Hydraulic feed device and hydraulic system

Patent metadata

Field	Value
Publication number	US-9841020-B2
Application number	US-201313926704-A
Country	US
Kind code	B2
Filing date	Jun 25, 2013
Priority date	Jun 26, 2012
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A hydraulic feed device may include a pendulum-slide cell pump having an internal rotor drivingly connected to an external rotor via pendulum slides. A hydraulic positioning device may have a positioning element for changing an eccentricity between the internal rotor and the external rotor. The positioning element may be preloaded by a spring device for setting a maximum eccentricity. The positioning device may have a first pressure adjusting and a second pressure adjusting chamber for adjusting the positioning element. The first pressure adjusting chamber may be permanently hydraulically connected to a pressure side of the pendulum-slide cell pump and configured to hydraulically counteract the spring device. The second pressure adjusting chamber may be controlled via a control valve and hydraulically connected to the pressure side of the pendulum-slide cell pump and configured to hydraulically counteract the spring device.

First claim

The invention claimed is:

1. A hydraulic system comprising:
a primary hydraulic circuit having a variable hydraulic pressure demand;
a secondary hydraulic circuit having a comparatively constant pressure demand in relation to the primary hydraulic circuit; and
a hydraulic feed device connected to the primary hydraulic circuit and the secondary hydraulic circuit, the hydraulic feed device including:
a pendulum-slide cell pump having a pressure side configured to supply a feed pressure for the primary hydraulic circuit and the secondary hydraulic circuit, the pendulum-slide cell pump including a housing and an internal rotor drivingly connected to an external rotor via pendulum slides, the internal rotor rotatable about a rotation axis and the external rotor having a longitudinal center axis eccentric to the rotation axis;
a hydraulic positioning device including a positioning element mounting the external rotor and configured to change an eccentricity between the internal rotor and the external rotor, wherein the positioning element is mounted on the housing pivotably adjustable about a pivot axis arranged about an outer surface of the positioning element, the pivot axis disposed in a position that extends parallel and eccentric to the rotation axis of the internal rotor;
the positioning element preloaded by a spring device for setting a maximum eccentricity;
the hydraulic positioning device further including a first pressure adjusting chamber for adjusting the positioning element and a second pressure adjusting chamber for adjusting the positioning element;
wherein the first pressure adjusting chamber is pressurized and permanently hydraulically connected to the pressure side of the pendulum-slide cell pump to provide a force acting on the position element to hydraulically counteract the spring device;
wherein the second pressure adjusting chamber is pressurized via a proportional control valve and selectively hydraulically connected to the pressure side of the pendulum-slide cell pump acting on the positioning element to hydraulically counteract the spring device when the second pressure adjusting chamber is pressurized;
a control device coupled to the primary hydraulic circuit, the secondary hydraulic circuit, and the proportional control valve, wherein the control device selectively actuates the proportional control valve into one of a plurality of positions via control signals communicated to the proportional control valve, said control signals correlating with a respective hydraulic pressure demand of the primary hydraulic circuit to adjust the feed pressure and provide a necessary hydraulic pressure for both the primary hydraulic circuit and the secondary hydraulic circuit;
wherein the proportional control valve is selectively actuated via said control signals to adjust between the plurality of positions to vary the adjustable forces acting in the second pressure adjusting chamber and vary the eccentricity depending on the respective hydraulic pressure demand of the primary hydraulic circuit and the secondary hydraulic circuit when a pressure on the pressure side is below a predetermined maximum pressure, the plurality of positions of the proportional control valve including a first position where the second pressure adjusting chamber is hydraulically disconnected from the pressure side and the pendulum-slide cell pump supplies a first feed pressure, a second position where the second pressure adjusting chamber is hydraulically connected to the pressure side and the pendulum-slide cell pump supplies a second feed pressure less than the first feed pressure, and a third position intermediate to the first position and the second position where the pendulum-slide cell pump supplies a third feed pressure between the first feed pressure and the second feed pressure; and
wherein the first pressure adjusting chamber is arranged proximal to the pivot axis, the second pressure adjusting chamber is arranged distal to the pivot axis, and the spring device is arranged distal to the pivot axis.

2. The system according to claim 1 , wherein the control device reduces the feed pressure provided on the pressure side via said second pressure adjusting chamber by actuating the proportional control valve via said control signals into the second position in response to said control signals indicating a reduced hydraulic pressure demand for the primary hydraulic circuit.

3. The system according to claim 1 , wherein the control device is coupled to a pressure sensor system that measures the hydraulic pressure provided by the hydraulic feed device.

4. The system according to claim 1 , wherein the secondary circuit is connected to the hydraulic feed device via a volume flow control valve.

5. The system according to claim 1 , wherein the primary circuit supplies oil to a hydraulic actuating device for actuating a clutch of a transmission while the secondary circuit supplies oil to lubrication points of the transmission.

6. The system according to claim 1 , wherein the proportional control valve provides the third feed pressure in the third position by adjusting a pressure in the second pressure adjusting chamber to fall within a pressure interval between the pressure on the pressure side and a pressure on a suction side of the pump when the pump is operating and the pressure on the pressure side is below the predetermined maximum pressure.

7. The system according to claim 1 , wherein the control device increases the feed pressure provided on the pressure side via the second pressure adjusting chamber by actuating the proportional control valve via said control signals in response to said control signals indicating a temporarily increased hydraulic pressure demand for the primary hydraulic circuit.

8. A hydraulic system, comprising:
at least two hydraulic circuits having a respective hydraulic pressure demand different from one another;
a hydraulic feed device for supplying hydraulic pressure to the at least two hydraulic circuits, the hydraulic feed device including:
a pendulum-slide cell pump having a pressure side coupled to the at least two hydraulic circuits and configured to output a feed pressure to said at least two hydraulic circuits at a necessary hydraulic pressure demand of the at least two hydraulic circuits, the pendulum-slide cell pump including an internal rotor drivingly connected to an external rotor via pendulum slides, the internal rotor rotatable about a rotation axis and the external rotor having a longitudinal center axis eccentric to the rotation axis;
a hydraulic positioning device for adjusting the feed pressure provided on the pressure side of the pendulum-slide cell pump, the hydraulic positioning device including a positioning element mounting the external rotor, the positioning element pivotably displaceable about a pivot axis arranged parallel and eccentric to the rotation axis for changing an eccentricity between the internal rotor and the external rotor;
the positioning element preloaded by a spring device for setting a maximum eccentricity;
the hydraulic positioning device further including a first pressure adjusting chamber for adjusting the positioning element, and a second pressure adjusting chamber for adjusting the positioning element;
the first pressure adjusting chamber permanently hydraulically connected to the pressure side of the pendulum-slide cell pump and pressurized to provide a force acting on the positioning element to hydraulically counteract the spring device;
the second pressure adjusting chamber controlled via a proportional control valve and selectively hydraulically connected to the pressure side of the pendulum-slide cell pump, the second pressure adjusting chamber selectively pressurized via the proportional control

Assignees

• Mahle Int Gmbh

Inventors

• Ammon Edgar
• Knauss Ruediger
• Tepler Mark
• Richter Christian
• Ristovski Robert

Classifications

• F04C2/332 Primary

  with vanes hinged to the outer member and reciprocating with respect to the inner member · CPC title

• F04C2240/81

  Sensor, e.g. electronic sensor for control or monitoring · CPC title

• F04C2210/206

  Oil · CPC title

• F04C14/22 Primary

  by changing the eccentricity between cooperating members · CPC title

• F04C14/226

  by pivoting the cam around an eccentric axis · CPC title