WO2015090311A1

WO2015090311A1 - Variable displacement pump

Info

Publication number: WO2015090311A1
Application number: PCT/DE2014/200659
Authority: WO
Inventors: Dominik Herkommer; Markus Baehr; Marco Grethel
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2013-12-18
Filing date: 2014-11-27
Publication date: 2015-06-25
Also published as: CN105829711A; DE112014005946A5; US20160252080A1; CN105829711B

Abstract

The invention relates to a variable displacement pump having two connections for supplying and withdrawing a volume flow guided by said variable displacement pump. The invention is characterized in that said variable displacement pump comprises an additional connection for providing and additional volume flow.

Description

variable

The invention relates to a variable displacement pump with two connections for supplying and discharging a volume flow delivered by the variable displacement pump. The invention further relates to a method for operating such a variable displacement pump.

German published patent application DE 199 30 648 A1 discloses an electrohydraulic pressure supply with a variable-speed electric drive motor and a variable displacement pump, the displacement of which can be changed by an adjusting member, with connection lines and consumer connections.

The object of the invention is to simplify the provision of independently adjustable volume flows.

The object is achieved with a variable displacement pump with two connections for supplying and discharging a volume flow delivered by the variable displacement pump in that the variable displacement pump has an additional connection for providing an additional volume flow. As a result, the supply of two hydraulic consumers with different, changing volumetric flow requirements is made possible in a simple manner. The hydraulic consumers are, for example, partial clutches of a double clutch. The variable displacement pump is preferably permanently drivingly connected to a drive device, for example an internal combustion engine drive device. The volumetric flows provided at the connection and the additional connection can advantageously be set separately from one another.

A preferred embodiment of the variable displacement pump is characterized in that the variable displacement pump is adjustable by independently adjustable physical signals so that the volume flows at two of the total of three ports are independently adjustable. One of the connections is a reservoir connection, via which a hydraulic medium to be delivered is sucked in. The hydraulic medium is, for example, hydraulic oil, which is also abbreviated as oil. The two other connections are inputs or outputs of the variable displacement pump. The adjustment can be two-dimensional or three-dimensional. A further preferred embodiment of the variable displacement pump is characterized in that the variable displacement pump is adjustable by independently adjustable physical signals so that the volume flows at two of the total of three ports are reversible with respect to their flow direction. The reversal of the flow direction can be carried out particularly advantageously without reversing the direction of rotation of the delivery pump. The type of adjustment signals depends on the type or design of the variable displacement pump.

Further preferred embodiments of the variable displacement pump are characterized in that the variable displacement pump is designed as a vane pump or as a radial piston pump. In the vane pump and in the radial piston pump, the adjustment is preferably carried out by a displacement of rotor axes against a contour on a pump housing. Different displacement directions determine the volume flow of each pump outlet.

A further preferred embodiment of the variable displacement pump is characterized in that the variable displacement pump is designed as an axial piston pump. In the case of the axial piston pump, the adjustment of the volume flow preferably results from a tilting of a swash plate or swash plate, which causes an axial movement of the pump piston. In this case, two tilting directions affect the volume flows that are provided at the connection and the additional connection.

In a method for operating a variable displacement pump described above, the above-mentioned object is alternatively or additionally achieved in that a volumetric flow is provided in each case at two connections. The two volume flows are separated and independently adjustable. The two independently controllable volume flows can be used, for example, to actuate a double clutch.

A preferred embodiment of the method is characterized in that the volume flows provided at the two ports are set independently by independently adjustable physical signals. The type of adjustment depends on the type of variable displacement pump used. Another preferred exemplary embodiment of the method is characterized in that at least one of the volume flows provided at the two connections is reversed with respect to its flow direction. The reversal of the flow direction is particularly advantageous without reversing the direction of rotation of the variable.

A further preferred exemplary embodiment of the method is characterized in that the volume flows provided at the two connections are combined to form a third volume flow. As a result, the functionality of the variable displacement pump according to the invention can be further increased.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, various embodiments are described in detail. Show it:

Figure 1 is a greatly simplified representation of a variable displacement pump according to a first

Embodiment;

Figure 2 is a similar view as in Figure 1 with wings additionally shown;

Figure 3 shows the variable displacement pump of Figure 2 with lines and arrows illustrating the operation of the variable;

Figure 4 is a perspective view of a running as axial piston pump

variable;

Figure 5 shows the variable displacement pump of Figure 4 in a different perspective and

Figure 6 is a simplified representation of a variable displacement pump designed as a radial piston pump.

In FIGS. 1 to 3 a variable displacement pump 1 with a housing 3 is shown in simplified form. In the housing 3, a rotor 5 is rotatably driven. In Figure 1 is indicated by double arrows in the center of the rotor 5, that the rotor 5 is movable in the housing 3 in order to adjust a delivery volume or displacement of the variable displacement pump 1. By lines 14 to 17 are indicated in Figure 1 adjustment directions, along which the rotor 5 can be moved in the housing 3.

The variable displacement pump 1 has a reservoir connection 10, a connection 11 and an additional connection 12 on the housing 3. The reservoir port 10 allows supply of hydraulic fluid from a hydraulic fluid reservoir (not shown).

The two terminals 1 1 and 12 are advantageously separated from each other adjustable. The terminal 1 1 is connected, for example, with a slave cylinder of a first part clutch a double clutch. The terminal 12 is then advantageously connected to a slave cylinder of a second part clutch of the double clutch.

The illustrated terminals 10 to 12 represent areas in which the terminals 10 to 12 are provided on the housing 3. In this case, the terminals 10 to 12 may be arranged in a lateral surface of the housing 3. However, the terminals 10 to 12 may also be arranged in an end face or an end face of the housing 3.

In FIG. 2 it can be seen that the rotor has slots for the radially movable arrangement of a total of eight wings 20. The wings 20 are arranged with their radially inner ends in the rotor slots. With their radially outer ends, the wings 20 bear against an inner contour of the housing 3.

In Figure 3 is indicated by an arrow 19 that the rotor 5 is driven in a clockwise direction. In operation, the rotor 5 rotates with the vanes 20 in the housing 3. An adjustment of the volume flows, which are provided in the conveying operation of the variable displacement pump 1, via a displacement of the rotor 5 relative to the housing third

The displacements indicated in FIGS. 1 and 2 by the double arrows in the center of the rotor 5 can be initiated from outside on the rotor 5 or on the housing 3. In a rotary-driven rotor 5, it may be useful to realize the relative movement required for adjusting the volume flows provided by the variable displacement pump 1 displacements on the housing 3.

The drive of the rotor 5 can be done for example by a fixed coupling with a drive train of a motor vehicle. Even if the shift to adjust the volu- Menströme can be done both through the housing 3 and through the rotor 5, the adjustment will be explained below with reference to a displacement of the rotor 5.

In Figure 3 are indicated by dashed lines 21 and 22 axes of movement along which the rotor 5 for adjusting the provided at the terminals 11 and 12 volume flows is movable. Arrows 23 and 24 indicate pumping direction indicators for a first consumer, for example a first partial clutch of a double clutch. The dashed line 21 represents a neutral line for the first consumer. Arrows 25 and 26 indicate pumping direction indicators for a second consumer, for example for a second partial clutch of the double clutch. The dashed line 22 represents a neutral line for the second consumer.

If the rotor 5 is displaced along the dashed line 21, the volume flow from the first consumer remains zero. Likewise, the volume flow from the second consumer remains zero when the rotor 5 is displaced along the dashed line 22.

If the rotor 5 is located exactly in the middle, as shown in FIG. 3, it is arranged on both neutral lines 21, 22. Then, the volume flow delivered by the variable displacement pump 1, or the two volume flows provided at the connections 11 and 12, are equal to zero, independently of a rotational speed of the rotor 5.

When the rotor 5 is moved from the neutral line 21 to the upper left, hydraulic fluid or fluid is sucked at the port 11 in the direction of the variable displacement pump, as indicated by the movement arrow 23. Likewise, in the same direction of rotation during a movement of the rotor 5 down to the right fluid or hydraulic fluid at the port 1 1 is pushed out of the variable displacement, as indicated by the movement arrow 24.

When the rotor 5 is moved from the neutral line 22 to the upper right, fluid is drawn at the connection 12 in the direction of the variable displacement pump, as indicated by the movement arrow 25. Likewise, in the same direction of rotation during a movement of the rotor 5 down to the left fluid at the port 12 is pushed out of the variable displacement pump, as indicated by the movement arrow 26. 4, a variable displacement pump 31 is shown in perspective in various views. The variable displacement pump 31 is designed as an axial piston pump and adjustable in a similar manner as the variable displacement pump 1 described above.

The axial piston pump 31 comprises a housing 33 with a disc 34. A revolver 35 corresponds to the rotor (5 in Figure 1) and is rotatably driven. In the revolver 35 pistons 36 are guided in the axial direction movable back and forth.

The pistons 36 are supported by sliding shoes 37 on a swash plate 38. On the swash plate 38 lever 39 are provided, symbolize the axes by which the swash plate 38 can be pivoted to adjust the delivery volume or absorption volume of the variable 31.

In the disc 34, a reservoir port 40 is provided. In addition, a port 41 and an additional port 42 are provided in the disc 34.

Compared to the variable displacement pump 1 described above, the volume flows of the variable displacement pump 31 provided at the ports 41 and 42 are displaced by an inclination of the swash plate 38 instead of being displaced. During operation of the variable displacement pump 31, the revolver 35 rotates relative to the disc 34 with the terminals 40 to 42. In this case, the revolver 35 also rotates relative to the swash plate 38, wherein the rotating revolver 35 entrains the piston 36.

The drive of the revolver 35 is not shown and can be done in various ways. The drive of the revolver 35 may be effected, for example, via a shaft which extends through the swash plate 38 or through the disc 34. Alternatively, the piston 35 can be driven directly via a toothing, which is formed on the revolver 35 itself.

The inclination of the swash plate 38 can be adjusted three-dimensionally. The control when adjusting the variable displacement pump 31 is analogous to the previously described adjustment of the vane pump 1. In contrast to the vane pump 1 is not deflected in the axial piston pump 31, but tilted.

The adjustment or adjustment of the variable displacement pump 31 is carried out with a separate mechanism whose connection is shown here only schematically in the form of lever 39. The in the figures 4 and 5 illustrated variable displacement pump 31 includes three pistons 36 in the turret 35. Differently than shown, in the revolver 35 but preferably more than three pistons 36, for example, five and six pistons 36, guided in the axial direction to and fro movable.

In Figure 5, the axial piston pump 31 is shown from a slightly different perspective with lifted disc 34. Since the disc 34 contains the terminals 40 to 42, the disc 34 is also referred to as a connection plate. The bearing 45 of the swash plate 38 takes place, as shown by way of example in FIG. 5, via a ball geometry.

FIG. 6 shows in simplified form a variable displacement pump 51 designed as a radial piston pump. The radial piston pump 51 comprises a housing 53, in which a rotor 55 is rotatably driven in the clockwise direction, as indicated by an arrow in the center of the rotor 55. In the rotor 55, a total of eight pistons 56 are guided back and forth movable radially outward.

The radially aligned pistons 56 are each arranged with their radially inner end in the rotor 55. With their respective radially outer end, the piston 56, optionally with the interposition of sliding shoes, in abutment against an inner contour of the housing 53. The housing 53 comprises in a similar manner as in the vane pump 1 shown in Figures 1 to 3, a reservoir port 60, a port 61 and an additional port 62.

During operation of the radial piston pump 51, the pistons 56 are pressed radially inwards. The adjustment of the volume flows provided at the connections 61 and 62 takes place analogously to the vane pump 1 shown in FIGS. 1 to 3 via a translation between the housing 53 and the rotor 55.

LIST OF REFERENCES

I variable displacement pump

2

3 housing

4

5 rotor

6

7

8th

9

10 reservoir connection

I I connection

12 additional connection

13

14 line

15 line

16 line

17 line

18

19 arrow

20 wings

21 dashed line

22 dashed line

23 arrow

24 arrow

25 arrow

26 arrow

27

28

29

30

31 variable displacement pump

32

33 housing disc

revolver

piston

shoe

Swashplate lever

Reservoir connection connection

additional connection

storage

Variable displacement pump housing rotor

piston

Reservoir connection connection

additional connection

Claims

claims

1. Variable displacement pump (1, 31, 51) with two connections (10, 1 1, 40, 41, 60, 61) for supplying and discharging a volume flow delivered by the variable displacement pump, characterized in that the variable displacement pump (1, 31, 51 ) has an additional port (12; 42; 62) for providing an additional volume flow.

2. Variable displacement pump according to claim 1, characterized in that the variable displacement pump (1; 31; 51) is adjustable by independently adjustable physical signals so that the volume flows at two of the total of three ports (10- 12; 40-42; 60- 63) are independently adjustable.

3. variable displacement pump according to one of the preceding connections, characterized in that the variable displacement pump (1; 31; 51) is adjustable by independently adjustable physical signals so that the volume flows at two of the total of three ports (10-12; 40-42; 60-63) are reversible with respect to their flow direction.

4. variable displacement pump according to one of the preceding connections, characterized in that the variable displacement pump (1) is designed as a vane pump.

5. variable displacement pump according to one of the preceding connections, characterized in that the variable displacement pump (51) is designed as a radial piston pump.

6. variable displacement pump according to one of the preceding connections, characterized in that the variable displacement pump (31) is designed as an axial piston pump.

7. A method for operating a variable displacement pump (1; 31; 51) according to any one of the preceding claims, characterized in that at two terminals

(1 1, 12, 41, 42, 61, 62) in each case a volume flow is provided.

8. Method according to claim 7, characterized in that the volume flows provided at the two connections (11, 12, 41, 42, 61, 62) are set independently of one another by independently adjustable physical signals.

9. The method according to claim 7 or 8, characterized in that at least one of the two ports (11, 12; 41, 42; 61, 62) provided volume flows is reversed with respect to its flow direction.

10. The method according to any one of claims 7 to 9, characterized in that at the two terminals (11, 12; 41, 42; 61, 62) provided volumetric flows are combined to form a third volume flow.