Hydraulic pump

Abstract

A hydraulic pump (10) has a motor housing (14) and a stator module (32) arranged within the motor housing (14). The stator module (32) has a carrier (34) which is received in a holding section (40) of the motor housing (14). The holding section (40) has first wall sections (42) with a first wall thickness (D) and second wall sections (44) with a second wall thickness (d), wherein the second wall thickness (d) is smaller than the first wall thickness (D). The second wall sections (44) are integrally connected to the carrier (34) of the stator module (32) by means of a welded connection (54).

Description

[0001] The invention relates to a hydraulic pump with a motor housing and a stator module arranged within the motor housing.

[0002] Such hydraulic pumps are known.

[0003] Due to the compact design of conventional hydraulic pumps, the motor housing has only very limited installation space for the stator module.

[0004] A challenge with conventional hydraulic pumps is securing the stator module within the motor housing without play to ensure reliable operation of the hydraulic pump. This has traditionally required a complex design and laborious assembly of the hydraulic pump.

[0005] The object of the invention is to provide a hydraulic pump in which the stator module is mounted within the motor housing with little effort.

[0006] The problem is solved by a hydraulic pump with a motor housing and a stator module arranged within the motor housing. The stator module has a support that is received in a holding section of the motor housing. The holding section has first wall sections with a first wall thickness and second wall sections with a second wall thickness, wherein the second wall thickness is smaller than the first wall thickness. Furthermore, the second wall sections are integrally connected to the support of the stator module by means of a welded joint.

[0007] According to the invention, it was recognized that the carrier can be welded to the holding section with little effort via the second wall sections, which have a reduced wall thickness compared to the first wall sections, and thus can be reliably connected. In particular, the welding can be performed radially from the outside through or by means of the second wall sections, so that no open access to the stator module is required to secure it within the motor housing.

[0008] In particular, the second wall sections form weakened areas in the housing wall of the motor housing, while the first wall sections correspond to the usual housing wall. In other words, the first wall sections do not merely represent specially reinforced wall sections of the motor housing, such as wall sections with ribs or pins, which, if at all, are usually only provided in relatively limited areas of the motor housing.

[0009] In one embodiment, the second wall sections are formed from a laser-transparent plastic. In particular, the second wall sections are laser-welded to the carrier. This allows the motor housing to be welded radially from the outside to the stator module particularly efficiently.

[0010] The second wall thickness can be a maximum of 2 mm, so that the heat input during welding quickly reaches a depth that ensures an effective weld between the holding section and the support. If the weld is formed using a laser welding process, the second wall section with such a wall thickness is sufficiently thin so that a sufficiently large proportion of the laser power penetrates the second wall section to ensure an effective weld.

[0011] Additionally or alternatively, the first wall thickness may be at least 3.6 mm so that the motor housing has a sufficiently high structural strength and thus provides a high level of protection.

[0012] In a further embodiment, the holding section has at least four first wall sections and at least four second wall sections. As a result, the holding section is welded to the stator module at several points, thus providing a particularly reliable connection.

[0013] Furthermore, it can be provided that the first wall sections and the second wall sections are arranged on a common circumference or a circumferential line. In other words, the first wall sections and the second wall sections are arranged one behind the other in the circumferential direction. In this way, the second wall sections, at which the motor housing is weakened and integrally connected to the support, are distributed over the outer circumference of the holding section, so that the motor housing and the hydraulic pump as a whole can be designed to be particularly stable.

[0014] Additionally or alternatively, adjacent second wall sections can each be separated from one another in the circumferential direction by at least one first wall section in order to ensure a particularly high strength of the motor housing despite the thinner second wall sections.

[0015] According to one embodiment, the second wall sections each extend over at least 5 mm in the circumferential direction, in particular over at least 10 mm. As a result, the second wall sections are wide enough so that an effective welded connection can be created with little effort.

[0016] According to a further embodiment, the second wall sections are welded to an axial end of the support facing a pump module of the hydraulic pump. In this way, the motor housing is welded to the stator module at a location that is usually no longer accessible after the stator module is arranged within the motor housing. This places fewer demands on the design of the hydraulic pump, allowing it to have a less complex structure.

[0017] Furthermore, at least some of the first wall sections can be arranged at the same angular positions as connecting sections of a pump housing of the hydraulic pump, to which a pump module of the hydraulic pump is attached. This has the advantage that the first wall sections, which are thicker than the second wall sections, are axially aligned with the connecting sections, which, like the first wall sections, are designed to be particularly stable. Thus, the hydraulic pump can have particularly high strength.

[0018] Furthermore, it can be provided that the motor housing is formed integrally with a pump housing of the hydraulic pump, in which a pump module of the hydraulic pump is accommodated. This allows the hydraulic pump to consist of very few individual parts and thus be designed particularly efficiently.

[0019] Further advantages and features are evident from the following description and the attached drawings. These show: - Fig. 1 in an axial sectional view of a hydraulic pump according to the invention with a stator module and a pump module, - Fig. 2 the hydraulic pump in a sectional view along the plane A - A in Fig. 1, wherein a stator winding of the stator module is not shown, - Fig. 3 the hydraulic pump in a sectional view along the plane B - B in Fig. 1, where the pump module is not shown, and - Fig. 4 the hydraulic pump in a sectional view along the plane C - C in Fig. 1, the pump module is not shown.

[0020] The following detailed description, taken in conjunction with the accompanying drawings, in which like numerals refer to like elements, is intended to describe various embodiments of the disclosed subject matter and is not intended to be the only embodiments. Each embodiment described in this disclosure is merely exemplary or illustrative and should not be construed as preferred or advantageous over other embodiments.

[0021] All features disclosed below with respect to the embodiments and / or the accompanying figures may be combined alone or in any sub-combination with features of the aspects of the present disclosure, including features of preferred embodiments, provided that the resulting combination of features is meaningful to a person skilled in the art.

[0022] In Fig. 1 shows a hydraulic pump 10, with only the components essential to the invention being shown for clarity. In particular, the rotor of the electric motor 18 and the electronics for controlling the hydraulic pump 10 have been omitted.

[0023] The hydraulic pump 10 is configured, for example, to provide a hydraulic oil flow for a drive train of a motor vehicle. This flow can be used to lubricate or cool drive train components. The hydraulic oil flow can also be used to convert actuators into an actuating stroke, for example, to engage a clutch.

[0024] The hydraulic pump 10 has a housing 12 with a motor housing 14, in the interior 16 of which an electric motor 18 (only partially shown) is arranged, and a pump housing 20, in the interior 22 of which a pump module 24 is accommodated.

[0025] The housing 12 is here constructed in one piece and has a pot shape, i.e. a bottom 26 and a side wall 28 which extends essentially in a hollow cylindrical shape against an axial direction Z from the bottom 26 to a housing edge 30.

[0026] In an alternative embodiment, the housing 12 consists of several individual parts.

[0027] In addition to the rotor (not shown), the electric motor 18 has a stator module 32 with a carrier 34 and a stator winding 36.

[0028] The carrier 34 is made of plastic and forms a slot insulation to which the stator winding 36 is attached.

[0029] In this context, the stator module 32 is arranged stationary in the housing 12, and the rotor is drivingly connected to the pump module 24, in particular to a pump rotor of the pump module 24, via a shaft (not shown).

[0030] The carrier 34 is fastened at its end 38 facing the pump module 24 to a holding section 40 of the motor housing 14.

[0031] The holding section 40 extends in the circumferential direction U (see Fig. 2) ring-shaped or closed around the carrier 34 and borders radially inwardly on it.

[0032] In the present embodiment, the holding section 40 has nine first wall sections 42 and nine second wall sections 44, which are arranged alternately one behind the other in the circumferential direction U on a common circumference 46 of the holding section 40.

[0033] In an alternative embodiment, the holding section 40 can have any number of first wall sections 42 and any number of second wall sections 44, but preferably at least four first wall sections 42 and at least four second wall sections 44.

[0034] Additionally or alternatively, the first wall sections 42 and the second wall sections 44 can be arranged in any order in the circumferential direction U. In particular, however, at least one first wall section 42 is arranged between two mutually adjacent second wall sections 44.

[0035] The first wall sections 42 have a first wall thickness D (see Fig. 3) of 4 mm, while the second wall sections 44 have a second wall thickness d of 1.8 mm.

[0036] In general, the first wall thickness D and the second wall thickness d can each be any size.

[0037] Preferably, the first wall thickness D is at least 3.6 mm, while the second wall thickness d is a maximum of 2 mm.

[0038] In all embodiments, the first wall thickness D is greater than the second wall thickness d.

[0039] The second wall sections 44 have a width u of 30 mm in the circumferential direction U and a height h in the axial direction Z (see Fig. 1) of 20 mm.

[0040] In an alternative embodiment, the second wall sections 44 can each have any width u and any height h.

[0041] Preferably, the width u is at least 5 mm, in particular at least 10 mm.

[0042] Furthermore, the height h is preferably at least 5 mm, in particular at least 10 mm.

[0043] In the present embodiment, six of the nine first wall sections 42 are arranged at the same angular positions in the circumferential direction U as connecting sections 48 (see Fig. 4) of the pump housing 20, by means of which the pump module 24 is attached to the pump housing 20.

[0044] This means that each connecting section 48 is assigned a first wall section 42 with the same angular position as the corresponding connecting section 48.

[0045] Of course, in an alternative embodiment, any part of the first wall sections 42 may be arranged at the angular positions of the connecting sections 48.

[0046] The connecting sections 48 each have a cylindrical retaining pin 50 extending in the axial direction Z, which ends in a mushroom-shaped retaining projection 52.

[0047] By means of the retaining projection 52, the pump module 24 is fixed in the interior 22 of the pump housing 20 in the axial direction Z.

[0048] In principle, the connecting sections 48 can be designed in any way.

[0049] In all embodiments, the support 34 is integrally connected to the second wall sections 44 via a welded joint 54.

[0050] In particular, the support 34 is laser welded to the second wall sections 44.

[0051] For this purpose, the housing 12 is made of a laser-transparent plastic which, in particular in the second wall sections 44, has a glass fiber content of at least 40%.

[0052] The housing 12, for example, is an injection-molded component.

[0053] In principle, the housing 12 can be formed from any material, as long as the motor housing 14 or at least the second wall sections 44 are formed from a laser-transparent plastic, which ensures an effective formation of the welded joint 54.

[0054] In the present embodiment, the first wall sections 42 are not connected to the carrier 34 by means of a welded joint 54.

[0055] In particular, the motor housing 14 is not connected to the carrier 34 via the first wall sections 42, but only via the second wall sections 44.

[0056] To assemble the hydraulic pump 10, the pump module 24 is first inserted into the pump housing 20 in the axial direction Z and fastened in the interior 22 by means of the connecting sections 48.

[0057] For this purpose, the retaining pins 50 are plastically deformed into the retaining projections 52 after the pump module 24 has been inserted.

[0058] The stator module 32 is then inserted in the axial direction Z into the interior 16 of the motor housing 14.

[0059] In a subsequent step, the stator module 32 is attached to the motor housing 14 by welding the holding section 40 to the carrier 34 via the second wall sections 44 from the radial outside, in particular by spot welding. This means that during welding, the laser penetrates from the outside through the respective second wall section 44 into the section of the carrier 34 that is arranged radially inwardly adjacent to the corresponding second wall section 44.

[0060] The formation of the welded joints 54 does not have to take place immediately after the insertion of the stator module 32, but can take place at any later time.

[0061] For example, in one embodiment, the stator module 32 may only be welded to the motor housing 14 after all components or assemblies have been inserted into the housing 12, in particular after the housing 12 has been closed with a cover.

[0062] In this way, a hydraulic pump 10 is provided which can be manufactured with little effort.

[0063] The stator module 32 is quickly and reliably fastened in the interior 16 of the motor housing 14, in particular at the end 38 of the carrier 34 facing the pump module 24.

Claims

[1] Hydraulic pump (10) with a motor housing (14) and a stator module (32) arranged within the motor housing (14), wherein the stator module (32) has a carrier (34) which is received in a holding section (40) of the motor housing (14), characterized by in that the holding section (40) has first wall sections (42) with a first wall thickness (D) and second wall sections (44) with a second wall thickness (d), wherein the second wall thickness (d) is smaller than the first wall thickness (D), wherein the second wall sections (44) are integrally connected to the carrier (34) of the stator module (32) by means of a welded connection (54). [2] Hydraulic pump (10) according to claim 1, characterized by that the second wall sections (44) are formed from a laser-transparent plastic, in particular wherein the second wall sections (44) are laser-welded to the carrier (34). [3] Hydraulic pump (10) according to claim 1 or 2, characterized bythat the second wall thickness (d) is a maximum of 2 mm, in particular wherein the first wall thickness (D) is at least 3.6 mm. [4] Hydraulic pump (10) according to one of the preceding claims, characterized by that the holding section (40) has at least four first wall sections (42) and at least four second wall sections (44). [5] Hydraulic pump (10) according to one of the preceding claims, characterized by that the first wall sections (42) and the second wall sections (44) are arranged on a common circumference (46). [6] Hydraulic pump (10) according to one of the preceding claims, characterized by that adjacent second wall sections (44) are each separated from one another in the circumferential direction (U) by at least one first wall section (42). [7] Hydraulic pump (10) according to one of the preceding claims, characterized bythat the second wall sections (44) each extend over at least 5 mm in the circumferential direction (U), in particular at least 10 mm. [8] Hydraulic pump (10) according to one of the preceding claims, characterized by that the second wall sections (44) are welded to an axial end (38) of the carrier (34) which faces a pump module (24) of the hydraulic pump (10). [9] Hydraulic pump (10) according to one of the preceding claims, characterized by that at least some of the first wall sections (42) are arranged at the same angular positions as connecting sections (48) of a pump housing (20) of the hydraulic pump (10), to which a pump module (24) of the hydraulic pump (10) is fastened. [10] Hydraulic pump (10) according to one of the preceding claims, characterized bythat the motor housing (14) is formed integrally with a pump housing (20) of the hydraulic pump (10), in which a pump module (24) of the hydraulic pump (10) is accommodated.

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