller Bearings

Figure 7 DEFAULT Line Amplitude Acceptance Limits for Precision Machine Tools

Figure 8 DEFAULT Band-Limited Overall Amplitude Acceptance Limits for Precision Machine Tools

Vibration Specifications Standards For Pumps and Vibration Alarm Limits

Pumps shall be defined in two (2) categories:• Positive Displacement --including, but not limited to Piston, Gear, and Vane.• Centrifugal

Operating Conditions• Non-cavitating non-separating condition.• No piping strain.• Shaft coupling aligned.• Straight suction pipe to pump. (Reference Hydraulic Institute Standard)• Certification shall be performed while pumps are operating within design specifications.

VIBRATION LIMITS FOR POSITIVE DISPLACEMENT & CENTRIFUGAL PUMPS

For purposes of Line Amplitude evaluations a "PUMPING FREQUENCY" (PF) band will be established. The PF Band will be centered on the Pumping Frequency (Number of pumping elements X Pump RPM). The band will extend + 2 lines of resolution on either side of the line of resolution containing the Pumping Frequency. (i.e. Bandwidth = 5 lines of resolution)

Excluding the lines of resolution contained in the Pumping Frequency (PF) Band, the Velocity Amplitude (Inch/sec-Peak) of any line of resolution, measured at bearing locations in any direction (as defined in Section 4) shall not exceed the Line-Amplitude Band Limit values specified and graphed, when determined in accordance using the frequency range from 0.3 X Running Speed (pump RPM) to Fmax = 120,000 CPM (2,000 Hertz)

The Velocity Band-Limited Overall Amplitude (Inch/sec - Peak) at bearing locations in any direction shall not exceed the Pumping Frequency Band Limited Overall Amplitude Acceptance Limit value specified in Table 9.4. and graphed when determined in accordance using the frequency range from 0.8 X PF to 1.2 X PF.

The Acceleration Band-Limited Overall Amplitude (g's Peak) at bearing locations in any direction shall not exceed the Band-Limited Overall Amplitude Acceptance Limit values specified and graphed when determined in accordance using the frequency range from 0.3 X Running Speed to 300,000 CPM.

Figure 1 Line Amplitude Acceptance Limits for Positive Displacement & Centrifugal Pumps

Figure 2 Band-Limited Overall Amplitude Acceptance Limits for Positive Displacement & Centrifugal Pumps

VIBRATION FOR VERTICAL MOUNTED PUMPS

Vertically mounted pump systems with a "Vertical Mount Height" greater than 5 feet will have an allowable increase in Velocity Amplitude Acceptance Limits in Bands 1, 2, and 3 of 5% per foot of "Vertical Mount Height" greater than 5 feet. (e.g. A 7 foot Vertical Mount Height would yield a 10% increase [(7 ft - 5 ft) x 5%/ft] Velocity Amplitude Acceptance Limits specified for Bands 1, 2, and 3. Therefore the limit for Band 1 would be [0.4 Inch/sec + (0.4 Inch/sec x 0.1)] = 0.44 Inch/sec-Peak.

Vertical Mount Height is defined as the furthest measurable distance from the machine mounting to the end of the driver or the end of the pump, which ever is greater.

Vibration Specifications Standards General Industrial Machines With Alarm Limits

If Vibration Limit values are not available for the machine being considered, the Specification Limit shall (unless specified otherwise by the purchaser) default to the following:

Non-machine Tools and Non-precision Machine Tools shall not exceed the Vibration Limits specified and graphically illustrated

Figure 1 DEFAULT Line Amplitude Acceptance Limits for Non-Machine Tools and Non-Precision Machine Tools

Figure 2 DEFAULT Band-Limited Overall Amplitude Acceptance Limits for Non-Machine Tools and Non-Precision Machine Tools

 

Specifications Standards For Shafts Alignment

Coupled shaft alignment is the positioning of two or more machines so that the rotational centerlines of their shafts are co-linear at the coupling center under operating conditions.

LASER SHAFT ALIGNMENT SYSTEM REQUIREMENTS

The Laser Alignment System used for Coupled Shafts Alignment shall use either a combined laser emitter and laser target detector unit or separate units for its laser emitter and laser target detector.

SHAFT ALIGNMENT TOLERANCES

All shaft-to-shaft centerline alignments shall be within the tolerances specified unless more precise tolerances are specified by the machine manufacturer or by the purchasing engineer for special applications.

COUPLED SHAFT ALIGNMENT TOLERANCE VALUES

JACKSHAFTS Below “critical speed” of Jackshaft Short coupling tolerances apply to each coupling of the jackshaft.Above “critical speed” of Jackshaft Short coupling tolerances apply relative to the centerlines of the two machines.

*References: “The Optalign Training Book, “ 1990, Ludeca Inc., Miami, FL.

The Tolerances specified are the maximum allowable deviations from Zero-Zero Specifications or ALIGNMENT TARGET SPECIFICATIONS (i.e. an intention targeted offset and/or angularity).

Acknowledging that machines often move after start-up due to THERMAL GROWTH, dynamic load shifts, etc., the alignment parameters shall be measured and adjusted for operating conditions.

COUPLED SHAFTS ALIGNMENT VERIFICATION

Laser alignment will be performed on the machine tool builder’s floor on all shaft coupled machines.

When verifying the alignment of coupled shafts the machine tool builder must document and provide the following data for each set of coupled shafts:

a. Alignment tolerances used.b. SOFTFOOTc. Vertical ANGULARITY (Pitch) at the COUPLING POINTd. Vertical OFFSET at the coupling point.e. Horizontal angularity (Yaw) at the coupling point.f. Horizontal offset at the coupling point.

This information shall be provided to the purchaser at the time of functional check out.

Verification of alignment and re-alignment will be conducted at the purchaser’s facility during installation of the equipment.

MACHINE BASES

MACHINE BASE CONSTRUCTION

A solid and rigid machine base is required to achieve and maintain shaft alignment.

Where bases are constructed using concrete or grouts final shaft alignment shall not be conducted until ample curing time has taken place. (A minimum of Thirty days is recommended)

Where the machine foundation installation specification does not require a concrete or grout base or the installation schedule does not permit the proper cure time for the concrete/grout

Where corrosion is or may be a problem the base must be fabricated of corrosive resistant materials. Where the machine base is constructed from commercially available steel or castings:

Use H, M, I, square, tube, and bar shapes with a minimum 0.5 inch (1.27 cm) thickness.

For machine bases consisting of a single steel plate, plate thickness must equal or exceed the thickness of the machine foot, but be no less than 1.0 inch (2.54 cm). The plate surface that the driver and driven machines will bolted to must be machine ground and of sufficient size to accommodate the machine components, push/pull blocks and/or jack screws. Jackscrews must not rest on any rounded edges.

Use of channel or angle stock is not recommended. Where use is necessary, the channel or angle stock must be reinforced using square bar or plate meeting the preceding thickness requirements.

After all welding and machining is completed, stress relieve the entire base.

FOOT CENTER LINES

The stiffness of the machine base shall be sufficient that no foot centerline shall deform or deflect more that .001” (.0254 mm) over the operating range from alignment conditions to full load conditions.

JOINING SHAPES TOGETHER

When joining shapes together they shall conform to the appropriate applicable A.S.M.E. and/or C.W.B. standard(s) for welding.

REQUIREMENTS FOR MACHINE PADS OR FLATS

After all welding and machining has been completed and the base has been stress relieved, the surface of all pads or flats for each machine to be installed on the base must be co-planar, within .001 inch (0.0254 mm).

MACHINE BASE SUPPORT

The feet of the driver and driven machines must not overhang the machine base.

JACKBOLTS

Jackbolts shall be located at the front and rear feet of the movable machine for horizontal alignment positioning. (This requirement also applies to vertically mounted units and vertically mounted flanged units). Jackbolts shall be parallel to the flat/pad surface and align on the center line formed by the hold down bolts in the cross machine direction. Ample room shall be left for removal and insertion of shims used in the vertical alignment of the coupled machines.

HOLD-DOWN BOLTS

The use of hold down bolts is the preferred method of fastening components to the base. Hold-down bolts shall meet the following specifications:

a. Hold-down bolts for both the driver and the driven machine(s) (in pairs or in trains) shall be positioned (spotted) after the machine’s shafts have been aligned.b. Hold-down bolts shall be centered in the hole of the machine foot.c. Hold-down bolts shall be the preferred method of fastening machines to the base.

d. Hold-down bolts shall not be undercut (“Chicagoed”) to achieve HORIZONTAL adjustment.

PIPING

Piping must be fitted, supported, and sufficiently flexible such that softfoot due to movement caused by tightening pipe flanges doesn’t exceed .002” (.051 mm). Piping must not restrict the minimum 180 degree rotation requirement of the laser alignment system.

SHIMS

Shims shall meet the following specifications:

a. Commercially die-cut.b. Made of corrosion and crush resistant stainless steel, which is dimensionally stable when subjected to high compression over long periods of time.c. Consistent over the whole shim area, without seams or folds from bending.d. Clean, free from burrs, bumps, nicks and dents of any kind.e. Size numbers or trademarks etched into the shim, not printed or stamped.f. The smallest commercial shim that will fit around the hold down bolts without binding shall be used.g. The overall shim pack shall not exceed a total of three (3) shims.h. Shims must rest on bare metal, not paint or other coatings.

MACHINE VERTICAL MOBILITY

All machines shall be installed with a minimum of .125 inch (3.0 mm) dimensionally stable shims under each surface mounting point for vertical mobility.

COUPLING PLAY/BACKLASH

OEM’s must use only the couplings specified unless otherwise agreed upon by the purchaser. During the alignment process coupling play or backlash must be eliminated to accomplish a precision shaft alignment.

AXIAL SHAFT PLAY

Axial shaft play or end play must be no greater than .125 inch (3.175 mm). Accommodation of end movement must be done without inducing abnormal loads in the connecting equipment.

MACHINE TOOL SPINDLE LASER ALIGNMENT

MACHINE TOOL SPINDLE ALIGNMENT GEOMETRY

Machine Tool Spindle Alignment addresses the geometric relationship between the spindle axis of rotation and a rotation and a reference datum (e.g. a Master Part)

LASER SPINDLE ALIGNMENT SYSTEM REQUIREMENTS

The Laser Alignment System used for Machine Spindle Laser Alignment shall use separate units for its laser emitter and laser target detector so that Tracking Error and Angular Error can be distinguished.

MACHINE SPINDLE ALIGNMENT TOLERANCES

The machine spindle alignment tolerance is MACHINE DEPENDENT and shall be developed by the purchaser and the machine tool builder based on the machining operation and tolerance requirements of the part being machined.

The machine spindle shall be checked relative to a master part/pallet or suitable reference and be within alignment TOLERANCE specifications for:

a. TRACKING ERRORb. ANGULAR ERRORc. POSITION ERROR

The torque applied to the spindle hold down bolts shall comply with the spindle manufacturer’s specification.

For features that require more than one machining operation on the same feature, the alignment tolerance for Tracking and Angular errors for all spindles in the process is the final pass tolerance.

MACHINE BASE AND MACHINE SPINDLE VERIFICATION

The following information shall be provided to the purchaser at the time of runoff.

MACHINE BASE VERIFICATION

When verifying the MACHINE BASE, the machine tool builder shall document and provide the following data:a. The FLATNESS of the surface to which the slide assembly will be bolted.b. The flatness of the QUALIFIED LEVELING POINTS, when the base is mounted in a STRESS FREE CONDITION.c. The COPLANAR condition of the Qualified Leveling Points.d. The Parallelism of the Qualified Leveling Points to the slide assembly mounting surface.e. A Graphic showing the integrity of Flatness and Coplanar conditions.

MACHINE SPINDLE ALIGNMENT VERIFICATION

Laser alignment will be performed at the machine tool vendors location for all Multi-spindle heads, and all box and motorized spindle applications.

When verifying the machine spindle alignment the machine tool builder must document and provide to the purchaser the following data for each spindle:

a. Alignment tolerancesb. Spindle manufacturers recommend torque and sequence of hold down bolts.c. Tracking error (Alignment readings)d. Angular error (Alignment readings)e. Position error (Alignment readings)f. Torque (actual) and torque sequence of hold down bolts.

Verification of alignment and re-alignment will be conducted at the purchasers facility during installation of the equipment.

MACHINE BASE

MACHINE BASE CONSTRUCTION

A solid and rigid machine base is required to achieve and maintain spindle alignment.

Proper Civil engineering and Soil base Sampling should take place prior to pouring the machine base foundation.

Where bases/foundations are constructed using concrete or grouts, final spindle alignment shall not be conducted until ample curing time has taken place. (A minimum of Thirty days is recommended)

The machine base shall meet Level, Flat, and Coplanar requirements in a stress free condition.

The base shall have qualified leveling points. the qualified leveling points allow the machine’s flatness and LEVEL to be checked quickly and easily.

a. The qualified leveling points shall be ACCESSIBLE and outside the projected area occupied by the machine components. (Motors, Pumps, Spindle, Slide, Guards, etc.)

b. The qualified leveling points shall be located above each machine mounting point.

After all welding and machining is completed, stress relieve the entire base.

MACHINE BASE TOLERANCES:

a. Those portions of the machine base surface that support the slide assembly and the qualified leveling points shall be flat within .0002 in per foot (0.0167 mm/meter).

b. The accumulative error in Flatness Surface Integrity over the entire machine base surface shall not exceed the value agreed upon by purchaser and builder.

c. Qualified leveling points shall be coplanar within .0005 inch (0.0127 mm).

d. The qualified leveling points shall be parallel to the slide assembly mounting surface with .0005 inch (0.0127 mm).

MACHINE BASE FLOOR MOUNTING

a. The machine base floor mounting technique shall be approved by the purchaser.

b. Machine base mounting points shall be accessible, adjustable and induce no unnecessary strains on the machine base.

MACHINE WAYS

MACHINE WAYS BOLTED TO MACHINE BASE

Where the individual machine ways are bolted directly to the machine base, shims and/or grinding may be used to achieve vertical angular alignment and a vertical position alignment as dictated by the process and part tolerance. Alignment methodology and tolerances to be determined and agreed upon by the purchaser and the machine builder.

MACHINE WAYS ASSEMBLY

The machine way assembly load bearing areas shall be mounted on individual FULL BEARING FITTING SPACER BLOCKS. The SPACER BLOCKS shall be used to adjust the way assembly VERTICAL angular alignment (PITCH) and vertical position alignment. The blocks shall have slotted holes for easy removal, have a nominal thickness of .250 inch (6.350 mm) and mounting surfaces (top and bottom) shall be parallel with .0005 inch. (0.0127 mm).

Individual spacer blocks at each bolt may be used where a full bearing fitting spacer block is not practical.

JACKBOLTS shall be used to move the way assembly vertically and be located adjacent to each shim/hold down bolt support point.

PUSH/PULL BLOCKS shall be used to adjust the way assembly’s HORIZONTAL angular alignment (YAW) and horizontal position alignment. The push/pull blocks shall be accessible.

The machine way assembly shall not be doweled to the machine base.

MACHINE SPINDLE ADJUSTMENT DESIGN

The design of an align-able machine spindle assembly shall incorporate the following:

SINGLE AXIS BOX SPINDLES AND BOX SPINDLE CLUSTERS

Push/pull blocks shall be used for tracking and position alignment in the horizontal plane.

Full bearing fitting spacer blocks located under the front, rear, and all other support points of the spindle shall be used for tracking and position alignment in the vertical plane. The blocks shall have slotted holes for easy removal, have a nominal thickness of .250 inch (6.350 mm) and mounting surfaces (top and bottom) shall be parallel within .0005 inch (0.0127 mm).

Flange mounted box spindles are not recommend.

MULTIPLE SPINDLES

Provide push/pull blocks for tracking and position alignment in the horizontal and vertical plane.

A reference spindle shall be designated by the purchaser.

All other spindle axes shall be parallel to the reference spindle axis within .0005 inch per foot (0.0417 mm/meter).

FLANGE MOUNTED SPINDLES

Push/pull blocks shall be used for position alignment in a plane parallel to the flange mounting.

Jackbolts shall be used for tracking error alignment.

BUSHING PLATES

Machine spindle and tooling shall be designed whenever possible to eliminate the need for Bushing Plates.

Where Bushing Plates are necessary:

Bushing liners shall not extend past or above the surface of the bushing plate. Bushing liner ID centerline shall be perpendicular to the bushing plate mounting surface within .0010 inch per foot (0.0833 mm. per meter).

Bushing plate liner position tolerances shall not exceed 5% of total part tolerance.

All bushing plate locating and mounting surfaces shall be ground to a known datum, square and parallel to .0010 inch per foot.(0.0833 mm. per meter).

LASER ALIGNMENT SUPPORT SYSTEMS

NOTE: Nominal English/Metric dimensioning is used for Laser/Target Holding Adapter I.D. and Bushings I.D.., therefore English to Metric I.D. conversions will not be exact, however the tolerance integrity must be maintained.

LASER/TARGET HOLDING ADAPTERS shall be:

a. Practical to install and use while machine is in a production environment.

b. Shall mount to represent the spindle’s axis of rotation.

c. Provided by machine tool builder.

d. Standard inside diameter of each Laser holding adapter shall be ground to .7500 inch +.0010/-.0000 inch I.D. (20 mm +.0250/-.0000 mm I.D.). If spacing or center distance constraints do not allow for a .7500 inch (20 mm) inside diameter, then the inside diameter may be reduced to the next appropriate nominal size +.0010/-.0000 inch (+.0250/-.0000 mm). Laser holding adapters shall be of a length that is as long as is practical and conditions allow, and runout of the inside diameter to the mounting journal shall not exceed .001 inch (0.0254 mm).

e. Standard inside diameter of each Target holding adapter shall be ground to .7500 inch +.0002/-.0000 inch I.D. (20 mm +.0051/-0000 mm I.D.) If spacing or center distance constraints do not allow for a .7500 inch (20 mm) inside diameter, then the inside diameter shall be reduced to the next appropriate nominal size +.0002/-.0000 inch (+.0051/-.0000 mm).

f. Laser and Target post sizes should be common within one machine.

Adapters are required for each line-up application to secure the laser or target.

Each adapter shall be black oxide coated and have the following information clearly stamped and filled with yellow paint on the body of the adapter.

a. Inside bore diameter.

b. Tooling number and detail number.

All adapter designs requiring tool numbers shall be approved prior to build.

TOOLING MASTERS/PALLETS AND FIXTURES SUPPORT SYSTEMS

The tooling masters/pallets shall be:

a. Practical to install and use while machine is in the production environment.

b. Accurately represent the part characteristic centerline and made to gage tolerances.

c. Traceable to N.I.S.T.(National Institute of Standards and Technology).

d. Provided by machine tool builder.

e. All Adapters and Masters are to be housed in an environmental proof permanent packaging suitable for gage storage.

Details with the master pallet/part shall duplicate the production pallet/part such as: pallet feet, clamp pads, registry system, transfer mechanism, etc.

All of the above details and the master pallet/part that may effect the REPEATABILITY of the master shall be inspected and documented.

The Master pallet base shall be Meehanite cast iron for stability. (Variance allowable subject to prior approval by purchaser).

The master part shall be Meehanite cast iron or metallurgical stable hardened steel as appropriate based on part size.

Bushings required to mount the target receiver to the master pallet shall be ground and lapped to .7500 inch + .0001/ - .0000 inch I.D. (20 mm +.0025/25/-0000 mm I.D.) If spacing or center distance constraints do not allow for a .7500 inch (20 mm) I.D. bushing, then the inside bushing diameter shall be reduced to the next appropriate size +.0001/-.0000 inch (+.0025/-.0000 mm). Where Bushings are not used, I.D. sizes may change due to size constraints, however I.D. + tolerances remain unchanged.

The head of the bushing shall be ground square to the bushing I.D. within .001 inch per foot (.0833 mm. per meter). Where there are multiple bushings, the total accumulative error must not exceed .001 inch per foot (.0833 mm per meter).

All bushings shall be a minimum of 1.5 inch (40 mm) in length and no blind bushing holes are acceptable with in the master unless approved by the purchaser.

Nominal cordial distances between all bushings or holes shall be within 5% of part tolerance maximum error, non-accumulative. Each transfer leg shall be reviewed to identify if common bushing/hole positions are required on both sides of the upright for lining up both left and right machining stations. All bushings/holes with the master upright assembly shall be tagged with appropriate hole number and station number, which provides exact control in positioning the machine.

The indexing direction of the pallet shall be clearly marked to eliminate incorrect loading by the operator.

The ability to index the master through each station with the transfer shall be considered during the initial design.

The master will be used to periodically master the pallet checking gauge and shall incorporate all design features for this inspection requirement.

All design concepts shall be approved by the purchaser prior to equipment build.

GUARDS & UTILITY CONNECTIONS

Guards shall have access covers and or be designed for easy removal ensuring that all alignments points, shims and adjustment bolts are accessible.

All hard lines will be routed such that all alignment points, shims and adjustment bolts are accessible.

GLOSSARY

1) ACCESSIBLE: The ability to reach and adjust the aligning feature. Consideration should be given to confined space restrictions, removing guards, bushing plates, hydraulic lines, lubrication lines, electric lines etc.

2) ALIGNMENT TARGET SPECIFICATIONS: Desired intentional offset and angularity at coupling center to compensate for thermal growth and/or dynamic loads. Most properly specified as an OFFSET, and an angle in two perpendicular planes, horizontal and vertical.

3) ANGULAR ERROR: A misalignment condition characterized by the angular error between the desired centerline and the actual centerline. This misalignment condition may exist in planes both horizontal and vertical to the axis of rotation.

4) ANGULARITY: The angle between the rotational centerlines of two shafts. Angularity is a “slope”expressed in terms of a rise (millimeters or thousandths of an inch)

over a run (meter or inches).

5) A.S.M.E.:American Society of Mechanical engineers345 East 47th StreetNew York, NY 1017212-705-7722

6) AXIAL PLAY, AXIAL FLOAT, END FLOAT: Shaft axial movement along its centerline caused by axial forces, thermal expansion or contraction, and permitted by journal bearings, sleeve bearings and/or looseness.

7) BASE PLATE: The surface , often made of steel plate or cast iron, to which the feet of a machine are attached.

8) CO-LINEAR: Co-linear means two lines that are positioned as if they were one line. Co-linear as used in alignment means two or more centerlines of rotation with no offset or angularity between them. Two or more lines are co-linear when there is no offset or angularity between them (i.e. they follow the same path).

9) COPLANAR: The condition of two or more surfaces having all elements in one plane. (per ANSI Y14.5)

10) COUPLING POINT: The phrase “COUPLING POINT” in the definition of SHAFT ALIGNMENT is an acknowledgment that vibration due to misalignment originates at a the point of power transmission, the coupling. The shafts are being aligned and the coupling center is just the measuring point.

11) C.W.B.: Canadian Welding Bureau:7250 West Credit AvenueMississauga, Ontario L5N5N1416-542-1312

12) FULL BEARING FITTING SPACER BLOCK: A single spacer block used for aligning the machine tool in the vertical plane.

13) FLATNESS: The condition of a surface having all elements in one plane. (Per ANSI Y 14.5.)

Note: As used in this specifications, a flat is a small surface flush with or cut into a BASE PLATE, machined flat, and co-planar with the other flats in the base plate. The flats support the Shims and/or feet of the machine to be installed. A pad is a small block of metal that serves to elevate the feet of the machine above the surface of the base plate. Pads are commonly used compensate for differences in machine center line heights, and for increased corrosion resistance by raising the machine feet out of any possible standing

fluids. Pads and flats have holes drilled and tapped in their centers to accept hold down bolts.

14) HORIZONTAL: Parallel to the mounting surface.

15) JACKBOLTS, JACKSCREWS , PUSH/PULL BLOCKS: Positioning bolts on the machine base which are located at, each foot of the machine and are used to adjust the position of the machines. Bolts mounted on the machine base or foundation, optimally at the machine foot locations, which provides exact control in positioning the machine.

16) LASER/TARGET ADAPTER: A laser/target adapter is an adapter which allows the laser/target to be mounted into the spindle or master part.

17) LEVEL: Parallel to a reference plane or a reference line established by a laser.

18) MACHINE: The total entity made up of individual machine components such as motors, pumps, spindles, fixtures, etc. Also reference MACHINE COMPONENT.

19) MACHINE BASE: The structure that supports the machine or machine components under consideration.

20) MACHINE COMPONENT: An individual unit such as a motor, pump, spindle, fixture, etc. often referred to as a machine in its own context.

21) MACHINE DEPENDENT: A condition which is dependent on the machining operation and the design requirement of the part being machined.

22) OFFSET: The distance (in thousands of an inch or in millimeters) between two reference centerlines such as a spindle center line and a part characteristic centerline or the rotational centerlines of two parallel shafts.

23) PITCH: An angular misalignment in the vertical plane. (ANSI/ASME b5.54-1991)

24) POSITION ERROR (CENTERLINE/OFFSET MISALIGNMENT): A misalignment condition that exist when the spindle/shaft centerline is parallel but not in line with (not coincidental) with the desired alignment centerline.

25) PUSH-PULL BLOCKS: Side push-pull adjustment blocks used for aligning machine tool in the horizontal plane.

26) QUALIFYING LEVEL POINTS: Qualified leveling points are locations which have their heights defined and must be in same plane. That plane must be parallel to the mounting surfaces of the slide assembly.

27) REPEATABILITY: The consistency of readings and results between consecutive sets of measurements.

28) SHAFT ALIGNMENT: Positioning two or more machines (e.g. a motor driving a hydraulic pump(s), etc.) so that the rotational centerlines of their shafts are collinear at the coupling center under operating conditions.

29) SPINDLE ALIGNMENT: The geometric relationship between the spindle axis or rotation and areference datum.

30) SOFT FOOT: A condition that exists when the bottom of all of the feet of the machinery components are not on the same plane (can be compared to a chair with one short leg). Soft foot is present if the machine frame distorts when a foot bolt is loosened or tightened. It must be corrected before the machine is actually aligned.

PARALLEL SOFT FOOT: A parallel gap between the machine foot and its support surface.

ANGULAR SOFT FOOT: An angled gap between the machine foot and its support surface.

INDUCED SOFT FOOT: A type of soft foot that is caused by external forces, ( pipe strain,coupling strain, etc.,) acting on a machine independent of the foot to base plate connection.

“SQUISHY” SOFT FOOT: A type of soft foot characterized by material, (could be Shims, paint, rust, grease, oil, dirt, etc.) acting, like a spring between the underside of the machine foot and the base plate contact area.

31) SPACER BLOCKS: See FULL BEARING FITTING SPACER BLOCK.

32) STRESS FREE CONDITION: The condition that exists when there are no forces acting on the structure of a machine, machine component, or machine base that would cause distortion in the structure such as bending, twist, etc.

33) THERMAL EFFECTS (GROWTH OR SHRINKAGE): This term is used to describe displacement of shaft axes due to machinery temperature changes (or dynamic loading effects) during start-up.

34) TOLERANCE, DEADBAND, WINDOW, OR ENVELOPE: An area where all misalignment forces sum to a negligible amount and no further improvement in alignment will reduce significantly the vibration of the machine or improve efficiency.

35) TOLERANCE VALUES: Maximum allowable deviation from the desired values, whether such values are zero or non-zero.

36) TRACKING/TRACKING ERROR: An angular MISALIGNMENT condition

between spindle centerline and the machine way centerline. This condition may be present in both parallel and perpendicular to the way centerline

37) VERTICAL: Perpendicular to the horizontal plane.

38) YAW MISALIGNMENT: An angular misalignment in the horizontal plane.

39) N.I.S.T.National Institute of Standards and TechnologyBuilding 304, Room 139Gaithersburg, MD 20899301-975-3503

Other Useful Information for vibration analysis is listed below: