Displacement pump, method for operating a displacement pump, steering system and transmission

Abstract

The invention relates to a positive displacement pump (10), in particular a vane pump for conveying a fluid to a consumer (6) of a motor vehicle, wherein the cover (12) and / or the end plate (14) has a recess (32, 34) which is designed to at least partially axially direct the fluid flow (F) to the pumping chamber (30). The invention further relates to a method for operating a positive displacement pump (10) and a steering system (1) for a motor vehicle. The invention also relates to a transmission (100) for a motor vehicle.

Description

[0001] The invention relates to a positive displacement pump, in particular a vane pump, for conveying a fluid to a consumer of a motor vehicle. The invention further relates to a method for operating the positive displacement pump, in particular the vane pump, for conveying the fluid to the consumer of the motor vehicle. The invention also relates to a steering system for a motor vehicle. The invention further relates to a transmission for a motor vehicle.

[0002] Vane pumps of a known type are generally constructed with a rotor rotating within a cam ring. The cam ring is enclosed on each side by an end plate forming a housing and by a control plate. The cam ring has a contour that is coaxial or non-coaxial with the rotor axis, depending on the design, and forms a pump chamber. Arranged across the rotor's circumferential surface are essentially radial slots across its width, in which radially movable vanes are guided. As the rotor rotates about its axis, the vanes are guided along the contour of the cam ring, with chambers of varying volume being formed between each two adjacent vanes.According to the rotational movement of the rotor, a suction area and a pump pressure chamber or pressure area are formed, whereby the suction area is arranged in the area of ​​increasing volume and the pressure area of ​​the pump pressure chamber is arranged in the area of ​​decreasing volume of the chambers.

[0003] US 2013 / 0052073 A1 discloses a vane pump with a pump housing comprising a cam ring, a cover, and a face plate. The face plate has a recess on an inner side facing the cam ring, which leads to a discharge chamber of the vane pump.

[0004] For further information on the state of the art, reference is also made to DE 10 2012 103 888 A1, DE 10 2012 104 804 A1, DE 23 12 873 A, DE 15 53 282 C3 and DE 41 19 207 A1.

[0005] WO 96 / 13665 discloses a vane pump in which a suction channel is divided into two symmetrically arranged, curved suction arms leading to suction zones, which are located in an end wall of the housing.

[0006] In pumps with a cam ring recessed in the suction area, where suction takes place primarily through cam ring openings, this arrangement causes filling problems, as the radially sucked fluid impacts a surface of the rotor and is reflected back in the impulse. This leads to a supply blockage of the vane cell being filled. Consequently, the suction volume of the vane cell cannot be used effectively.

[0007] The invention is therefore based on the object of providing a positive displacement pump, in particular a vane pump for conveying a fluid for a consumer, which enables effective filling of the suction volume of the vane cells.

[0008] The object is achieved with a positive displacement pump, in particular a vane pump for conveying a fluid for a consumer of a motor vehicle, having the features of patent claim 1. Furthermore, the object is achieved with a method for operating a positive displacement pump, in particular a vane pump for conveying a fluid for a consumer of a motor vehicle, having the features of patent claim 5. Furthermore, the object is achieved with a steering system having the features of patent claim 7. Furthermore, the object is achieved with a transmission having the features of patent claim 9.

[0009] The present invention provides a positive displacement pump, in particular a vane pump for conveying a fluid for a consumer of a motor vehicle, wherein the cover has a recess which is designed to at least partially axially supply the fluid flow to the conveying chamber.

[0010] The present invention further provides a method for operating a positive displacement pump, in particular a vane pump for conveying a fluid for a consumer of a motor vehicle, wherein the fluid flow is at least partially supplied axially to the conveying chamber via a recess formed in the cover.

[0011] The present invention further provides a steering system with at least one consumer and a positive displacement pump for conveying a fluid for the at least one consumer of the steering system.

[0012] The present invention further provides a transmission with at least one consumer and a positive displacement pump for conveying a fluid for the at least one consumer of the transmission.

[0013] One idea of ​​the present invention is to supply the fluid flow to the delivery chamber at least partially axially by providing the recess formed in the cover. This allows suction to occur not only radially via the cam ring openings, but also axially via the recess formed in the cover. This advantageously allows for efficient filling of a respective delivery chamber of the working chamber of the positive displacement pump.

[0014] Advantageous embodiments and further developments emerge from the subclaims and from the description with reference to the figures.

[0015] According to the invention, the recess in the cover is formed, at least in sections, between the cam ring and a radial end section of the cover in the radial direction of the cover. Thus, the fluid flow can be directed to the recess formed in the cover in a streamlined manner.

[0016] According to the invention, the recess in the cover has, at least in sections, an axial inclination extending from a surface of the cover to a supply area of ​​the recess formed in the cover, arranged adjacent to the at least one recess in the cam ring. Thus, an at least partially axial supply of the fluid flow from the supply area of ​​the recess formed in the cover can be advantageously achieved.

[0017] According to the invention, the axial inclination formed at least in sections in the cover has an inclination angle of up to 45°, preferably up to 30°. Thus, the fluid flow can be fed to the supply area in a streamlined manner.

[0018] According to the invention, the recess of the cover has, at least in sections, a first, concentric curve and, at least in sections, a second curve, which is designed to redirect the fluid flow from an axial direction of the cover into a radial direction of the cover. By providing the second curve, which is designed to redirect the fluid flow from the axial direction of the cover into the radial direction of the cover, the fluid flow can be efficiently fed to the suction zone of the working chamber through the second curve.

[0019] According to a further preferred development, the recess of the cover, in the supply area adjacent to the at least one recess of the cam ring, has a third curve along the recess of the cam ring, which opens into the delivery chamber. By providing the third curve, the fluid flow can advantageously be fed at least partially axially to the delivery chamber.

[0020] According to a further preferred development, the third curvature of the supply region of the cover recess, which opens into the delivery chamber, is designed to at least partially axially supply the fluid flow to the delivery chamber, wherein the fluid flow can be supplied to the delivery chamber at an angle of 0 to 90°. Depending on the design of the third curvature, an angle at which the fluid flow is supplied to the delivery chamber can thus be advantageously determined.

[0021] The described designs and further training courses can be combined as desired.

[0022] Further possible embodiments, further developments and implementations of the invention also include combinations of features of the invention described previously or below with regard to the exemplary embodiments that are not explicitly mentioned.

[0023] The accompanying drawings are intended to provide a further understanding of embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention.

[0024] Other embodiments and many of the aforementioned advantages will become apparent upon review of the drawings. The elements illustrated in the drawings are not necessarily drawn to scale.

[0025] They show: Fig. 1 is a longitudinal sectional view of a positive displacement pump for delivering a fluid to a consumer of a motor vehicle according to a preferred embodiment of the invention; Fig. 2 a cross-sectional view of a portion of the positive displacement pump for conveying the fluid for the consumer of the motor vehicle according to the preferred embodiment of the invention; Fig. 3 is a perspective view of the positive displacement pump for delivering the fluid to the consumer of the motor vehicle according to the preferred embodiment of the invention; Fig. 4 is a perspective view of the positive displacement pump for delivering the fluid to the consumer of the motor vehicle according to the preferred embodiment of the invention; Fig. 5 is a flowchart of a method for operating the positive displacement pump for delivering the fluid to the consumer of the motor vehicle according to the preferred embodiment of the invention; Fig. 6 a steering system for a motor vehicle with the displacement pump for conveying the fluid for the consumer of the motor vehicle according to the preferred embodiment of the invention; and Fig. 7 a transmission for a motor vehicle with the positive displacement pump for conveying the fluid for the consumer according to the preferred embodiment of the invention.

[0026] In the figures of the drawings, the same reference symbols designate the same or functionally equivalent elements, parts or components, unless otherwise stated.

[0027] Fig. 1 shows a longitudinal sectional view of a positive displacement pump for conveying a fluid for a consumer of a motor vehicle according to a preferred embodiment of the invention.

[0028] The positive displacement pump 10 preferably has a pump housing 18. The pump housing 18 preferably has a cover 12 and a face plate 14.

[0029] A cam ring 20 is inserted into the pump housing 18. A rotor 24 is also arranged within the cam ring 20, which is mounted by a drive shaft 22 and driven by a drive pinion 23. A working chamber 26 is preferably formed between the cam ring 20 and the rotor 24. The working chamber 26 is preferably delimited in the axial direction by the cover 12 and the end plate 14.

[0030] The cam ring 20 preferably has a first recess 20b and a second recess 20c in a section 20a adjacent to a suction zone 28 of the working chamber 26. A fluid flow F can preferably be supplied to a delivery chamber 30 arranged in the suction zone 28 of the working chamber 26 via the first recess 20b and the second recess 20c of the cam ring 20.

[0031] As an alternative to providing the first recess 20b and the second recess 20c, the cam ring 20 can, for example, be designed such that it has only one recess on a predetermined side of the cam ring, via which the fluid flow F can be fed to the delivery chamber 30. The cover 12 preferably has a recess 32 which is designed to at least partially axially feed the fluid flow F to the delivery chamber 30. The end plate 14 preferably has a recess 34 which is designed to at least partially axially feed the fluid flow F to the delivery chamber 30. A lateral surface 24a of the rotor 24 is preferably concave.

[0032] Fig. 2 shows a cross-sectional view of a portion of the positive displacement pump for delivering the fluid to the consumer of the motor vehicle according to the preferred embodiment of the invention.

[0033] The recess 32 of the cover 12 preferably has a feed region 36 arranged adjacent to the first recess 20b of the cam ring 20 and the second recess 20c of the cam ring 20. The feed region 36 is preferably formed along a length of the first recess 20b of the cam ring 20 and the second recess 20c of the cam ring 20 in the region of the recess 32 of the cover 12.

[0034] The recess 32 of the cover 12 preferably has a first, concentric curvature K1, wherein the first recess 32 of the cover 12 is formed in the radial direction of the cover 12 between the cam ring 20 and a radial end portion of the cover 12. The recess 32 of the cover 12 further has a (in Fig. 2 not shown) which is designed to deflect the fluid flow F from an axial direction of the cover 12 into a radial direction of the cover 12.

[0035] The recess 32 of the cover 12 furthermore has a third curvature K3, which is formed in the supply region 36 and which opens into the delivery chamber 30. The third curvature K3 of the supply region 36 of the recess 32 of the cover 12, which opens into the delivery chamber 30, is preferably designed to at least partially axially supply the fluid flow F to the delivery chamber 30. The third curvature K3 preferably merges smoothly into the delivery chamber 30 of the positive displacement pump 10. Alternatively, the third curvature K3 can open into the delivery chamber 30 of the positive displacement pump 10, for example, at a definable angle.

[0036] The (in Fig. 1) recess 34 of the end plate 14 preferably has a recess arranged adjacent to the first recess 20b of the cam ring 20 and the second recess 20c of the cam ring 20 (in Fig. 1) feed region 38. The feed region 38 is preferably formed along a length of the first recess 20b of the cam ring 20 and the second recess 20c of the cam ring 20 in the region of the recess 32 of the cover 12.

[0037] The recess 34 of the end plate 14 preferably has a first, concentric curvature (not shown in the figures), wherein the recess 34 of the end plate 14 is formed in the radial direction of the end plate 14 between the cam ring 20 and a radial end portion of the end plate 14. The recess 34 of the end plate 14 further has a second curvature (not shown in the figures), which is designed to redirect the fluid flow F from an axial direction of the end plate 14 into a radial direction of the end plate 14.

[0038] The recess 34 of the front plate 14 also has a (in Fig. 1) which is formed in the supply region 38 and which opens into the delivery chamber 30. The third curvature K3 of the supply region 38 of the recess 34 of the end plate 14, which opens into the delivery chamber 30, is preferably designed to at least partially axially supply the fluid flow F to the delivery chamber 30. The third curvature K3 preferably merges smoothly into the delivery chamber 30 of the positive displacement pump 10. Alternatively, the third curvature K3 can open into the delivery chamber 30 of the positive displacement pump 10, for example, at a definable angle.

[0039] Fig. 3 shows a perspective view of the positive displacement pump for conveying the fluid for the consumer of the motor vehicle according to the preferred embodiment of the invention.

[0040] The recess 32 of the cover 12 is formed in the radial direction of the cover 12 in the region of the first curvature K1 between the cam ring 20 and the radial end portion of the cover 12. The recess 32 of the cover 12 has an axial inclination α in a first portion 32a, which extends from a surface 12a of the cover 12 to the feed region 36 of the recess 32 formed in the cover 12, said feed region being arranged adjacent to the first recess 20b of the cam ring and the second recess 20c of the cam ring.

[0041] The axial inclination α formed in the cover 12 preferably has an inclination angle of 15°. Alternatively, the inclination angle α can be up to 30°. Furthermore, the inclination angle α can be up to 45°.

[0042] The recess 32 of the cover 12 has the first, concentric curvature K1 in the first section 32a, with the cam ring 20 and the cover 12 preferably also having a concentric curvature. Thus, the recess 32 of the cover 12 is formed in the region of the first, concentric curvature K1 in the radial direction of the cover 12 between the cam ring 20 and the radial end section of the cover 12.

[0043] The recess 32 of the cover 12 preferably has a second curvature K2 in a second section 32b of the recess 32. The second curvature K2 is preferably designed to redirect the fluid flow F from the axial direction R1 of the cover 12 into the radial direction R2 of the cover 12. Thus, a flow-optimized supply of the fluid into the delivery chamber 30 can be achieved.

[0044] The recess 34 of the front plate 14 is in the radial direction of the front plate in the area of ​​(in Fig. 3 not shown) first curvature of the recess 34 between the cam ring 20 and the radial end portion of the end plate 14. The recess 34 of the end plate 14 has in a first (in Fig. 3) has an axial inclination which extends from a surface of the end plate 14 to the feed region 38 of the recess 34 formed in the end plate 14, which is arranged adjacent to the first recess 20b of the cam ring and the second recess 20c of the cam ring.

[0045] The axial inclination formed in the end plate 14 preferably has an inclination angle of 15°. Alternatively, the inclination angle can be up to 30°. Furthermore, the inclination angle can be up to 45°.

[0046] The recess 34 of the end plate 14 has the first, concentric curvature in the first section, with the cam ring 20 and the end plate 14 preferably also having a concentric curvature. Thus, the recess 34 of the end plate 14 is formed in the region of the first, concentric curvature in the radial direction of the end plate 14 between the cam ring 20 and the radial end section of the end plate 14.

[0047] The recess 34 of the front plate 14 preferably has a (in Fig. 3) has a second curvature. The second curvature is preferably designed to redirect the fluid flow F from the axial direction R1 of the end plate 14 into the radial direction R2 of the end plate 14. Thus, a flow-optimized supply of the fluid into the delivery chamber 30 can be achieved.

[0048] Fig. 4 shows a perspective view of the positive displacement pump for conveying the fluid for the consumer of the motor vehicle according to the preferred embodiment of the invention.

[0049] The first recess 20b of the cam ring 20 and the second recess 20c of the cam ring 20 are preferably arranged adjacent to the supply region 36 of the recess 32 of the cover 12. The supply region 36 has the third curvature K3, which opens into the delivery chamber 30. The fluid flow F can thus be supplied to the delivery chamber 30 in a flow-optimized manner, since the third curvature K3 merges smoothly into the delivery chamber 30. The fluid flow F can thus be supplied to the delivery chamber 30 at an angle of 0 to 90° with respect to the outer surface of the rotor, i.e., a bottom surface of the delivery chamber.

[0050] Fig. 5 shows a flow chart of a method for operating the positive displacement pump for conveying the fluid for the consumer of the motor vehicle according to the preferred embodiment of the invention.

[0051] The method comprises providing S1 a cam ring inserted into a pump housing and a drive shaft mounted with a rotor, wherein a working chamber is formed between the cam ring and the rotor. The method further comprises providing S2 the cam ring at a section adjacent to a suction zone of the working chamber, said cam ring having a first recess and a second recess, wherein a fluid flow can be supplied to a delivery chamber arranged in the suction zone via the first recess and the second recess of the cam ring. The method further comprises sucking S3 the fluid into the delivery chamber, wherein the fluid flow is supplied at least partially axially to the delivery chamber via a recess formed in the cover and the end plate.

[0052] As an alternative to forming a recess in the cover and the end plate, only the cover or only the end plate can have a recess. Furthermore, as an alternative to forming the cam ring with a first recess and a second recess, the cam ring can, for example, have only one recess.

[0053] The method further comprises deflecting the fluid flow from an axial direction of the cover and the end plate into a radial direction of the cover and the end plate by means of a first concentric curvature formed in sections in the recess of the cover and the recess of the end plate and a second curvature formed in sections.

[0054] The method further comprises a third curvature of a supply region of the cover recess and the end plate recess, formed along the first recess and the second recess of the cam ring, opening into the delivery chamber. The fluid flow is preferably fed to the delivery chamber at least partially axially at an angle of 0 to 90°.

[0055] Fig. 6 shows a steering system for a motor vehicle with the positive displacement pump for conveying the fluid for the consumer of the motor vehicle according to the preferred embodiment of the invention.

[0056] The steering system 1 is located in a motor-driven vehicle, in particular a passenger car or a commercial vehicle. The steering system 1 comprises a steering wheel 2, which is operated by the driver and which, via a steering column 3, acts on a vehicle wheel via a steering gear 4 and adjusts the wheel according to the driver's command.

[0057] A steering angle torque sensor 5 is symbolically incorporated into the steering column 3, via which the steering angle and, if applicable, also the steering angle speed are to be determined and fed as an input signal to a control and regulating unit in which the input signals are processed and which, together with other vehicle state and operating variables, generates control signals via which the various units of the vehicle, including the steering system 1 and the drive motor, are to be adjusted.

[0058] The steering system 1 has at least one consumer or actuating cylinder 6. The actuating cylinder 6 has two separate chambers 6a and 6b, each connected to a pressure control valve 8 via hydraulic lines 8a, 8b. The positive displacement pump 10 is preferably designed as a vane pump. The positive displacement pump 10 preferably generates a hydraulic pressure, so that hydraulic fluid under pressure is supplied to the pressure control valve 8 via the positive displacement pump 10. Furthermore, a drive motor 9a is provided, which is connected to the positive displacement pump 10 by means of a coupling 9b. Furthermore, a hydraulic reservoir 11 is provided, via which recirculated hydraulic medium can be supplied to the positive displacement pump 10.

[0059] Fig. 7 shows a transmission for a motor vehicle with the positive displacement pump for conveying the fluid for the consumer according to the preferred embodiment of the invention.

[0060] The transmission 100 is located in a motor-driven vehicle, in particular a passenger car or a commercial vehicle. The positive displacement pump 10 is preferably designed as a vane pump. The positive displacement pump 10 generates hydraulic pressure for the consumer 106.

[0061] Although the present invention has been described above using preferred embodiments, it is not limited thereto, but can be modified in a variety of ways. In particular, the invention can be changed or modified in a variety of ways without deviating from the essence of the invention.

[0062] For example, the recess of the cam ring and / or the recess of the cover and the front plate can have another suitable shape or design which, depending on the structural design of the positive displacement pump, enables effective filling of the delivery chamber on the suction side of the positive displacement pump. List of reference symbols 1 steering system 2 steering wheel 3 Steering column 4 steering gears 5 Steering angle torque sensor 6, 106 actuating cylinders 6a, 6b Chamber 8 Pressure control valve 8a, 8b hydraulic line 9a Drive motor 9b Coupling 10 Positive displacement pump 12 lids 12a Surface of the lid 14 Front plate 18 Pump housing 20 Curve ring Section 20a 20b, 20c recess 22 Drive shaft 23 drive pinions 24 rotors 24a Rotor surface 26 Working Chamber 28 suction zone 30 production chamber 32, 34 recess 36, 38 Feed area F Fluid flow α inclination K1 first curvature K2 second curvature K3 third curvature R1 axial direction R2 radial direction

Claims

[1] Positive displacement pump (10), in particular a vane pump for conveying a fluid for a consumer (6) of a motor vehicle, with a pump housing (18) having a cover (12) and a front plate (14), into which a cam ring (20) is inserted and a drive shaft (22) with a rotor (24) is mounted, wherein a working chamber (26) is formed between the cam ring (20) and the rotor (24), which working chamber is delimited in the axial direction by the cover (12) and the front plate (14), wherein the cam ring (20) has at least one recess (20b, 20c) in a section (20a) adjacent to a suction zone (28) of the working chamber (26), wherein a fluid flow (F) can be supplied to a conveying chamber (30) arranged in the suction zone (28) via the at least one recess (20b, 20c) of the cam ring (20), characterized bythat the cover (12) has a recess (32) which is designed to at least partially axially feed the fluid flow (F) to the delivery chamber (30), wherein the recess (32) of the cover (12) is formed in the radial direction of the cover (12) at least in sections between the cam ring (20) and a radial end section of the cover (12), wherein the recess (32) of the cover (12) has at least in sections an axial inclination (α) which extends from a surface (12a) of the cover (12) to a feed region (36) of the recess (32) formed in the cover (12) arranged adjacent to the at least one recess (20c) of the cam ring (20), wherein the axial inclination (α) formed at least in sections in the cover (12) has an inclination angle of up to 45°, and wherein the recess (32) of the cover (12) at least in sections a first,concentric curvature (K1) and at least partially a second curvature (K2) which is designed to deflect the fluid flow (F) from an axial direction (R1) of the cover (12) into a radial direction (R2) of the cover (12). [2] Positive displacement pump according to claim 1, characterized by that the axial inclination (α) formed at least in sections in the cover (12) has an angle of inclination of up to 30°. [3] Positive displacement pump according to claim 1 or 2, characterized by that the recess (32) of the cover (12) in the feed region (36) arranged adjacent to the at least one recess (20c) of the cam ring (20) has a third curvature (K3) along the recess (20c) of the cam ring (20), which third curvature opens into the conveying chamber (30). [4] Positive displacement pump according to claim 3, characterized bythat the third curvature (K3) of the feed region (36) of the recess (32) of the cover (12) opening into the feed chamber (30) is designed to feed the fluid flow (F) to the feed chamber (30) at least partially axially, wherein the fluid flow (F) can be fed to the feed chamber (30) at an angle of 0° to 90°. [5] Method for operating a positive displacement pump (10), in particular a vane pump for conveying a fluid for a consumer (6) of a motor vehicle, comprising the steps: Providing (S1) a cam ring (20) inserted into a pump housing (18) and a drive shaft (22) mounted with a rotor (24), wherein a working chamber (26) is formed between the cam ring (20) and the rotor (24); Providing (S2) the cam ring (20) at a section (20a) adjacent to a suction zone (28) of the working chamber (26) with at least one recess (20b, 20c), wherein a fluid flow (F) can be supplied to a delivery chamber (30) arranged in the suction zone (28) via the at least one recess (20b, 20c) of the cam ring (20); and Suction (S3) of the fluid into the delivery chamber (30), characterized bythat the fluid flow (F) of the delivery chamber (30) is at least partially axially supplied via a recess (32) formed in the cover (12), wherein the recess (32) of the cover (12) is formed in the radial direction of the cover (12) at least in sections between the cam ring (20) and a radial end section of the cover (12), wherein the recess (32) of the cover (12) at least in sections has an axial inclination (α) which extends from a surface (12a) of the cover (12) to a supply region (36) of the recess (32) formed in the cover (12) arranged adjacent to the at least one recess (20c) of the cam ring (20), wherein the axial inclination (α) formed at least in sections in the cover (12) has an angle of inclination of up to 45°, and wherein the fluid flow (F) is directed by means of a in the recess (32) of the cover (12) at least partially formed first,concentric curvature (K1) and a second curvature (K2) formed at least in sections from an axial direction (R1) of the cover (12) into a radial direction (R2) of the cover (12). [6] Method according to claim 5, characterized by that a third curvature (K3) of a feed region (36) of the recess (32) of the cover (12), formed along the at least one recess (20c) of the cam ring (20), opens into the delivery chamber (30), wherein the fluid flow (F) of the delivery chamber (30) is fed at least partially axially at an angle of 0° to 90°. [7] Steering system (1) for a motor vehicle, comprising: at least one consumer (6); and a positive displacement pump (10) according to one of claims 1 to 4 for conveying a fluid for the at least one consumer (6) of the steering system (1). [8] Steering system according to claim 7, characterized bythat the displacement pump (10) is designed as a vane pump. [9] Transmission (100) for a motor vehicle, comprising: at least one consumer (106); and a positive displacement pump (10) according to one of claims 1 to 4 for conveying a fluid for the at least one consumer (106) of the transmission (100). [10] Transmission according to claim 9, characterized by that the displacement pump (10) is designed as a vane pump.

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