Tracker hydraulic assistance device for a slave craft

Patent metadata

Field	Value
Publication number	US-10821825-B2
Application number	US-201716472566-A
Country	US
Kind code	B2
Filing date	Dec 22, 2017
Priority date	Dec 22, 2016
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

The invention relates to a hydraulic assistance device comprising: a hydraulic machine ( 30 ) capable of driving a wheel (W) of the craft; a variable displacement pump ( 10 ) comprising a double-acting actuator ( 12 ) defining two control chambers ( 12 a, 12 b ) for hydraulically controlling the capacity of said pump ( 10 ); two supply lines ( 40 a, 40 b ) that connect the hydraulic machine ( 30 ) and the variable displacement pump ( 30 ) in order to form a closed circuit, characterised in that the device further comprises: two control lines ( 80 a, 80 b ), each being respectively drawn from one of the two supply lines ( 40 a, 40 b ) and being configured to respectively supply one of the two control chambers ( 12 a, 12 b ); two electrically calibratable pressure limiters ( 90 a, 90 b ) respectively disposed on the two control lines ( 80 a, 80 b ).

First claim

The invention claimed is:

1. A hydraulic assistance device comprising:
a hydraulic machine ( 30 ), capable of motorising a wheel (W) of the vehicle,
a variable displacement pump ( 10 ), comprising a double actuating actuator ( 12 ) defining two control chambers ( 12 a , 12 b ), to hydraulically pilot the displacement of said pump ( 10 ),
two supply lines ( 40 a , 40 b ), which connect the hydraulic machine ( 30 ) and the variable displacement pump ( 10 ) to form a closed circuit,
wherein the device further comprises:
two control lines ( 80 a , 80 b ), each one sampled respectively on one of the two supply lines ( 40 a , 40 b ) and configured to respectively supply one of the two control chambers ( 12 a , 12 b ),
two electrically calibratable pressure limiters ( 90 a , 90 b ) respectively arranged on the two control lines ( 80 a , 80 b ).

2. The hydraulic assistance device according to claim 1 , wherein the two pressure limiters ( 90 a , 90 b ) are calibrated to let the pressurised oil go through simultaneously.

3. The hydraulic assistance device according to claim 1 , wherein the two pressure limiters ( 90 a , 90 b ) are calibratable starting from a value ranging between 0 and 5 bars and preferably starting from 0 bar.

4. The hydraulic assistance device according to claim 1 , wherein the pressure limiters ( 90 a , 90 b ) are calibrated at their minimum value when they are not piloted electrically.

5. The hydraulic assistance device according to claim 1 , wherein the control lines ( 80 a , 80 b ) each comprise a sampling nozzle upstream of the pressure limiters ( 90 a , 90 b ) so that the control lines ( 80 a , 80 b ) carry out a tapping on the supply lines ( 40 a , 40 b ).

6. The hydraulic assistance device according to claim 1 , wherein the control lines ( 80 a , 80 b ) each comprise a leakage nozzle downstream of the pressure limiter ( 90 a , 90 b ), connected to a tank (R) via a tapping.

7. The hydraulic assistance device according to claim 1 , wherein the variable displacement pump ( 10 ) is driven by a power take-off ( 14 ).

8. The hydraulic assistance device according to claim 1 , further comprising an engagement valve ( 60 ), arranged on the supply lines ( 40 a , 40 b ) to clutch or unclutch the hydraulic machine ( 30 ).

9. The hydraulic assistance device according to claim 1 , further comprising a booster pump ( 20 ) and a control valve ( 70 ), adapted to hydraulically pilot the engagement valve ( 60 ) from the pressure of the booster pump (Pg).

10. The hydraulic assistance device according to claim 1 , comprising a computing unit (CALC), said computing unit (CALC) allowing to pilot the electrically calibratable flow limiters ( 90 a , 90 b ).

11. The hydraulic assistance device according to claim 10 , wherein the computing unit (CALC) is configured to pilot the pressure limiter ( 90 a , 90 b ) connected to the highest pressure supply line ( 40 a , 40 b ) between the two supply lines ( 40 a , 40 b ).

12. The hydraulic assistance device according to claim 10 , for a non-slave vehicle, wherein the computing unit (CALC) receives speed or torque instructions.

13. A method according to claim 12 , wherein the choice of the pressure limiter ( 90 a , 90 b ) to calibrate and/or its calibrating value is performed according to the data obtained by a sensor.

14. The hydraulic assistance device according to claim 10 , wherein the computing unit (CALC) is configured to simultaneously pilot the two pressure limiters ( 90 a , 90 b ) or to simultaneously not pilot the two pressure limiters ( 90 a , 90 b ).

15. The hydraulic assistance device according to claim 1 , for a slave vehicle.

16. A vehicle comprising a device according to claim 1 .

17. A pair of vehicles comprising a master vehicle ( 3 ) to which is fastened a slave vehicle ( 2 ) according to claim 16 , for example two vehicles connected by a coupling or two axles of a vehicle.

18. The pair of vehicles according to claim 17 , wherein the master vehicle ( 3 ) comprises a power take-off ( 14 ) for supplying the variable displacement hydraulic pump ( 10 ) of the slave vehicle ( 2 ).

19. A hydraulic assistance method using a device according to a pair of vehicles according to claim 18 , comprising the following steps:
piloting at least one of the electrically calibratable pressure limiters ( 90 a , 90 b ).

20. A hydraulic assistance method using a device according to a pair of vehicles according to claim 17 , comprising the following steps:
piloting at least one of the electrically calibratable pressure limiters ( 90 a , 90 b ).

21. A hydraulic assistance method using a vehicle according to claim 16 , comprising the following steps:
piloting at least one of the electrically calibratable pressure limiters ( 90 a , 90 b ).

22. A hydraulic assistance method using a device according to claim 1 , comprising the following steps:
piloting at least one of the electrically calibratable pressure limiters ( 90 a , 90 b ).

23. A method according to claim 22 , comprising the following steps:
unpiloting the two pressure limiters ( 90 a , 90 b ),
clutching the hydraulic machine ( 30 ),
piloting only one of the two pressure limiters ( 90 a , 90 b ).

Assignees

• Poclain Hydraulics Ind

Inventors

• Sohier Vincent

Classifications

• B60K7/0015 Primary

  the motor being hydraulic · CPC title

• B60K17/356

  having fluid or electric motor, for driving one or more wheels · CPC title

• B60Y2200/147

  Trailers, e.g. full trailers or caravans · CPC title

• F16H61/431 Primary

  Pump capacity control by electro-hydraulic control means, e.g. using solenoid valves · CPC title

• F16H61/433

  Pump capacity control by fluid pressure control means · CPC title