Housing component assembly, in particular for a drive unit in a motor vehicle

Abstract

A housing part assembly comprises a first and a second housing part which can be connected to one another by means of at least one connecting element, wherein the connecting element is guided through a connecting opening in which a force transmission bushing made of a harder material than the housing parts is inserted.

Description

Technical Field

[0001] The invention relates to a housing part assembly for a drive unit, in particular for a motor vehicle, for example for a steering drive unit. Background Art

[0002] DE 10260104 A1 discloses a drive unit for a servo drive in a motor vehicle, which has two housing parts connected to one another, wherein a first housing part forms a pole pot of an electric motor and a second housing part forms a transmission housing. The connection between the housing parts is made by a screw connection, in that a connecting screw is guided through a bearing hole on the first housing part and screwed into a flange on the second housing part. In addition, a centering ring protruding in the axial direction is formed on the flange on the second housing part, which centering ring can be inserted into an associated annular groove on the first housing part. In this way, an exact orientation of the two housing parts relative to one another can be achieved.

[0003] The housing parts can be made of aluminum and produced by aluminum die-casting. In order to reduce costs, extruded alloys can be used. In order to achieve the strength required for the screw connection, expensive heat treatment is required for these housings. Summary of the invention

[0004] According to the present invention, the housing part assembly comprises a first housing part and a second housing part, which can be connected to each other by means of at least one connecting element, wherein the connecting element is guided through a connecting hole arranged on the first housing part, a force transmission sleeve having a radially protruding support edge is inserted into the connecting hole, the support edge is axially supported on a housing flange comprising the connecting hole, wherein the end side of the force transmission sleeve has an axial spacing relative to the end side of the connecting hole, wherein the force transmission sleeve is made of a material that is stronger than the first housing part, wherein the force transmission sleeve is placed with its radially widened support edge on the end side of a mating flange on the second housing part, wherein the first housing part having the connecting hole forms a motor housing of the electric motor.

[0005] As described above, the housing part assembly according to the invention comprises a first and a second housing part, which can be connected to one another and can preferably be used as components of a drive unit, in particular in a motor vehicle. In the housing part assembly, the first and the second housing parts are connected to one another, wherein the first housing part forms, by way of example, the motor housing of an electric motor and the second housing part forms, for example, a transmission housing of a steering gear in a motor vehicle, for example, which is used to generate a servo torque supporting a steering movement. The housing part assembly can be installed in the drive unit, which in turn comprises an electric motor and another structural unit that cooperates with the electric motor, wherein the motor housing of the electric motor is formed by the first housing part and wherein the housing of the structural unit forms the second housing part. The structural unit comprising the second housing part is, in particular, a transmission for realizing a drive movement of the electric motor.

[0006] The first and second housing parts are connected by means of connecting elements, in particular connecting screws. The connecting elements are guided through connecting holes on the first housing part, which are located in a housing flange of the first housing part, in particular in a radially or laterally projecting housing flange. On the side of the second housing part, the connecting elements are connected to an associated counter-flange, which can also project laterally or radially on the second housing part.

[0007] The radial direction extends transversely to the longitudinal axis of the connecting element, which at the same time represents the direction of transmission of the connecting forces between the two housing parts. Correspondingly, the axial direction is identical to the longitudinal axis of the connecting element.

[0008] A force transmission sleeve is inserted into the connecting hole, and the connecting element extends into the force transmission sleeve. The force transmission sleeve is made of a material stronger than the first housing part, and is inserted into the housing flange of the first housing part having the connecting hole. The force transmission sleeve has a radially extending support edge, and the force transmission sleeve is axially supported on the housing flange having the connecting hole by means of the support edge.

[0009] Since the material strength of the force transmission sleeve is higher than that of the first housing part or the housing flange with the connecting hole on the first housing, the force transmission sleeve can transmit higher connecting forces between the housing parts without the risk of plastic deformation. This makes it possible to apply a higher connecting force between the housing parts without the risk of material damage than can be achieved without the use of a force transmission sleeve. Expensive heat treatment of the extruded housing can be avoided.

[0010] It may be expedient if the end face of the force transmission sleeve is arranged at an axial distance from the nearest end face of the connecting hole. In principle, it is sufficient if the force transmission sleeve is designed as a cushion with a shaped connecting piece, which extends into the connecting hole. In this embodiment, the axial length of the connecting piece of the force transmission sleeve is advantageously significantly smaller than the axial length of the connecting hole, wherein it may be expedient if the overall axial length of the force transmission sleeve or, if necessary, the axial length of the connecting piece on the force transmission sleeve is at least 10% of the axial length of the connecting hole.

[0011] The inner wall of the connecting hole can have an annular shoulder, which forms a circumferential inner shoulder and on which the end side of the connecting pipe on the force transmission sleeve is axially supported. In this embodiment of the force transmission sleeve with the formed connecting pipe, axial support is achieved on the one hand by the radially protruding support edge on the force transmission sleeve and on the other hand on the opposite end side of the force transmission sleeve, wherein the force transmission sleeve is supported on the inner annular shoulder in the connecting hole. By means of this overall enlarged support surface, a uniform force distribution of the connecting forces between the housing parts is achieved. Due to the enlarged support surface, the risk of plastic deformation of the material of the housing flange with the supporting hole due to the connecting forces is reduced.

[0012] In an advantageous embodiment, the force transmission sleeve has an axial length which is approximately the same as the axial length of the connecting hole in the housing flange. It may be expedient for the axial difference between the end side of the force transmission sleeve and the end side of the connecting hole to be at most 10% of the axial length of the force transmission sleeve, wherein smaller axial differences, such as at most 5%, at most 2% or at most 1%, are also conceivable if necessary. With the establishment of the connection between the housing parts, as soon as the connecting force exceeds the elastic yield point of the material of the first housing part, plastic deformation begins on the housing flange, but the plastic deformation is limited to the axial difference relative to the end side of the force transmission sleeve. This deformation is carried out in particular for the case where the end side of the force transmission sleeve ends inside the connecting hole. The advantage of this embodiment is that with the establishment of the connection between the housing parts by the connecting element, the two housing parts are first clamped together, so that there is no gap between the housing parts and manufacturing tolerances are compensated. Gaps caused by different thermal expansions between the housing parts, the connecting element and the force transmission sleeve can also be prevented by the prestressing. In the further course of the process, as the connecting force increases, a large portion of the connecting force is transmitted via the force transmission sleeve, so that a further deformation of the housing flange is avoided.

[0013] In an alternative embodiment, it is also possible that the force transmission sleeve projects beyond the connecting hole. In this embodiment, the end side of the connecting sleeve, which is opposite the radially protruding supporting edge, is outside the end side of the connecting hole on the housing flange. This embodiment has the advantage that, as the connection between the housing parts is established, the protruding edge area of ​​the force transmission sleeve is plastically embedded in the counter-flange, wherein the counter-flange on the second housing part advantageously also has a lower material strength than the force transmission sleeve. A gap-free, form-fitting connection is produced, which can transmit high forces. As the connecting force increases further, the connecting force is distributed to the force transmission sleeve and the flange of the first housing part, so that the connecting force is introduced into the flange of the second housing part over a large area and no further deformation occurs.

[0014] The two housing parts can also be made of the same material. However, in an alternative embodiment, it is also possible to manufacture the housing parts from different materials. The force transmission sleeve is anyway made of a material having a higher strength than the first housing part and, if necessary, also than the second housing part. The first housing part has the housing flange with the connecting hole, and the first housing part is made of aluminum, for example. The second housing part can also be made of aluminum if necessary.

[0015] According to another advantageous embodiment, the force transmission sleeve has a smooth inner surface. In the embodiment as a connecting screw, the connecting element can be screwed together with a counterpart, which is arranged or supported on a counterpart flange of the second housing part. The counterpart is, for example, a nut on the side facing away from the recess in the counterpart flange or an internal thread in the second housing part.

[0016] In an alternative embodiment, the force transmission sleeve has an internal thread, with which the connecting screw is screwed. In this embodiment, the widened screw head of the connecting screw is preferably supported on a counterflange of the second housing part. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further advantages and suitable embodiments can be seen from other preferred embodiments, the description of the drawings and the drawings. Among them:

[0018] Figure 1 A connecting hole on a first housing part is shown in a perspective view, the first housing part forming, for example, a motor housing of an electric motor, wherein a force transmission sleeve is inserted into the connecting hole.

[0019] Figure 2 The view from below shows the Figure 1 Theme,

[0020] Figure 3 shows a section through a housing flange with a connecting bore and an inserted force transmission sleeve,

[0021] Figure 4 An enlarged illustration of the end region of the connecting bore and the force transmission sleeve is shown,

[0022] Figure 5 A section through a housing part assembly having a first housing part forming a motor housing and a second housing part forming a transmission housing is shown, wherein the housing parts are connected by connecting screws which are guided through force transmission sleeves in connecting holes in the first housing part.

[0023] Figure 6 The housing assembly is shown in a perspective view. Figure 5 connection,

[0024] Figure 7 The section through the screw head of the connecting screw and the force transmission sleeve in the housing flange is shown, which is shown with the screw head loosely contacting the motor housing.

[0025] Figure 8 Shows the corresponding Figure 7 but shown in a tightened connecting bolt, the bolt head of which is in contact with the force transmission sleeve,

[0026] Fig. 9 An embodiment variant of the force transmission sleeve in the connecting hole is shown.

[0027] Fig.10 The end face of the force transmission bushing in the connecting bore is shown in an enlarged illustration.

[0028] In the figures, identical components are provided with the same reference numerals. DETAILED DESCRIPTION

[0029] exist Figures 1 to 8 A first embodiment is shown in FIG. 1 , in which the first housing member 1 is connected to the second housing member 6 by connecting bolts 7 ( Figure 5 , 6 ). The first housing part 1 is, for example, a motor housing of an electric motor, and the second housing part 6 is a transmission housing of a steering gear. Accordingly, the electric motor and the steering gear together form a drive unit for a steering system in a motor vehicle. As an alternative, other drive units are also conceivable, which are, for example, used for adjusting a seat in a motor vehicle, are constructed as a window lifter in a motor vehicle, or are constructed in the form of a windshield wiper drive unit.

[0030] A lateral housing flange 2 is integrally formed on the first housing part 1, which has a connecting hole 3 in the form of a through recess. A force transmission sleeve 4 is inserted into the connecting hole 3. The common longitudinal axis of the connecting hole 3 and the force transmission sleeve 4 is denoted by the reference numeral 5. The longitudinal axis 5 preferably extends parallel to the longitudinal axis of the housing part 1, wherein a non-parallel orientation of the longitudinal axis 5 through the connecting hole 3 and the longitudinal axis of the housing part 1 is also conceivable.

[0031] The force transmission sleeve 4 inserted into the connecting hole 3 is made of a material having a higher strength than the first housing part 1 including the housing flange 2. The material of the force transmission sleeve 4 is, for example, steel, and the material of the first housing part 1 including the housing flange 2 is, for example, aluminum. The second housing part 6 can also be made of aluminum.

[0032] The force transmission sleeve 4 is composed of a cylindrical sleeve section 4a and a radially protruding support edge 4b ​​on the end side of the force transmission sleeve. The support edge 4b ​​is supported on the end side of the housing flange 2. The axially opposite end side of the sleeve section 4a ends at an axial spacing 8 relative to the end side of the housing flange 2, into which the connecting hole 3 is hollowed. Here, the sleeve section 4a of the force transmission sleeve 4 is still inside the connecting hole 3. The axial length of the difference 8 between the end side of the sleeve section 4a and the end side of the housing flange 2 is preferably in the single-digit percentage range relative to the axial total length of the force transmission sleeve 4. The axial spacing 8 is exemplarily a maximum of 1 mm.

[0033] exist Figures 5 to 8 In the embodiment, the connecting bolt 7 is inserted into the force transmission sleeve 4 and screwed together with the counter flange 10 belonging to the second housing part 6. The widened bolt head 7a is placed on the washer 9, which is located on the end side of the housing flange 2 and the sleeve section 4a of the force transmission sleeve 4 on the first housing part 1. As the connecting bolt 7 is screwed in, the bolt head 7a is pressed toward the washer 9 and toward the end side of the housing flange 2 and the sleeve section 4a of the force transmission sleeve 4. Figure 7 , a state is shown in which the connecting screw 7 is screwed in only loosely, so that the washer 9 is in contact with the end face of the housing flange 2 without axial force or with only a small axial force.

[0034] And in Figure 8The connecting bolt 7 is then screwed in tightly, wherein a screwing force acts in the axial direction and simultaneously represents a connecting force between the housing parts 1 and 6, which causes a deformation in the region of the end side of the housing flange 2. This deformation can occur in the plastic range and is achieved due to the softer material of the housing flange 2. The deformation is carried out to such an extent that the washer 9 is placed on the end side of the sleeve section 4a of the force transmission sleeve 4 due to the screwing force. Due to the stronger material of the force transmission sleeve 4, this force transmission sleeve also does not deform plastically as the screwing force continues to increase. As a result, the majority of the axial screwing force or connecting force is transmitted through the force transmission sleeve 4, which is placed with its radially widened support edge 4b ​​on the end side of the counter flange 10 on the second housing part 6. In the contact area between the support edge 4b ​​of the force transmission sleeve 4 and the counter flange 10, no deformation or only a small deformation occurs due to the larger support surface of the support edge 4b.

[0035] exist Fig. 9 and 10 , another embodiment is shown, in which the force transmission sleeve 4 has in principle the same construction as in the first embodiment, but the axial thickness of the support edge 4b ​​is smaller. Furthermore, the support edge 4b ​​serves to receive the screw head when connecting the two housing parts, so that the screw head of the connecting screw rests directly on the support edge 4b ​​and presses it axially toward the housing flange 2. As can be seen from Fig.10 As can be seen in FIG. 1 , the axial end side of the sleeve section 4a of the force transmission sleeve 4, which is opposite the supporting edge 4b, ends at an axial distance in front of the end side of the housing flange 2 in the region of the connecting hole 3. When connecting to a counter-flange on the second housing part, the end side of the housing flange 2 comes into contact with the counter-flange and deforms as the connecting force increases until the end side of the sleeve section 4a comes into contact with the counter-flange, so that at the end of the screwing process, a large part of the screwing force or the connecting force is transmitted via the force transmission sleeve 4.

[0036] It is appropriate to Figures 1 to 8 In the embodiment of Fig. 9 and 10 In the manner shown and described in FIG. 1 , the force transmission sleeve 4 is embodied with respect to its structural design and its arrangement for connecting the housing parts.

Claims

1. A housing part assembly comprising a first housing part (1) and a second housing part (6), wherein the first housing part and the second housing part can be connected to each other by means of at least one connecting element, wherein the connecting element is guided through a connecting hole (3) arranged on the first housing part (1), characterized in that: A force transmission sleeve (4) having a radially protruding support edge (4b) is inserted into the connecting hole (3), the support edge (4b) being axially supported on a housing flange (2) comprising the connecting hole (3), wherein the end side of the force transmission sleeve (4) has an axial spacing relative to the end side of the connecting hole (3), wherein the force transmission sleeve (4) is made of a material that is stronger than the first housing part (1), The force transmission sleeve (4) is placed with its radially widened supporting edge (4b) on the end side of a counter flange (10) on the second housing part (6). The first housing part (1) having the connecting opening (3) therein forms the motor housing of the electric motor.

2. The housing assembly according to claim 1, characterized in that: The end side of the force transmission sleeve (4) is located inside the connecting hole (3).

3. The housing assembly according to claim 1, characterized in that: The end side of the force transmission sleeve (4) protrudes beyond the end side of the connecting hole (3).

4. The housing assembly according to any one of claims 1 to 3, characterized in that: The axial length of the force transmission sleeve (4) is at least 10% of the axial length of the connecting hole (3).

5. The housing assembly according to any one of claims 1 to 3, characterized in that: The axial difference between the end side of the force transmission sleeve (4) and the end side of the connecting hole (3) is a maximum of 10% of the axial length of the force transmission sleeve (4).

6. The housing assembly according to any one of claims 1 to 3, characterized in that: The connecting element is designed as a connecting screw (7), wherein the screw head (7a) faces the radially non-widened end side of the force transmission sleeve (4).

7. The housing assembly according to any one of claims 1 to 3, characterized in that: The connecting element is designed as a connecting screw (7), wherein the screw head (7a) faces the radially widened end side of the force transmission sleeve (4).

8. The housing assembly according to any one of claims 1 to 3, characterized in that: An internal thread is introduced into the force transmission sleeve (4).

9. The housing assembly according to any one of claims 1 to 3, characterized in that: The first housing member (1) and the connecting hole (3) are made of aluminum.

10. The housing assembly according to any one of claims 1 to 3, characterized in that: The second housing part (6) forms a gear housing of the steering gear.

11. The housing assembly according to any one of claims 1 to 3, characterized in that: The housing part assembly is used for a drive unit in a motor vehicle.

12. Drive unit having a housing part combination according to any one of claims 1 to 11.

13. The drive unit according to claim 12, characterized in that As an embodiment of a steering drive unit in a motor vehicle.

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