DRIVE SYSTEM HAVING AT LEAST ONE HYDRAULIC ACTUATOR

• US 20130074487A1
• Filed: 03/15/2011
• Published: 03/28/2013
• Est. Priority Date: 05/11/2010
• Status: Abandoned Application

• Current Assignee: Hydac Electronic GmbH
• Original Assignee: Hydac Electronic GmbH
• Inventors: Herold, Frank, Remus, Kai, Kattler, Frank
• Application Number:
  US13/261,508
• Publication Number:
  US 20130074487A1
• Time in Patent Office: Days
• US Class Current: 60/455
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F15B 2211/20515 Electric motor
• CPC Class Codes: F15B 2211/20561 reversible
• CPC Class Codes: F15B 2211/27 Directional control by means of the pressure source
• CPC Class Codes: F15B 2211/30505 Non-return valves, i.e. check valves
• CPC Class Codes: F15B 2211/61 Secondary circuits
• CPC Class Codes: F15B 2211/625 Accumulators
• CPC Class Codes: F15B 2211/6658 Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode
• CPC Class Codes: F15B 2211/7053 Double-acting output members
• CPC Class Codes: F15B 2211/7058 Rotary output members
• CPC Class Codes: F15B 2211/7128 the chambers being connected in parallel
• CPC Class Codes: F15B 7/006 Rotary pump input

Abstract

The invention relates to a drive system having at least one hydraulic actuator (2), which is supplied with pressure medium (4) by means of at least one pressure-medium pump (3) in a main circuit, the pressure-medium pump (3) being a rotational-speed-controlled pressure-medium pump that is driven by a motor (5) at a variable rotational speed and a controlled torque, said drive system being characterized in that leakage fluid (7) that escapes from a displacement chamber (6) of the pressure-medium pump (3) is discharged through a fluid-conducting connection (8) having at least one check valve (9, 16), and the at least one check valve (9, 16) is installed in the fluid-conducting connection (8) in such a way that the check valve prevents pressure medium from flowing back out of the main circuit into the displacement chamber (6) or another interior chamber of the pressure-medium pump (3) and feeds leakage fluid (7) into the main circuit of the drive system (1) when there is a slight excess pressure.

Claims

1. A drive system having at least one hydraulic actuator (2), which is supplied with a pressure medium (4) by means of at least one pressure medium pump (3) in a main circuit, wherein the pressure medium pump (3) is a speed-controlled pressure medium pump, which is driven by a motor (5) at a variable speed and a controlled torque, characterized in that the leakage fluid (7), escaping from a displacement chamber (6) of the pressure medium pump (3), is discharged through a fluid-conducting connection (8) having at least one check valve (9, 16), and that the at least one check valve (9, 16) is installed in the fluid-conducting connection (8) in such a way that the check valve prevents the pressure medium from flowing back out of the main circuit into the displacement chamber (6) or another interior chamber of the pressure medium pump (3) and feeds the leakage fluid (7) into the main circuit of the drive system (1) when there is a slight excess pressure.

2. The drive system according to claim 1, characterized in that the pressure medium pump (3) has at least one low pressure port (14, 14′

) and/or at least one high pressure port (15, 15′

).

3. The drive system according to claim 2, characterized in that the leakage fluid (7) is discharged at least at one low pressure port (14, 14′

) of the pressure medium pump (3).

4. The drive system according to claim 2, characterized in that the fluid-conducting connection (8) runs through the respective low pressure port (14, 14′

) to at least one high pressure port (15, 15′

); and

that each port (2) of the connection (8) has a check valve (9, 16).

5. The drive system according to claim 1, characterized in that the pressure medium pump (3) is an axial piston machine;

and that two check valves (9, 16) that open in opposite directions are activated in the fluid-conducting connection (8);

and the fluid-conducting connection (8) is connected in parallel to a high pressure port (15, 15′

) respectively of the axial piston machine.

6. The drive system according to claim 1, characterized in that the pressure medium pump (3) is bi-directional in the two-quadrant operating mode or is speed-controlled in the four-quadrant operating mode.

7. The drive system according to claim 1, characterized in that the pressure medium pump (3) charges a pressure accumulator (10) with a pressure medium (4);

and this pressure accumulator also charges the hydraulic actuator (2) with pressure medium (4).

8. The drive system according to claim 1, characterized in that the hydraulic actuator (2) is an actuating device (11) for a hydraulic system for roll stabilization of a vehicle.

9. The drive system according to claim 7, characterized in that the pressure accumulator (10) prestresses the pressure medium (4) on the intake side (12) of the pressure medium pump (3).

10. The drive system according to claim 7, characterized in that the pressure accumulator (10) charges the pressure medium (4) in a working chamber (13, 13′

) of the hydraulic actuator (2).

11. The drive system according to claim 7, characterized in that the hydraulic actuator (2) and the pressure medium container are actuated by a directional control valve in such a way that a suction process is realized.

12. The drive system according to claim 1, characterized in that the pressure medium pump (3) is used for supplying pressure medium to two hydrostatic working cylinders (17) that work in opposite directions.

13. The drive system according to claim 12, characterized in that the working cylinders (17) that work in opposite directions are connected in each instance to a valve (18) for draining the pressure medium (4) out of each one of their working chambers (13, 13′

).

14. The drive system according to claim 13, characterized in that a check valve (R) is arranged parallel to the valve (18) in a pressure medium line bridging the valve (18);

and that at least one check valve (R) enables the pressure medium (4) to flow out of the pressure medium container to the respective hydraulic actuator (2).