초록 ▼

A system and method for electronically controlling the displacement of hydraulic pumps, IHTs or HSTs. The IHT and HST includes a hydraulic transmission mounted within the casing that includes a rotatable hydraulic pump in fluid communication with a rotatable hydraulic motor and a moveable swash plat

A system and method for electronically controlling the displacement of hydraulic pumps, IHTs or HSTs. The IHT and HST includes a hydraulic transmission mounted within the casing that includes a rotatable hydraulic pump in fluid communication with a rotatable hydraulic motor and a moveable swash plate cooperable with the rotatable hydraulic pump for controlling the speed and direction of rotation of the rotatable hydraulic motor. The rotation of the hydraulic motor is used to drive an axle shaft. For controlling the positioning of the swash plate, the transaxle further includes a rotatable trunnion arm coupled to the moveable swash plate. The rotatable trunnion arm extends from the casing and is coupled to a control arm. The control arm is further connected to the electronic actuation drive, which is mounted to the casing and is used to electronically control the rotation of the rotatable control arm to change the orientation of the swash plate and to change the speed and direction of rotation of the rotatable hydraulic motor.

대표청구항 ▼

1. A drive system for electronically controlling a rotatable hydraulic pump, comprising:a moveable swash plate cooperable with the rotatable hydraulic pump for controlling the displacement of the pump; a rotatable control arm coupled to the moveable swash plate; an electronic actuation drive connect

1. A drive system for electronically controlling a rotatable hydraulic pump, comprising:a moveable swash plate cooperable with the rotatable hydraulic pump for controlling the displacement of the pump; a rotatable control arm coupled to the moveable swash plate; an electronic actuation drive connected to the control arm for electronically controlling rotation of the control arm to change orientation of the swash plate; and wherein the electronic actuation drive will automatically rotate the control arm to return the swash plate back to a neutral position in response to detecting a predefined condition. 2. The system described in claim 1, further comprising a casing that houses the rotatable hydraulic pump and wherein the electronic actuation drive is mounted to the casing.3. The system described in claim 1, further comprising a casing that houses the rotatable hydraulic pump and wherein the electronic actuation drive is mounted within the casing.4. The system described in claim 1, further comprising a control handle that generates a signal representative of the position of the control handle for causing the electronic actuation drive to move the control arm to a position that corresponds to the position of the control handle.5. A drive system for electronically controlling a rotatable hydraulic pump, comprising:a moveable swash plate cooperable with the rotatable hydraulic pump for controlling the displacement of the pump; a rotatable control arm coupled to the moveable swash plate; an electronic actuation drive connected to the control arm for electronically controlling rotation of the control arm to change orientation of the swash plate; a control handle that generates a signal representative of the position of the control handle for causing the electronic actuation drive to move the control arm to a position that corresponds to the position of the control handle; and comparator circuitry cooperable with the electronic actuation drive for providing a signal representative of the position of the control handle relative to the control arm to the electronic actuation drive. 6. The system described in claim 5, where the comparator circuitry further comprises a hall effect sensor for producing the signal representative of the position of the control handle relative to the control arm.7. The system described in claim 5, where the comparator circuitry further comprises a potentiometer for producing the signal representative of the position of the control handle relative to the control arm.8. A drive system for electronically controlling a hydraulic transmission, comprising:a rotatable hydraulic pump coupled to the hydraulic transmission and in fluid communication with a rotatable hydraulic motor; a moveable swash plate cooperable with the rotatable hydraulic pump for controlling displacement of the hydraulic pump and the corresponding displacement of the hydraulic motor, the hydraulic motor being capable of driving an axle; a control arm coupled to the moveable swash plate; an electronic actuation drive connected to the control arm for electronically controlling rotation of the control arm to change orientation of the swash plate; and wherein the electronic actuation drive will automatically rotate the control arm to return the swash plate back to a neutral position in response to detecting a predefined condition. 9. The system described in claim 8, wherein the predefined condition comprises activating a brake on a vehicle associated with the system.10. The system described in claim 8, wherein the predefined condition comprises turning off power to a vehicle associated with the system.11. The system described in claim 8, further comprising a casing that houses the hydraulic transmission and wherein the electronic actuation drive is mounted to the casing.12. The system described in claim 8, further comprising a casing that houses the hydraulic transmission and wherein the electronic actuation drive is mounted within the casing.13. The system described in claim 8, further comprising a control handle that generates a signal representative of the position of the control handle for causing the electronic actuation drive to move the control arm to a position that corresponds to the position of the control handle.14. A drive system for electronically controlling a hydraulic transmission, comprising:a rotatable hydraulic pump coupled to the hydraulic transmission and in fluid communication with a rotatable hydraulic motor; a moveable swash plate cooperable with the rotatable hydraulic pump for controlling displacement of the hydraulic pump and the corresponding displacement of the hydraulic motor, the hydraulic motor being capable of driving an axle; a control arm coupled to the moveable swash plate; an electronic actuation drive connected to the control arm for electronically controlling rotation of the control arm to change orientation of the swash plate; a control handle that generates a signal representative of the position of the control handle for causing the electronic actuation drive to move the control arm to a position that corresponds to the position of the control handle; and comparator circuitry cooperable with the electronic actuation drive for providing a signal representative of the position of the control handle relative to the control arm to the electronic actuation drive. 15. The system described in claim 14, where the comparator circuitry further comprises a hall effect sensor for producing the signal representative of the position of the control handle relative to the control arm.16. The system described in claim 14, where the comparator circuitry further comprises a potentiometer for producing the signal representative of the position of the control handle relative to the control arm.17. A drive system for electronically controlling forward and reverse movement and speed of a vehicle, comprising:a casing attached to the vehicle being adapted to carry an axle; a hydraulic transmission mounted within the casing comprising a rotatable hydraulic pump in fluid communication with a rotatable hydraulic motor; a moveable swash plate cooperable with the hydraulic pump for controlling the displacement of the hydraulic pump and the corresponding displacement of the hydraulic motor, the hydraulic motor being capable of driving the axle and the vehicle; a rotatable trunnion arm coupled to the moveable swash plate; a control arm coupled to the trunnion arm and extending from the casing; an electronic actuation drive connected to the control arm for electronically controlling rotation of the control arm and the trunnion arm to change orientation of the swash plate; and wherein the electronic actuation drive will automatically rotate the control arm to return the swash plate back to a neutral position in response to detecting a predefined condition. 18. The system described in claim 17, wherein the predefined condition comprises activating a brake associated with the vehicle.19. The system described in claim 17, wherein the predefined condition comprises turning off power to the vehicle.20. The system described in claim 17, where the electronic actuation drive is mounted to the casing.21. The system described in claim 17, where the electronic actuation drive is mounted within the casing.22. The system described in claim 17, further comprising a control handle that generates a signal representative of the position of the control handle for causing the electronic actuation drive to move the control arm to a position that corresponds to the position of the control handle.23. A drive system for electronically controlling forward and reverse movement and speed of a vehicle, comprising:a casing attached to the vehicle being adapted to carry an axle; a hydraulic transmission mounted within the casing comprising a rotatable hydraulic pump in fluid communication with a rotatable hydraulic motor; a moveable swash plate cooperable with the hydraulic pump for controlling the displacement of the hydraulic pump and the corresponding displacement of the hydraulic motor, the hydraulic motor being capable of driving the axle and the vehicle; a rotatable trunnion arm coupled to the moveable swash plate; a control arm coupled to the trunnion arm and extending from the casing; an electronic actuation drive connected to the control arm for electronically controlling rotation of the control arm and the trunnion arm to change orientation of the swash plate; a control handle that generates a signal representative of the position of the control handle for causing the electronic actuation drive to move the control arm to a position that corresponds to the position of the control handle; and comparator circuitry cooperable with the electronic actuation drive for providing a signal representative of the position of the control handle relative to the control arm to the electronic actuation drive. 24. The system described in claim 23, where the comparator circuitry further comprises a hall effect sensor for producing the signal representative of the position of the control handle relative to the control arm.25. The system described in claim 23, where the comparator circuitry further comprises a potentiometer for producing the signal representative of the position of the control handle relative to the control arm.26. A method for electronically controlling operation of a vehicle including a hydraulic motor adapted to drive an axle, the hydraulic motor being in fluid communication with a hydraulic pump having a plurality of axially moveable pump pistons, wherein a swash plate is positioned to cooperatively engage the pump pistons and a control arm is linked to the swash plate to change the angular orientation of the swash plate to affect the displacement of fluid from the hydraulic pump to the hydraulic motor, the method comprising:receiving a signal indicative of the vehicle assuming a predefined condition; using an electronic actuation drive to rotate the control arm to electronically control angular orientation of the swash plate in response to the signal indicative of the predefined condition; and wherein the predefined condition comprises activation of a brake to prevent rotation of the axle. 27. A method for electronically controlling operation of a vehicle including a hydraulic motor adapted to drive an axle, the hydraulic motor being in fluid communication with a hydraulic pump having a plurality of axially moveable pump pistons, wherein a swash plate is positioned to cooperatively engage the pump pistons and a control arm is linked to the swash plate to change the angular orientation of the swash plate to affect the displacement of fluid from the hydraulic pump to the hydraulic motor, the method comprising:receiving a signal indicative of the vehicle assuming a predefined condition; using an electronic actuation drive to rotate the control arm to electronically control angular orientation of the swash plate in response to the signal indicative of the predefined condition; and causing the electronic actuation drive to rotate the control arm and the swash plate in a reverse direction toward a neutral position in response to the predefined condition when the control arm is in a forward position. 28. A method for electronically controlling operation of a vehicle including a hydraulic motor adapted to drive an axle, the hydraulic motor being in fluid communication with a hydraulic pump having a plurality of axially moveable Rump pistons, wherein a swash plate is positioned to cooperatively engage the pump pistons and a control arm is linked to the swash plate to change the angular orientation of the swash plate to affect the displacement of fluid from the hydraulic pump to the hydraulic motor, the method comprising:receiving a signal indicative of the vehicle assuming a predefined condition; using an electronic actuation drive to rotate the control arm to electronically control annular orientation of the swash plate in response to the signal indicative of the predefined condition; and causing the electronic actuation drive to rotate the control arm and the swash plate in a forward direction toward a neutral position in response to the predefined condition when the control arm is in a reverse position. 29. The method described in claim 28, wherein the electronic actuation drive is further comprised of a rotatable control handle for causing the electronic drive to move the control arm.30. The method described in claim 29, wherein the predefined condition comprises placing the control handle in a neutral position.31. The method described in claim 30, further comprising the step of allowing an engine used to drive the hydraulic pump to be activated in response to the predefined condition.32. The method described in claim 29, wherein the predefined condition comprises placing the control handle in a non-neutral position.33. The method described in claim 32, further comprising the step of preventing an engine used to drive the hydraulic pump from being activated in response to the predefined condition.34. The method described in claim 29, wherein the predefined condition comprises turning off an electrical system of the vehicle.35. The method described in claim 34, further comprising the step of causing the electronic actuation drive to rotate the control arm to place the swash plate in a neutral position in response to the predefined condition.36. The method described in claim 35, further comprising the step of causing the electronic actuation drive to be powered down in response to the swash plate being placed in the neutral position.