Claims
- 1. A tensioner for a power transmission belt that operates on an endless path and that utilizes asymmetric motion control, the tensioner comprising:
an arm comprising a belt engaging section and a drum section; a support member for securing the tensioner relative to the belt, the arm pivoting on the support member; a spring that urges the arm to pivot about the support member in a first direction and urges the belt engaging section against the belt with a force to tension the belt; a fluid containing chamber located inside a portion of the drum section of the arm; and a valve pivotally attached to the tensioner so that the valve extends across the fluid containing chamber.
- 2. The tensioner of claim 1, further comprising sealing devices.
- 3. The tensioner of claim 1, wherein the valve is biased by a weighted device.
- 4. The tensioner of claim 1, wherein the valve is biased by a spring device.
- 5. The tensioner of claim 1, wherein a fluid in the fluid filled chamber is a hydraulic fluid with a predetermined viscosity, such that the tensioner can be tuned and an desired viscous damping coefficient can be established.
- 6. The tensioner of claim 1, wherein the valve is coupled to the drum section and the chamber moves with respect to the valve, wherein when the chamber moves in a first direction the valve opens and when the chamber moves in a second direction the valve closes and locks against a portion of the tensioner such that a damping force is generated based on the fluid in the chamber pushing against the closed and locked valve.
- 7. The tensioner of claim 1, further comprising:
a stationary valve plate coupled to a first portion of the drum section, wherein the valve is coupled to the stationary valve plate; wherein the chamber is coupled to a second portion of the drum section; wherein the chamber moves with respect to the valve, wherein when the chamber moves in a first direction the valve opens and when the chamber moves in a second direction the valve closes and locks against a portion of the tensioner such that a damping force is generated based on the fluid in the chamber pushing against the closed and locked valve.
- 8. The tensioner of claim 1, wherein the valve and the chamber move relative to each other and wherein the valve remains open in a first direction of motion and closes and locks against a portion of the tensioner in a second direction of motion to lock, such that a damping force is generated through the locking.
- 9. The tensioner of claim 1, wherein the support member comprises a hub about which the arm pivots.
- 10. The tensioner of claim 1, wherein the belt engaging section includes a pulley.
- 11. The tensioner of claim 1, wherein the support member comprises a housing for the spring.
- 12. The tensioner of claim 11, wherein after the valve locks against the portion of the tensioner a predetermined amount of a fluid in the chamber leaks adjacent the valve.
- 13. The tensioner of claim 1, wherein the chamber is approximately a length of a stroke of the tensioner.
- 14. A method of utilizing a tensioner for maintaining a predetermined tension on a power transmission belt to be operated on an endless path, the method comprising the steps of:
providing an arm comprising a belt engaging section and a drum section; providing a support member configured to be secured relative to the belt, the support member comprising a hub having a longitudinal axis and being fixed from movement relative to the belt engaging section, the hub moveably holding the arm; providing a spring operatively interconnected to the arm and the support member, the spring being configured to urge the belt engaging section relative to the support member and against the belt with a force to provide the predetermined tension on the belt; providing a fluid containing chamber located inside a portion of the drum section of the arm; and; and providing a valve pivotally attached to the tensioner so that the valve extends across the fluid containing chamber.
- 15. The method of claim 14, further comprising the step of providing sealing devices.
- 16. The method of claim 14, further comprising the step of moving the chamber relative to the valve wherein in a first direction the valve remains open and in a second direction the valve closes and locks against a portion of the tensioner, such that a damping force is generated.
- 17. The method of claim 14, wherein the valve is coupled to the drum section and the chamber moves with respect to the valve, wherein when the chamber moves in a first direction the valve opens and when the chamber moves in a second direction the valve closes and locks against a portion of the tensioner such that a damping force is generated based on the fluid in the chamber pushing against the closed and locked valve.
- 18. The method of claim 14, further comprising the step of:
providing a stationary valve plate coupled to a first portion of the drum section, wherein the valve is coupled to the stationary valve plate; wherein the chamber is coupled to a second portion of the drum section; wherein the chamber moves with respect to the valve, wherein when the chamber moves in a first direction the valve opens and when the chamber moves in a second direction the valve closes and locks against a portion of the tensioner such that a damping force is generated based on the fluid in the chamber pushing against the closed and locked valve.
- 19. The method of claim 14, wherein a length of the chamber is approximately a length of a stroke of the tensioner.
- 20. An endless power transmission belt asymmetric, hydraulic, vicious damping tensioning system comprising:
an engine; an endless power transmission belt coupled to the engine; and the tensioner set forth in claim 1 coupled to the belt.
- 21. A tensioner for generating tension in a power-transmitting belt as the belt traverses a first sheave and a second sheave, the tensioner comprising:
a base; an arm pivotably attached to the base; a pulley rotatably attached to the arm for engaging the belt; a spring operatively connected to the arm and the base for urging the arm to pivot relative to the base in a first direction, thereby urging the pulley into engagement with the belt with a force to tension the belt; and an asymmetric fluid damper comprising a fluid containing chamber located between the base and the arm, the chamber moving with the arm relative to the base, and a valve pivotably attached to the base and pivotable between an open position and a closed position, the valve pivoting to the open position when the arm moves in the first direction and pivoting to the closed position when the arm moves in a second direction, the valve positioned in the fluid containing chamber to restrict fluid flow when in the closed position, thereby resisting movement of the arm in the second direction.
- 22. The tensioner of claim 21 wherein the valve is biased toward the closed position.
- 23. The tensioner of claim 22 wherein the valve is biased by a weight.
- 24. The tensioner of claim 23 wherein the base includes a hub about which the arm pivots and wherein the fluid containing chamber is located, at least in part, below the hub.
- 25. The tensioner of claim 22 further comprising a solenoid having a plunger movable between a retracted position and an extended position, the plunger engaging the valve to lock the valve in the closed position when in the extended position, thereby resisting movement of the arm in the first and second directions.
- 26. The tensioner of claim 25 wherein the valve includes a recess for receiving the plunger.
- 27. The tensioner of claim 26 wherein the recess in the valve is aligned with the plunger to receive the plunger only when the valve is in the closed position.
- 28. The tensioner of claim 25 for use with an automobile engine, the tensioner further comprising:
a sensor for obtaining a condition of the engine; and a controller operatively coupled to the sensor for receiving a signal therefrom, the controller operable to move the solenoid plunger between the retracted and extended positions based, at least in part, on the signal received from the sensor.
- 29. The tensioner of claim 28 wherein the sensor is an engine speed sensor.
- 30. A tensioner system for generating tension in a power-transmitting belt as the belt traverses a first sheave and a second sheave of an automobile engine, the tensioner system comprising:
a first tensioner having a base, an arm pivotably attached to the base, a pulley rotatably attached to the arm for engaging a first span of the belt located between the first sheave and the second sheave, a spring operatively coupled to the arm and the base for urging the arm to pivot in a direction toward the belt, thereby urging the pulley into engagement with the first span of the belt with a force to tension the belt, an asymmetric fluid damper comprising a fluid containing chamber located between the base and the arm, the chamber moving with the arm relative to the base, and a valve pivotably attached to the base and pivotable between an open position and a closed position, the valve pivoting to the open position when the arm moves in the direction toward the belt and pivoting to the closed position when the arm moves in a direction away from the belt, the valve positioned in the fluid containing chamber to restrict fluid flow when in the closed position, thereby resisting movement of the arm in the direction away from the belt, and a solenoid having a plunger movable between a retracted position and an extended position, the plunger engaging the valve to lock the valve in the closed position when in the extended position, thereby resisting movement of the arm in both directions; a second tensioner having a base, an arm pivotably attached to the base, a pulley rotatably attached to the arm for engaging a second span of the belt, a spring operatively coupled to the arm and the base for urging the arm to pivot in a direction toward the belt, thereby urging the pulley into engagement with the second span of the belt with a force to tension the belt, an asymmetric fluid damper comprising a fluid containing chamber located between the base and the arm, the chamber moving with the arm relative to the base, and a valve pivotably attached to the base and pivotable between an open position and a closed position, the valve pivoting to the open position when the arm moves in the direction toward the belt and pivoting to the closed position when the arm moves in a direction away from the belt, the valve positioned in the fluid containing chamber to restrict fluid flow when in the closed position, thereby resisting movement of the arm in the direction away from the belt, and a solenoid having a plunger movable between a retracted position and an extended position, the plunger engaging the valve to lock the valve in the closed position when in the extended position, thereby resisting movement of the arm in both directions; a sensor for obtaining a condition of the engine; and a controller operatively coupled to the sensor for receiving a signal therefrom, the controller operable to independently move the plunger of the first tensioner and the plunger of the second tensioner, respectively, between the retracted positions and the extended positions, based, at least in part, on the signal received from the sensor.
- 31. The tensioner system of claim 30 wherein the sensor is an engine speed sensor.
- 32. The tensioner system of claim 31 wherein the tensioner system is operable in at least three operating conditions including
a first operating condition in which the plunger of the first tensioner is in the extended position thereby locking the valve of the first tensioner in the closed position and the plunger of the second tensioner is in the retracted position thereby permitting the valve of the second tensioner to pivot; a second operating condition in which the plungers of the first tensioner and the second tensioner are in the extended position thereby locking the valves of the first tensioner and the second tensioner in the closed position; and a third operating condition in which the plunger of the first tensioner is in the retracted position thereby permitting the valve of the first tensioner to pivot and the plunger of the second tensioner is in the extended position thereby locking the valve of the second tensioner in the closed position.
- 33. The tensioner system of claim 32 wherein the tensioner system operates in the first condition when the sensor detects an engine speed in a first range, in the second condition when the sensor detects an engine speed in a second range, and in the third condition when the sensor detects an engine speed in a third range.
- 34. The tensioner system of claim 33 wherein the tensioner system operates in the first condition when the sensor detects an engine speed in a fourth range.
- 35. The tensioner system of claim 30 wherein the controller is operable to obtain a rate of change of the engine speed from the signal received from the sensor and is operable to move the plunger of the first tensioner and the plunger of the second tensioner based, at least in part, on the rate of change of the engine speed.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 10/071,629, filed Feb. 7, 2002.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
10071629 |
Feb 2002 |
US |
Child |
10421451 |
Apr 2003 |
US |