roller gearing and power transmission mechanism pál bogár sincroll drive technologies 1

Roller Gearing and Power Transmission Mechanism

Pál Bogár

Sincroll Drive Technologies

1

Agenda

• The Innovative Idea - what new we do

• Realisation of the Idea - how we do it

• Example Designs - what it can be used for

• Benefits and Advantages - why we do it / how good it can get

• Prototype Tests - how much we achieved so far

• Potential Applications - what business potential we foresee

• The Sincroll Company - who we are: business, skills, facilities

• Potential for Collaboration - what Nissan and us can do together

2

The Innovative Idea

Brand new technology - 4 months in the market

Trivial problem – non-trivial solution

• Rollers connect the wheels– wheels do not connect directly

(there are no “teeth”)

• Rollers roll along grooves on both wheels simultaneously– rigid coupling between the wheels

• Rollers do pure rolling motion without sliding– ensured by the shape of the

grooves

3

Realisation of the Idea

• Force and torque are transmitted through the contact points between the rollers and the grooves

• Properly selected line of contact points i.e. the curve of the grooves ensure proper forces acting and thus pure rolling motion

• The ensemble of grooves determines the shape of the wheel

4

Realisation of the Idea - continued

Complex physics

G: the roller (ball)

P1, P2: contact points between the balls and the wheels

gp: path travelled by the ball’s centre when in coupling

g1, g2: paths travelled by the contact points

u, v: various velocity vectors

1, 2: angular velocity vectors of the two wheels

5

non-intersecting axesaxes angle = 90o

gearing ratio = 1:1ball diameter = 4mmcontact factor = 8

6

intersecting axesaxes angle = 90o


7

parallel axesaxes angle = 0o


8

parallel axesdirection of rotation = samegearing ratio = 1:5ball diameter = 4mmcontact factor = 9

9

parallel axesdirection of rotation = oppositegearing ratio = 23:25ball diameter = 4mmcontact factor = 19

10



11



12



13

parallel axes gear rackaxes angle = 45o

gearing ratio = n/aball diameter = 4mmcontact factor = 16

14

perpendicular axes gear rackaxes angle = 90o

gearing ratio = n/aball diameter = 4mmcontact factor = 10

15

internal coupling non-intersecting axesaxes angle = 45o


16

micro-rollers non-intersecting axesaxes angle = 45o


17

worm gearaxes angle = 90o

gearing ratio = 1:50ball diameter = 4mmcontact factor = n/a

18

planetary gear systemaxes angle = collineargearing ratio = 1:300ball diameter = 4mmcontact factor = 8

19

Main Advantages

Three main advantages – plus their implications …

• Power efficiency close to 100% – due to pure rolling motion done by the rollers – sliding friction is practically eliminated

• Contact factor up to 20 or more– load distributes over many rollers

• Back-lash free– easy to eliminate back-lash by forcing the wheels together– compromise in performance i.e. efficiency in-significant

20

Implied Advantages

High power efficiency

• No sliding friction• Lower energy losses• Lower starting torque• Smaller motor needed• Friendlier to the

environment – a green technology

• Lower operating costs• Reduced heating up• Reduced abrasion• Less cooling and

lubrication needed• Less wear and

deterioration• Longer lifetime• Less vibration and noise

High contactor factor

• Smaller size• Special shape (e.g.

very thin) - more flexibly adjustable

• Higher power density• Smoother and steadier

movements• Precise movements• Lower noise• Greater reliability

No back-lash

• Precise movements• Less vibrations and

resonances• Longer lifetime

21

Other Selected Features

• Flexibility in design– more control parameters for the designer– a richer and more adjustable system– one gear problem but many solutions

• New framework – new intuition– conventional gear design intuition may not work here– this is more like a generalised ball screw or roller bearing

• Lot of potential for further R&D advances in the future– e.g. optimisation of roller movement, parallel grooves, non-ball

rollers, micro roller “liquid” etc.– a lot of applications need to be developed

22

Other Selected Features - continued

• Performance determined on the “micro” level at the contact of the rollers and the grooves– performance relatively insensitive to overall gear geometry– e.g. can change gearing ratio without changing the wheel

diameters directly– can also change direction of rotation without adding extra wheels

• Hertz stress benign– curvature of balls and grooves are similar and are the same sign– point-like contact expands into a surface-like contact and Hertz

stress drops– yet frictional losses do not increase much because of low relative

velocities of the (now sliding) contact surfaces

23

Prototype Tests

• Prototype tested was 1:10 ratio, non-intersecting, 45o axes• Made of steel with nitriding finish of grooves surfaces• Made by Sincroll

• Test lab was at the Budapest University of Technology• Tests supervised by the Department of Machine and Product Design

• Tests performed: All this was done: – Basic checks of operations - With and without back-lash– Kinematics and noise checks - For both directions of rotation– Static power efficiency - For both directions of load– Dynamic power efficiency - For various angular velocities– Movement precision

24

non-intersecting axes T E S T P R O T O T Y P Eaxes angle = 45o


25



26



27



28



29

The Test Rig

30

Test Data for Movement Precision

31

Summary of Test Results

32

• Basic operations, kinematics, noise and reliability – no particular issues, performance was quite good in all respect

• All tests were insensitive (in terms of statistical significance) to– changing direction of rotation– changing the direction of the load– and whether the back-lash was eliminated or not

• Static efficiency at least 98% - this was independent of – roller recycling device being in place or not – back-lash has been eliminated or not (surprise!)

Summary of Test Results

33

• Dynamic efficiency – first measurement 92%– after improving the surface quality of the roller recycling channel the

efficiency went up to 94% – groove surfaces were sub-optimal as a result of nitriding– we will re-test again soon with polished groove finish and improved roller

recycling device

• Movement precision showed a periodic structure that where the periodicity was the same as the period of revolutions of the larger wheel in the gear. This shows there was a manufacturing error in the larger wheel.

– the error was about +/- 0.2 degrees – looks like a normal amount of inaccuracy and should not be a cause for alarm

– we want to retest with a higher precision electronics to see if anything else besides the larger wheel has an effect on precision

parallel axes A L U M I N I U M P R O T O T Y P Eaxes angle = 0o gearing ratio = 26:23ball diameter = 4mmcontact factor = 8

34

parallel axesaxes angle = 0o


35

Potential Applications

• High-power drives– due to low operating costs, small size and great reliability

• All Vehicles– due especially to high efficiency and high power density

• Material handling machines– due especially to smaller starting torque

• Machine tools– due to no back-lash– an alternative to ball-screw drives

• Wind power generators– high energy efficiency, high gear-up ratio and backlash-free

adjustments

• Standard gear and transmission families

36

Applicable Industries

• Cement, stone and ore industries– Grinding machines, rolling mills, presses, separators, mixers,

elevators etc

• Chemical and environmental industries– Agitators, mixers, pumps and compressors, cooling towers, dryers,

turbines, aerators and thickeners in sewage treatment etc.

• Electric power generation– Wind, gas, coal, oil, water and nuclear power generators etc.

• Food and agri industries– Cutters, feeders, mixers, harvesters, combines, sewage treatment

machinery etc.

• Machine tools industries– Table movers, rotators, dividers, gear racks, spindle drives etc.

37

Applicable Industries - continued

• Materials handling machines– Various kind of cranes, lifts, hoisters, elevators, escalators,

excavators, conveyors, ropeways, factory assembly lines etc.

• Mining industries– Excavators, conveyors, lifters, hoisters etc.

• Paper, packaging and printing machines– Cutters, feeders, dryers etc.

• Plastics and rubber industries– Extruders etc.

• Steel and iron industries– Conveyors, elevators, metal working machinery etc.

38

Applicable Industries - continued

• Sugar industries– Cutters, feeders, shredders, mills etc.

• Textile industries– Cutters, feeders, dryers, spinning machines etc.

• Vehicles– Cars, motorbikes, bicycles: gearboxes, steering gears, differential

gears etc.– Trucks and special purpose vehicles: gearboxes, steering gears,

differential gears etc.– Railway vehicles such as trams, locomotives, regional railways,

metro-underground etc.– Ships and boats: gearboxes, generators, dredger drives etc.– Airplanes, fixed and rotating wings

• Wood and forestry industries– Special purpose vehicles, cranes, conveyors etc.

39

• Our primary business is – research and development – commercialisation– technology transfer of the new roller gear technology

• This includes– continued independent work same as what we have been doing thus far– as well as new collaborations with partners via e.g. license agreements

• Our skills and tens of years of experience are in design and development including

– theoretical research and computer design and simulation– applications design and development, evaluation, lab experiments and

testing

The Sincroll Company

40

• Our management skills come from 10-20 years of scientific research, corporate and entrepreneurial experiences

• We also have direct access to limited but high-quality machining facilities

– we manufacture high-quality prototypes and perform basic tests– we also do production on a relatively small scale (secondary business)

• In this way we can offer a wide range of services to our customers and our partners

– starting from basic R&D, theoretical and experimental work – all the way up to prototype and equipment manufacture and pilot and

small scale production

The Sincroll Company - continued

41

• Looking for a partner is a new idea– we came to the market four months ago only– Following about five years of intensive R&D

• We believe the technology is mature enough now to be successfully applied in commercial applications

• We need partners to help us to find the best applications that we can develop with the ultimate target of a commercial product in the focus

• We also need partners to contribute in the partnership with production capacity and skills as well as market knowledge, sales and marketing networks and customer relationships

Potential for Collaboration

42

• In return we provide the technology through e.g. a licence agreement as well as our R&D and pilot production services in order to progress the developments of the technology further

Potential for Collaboration – continued

43

THANK YOU

44

roller gearing and power transmission mechanism pál bogár sincroll drive technologies 1

Documents

parallel axes axes angle

contact factor

o gearing ratio

na ball diameter

worm gear axes angle

collinear gearing ratio

opposite gearing ratio

roller gearing