What is Clutch: Definition and 37 Discussions

A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft (driving shaft) to a driven shaft. The clutch acts as a mechanical linkage between the engine and transmission; and briefly disconnects, or separates the engine from the Transmission system, and therefore the drive wheels, whenever the pedal is depressed, allowing the driver to smoothly change gears.
In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). In these devices, one shaft is typically attached to an engine and other to power unit (the driving member).
While the other shaft (the driven member) provides output power for work and typically the motions involved are rotary, linear clutches are also possible.
In a torque-controlled drill, for instance, one shaft is driven by a motor, and the other drives a drill chuck. The clutch connects the two shafts so they may be locked together and spin at the same speed (engaged), locked together but spinning at different speeds (slipping), or unlocked and spinning at different speeds (disengaged).

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  1. I

    Disengagement of a multi plate clutch

    I am a student at a mechanical college, current topic of discussion is multi plate clutches. I understand that the clutch is engaged when the pedal is released, with allows the springs to expand, pushing together the plates, that will transfer the torque in to the drive shaft (if in very brief...
  2. M

    Help with flywheel / clutch calculations

    Hey everyone, I have a problem with sizing a clutch for my machine. My problem is, I don't know how to calculate the needed value (Nm) for the clutch to withstand the torque affected by the flywheel. I have a flywheel that weighs 90kg and is 600mm in diameter. It is rotating at 500rpm...
  3. K

    Automotive Why don't motorcycle clutches need torsional damper springs?

    I was reading the difference in construction between a car clutch (dry, single plate) and a motorcycle clutch (wet, multiplate). I understand wet multiplate clutches do not have torsional springs in them. How is the Engine vibration damped then? Can we not use this same arrangement in a car?
  4. K

    Automotive Dual mass flywheel clutch - How does it make a difference?

    I was going through these two documents: https://www.schaeffler.com/remotemedien/media/_shared_media/08_media_library/01_publications/schaeffler_2/symposia_1/downloads_11/4_DMFW_1.pdf http://www.partinfo.co.uk/docs/140 My primary interest was to understand why and how Dual Mass Flywheel (DMF)...
  5. S

    Automotive Effect of machine weight on clutch Power/Energy

    Why does increase in machine weight doesn't have much effect on clutch's power and energy? I do understand weight is basically normal force, and increase in normal force should make it harder for the transmission to push the increased amount of torque? What is the math behind it?
  6. CorvetteAB

    Automotive Replacing a centrifugal clutch with an Electromagnetic clutch

    Hello friends, Anyone ever thought of, or tried, or has come across an automobile with an EM clutch, probably electronically controlled? We have a CVT driven 2 wheeler with a centrifugal clutch, but we need to disconnect power at will (electronically), so an EM clutch was suggested. Anyone...
  7. M

    Does the load matter to a clutch?

    Does the weight of a car or length of gears it has change the requirements for clutch strength or is the requirement solely dependent on the torque the engine applies to it? I see a lot of consensus that says the former, but I think it is the latter. An engine making 300 lb-ft should need a...
  8. S

    Motors in series: how do you stop one motor from spinning?

    Hi All, I've been reading up on hybrid vehicles and how the Honda Insight has an electric motor attached directly to the gas engine driveshaft. Their combined output causes the wheels to spin. My question is in regards to when the electric motor is off but the gas engine is on. Why doesn't the...
  9. B

    One way clutch for motorized cable reel?

    I am newbie in the area of clutches. I am making a motorized cable reel (DC motor) which I needed to make it easy for anyone to pull the cable reel out manually without much effort. Only pulling the cable out is manual. The retraction of the cord is done automatically via the DC motor. So, based...
  10. R

    Freewheel/Ratchet Clutch - Combining multiple torque inputs

    Hi, I am required to design a tandem bike where multiple torque inputs will be present at different speeds since persons on the bike will not be cycling at the same rotational velocity. From my understanding of freewheel clutches to transmit all the torques produced by the cyclists using...
  11. C

    Troubleshooting Clutch Torque Calculation Errors for Scientists

    Hi, first time poster. I'm trying to calculate the clutch torque output using the following formula: torque = force (450KG ((pressure plate calculated force) x gyration radius ( 0.09 Metres (( square root of inner radius squared x outer radius squared divided by 2) x coefficient of friction (...
  12. kanibal

    How to calculate (mechanical) clutch forces

    Hello i am working on a small clutch cable testing machine this machine can give the lifetime of clutch cable i need some assistance to figure out how much forces i need to apply on this mechanism , and because the cable related directly in the clutch I'm asking if the force in the clutch in the...
  13. I

    Automotive Hydroboost on clutch line (car)

    I want to install a hydroboost (VH44) to make the clutch easier to use (because of an injury/disability). From what I've read, it'll reduce the pedal travel distance *and* tension. What would happen if I installed two hydroboosters, in series? Reduce travel? Tension? Both? Nothing at all...
  14. M

    Looking for mechanical clutch solution

    Hi, I made an electronics project but I'm having some mechanical problems. Particularly, I'm having issues finding a good clutch for my problem. What I'm trying to do: A motor is connected to shaft 1, a human can manually rotate shaft 2. I want that when the motor isn't doing anything, a...
  15. T

    Torque Reaction Force of Transmission and Drivetrain

    Hello, As I understand it there is an equal and opposite reaction for every mechanical action. In the case of a vehicle drivetrain the engine generates a torque at the flywheel or flex plate which becomes an input to the transmission and ultimately the wheels. The rollong resistance of the...
  16. K

    Clutch stiffness and hysteresis - Role in gearbox NVH

    Hi, There is a rattling noise in one of the automobile passenger car gearboxes that we designed. After few experiments and observations, it was found that the noise is because of incorrect clutch stiffness and hysteresis behavior. I have got some fundamental questions about both: 1. Clutch...
  17. S

    Why does the clutch disc disengages the flywheel?

    Hi! I am creating this thread to ask what is the physical phenomena that drive the smooth disengagement of clutch discs from flywheels. I am thinking about car clutches, specifically a longitudinal front engine, rear wheel drive clutch type. I've been reading some books that describe the...
  18. S

    What is the Maximum Torque Transmission Capability of a Cone Clutch?

    Hi. I am trying to develop a cone clutch for torque transmission. I have looked a lot over the internet but I cannot find how to calculate the maximum torque transmission capability of a cone clutch. Everywhere they use the equations with inputs of axial force. I want to find the maximum torque...
  19. Q

    Alternative clutch technologies?

    Is there any clutch technology which is a good alternative to the present ones used in cars for transmission. I mean clutches which do not rely on frictional force between the flywheel and clutch plate to deliver the engine power to the wheels.
  20. L

    Help with Magnetic Clutch design

    I'm just designing a simple magnetic clutch that i can can alter the Break-away force by changing the air gap between the two diametric magnets. I guess I'm having a hard time understanding the practical difference between flux density, field strength and Force at a given distance of magnets…...
  21. marellasunny

    Frictional mechanical clutch slip(dry clutch)

    During the short period of engagement of the friction clutch(say t=1sec),energy is obviously lost as heat.I've been asked to calculate this loss of heat by my teacher. I've been given: 1.Input power(engine)= 50kW 2.Slip decreases linearly with time 3.Engagement process time,t=1sec Now,I...
  22. R

    Archived Dynamics - 2 shafts rotating & connected with a clutch

    Dynamics -- 2 shafts rotating & connected with a clutch During the operation of a machine, two shafts rotate in opposite directions and are then connected by a clutch system. Shaft 1 has a rotational speed of 800 rev/min, a mass of 35 kg and a radius of gyration of 375 mm. Shaft 2 has a...
  23. R

    Gears and Clutch: How to Have Both Rotating

    Hi, If I have a clutch that meshes on an axle and two idler gears with clutch teeth how do I: Have both gears rotating but when one of the idlers is engaged stop the opposite gear spinning, so just this one spins. The clutch is double sided of course so there is a gear either side. id...
  24. Femme_physics

    Machine parts, conic clutch two teachers, two different results

    Machine parts, conic clutch...two teachers, two different results! :( So a friend of mine who studies for the same test scanned me his teacher's solution to a problem they solved in class. We solved the same problem with a different teacher. I could really use your help to figure out who out of...
  25. K

    Calculation of clutch lever ratio

    Hi, I recently got an opportunity to work on a clutch assembly. The clutch is an old model one which has six helical springs that keep pressing the pressure plate, clutch plate and engine flywheel against each other. The cross section is: To give a brief working principle, when the...
  26. K

    Belleville spring characteristics on clutch actuation

    Hi, I have been working on designing something for a clutch. The clutch plate is pressed against the pressure plate using a belleville spring. The belleville spring is connected to the clutch pedal using a linkage with leverage. I came across a graph that describes the displacement of the...
  27. B

    Exploring the Pros and Cons of Electromagnetic CCB Units

    There are different types of CCB units. Hydraulically powered, pneumatic, electromagnetic and of course mechanical. But, can anyone give me the proper advantages and disadvantages of electromagnetic CCB over other variants. Googled it. But invain. Regards.
  28. L

    Does clutch control affect torque output in cars?

    Does anyone understand this? How do you get more torque by slipping the clutch? I slip the clutch to reduce torque to the wheels until I get going while maintaining power by keeping the rpms high.
  29. S

    What does a clutch in a manual car do and how it works?

    Hello everyone, I don't know if this is the right section to post this but I want to know what does the clutch in a manual car do. I have absolutely zero knowledge on car mechanics and would be greatful if someone can explain this to me simply. 1. Why do you need a clutch? I don't...
  30. A

    Difference between Torque Converter and Clutch ?

    i am working on GE GAS TURBINE's Torque converter beginners understanding ... em so confused into a clutch and torque converter ... Can u please briefly make me understand the function of both ... and importance ...
  31. H

    Calculating Spring Force for a Multi Plate Clutch

    A multi plate clutch has 4 frictional surfaces, imternal diameter 120mm and external diameter 200mm. The coefficent of friction is 0.3 What spring force will be required to transmit 20KW of power at 1440 RPM if the clutch is under uniform pressure conditions?
  32. H

    One-way centrifugal clutch - seatbelt clutch

    Hello everyone, I'm new to the forum here and have a question that is probably fairly easy for engineers to answer. I'm searching for a clutch that provides the same functionality as a seat belt clutch, i.e. it rotates both directions at slow rpms but when pulled quickly in ONLY one of...
  33. R

    Understanding Torque Transmission in Engine Clutches

    Hi guys I read somewhere that "the actual torque transmitted from the engine to the clutch is the total engine torque subtacted by the amount of torque required to accelerate the inertia of rotating components of engine.i.e:" T(c) = T(e) - [ I(e) x \alpha(e) ] where T(c)=Torque at clutch...
  34. P

    Designing a Centrifugal Clutch: How to Achieve Optimal Engagement

    can anyone help me how to design a centrifugal clutch
  35. A

    Alternatives to Clutch Mechanisms - Automated Solutions

    Dear all, I need to find alternate to clutch mechanism Is there anything similar to alternate clutch part...? That one could be automated one not to be manually operate... Thanks Praksh
  36. D

    Calculating Clutch Power Transmission at Speed

    Hi How do i calculate the power transmitted by a clutch at a particular speed with a coefficient of friction between the shoes and drum? I can't find any reference in my textbook.:confused: Cheers Daredvl
  37. Clausius2

    Should we press the clutch pedal while braking?

    Many traffic warnings issues tell it's much better to brake without pressing the clutch pedal. For instance, we drive a car at 120 km/h and suddenly we have to brake in the shortest distance as possible due to some obstacle on the road. What is better? 1) Should we press the clutch pedal at the...