Low-loss drive system for a plurality of hydraulic actuators

• US 6,205,780 B1
• Filed: 02/16/1999
• Issued: 03/27/2001
• Est. Priority Date: 01/10/1996
• Status: Expired due to Term

• Current Assignee: Aeroquip-Vickers International GmbH
• Original Assignee: Aeroquip-Vickers International GmbH
• Inventors: Zervas, Bernhard
• Primary Examiner(s): Lopez, F. Daniel
• Application Number:
  US09/101,502
• Time in Patent Office: 770 Days
• Field of Search: 604/21, 604/23, 604/28, 604/29, 604/30, 604/65, 604/86
• US Class Current: 60/421
• CPC Class Codes: F15B 11/08 with only one servomotor
• CPC Class Codes: F15B 11/17 using two or more pumps
• CPC Class Codes: F15B 2211/20561 reversible
• CPC Class Codes: F15B 2211/20576 with multiple pumps
• CPC Class Codes: F15B 2211/2658 by control of the prime movers
• CPC Class Codes: F15B 2211/27 Directional control by means of the pressure source
• CPC Class Codes: F15B 2211/30585 having a single valve for multiple output members
• CPC Class Codes: F15B 2211/6303 using input signals
• CPC Class Codes: F15B 2211/6336 representing a state of the output member, e.g. position, speed or acceleration
• CPC Class Codes: F15B 2211/6651 Control of the prime mover, e.g. control of the output torque or rotational speed
• CPC Class Codes: F15B 2211/6658 Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode
• CPC Class Codes: F15B 2211/71 Multiple output members, e.g. multiple hydraulic motors or cylinders

Abstract

The invention related to a drive system with at least two hydraulic actuators, which are supplied with a hydraulic fluid by means of at least one pump. The drive system comprises at least one further second pump (15′) arranged parallel to the first pump (15), wherein the pumps are bi-directionally speed-regulated, and a valve arrangement (59) with one inlet per pump (61.1, 61.2), wherein each one of the inlets is connected to a pump (15), and with a number of outlets (63.1, 63.1′, . . . 63.4, 63.4′) which are connected to the actuators (1.1 . . . 1.4), wherein the inlets (61) can be connected to the outlets (63) in a pre-determined manner.

Claims

1. A drive system comprising:

at least two hydraulic actuators;

a first pump and at least one further pump that are configured to supply hydraulic fluid to the actuators, wherein the pumps are bi-directionally speed-regulated; and

a valve arrangement having one inlet for each pump and a number of outlets connected to the actuators, wherein each of the inlets is connected to a pump and wherein the inlets are connected to the outlets in a pre-determined manner;

wherein, in a first switching position of the valve arrangement, a first inlet of the valve arrangement is connected to a first outlet of the valve arrangement and a second inlet of the valve arrangement is connected to a second outlet of the valve arrangement, wherein the first and second outlets are connected to the same actuator.

2. The drive system as recited in claim 1, wherein the valve arrangement is switchable between the first switching position and a second switching position, wherein, in the second switching position, the first and second inlets of the valve arrangement are connected to one outlet of the valve arrangement such that both pumps jointly supply one actuator.

3. The drive system as recited in claim 1, wherein the valve arrangement is switchable between the first switching position and a second switching position, wherein, in the second switching position, the two pumps are connected to different actuators.

4. The drive system as recited in claim 1, wherein at least one of said pumps has a fixed displacement volume.

5. The drive system as recited in claim 1, wherein at least one of said pumps comprises a variable displacement pump.

6. A drive system comprising:

at least two hydraulic actuators;

a first pump and at least one further pump which are configured to supply hydraulic fluid to the actuators, wherein the pumps are bi-directionally speed-regulated; and

a valve arrangement having one inlet for each pump and a number of outlets connected to the actuators, wherein each of the inlets is connected to a pump and wherein the inlets are connected to the outlets in a pre-determined manner;

wherein, in a first switching position of the valve arrangement, the two pumps are connected to different actuators;

wherein the valve arrangement is switchable between the first switching position and a second switching position; and

wherein in the second switching position, both pumps are connected jointly to one outlet, in order to supply one actuator.

7. The drive system as recited in claim 6, wherein at least one of said pumps comprises a variable displacement pump.

8. The drive system as recited in claim 6, wherein each of the two pumps has a separate drive assembly.

9. The drive system as recited in claim 8, further comprising a control circuit configured to control the drive assemblies.

10. The drive system as recited in claim 9, wherein the control circuit comprises at least one sensor adapted to detect a parameter of at least one actuator.

11. The drive system as recited in claim 6, further comprising:

a regulating circuit configured to control at least one parameter of at least one actuator.

12. The drive system as recited in claim 6, further comprising:

at least one electric motor adapted to drive at least one of the pumps, the electric motor having variable speed for each direction of rotation.

13. A drive system comprising:

at least two hydraulic actuators;

a first pump and at least one further pump which are configured to supply hydraulic fluid to the actuators, wherein the pumps are bi-directionally speed-regulated; and

a valve arrangement having one inlet for each pump and a number of outlets connected to the actuators, wherein each of the inlets is connected to a pump and wherein the inlets are connected to the outlets in a pre-determined manner;

wherein each of the pumps is associated with a separate electric motor adapted to drive the pump, each electric motor having a variable speed for each direction of rotation;

wherein the valve arrangement is switchable between a first switching position and a second switching position;

wherein, in the first switching position of the valve arrangement, the two pumps are connected to different actuators, and in the second switching position of the valve arrangement, both pumps are connected jointly to one outlet, in order to supply one actuator.

14. The drive system as recited in claim 13, wherein at least one of said pumps comprises a variable displacement pump.

15. The drive system as recited in claim 13, further comprising at least one control circuit configured to control the electric motors.

16. The drive system as recited in claim 15, wherein the control circuit comprises at least one sensor adapted to detect a parameter of at least one actuator.

17. The drive system as recited in claim 13, further comprising:

a regulating circuit configured to control at least one parameter of at least one actuator.