Unidirectional Clutch
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A coupling that transmits power in one direction.
blockType: Engee1DMechanical.Clutches.Unidirectional
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Description
Block Unidirectional Clutch simulates an ideal one-way coupling based on a connected ring and hub. The unit transmits torque when the relative rotational speed of the hub and ring becomes positive or negative, depending on the specified direction of transmission. For more information about the model, see Equations.
Equations
The figure shows the geometry of a one-way coupling.
In the locking state, the clutch transfers torque from the hub to the ring. In the unlocked state, the clutch does not transmit torque. The clutch is not in the unlocked state, but is switched on, i.e. it transmits torque. Relative angular velocity (slippage) — this is the angular velocity of the hub relative to the speed of the ring That is , .
Block Unidirectional Clutch Realizes the ideal one-way coupling model and does not contain any internal dynamic elements such as rollers and springs.
Blocking condition
The transmission direction determines the blocking condition.
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If a positive transmission direction is selected, the clutch is locked when and vanishes at positive values. At the same time slippage it remains equal to zero, and the clutch transmits torque.
If the dynamics of the transmission leads to the fact that During the simulation, the clutch is abruptly unlocked and stops transmitting torque.
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If a negative transmission direction is selected, the clutch is locked when and vanishes at negative values. At the same time slippage it remains equal to zero, and the clutch transmits torque.
If the dynamics of the transmission leads to the fact that During the simulation, the clutch is abruptly unlocked and stops transmitting torque.
For example, the locking and transmission of torque in the positive direction is carried out as follows.
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When the hub rotates faster than the ring ( ), the small gap provided in advance between the hub and the ring disappears. The spring-loaded rollers are wedged between the hub and the ring, causing them to touch, lock and rotate together; meaning reset to zero. (Clockwise rotation is assumed in the figure.)
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If the ring rotates faster than the hub ( ), the rollers come out of contact and the clutch is unlocked.
For the coupling diagram, see Equations.
Power dissipated by the clutch
The one-way coupling is perfect and does not dissipate power. Either the clutch is unlocked and does not engage kinetic friction, or it is locked (without slippage) and engages only static friction.
Parameters
Parameters
#
Transmission direction —
relative direction of rotation
From hub to ring for positive rotation | From hub to ring for negative rotation
Details
The relative direction of rotation in which the clutch locks and transmits the torque.
| Values |
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| Default value |
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| Program usage name |
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| Evaluatable |
Yes |
#
Initial state —
initial condition of the coupling
Unlocked | Locked
Details
The condition of the coupling at the beginning of the simulation. The coupling can be in one of two states: locked or unlocked. A locked clutch causes the drive and driven shafts to rotate at the same speed, that is, as a single unit. The unlocked clutch allows the two shafts to rotate at different speeds, which causes the clutch discs to slip.
| Values |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |