Geared Clutch

A Total Makeover

By

Dhruval M Bhansali

Introduction:

Clutch in general:

• Power transmitting device

• Quick engagement and disengagement

• Slips when large RPM difference to ensure gradual increase in power

transmission and avoid jerks

• Completes the mentioned task using frictional engagement

Concept:

Diagram:

•First figure represent bevel gear arrangement for the required concept

followed by a BOM

•As conventional clutch, it has 3 modes of operation namely: engaged or

lock position, disengaged position and slipping of clutch

Engaged position:

•This position is achieved by locking of topgear rotation around its own

axis

•This would ensure a rigid connection between the 2 sidegear (one from

engine side and other represent the gearbox side) hence transmitting whole

speed and torque

Disengaged position:

•With no resistance to rotation to topgear, topgear will rotate around its axis

as well as revolve around sidegear

•This will ensure a non rigid connection between the 2 sidegear’s hence

there would be no power and speed transmission between them

Slipping of clutch:

•As the topgear resistance to rotation is increased gradually from 0 to max,

power transmission between 2 gears too would increase gradually,

creating a effect of slip

•In disengaged position as cage speed is equal to driver gear speed, as

resistance to rotation of topgear increases, the cage speed remains constant

and driven gear speed starts increasing with proportionate decrease in

topgear speed until topgear stops and engaged position is achieved

Final design:

Fig 1

Fig 2

Fig 3

Fig 4

Fig 5

Working:

3 modes of operation:

• Disengaged mode: no resistance to topgear 's rotation around its own axis

• Slipping mode: In order to gradually increase power transmission,

according to concept, topgear speed is gradually reduced, in the final

design, it is done by firstly slowing down by eddy braking system as

shown, and further stopped by locking mechanism, consisting of a slotted

disc, a wedge which will enter the slot and end of slot will consist of spring

And damper system (not shown) to absorb shock and avoid breaking or

damage to the wedge, this will ensure gradual but at the end total

restriction to the topgear rotation

•Engaged mode: After engagement of locking mechanism, topgear

rotation along its own axis would be totally constrained and hence

providing the required one rigid connection for total power

transmission

Dimensions: 250x160mm

Costing:

• Spiral bevel gears (material: c45) = Rs 1500 each i.e. Rs 6000

• Neodymium magnets (42EH) = Rs 500 each i.e. Rs 1000

• 2 springs and other material cost = approx Rs 1500

• Machining cost for material = approx Rs 1500

• Release mechanism cost = approx Rs 2000

• Hence total cost= Rs 12000

Advantage (over conventional):

• Better control over slipping of clutch hence lesser heat generation.

• Zero transmission loss during engaged position.

• Twice the life then conventional.

• No dip in performance with time.

• Lighter to operate.

Disadvantages:

• Costing is 2 to 3 times of conventional clutch

• Needs lubrication system similar to crankshaft of engine

• Need to provide extra connection with braking system

Commercial advantages:

• New and improved product in a field untouched for over a century giving

the company advantage over competition on the topic of innovation.

• Rights to claim to have the only clutch product to provide consistently

same performance over a longer duration of use.

• Increasing overall vehicle efficiency and mileage providing customers

more and more reason to purchase your product.

• Rights to claim to have clutch with twice the life of conventional clutch.