Fluid energy machine and method for producing a fluid energy machine

Abstract

The invention relates to a fluid energy machine (10) with a housing (5) comprising at least two housing parts (1, 2) which are fastened to one another by means of a fastening device in at least one fastening area such that sealing surfaces (8) provided on the housing parts (1, 2) come into sealing contact with one another in at least one sealing area (9) spaced apart from the fastening area, directly or with the interposition of a sealing device. In order to improve the fluid energy machine (10) functionally and / or in terms of manufacturing technology, the housing parts (1, 2) have a geometric design in the fastening area, with the aid of which a prestress generated by the fastening device is shifted wholly or partly from the fastening area into the sealing area (9).

Description

[0001] The invention relates to a fluid energy machine with a housing comprising at least two housing parts that are fastened to one another in at least one fastening region by means of a fastening device such that sealing surfaces provided on the housing parts come into sealing contact with one another in at least one sealing region spaced from the fastening region, either directly or with the interposition of a sealing device. The invention further relates to a method for manufacturing such a fluid energy machine. The fluid energy machine is designed, for example, as a pump.

[0002] The German patent application DE 10 2011 079 311 A1 discloses a coolant pump for a coolant circuit of an internal combustion engine.

[0003] The object of the invention is to improve a fluid energy machine according to the preamble of patent claim 1 functionally and / or in terms of manufacturing technology.

[0004] The object is achieved in a fluid energy machine with a housing comprising at least two housing parts which are fastened to one another by means of a fastening device in at least one fastening area such that sealing surfaces provided on the housing parts come into sealing contact with one another in at least one sealing area spaced from the fastening area, directly or with the interposition of a sealing device, in that the housing parts have a geometric design in the fastening area with the aid of which a prestress generated by the fastening device is shifted wholly or partially from the fastening area to the sealing area. Fluid energy machines are machines in which mechanical work is exchanged with a fluid. The housing parts of the fluid energy machine are preferably joined housing parts.The fastening device comprises, for example, at least two screw connections with which the joined housing parts are fastened together. When screw connections are tightened, a preload is generated at the screw connection points. In conventional fluid energy machines, this preload is generally greater at the screw connection points than in a sealing area where the sealing surfaces of the housing parts come into contact with one another to form a seal. Depending on the design and type of materials used, the sealing surfaces can come into contact with one another to form a seal. However, a sealing device, for example in the form of a suitable seal made of a special sealing material, can also be arranged between the sealing surfaces. Due to the claimed geometric design of the housing parts, the preload generated by the fastening device can be advantageously shifted to the sealing area. This can effectively increase the tightness.The fastening device, for example, the screws used to hold it in place, and / or the housing components can advantageously be made smaller or less robust. If necessary, an otherwise required seal can be omitted.

[0005] A preferred embodiment of the fluid energy machine is characterized in that the fluid energy machine is designed as a hydraulic pump or a hydraulic fluid machine. The hydraulic pump serves, for example, in a hydraulic system to generate the hydraulic pressure required to perform a desired actuating function. The hydraulic fluid machine is required in the hydraulic system, for example, to provide a volume flow with which a cooling function is performed in the hydraulic system.

[0006] A further preferred embodiment of the fluid energy machine is characterized in that the sealing surfaces are arranged parallel to the fastening surfaces. In conventional fluid energy machines, the sealing surfaces and the fastening surfaces are usually arranged in one plane. In the claimed fluid energy machine, the sealing surfaces and the fastening surfaces are not arranged in one plane, at least before the screw connections of the fastening device are tightened. By means of a corresponding offset, the preload in the sealing area can be effectively increased in a simple manner, for example, when screw connections in the fastening area are tightened.

[0007] A further preferred embodiment of the fluid energy machine is characterized in that the geometric design includes a surface offset between the mounting surfaces and at least one of the sealing surfaces. Unlike a conventional housing, the arrangement of the mounting surfaces and the sealing surfaces relative to each other is deliberately altered. This targeted alteration can achieve a desired increase in contact pressure for the joined housing parts.

[0008] A further preferred embodiment of the fluid energy machine is characterized in that the fastening device comprises at least two screw connections, by which the housing parts are clamped against each other by applying a preload force in two fastening areas. Thus, when tightening the screw connections, the desired high preload can be easily generated in the sealing area, so that the sealing surfaces in the sealing area bear against each other, particularly in a high-pressure tight manner.

[0009] A further preferred embodiment of the fluid energy machine is characterized in that the housing parts are spaced apart from one another in the at least one fastening area. This easily provides a reserve or excess that enables the desired increase in contact pressure in the sealing area. When tightening screw connections that serve to form the fastening device, this distance can be overcome until the housing parts are in a blocking position. Depending on the design, however, it may also be sufficient for the housing parts to be clamped against one another up to a predetermined distance. A corresponding preload force can be specified via a tightening torque when tightening the screw connections.

[0010] A further preferred embodiment of the fluid energy machine is characterized in that the housing parts abut one another in the at least one fastening area with a lower preload than the sealing surfaces. This design simplifies assembly because the screw connections, which serve to form the fastening device, can simply be tightened until the housing parts abut one another in the fastening area.

[0011] In a method for manufacturing, in particular assembling, a fluid energy machine described above, the above-mentioned object is achieved alternatively or additionally by clamping the housing parts against each other in the fastening area with a lower preload than in the sealing area. This is advantageously achieved by the geometric design of the housing parts.

[0012] In a method for manufacturing, in particular designing, a fluid energy machine described above, the above-mentioned object is achieved alternatively or additionally by geometrically modifying the housing parts in the fastening area in such a way that the preload generated by the fastening device is shifted entirely or partially from the fastening area to the sealing area. This can be achieved, for example, by the previously described offset between the fastening surfaces and at least one of the sealing surfaces.

[0013] The invention further relates to a housing, a housing part, and / or a fastening device for a fluid energy machine as described above. These parts are sold separately.

[0014] Further advantages, features, and details of the invention will become apparent from the following description, in which various embodiments are described in detail with reference to the drawings. They show: Fig. 1 a perspective view of a housing part of a fluid energy machine; Fig. 2 the housing part Fig. 1 in a section with a second housing part indicated only by a line before tightening screw connections of a fastening device; and Fig. 3 the same representation as in Fig. 2 after tightening the screw connections.

[0015] In the Fig. Figures 1 to 3 show various views of a housing 5 of a fluid energy machine 10. The fluid energy machine 10 is a hydraulic pump that operates according to the gerotor principle. The housing 5 comprises two housing parts 1 and 2.

[0016] The housing part 1 is in Fig. 1 is shown in perspective. In the Fig. 2 and Fig. 3 shows the housing part 1 in section. A housing part 2 is shown in the Fig. 2 and Fig. 3 indicated only by a horizontal line.

[0017] The two housing parts 1 and 2 are provided with a geometric design 3, which includes a surface offset 4. In Fig. Figure 2 shows the surface offset 4 before tightening the screw connections 21, 22 of a fastening device 20. In practice, the surface offset 4 is, for example, hundredths to tenths of a millimeter. Fig. 3, the surface offset 4 is reduced to zero by tightening the screw connections 21, 22 of the fastening device 20.

[0018] The housing part 1 comprises a mounting flange 6, which is connected via webs 7 to a sealing surface 8 in a sealing area 9. In Fig. 2 shows that the surface offset 4 is specified between the sealing surface 8 and a fastening surface 11. This surface offset 4 is specifically specified between fastening areas 23, 24 of the fastening device 20 and the sealing area 9.

[0019] The fastening device 20 comprises screw connections 21, 22, which are indicated only by dashed lines. The axial offset 4 is implemented, for example, as an axial offset between the fastening surface 11 and the sealing surface 8. The term "axial" refers to an axis 13 of the fluid energy machine 10.

[0020] The sealing surface 8 defines a fluid chamber 12 inside the housing part 1. During operation of the fluid energy machine 10, a fluid pressure builds up in the fluid chamber 12. The sealing surface 8 has the shape of a circular ring surface that seals the fluid chamber 12 in a fluid-tight manner when the two housing parts 1 and 2 are tightly abutting one another in the sealing area 9 after tightening the screw connections 21, 22.

[0021] From a summary of the Fig. 2 and Fig. 3 shows that when the screw connections 21, 22 are tightened in conjunction with a corresponding elasticity of the housing 5, an additional elastic prestress is created on the sealing surfaces 8 of the housing parts 1, 2, which either increases the contact pressure of the housing parts 1, 2 and thus the tightness or makes a smaller number of screw connections 21, 22, smaller screws or less stable housing parts possible without the sealing function being restricted thereby.

[0022] By using different dimensions for the surface offset 4, specific areas with higher prestress can also be specifically created, for example in the area of a suction kidney of the fluid energy machine 10, in order to avoid air intake when the fluid energy machine 10 starts up at low temperatures.

[0023] If only a maximum of two levels are to be manufactured, for the sealing area 9 and the fastening areas 23, 24, the preload in the housing 5 can be optimally distributed by appropriate ribbing or design of the housing parts 1, 2, if necessary in conjunction with a corresponding stiffness adjustment.

[0024] The measures described above can be applied regardless of whether the housing parts 1, 2 are directly connected to one another, in particular screwed, or whether additional sealing devices, such as seals and / or sealing plates, are used.

[0025] The surface offset 4 can be applied to exactly one of the housing parts 1, 2 or the flange partner. However, the surface offset 4 can also be applied to both housing parts 1, 2 of the split housing 5. Furthermore, the surface offset 4 can be applied to all screw connection points. Depending on the design, the surface offset 4 can also be applied to only a few specific screw connection points. List of reference symbols 1 housing part 2 Housing part 3 geometric design 4 Surface offset 5 housings 6 Mounting flange 7 bridges 8 Sealing surface 9 Sealing area 10 Fluid energy machine 11 Mounting surface 12 Fluid chamber 13 Axis 20 Fastening device 21 Screw connection 22 screw connection 23 Mounting area 24 Mounting area QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2011 079 311 A1

[0002]

Claims

[1] Fluid energy machine (10) with a housing (5) comprising at least two housing parts (1, 2) which are fastened to one another by means of a fastening device (20) in at least one fastening area (23) in such a way that sealing surfaces (8) provided on the housing parts (1, 2) come into contact with one another in a sealing manner in at least one sealing area (9) spaced apart from the fastening area (23) directly or with the interposition of a sealing device, characterized by that the housing parts (1, 2) have a geometric design (3) in the fastening area (23) with the aid of which a prestress generated by the fastening device (20) is shifted wholly or partly from the fastening area (23) into the sealing area (9). [2] Fluid energy machine according to claim 1, characterized by that the fluid energy machine (10) is designed as a hydraulic pump or as a hydraulic flow machine. [3] Fluid energy machine according to one of the preceding claims, characterized by that the sealing surfaces (8) are arranged parallel to fastening surfaces (11). [4] Fluid energy machine according to claim 3, characterized by that the geometric design (3) comprises a surface offset (4) between the fastening surfaces (11) and at least one of the sealing surfaces (8). [5] Fluid energy machine according to one of the preceding claims, characterized by that the fastening device (20) comprises at least two screw connections (21, 22) by means of which the housing parts (1, 2) are clamped against one another by applying a prestressing force in two fastening areas (23, 24). [6] Fluid energy machine according to one of the preceding claims, characterized by that the housing parts (1,2) are spaced apart from one another in the at least one fastening region (23,24). [7] Fluid energy machine according to one of claims 1 to 5, characterized bythat the housing parts (1,2) in the at least one fastening area (23,24) abut one another with a lower preload than the sealing surfaces (8). [8] Method for producing, in particular assembling, a fluid energy machine (10) according to one of claims 1 to 7, characterized by that the housing parts (1,2) are clamped against each other in the fastening area (23,24) with a lower preload than in the sealing area (9). [9] Method for manufacturing, in particular designing, a fluid energy machine (10) according to one of claims 1 to 7, characterized by that the housing parts (1, 2) in the fastening area (23, 24) are geometrically modified in a targeted manner so that the prestress generated with the aid of the fastening device (20) is shifted wholly or partly from the fastening area (23, 24) into the sealing area (9). [10] Housing (5), housing part (1, 2) and / or fastening device (20) for a fluid energy machine (10) according to one of claims 1 to 7.

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