Gear pump arrangement and method for mounting a gear pump arrangement in a housing recess of a housing

Abstract

The invention relates to a gear pump assembly (1), in particular a gear pump assembly (1) of an axial piston machine in swashplate design, wherein the gear pump assembly (1) comprises a gear assembly (2) configured to convey hydraulic fluid from a suction side to a delivery side, wherein the gear assembly (2) is arranged in a housing recess (3) of a housing (4) of the gear pump assembly (1) and is fixed axially in the housing recess (3) by means of a cover (16) that closes the housing recess (3), wherein a compensating element (20) is arranged between the gear assembly (2) and the cover (16). The compensating element (20) is designed as a plastically deformable ring element (30) which is plastically deformable during the assembly process of the cover (16) on the housing (4).

Description

[0001] The invention relates to a gear pump arrangement, in particular a gear pump arrangement of an axial piston machine in swashplate construction, wherein the gear pump arrangement has a gear arrangement configured to convey pressure medium from a suction side to a delivery side, wherein the gear arrangement is arranged in a housing recess of a housing of the gear pump arrangement and is fixed in the housing recess in the axial direction by means of a cover closing the housing recess, wherein a compensating element is arranged between the gear arrangement and the cover.

[0002] The invention further relates to a method for mounting a gear pump assembly in a housing recess of a housing, wherein the gear pump assembly comprises a gear assembly configured to convey pressure medium from a suction side to a delivery side, wherein the gear assembly is arranged in the housing recess of the housing of the gear pump assembly and is fixed in the housing recess in the axial direction by means of a cover closing the housing recess, wherein a compensating element is arranged between the gear assembly and the cover.

[0003] Gear pump arrangements of this type are used, for example, in axial piston machines with swashplate construction as feed pumps that generate a feed pressure.

[0004] The gear assembly of the gear pump assembly is arranged in a housing recess of a housing of the gear pump assembly and is fixed in the housing recess in the axial direction by means of a cover closing the housing recess.

[0005] To transmit the torque generated by the gear assembly and to ensure a tight seal of the resulting axial gaps between the gear assembly and the housing recess, an axially acting pressing force must be provided, with which the gear assembly is pressed against a contact surface of the housing recess.

[0006] However, this results in high component tolerances, determined by the depth of the housing recess and the width of the gear assembly. To provide the desired axially acting clamping force, it is known to include a compensating element between the gear assembly and the cover. The thickness of this element is selected to provide a specific interference fit, which, when the cover is attached to the housing, generates the desired axially acting clamping force. It is important to ensure that the interference fit provided by the compensating element is not too large, as this can lead to warping of the cover when it is mounted to the housing. If an additional hydraulic pump is mounted to the cover as an add-on pump, warping of the cover will result in an undesirable, uneven mounting surface for the additional pump.

[0007] In order to generate the desired axially acting pressing force when attaching the cover to the housing, given given component tolerances (depth of the housing recess, width of a gear assembly to be installed in the housing recess), it is known in known gear pump arrangements to measure the width of the gear assembly to be installed and the depth of the housing recess before mounting the gear assembly into the housing recess, and then to determine a thickness dimension of the compensating element necessary for the given component tolerances and to select a compensating element with a suitable thickness dimension from a set of different compensating elements with different thickness dimensions, for example, stepped thickness dimensions, which is inserted between the gear assembly and the housing cover.The required measurement process is complex and time-consuming, resulting in long assembly times for mounting and thus installing the gear assembly into the housing. Furthermore, with known gear pump assemblies, a set of different compensating elements with varying thicknesses must be kept and provided, which further increases the assembly effort.

[0008] The present invention is based on the objective of providing a gear pump arrangement and a method for mounting a gear pump arrangement in a housing recess of a housing of the type mentioned at the outset, which is improved with regard to assembly time and assembly effort.

[0009] According to a first aspect, this problem is solved according to the invention by the fact that the compensating element is designed as a plastically deformable ring element which is plastically deformable during the assembly process of the cover on the housing.

[0010] A compensating element, designed as a plastically deformable ring element that deforms plastically during the cover assembly process on the housing, allows for the compensation of component tolerances (depth of the housing recess, width of a gear assembly to be installed in the housing recess) with just one variant of the ring element. Simultaneously, it generates a desired axially acting pressing force between the gear assembly and the housing recess, pressing the gear assembly against a contact surface of the housing recess after the cover is installed. This reduces assembly time and simplifies the assembly process, as there is no need for time-consuming measurements of the width of the gear assembly and the depth of the housing recess, nor for selecting a compensating element with a thickness dimension suitable for the existing component tolerances.Furthermore, only one variant of the ring element is required, since the plastically deformable ring element can be easily designed to compensate for all possible component tolerances. This reduces assembly effort. Using the ring element according to the invention as a compensating element also results in increased assembly reliability and lower assembly costs for the gear pump assembly.

[0011] The plastically deformable ring element, which is inserted into the housing between the gear assembly and the cover for mounting the gear assembly, is plastically deformed during the cover assembly process. After assembly, sufficient elastic springback of the deformed ring element remains, generating the desired axial contact force with which the gear assembly is pressed against a contact surface of the housing recess.

[0012] According to an advantageous embodiment of the invention, the plastically deformable ring element is designed as a ring-shaped, bent hollow tube. Such a hollow tube requires little manufacturing effort and can be easily plastically deformed during the assembly of the cover to generate the desired axial contact force with which the gear assembly is pressed against a contact surface of the housing recess.

[0013] According to an advantageous embodiment of the invention, a separation gap is formed between the pipe ends of the plastically deformable tube. This leads to a further reduction in the manufacturing costs of the ring element and thus to a further reduction in the assembly costs of the gear pump assembly.

[0014] The plastically deformable ring element, designed as a ring-shaped bent hollow tube, can be easily manufactured from straight tube sections that are bent into a ring element.

[0015] The plastically deformable ring element, designed as a ring-shaped bent hollow tube, can alternatively be produced in a simple manner from a helically wound coil by cutting, since the ring element is pressed towards a flat contact surface on the gear assembly during the assembly of the cover.

[0016] According to an advantageous embodiment of the invention, the plastically deformable tube is made of structural steel. The material of the plastically deformable tube is therefore structural steel. Structural steel has a pronounced yield strength, which allows the plastically deformable tube to be easily deformed during the assembly of the cover. After the cover assembly process, sufficient elastic springback of the deformed ring element remains, generating the desired axial contact force with which the gear assembly is pressed against a contact surface of the housing recess.

[0017] According to an advantageous embodiment of the invention, an axial disk is arranged between a contact surface of the housing recess and the gear assembly. The plastically deformable ring element according to the invention can reliably seal axial gaps between the axial disk and the housing recess by means of the generated axial contact force.

[0018] According to an advantageous embodiment of the invention, the housing of the gear pump assembly is designed as the housing cover of an axial piston machine, in particular an axial piston machine with a swashplate design, wherein a suction channel and a pressure channel of the axial piston machine are formed in the housing cover. The plastically deformable ring element according to the invention simplifies the assembly of a gear pump assembly, for example a feed pump, in the housing cover of the axial piston machine, thus enabling quick and cost-effective assembly of the axial piston machine.

[0019] The invention further relates to a method for mounting a gear pump assembly in a housing recess of a housing, wherein the gear pump assembly comprises a gear assembly configured to convey pressure medium from a suction side to a delivery side, wherein the gear assembly is arranged in the housing recess of the housing of the gear pump assembly and is fixed in the housing recess in the axial direction by means of a cover closing the housing recess, wherein a compensating element is arranged between the gear assembly and the cover.

[0020] The aforementioned task is solved procedurally according to a second aspect through the following steps: • As a first step: Inserting the gear assembly into the housing recess, • In a subsequent second step: Inserting a plastically deformable ring element, in particular a ring-shaped bent hollow tube, as a compensating element between the gear assembly and the cover, • In a subsequent third step: mounting the cover onto the housing, whereby the ring element is plastically deformed during the mounting of the cover onto the housing.

[0021] The inventive method allows the assembly time to be reduced and the assembly process of the gear assembly in the housing to be simplified by using a plastically deformable tube as a compensating element between the gear assembly and the cover, since no time-consuming measuring of the width of the gear assembly to be installed and the depth of the housing recess is required, nor is it necessary to select a compensating element with a thickness dimension suitable for the existing component tolerances.

[0022] According to an advantageous embodiment of the invention, the plastically deformable ring element can be inserted in its undeformed state between the gear assembly and the cover.

[0023] According to an alternative and equally advantageous embodiment of the invention, the plastically deformable ring element can be inserted between the gear assembly and the cover in an axially pre-compressed state. If the plastically deformable ring element is inserted between the gear assembly and the cover in an axially pre-compressed state, a reduction in the assembly path of the cover can be achieved, which leads to a further reduction in assembly time and effort.

[0024] Further advantages and details of the invention are explained in more detail with reference to the exemplary embodiments shown in the schematic figures. Here, Fig. 1 a longitudinal section of a prior art gear pump arrangement, Fig. 2 an excerpt of the Fig. 1 in an enlarged view, Fig. 3 a longitudinal section of a gear pump arrangement according to the invention before the cover is mounted, Fig. 4 a longitudinal section of a gear pump arrangement according to the invention after the cover has been fitted, Fig. 5 a longitudinal section of a further embodiment of a gear pump arrangement according to the invention before the mounting of the cover and Fig. 6 a compensating element of the gear pump arrangement according to the invention in a side view and in a top view.

[0025] In the Fig. 1 and Fig. Figure 2 shows a gear pump arrangement 1 of the prior art in a longitudinal section.

[0026] The gear pump assembly 1 comprises a gear assembly 2 configured to convey pressure medium from a suction side (not shown) to a delivery side (not shown). The gear assembly 2 is arranged in a housing recess 3 of a housing 4 of the gear pump assembly 1.

[0027] In the Fig. 1 and Fig. 2 the housing 4 of the gear pump arrangement 1 is designed as a housing cover 4a of an axial piston machine not shown in detail, in particular an axial piston machine in swashplate design, wherein a suction channel S and a pressure channel P of the axial piston machine are formed in the housing cover 4a.

[0028] The housing 4 is provided with a through-bore 5 in which a drive sleeve 6 of the gear pump assembly 1 is arranged to be rotatable about a longitudinal axis L. The drive sleeve 6 is in motive connection with a drive shaft of the axial piston machine (not shown) projecting into the through-bore 5 and serves to drive the gear assembly 2 of the gear pump assembly 1.

[0029] The housing recess 3 is formed by a diameter expansion at the through-bore 5. The housing recess 3 extends from the, into the Fig. 1, Fig. 2 right end face 10 of the housing 4, which is preferably arranged perpendicular to the longitudinal axis L, to a contact surface 11 in the housing 4, which is parallel to the right end face 10 and preferably also perpendicular to the longitudinal axis L.

[0030] The housing recess 3 has a depth s in the axial direction, i.e. in the direction of the longitudinal axis L, between the end face 10 and the contact surface 11. Geh on.

[0031] In the Fig. 1 and Fig. 2 - viewed in the axial direction - an axial disk 15 is arranged between the end wall 11 and the gear assembly 2.

[0032] The housing recess 3 can be closed by means of a cover 16 which can be attached to the housing 4. Several fastening screws 17 are provided for fastening the cover 16.

[0033] For sealing purposes, a seal 18 is arranged between the housing 4 and the cover 16.

[0034] The cover 16 can be designed as an output cover for the axial piston machine or as a mounting flange to which another hydraulic pump can be attached to the axial piston machine.

[0035] The gear assembly 2 is axially fixed in the housing 4 by means of the cover 16 attached to the housing 4. A compensating element 20 is arranged between the gear assembly 2 and the cover 16, which is located in the Fig. 1 and Fig. 2 as disk 21 with a thickness t r is trained.

[0036] The disk 21 rests with its right end face against the cover 16 and with its left end face against an end-face contact surface 2a of the gear arrangement 2.

[0037] The width dimension of the gear assembly 2 installed in the housing recess 3, which extends from the contact surface 11 in the housing 4 to the contact surface 2a of the gear assembly 2, is shown in the Fig. 1, Fig. 2 with s Zapu clarifies.

[0038] In gear pump arrangement 1 of the Fig. 1 and Fig. 2 The gear assembly 2 is fixed to the housing 4 by means of the cover 16 and the fastening screws 17 by bearing against the contact surface 11 in the axial direction. A pressing axial force is required to transmit the torque generated by the gear assembly 2 and to ensure a tight seal of the axial gaps between the axial disk 15 and the housing 4.

[0039] Due to the relatively high component tolerances of the depth s Geh the housing recess 3 and the width dimension s Zapu For the gear assembly 2 installed in the housing recess 3, it is necessary to use the disc 21, which acts as an adjusting ring and has a thickness t, to adjust the gear arrangement 2 by means of the disc 21 with thickness t. r to set a targeted oversize so that when screwing the cover 16 onto the housing 4, an axially acting force is achieved which presses the gear assembly 2 onto the contact surface 11.

[0040] In the prior art arrangement, the width s is measured before the gear assembly 2 is mounted in the housing recess 3. Zapu the gear assembly 2 to be installed and the depth s Geh The housing recess 3 of the housing 4 was measured, and then a thickness dimension t necessary for the existing component tolerances was determined. r the disk 21 is determined and selected from a set of different disks 21 with different thickness dimensions t r , for example, stepped thickness dimensions, a disc 21 with the appropriate thickness dimension t r The selected disc is inserted between the gear assembly 2 and the housing cover 16. The required measuring process is complex and time-consuming, resulting in long assembly times for mounting and thus installing the gear assembly 2 into the housing 4. Furthermore, for known gear pump assembly 1, a set of different discs 21 with varying thicknesses t must be selected. rto be held and made available, from which a disc 21 with a suitable thickness dimension t can be extracted. r is selected, which still results in a high assembly effort.

[0041] In the Fig. 3, Fig. 4, Fig. 5 to Fig. 6 shows a gear pump arrangement 1 according to the invention, wherein with the Fig. 1 and Fig. Two identical components are provided with the same reference numerals.

[0042] In the gear pump arrangement 1 according to the invention, the compensating element 20, which is arranged between the end face contact surface 2a of the gear arrangement 2 and the cover 16, is designed as a plastically deformable ring element 30, which is plastically deformable during the assembly process of the cover 16 on the housing 4.

[0043] The plastically deformable ring element 30 is - as shown from the Fig. 6 can be seen in which the left illustration shows a longitudinal section and the right illustration shows a top view of the ring element 30 - designed as a ring-shaped curved hollow tube 31.

[0044] As can be seen from the right-hand representation of the Fig. As can be seen in Figure 6, a separating gap 32 is formed between the two pipe ends of pipe 31 that face each other.

[0045] The plastically deformable tube 31 is made of structural steel.

[0046] The tube 31 can, for example, be made from a straight section of pipe that is bent into a ring.

[0047] The diameter D of the tube 31 in its undeformed state is chosen such that all possible component tolerances s Zapu and s Geh with an embodiment of the tube 31.

[0048] In the gear pump assembly 1 according to the invention, during the assembly of the gear pump assembly 1 in the housing recess 3 of the housing 4, the gear assembly 2 and, optionally, the axial disk 15 are inserted into the housing recess 3 in a first step. In a subsequent second step, the plastically deformable tube 31 is inserted between the gear assembly 2 and the cover 16, and in a subsequent third step, the cover 16 is mounted and fastened to the housing 4 by means of the fastening screws 17, whereby the hollow tube 31 is plastically deformed during the mounting of the cover 16 to the housing 2. After the mounting process of the cover 16, sufficient elastic springback of the deformed tube 31 remains to provide the necessary axially acting force that presses the gear assembly 2 onto the contact surface 11.

[0049] In the Fig. Figure 3 shows the gear pump arrangement 1 according to the invention before the fastening screws 17 of the cover 16 are attached and tightened, with dimension t m A gap is illustrated which, given the diameter D of the undeformed tube 31, results as an interference between the right end face 10 of the housing 4 and the left end face of the cover 16. In the Fig. 3 the hollow tube 31 is inserted in an undeformed state between the gear arrangement 2 and the cover 16.

[0050] In the Fig. Figure 4 shows the cover 16 after tightening the fastening screws 17. Tightening the fastening screws 17 reduces the gap t. m eliminated and given the dimensions s Zapu and s Geh The hollow tube 1 is plastically deformed, thereby generating the desired axial contact force with which the gear assembly 2 is pressed against the contact surface 11 of the housing recess 3.

[0051] In the gear pump arrangement 2 according to the invention, no complex measuring process is required when mounting the gear arrangement 2 in the housing recess 3, and no selection of a suitably thick disc 21 as a compensating element 20 is required, which simplifies the assembly process of the gear pump arrangement 2 and results in assembly with short assembly times, low assembly effort and low assembly costs.

[0052] The Fig. Figure 5 shows a gear pump arrangement 1 according to the invention before the fastening screws 17 of the cover 16 are attached and tightened, wherein the hollow tube 31 has been axially pre-compressed and is inserted in the axially pre-compressed state between the gear arrangement 2 and the cover 16. By axially pre-compressing the hollow tube 31, compared to the Fig. 3 - a reduced gap t mAn excess dimension will be achieved between the right end face 10 of the housing 4 and the left end face of the cover 16. In the Fig. 5 When screwing the cover 16 on using the fastening screws 17, only the reduced gap t must be used. m can be eliminated, which will result in a further reduction in assembly times.

Claims

[1] Gear pump assembly (1), in particular gear pump assembly (1) of an axial piston machine in swashplate design, wherein the gear pump assembly (1) has a gear assembly (2) configured to convey pressure medium from a suction side to a delivery side, wherein the gear assembly (2) is arranged in a housing recess (3) of a housing (4) of the gear pump assembly (1) and is fixed in the housing recess (3) in the axial direction by means of a cover (16) closing the housing recess (3), wherein a compensating element (20) is arranged between the gear assembly (2) and the cover (16), characterized by , that the compensating element (20) is designed as a plastically deformable ring element (30) which is plastically deformable during the assembly process of the cover (16) on the housing (4). [2] Gear pump arrangement according to claim 1, characterized by, that the plastically deformable ring element (30) is designed as a ring-shaped bent hollow tube (31). [3] Gear pump arrangement according to claim 2, characterized by , that a separation gap (32) is formed between the pipe ends of the plastically deformable pipe (31). [4] Gear pump arrangement according to claim 2 or 3, characterized by , that the plastically deformable tube (31) is made of structural steel. [5] Gear pump arrangement according to any one of claims 1 to 4, characterized by , that an axial disk (15) is arranged between a contact surface (11) of the housing recess (4) and the gear arrangement (2). [6] Gear pump arrangement according to any one of claims 1 to 5, characterized by, that the housing (4) of the gear pump arrangement (1) is designed as a housing cover (4a) of an axial piston machine, in particular an axial piston machine in swashplate design, wherein a suction channel (S) and a pressure channel (P) of the axial piston machine is formed in the housing cover (4a). [7] Method for mounting a gear pump assembly (1) in a housing recess (3) of a housing (4), wherein the gear pump assembly (1) comprises a gear assembly (2) configured to convey pressure medium from a suction side to a delivery side, wherein the gear assembly (2) is arranged in the housing recess (3) of the housing (4) of the gear pump assembly (1) and is fixed axially in the housing recess (3) by means of a cover (16) closing the housing recess (3), wherein a compensating element (20) is arranged between the gear assembly (2) and the cover (16), in particular a method for mounting a gear pump assembly (1) according to one of the preceding claims, characterized by the following steps: • In a first step: Inserting the gear assembly (2) into the housing recess (3), • In a subsequent second step: Inserting a plastically deformable ring element (31), in particular a ring-shaped bent hollow tube (31), as a compensating element (20) between gear arrangement (2) and cover (16), • In a subsequent third step: mounting the cover (16) onto the housing (4), wherein the ring element (31) is plastically deformed during the mounting of the cover (4) onto the housing (2). [8] Method according to claim 7, characterized by , that the plastically deformable ring element (31) is inserted in the undeformed state between gear arrangement (2) and cover (16). [9] Method according to claim 7, characterized by , that the plastically deformable ring element (31) is inserted in an axially pre-compressed state between gear arrangement (2) and cover (16).

Images