Shaft hub assembly
By designing a shaft hub assembly with multiple axial parts, using shape locking and frictional connections, the problem of no clearance torque transmission in the prior art is solved, and high-efficiency and low noise high torque transmission effect is achieved.
Patent Information
- Application Number
- CN202380051119.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-06
- Filing Date
- 2023-06-29
- Publication Date
- 2025-02-28
AI Technical Summary
Existing hub assemblies cannot achieve a gap-free connection when transmitting radial torque and axial forces, resulting in noise problems and the prior art is difficult to meet the torque transfer requirements for high load applications.
A hub assembly is designed, wherein the shaft includes a first axial portion, a second axial portion and a third axial portion, and a higher torque transmission capability is achieved through the shape locking and frictional connection of the third axial portion.
A clearance-free connection between the shaft and the hub is achieved, which can efficiently transmit high torque without noise, reduce production costs and simplify the manufacturing process.
Smart Images
Figure CN119546866A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a shaft-hub assembly, comprising: a hub provided with an axially extending opening, and a shaft inserted into the opening of the hub, wherein the shaft comprises at least: a first axial portion in which the shaft has a substantially constant cross section; and a second axial portion, starting from the first axial portion, the second axial portion substantially extending from a first cross section corresponding to the cross section of the first axial portion to a larger second cross section. Furthermore, the present invention relates to a method for producing such a shaft-hub assembly. Background Art
[0002] For shaft-hub assemblies of this type, a play-free connection is required to transmit radial torques and axial forces. However, it is obvious that the riveted connections known from the prior art generally have the disadvantage that they do not allow a play-free torque transmission. In such connections, it is generally also required that the connection between shaft and hub must not only withstand static forces but also ensure its mechanical integrity, in particular under dynamic axial and radial loads. If the corresponding connection had no play, undesirable noises might occur, both in the radial direction and in the axial direction. However, this is unacceptable to users of this assembly and must be prevented in any case.
[0003] Furthermore, it is known from the prior art to provide in such an assembly a shaft made of a harder material, which shaft has a plurality of radially protruding ribs parallel to the axis. The shaft is pressed into an axially extending opening of a hub, the diameter of which opening substantially corresponds to the diameter of the shaft without ribs. Since the hub is made of a softer material than the shaft, the ribs will cut into the wall of the hub opening when radially inserted. Thus, a play-free torque transmission between shaft and hub is intended to be achieved.
[0004] However, in this configuration of the shaft-hub assembly it has been shown that the play-free connection between shaft and hub exists only at the ribs, but that due to manufacturing tolerances play also exists between the cylindrical outer surface of the shaft and the cylindrical wall of the hub opening.
[0005] Furthermore, methods have been sought to combine a form-locking connection with an axial fixation by a riveted connection, as a result of which torques and axial forces can be transmitted to a certain extent. This principle is implemented in the prior art by serrations and flat rivets that are intended to interact in the desired manner. Furthermore, the method is also used to achieve a form-locking connection between shaft and hub by means of chamfers.
[0006] However, it is obvious here that none of the solutions known from the prior art are suitable for transmitting torque and axial forces completely without play. As mentioned above, a purely axial riveted connection cannot transmit torque, while a combination of a form-locking connection with an axial fixation by a riveted connection is in principle capable of transmitting torque and absorbing axial forces, but this connection cannot achieve the required degree of playlessness. In order to counteract the noise that is generated thereby, an adhesive bond must be further established in such an assembly, but this means that the production of such an assembly requires more effort.
[0007] The latter method is a form-locking connection between shaft and hub with the aid of chamfers, which makes it possible to achieve a play-free connection without the additional use of adhesives, but the play-free torque that can be transmitted is not sufficient for certain applications with higher load requirements. Summary of the invention
[0008] The object of the present invention is therefore to provide a shaft-hub assembly of the above-mentioned type, which comprises a play-free connection for transmitting radial torques and axial forces, which on the one hand is inexpensive to manufacture and does not require additional bonding, and on the other hand is capable of transmitting high torques without generating noise.
[0009] To this end, as described above, the shaft of the shaft-hub assembly according to the present invention comprises at least: a first axial portion in which the shaft has a substantially constant cross-section; and a second axial portion, which starts from the first axial portion and substantially expands from a first cross-section corresponding to the cross-section of the first axial portion to a larger second cross-section, wherein according to the present invention, the shaft also comprises a third axial portion, which is adjacent to the second axial portion and has a substantially constant third cross-section, which is the same as or larger than the second cross-section, and wherein the third axial portion forms an axial end of the shaft, and the first axial portion to the third axial portion have corresponding toothed or corrugated profiles on their outer sides.
[0010] Thus, in the shaft-hub assembly according to the invention, an increase in the contact area of the form-locking connection between shaft and hub is achieved compared to the above-mentioned prior art solutions, which allows the transmission of higher torques. In particular, this is achieved by additional radial support of forces and torques.
[0011] In particular, the third axial portion of the shaft can be pressed into the material of the hub. In this way, an additional form-locking and frictional connection is created on the outer wall of the shaft.
[0012] For this purpose, in the assembly according to the invention, the shaft can be formed of a harder material than the hub, so as to simplify pressing the shaft into the material of the hub. In particular, the shaft can be formed of a metal material, and the hub can be formed of a relatively softer metal material or plastic material.
[0013] Furthermore, according to the invention, a radial step can be provided between the second axial section and the third axial section of the shaft, so that the constant third cross section of the third axial section is larger than the second cross section to which the shaft widens in the second axial section starting from the first axial section. Thus, additional axial support is provided in the step area and the connection between the shaft and the hub is further improved.
[0014] Furthermore, in the shaft-hub assembly according to the invention, the second axial portion of the shaft can expand substantially conically from the first axial portion to the third axial portion. However, alternatively, other courses of the second axial portion are also conceivable, such as an arcuate increase in the cross section of the shaft in this region.
[0015] Furthermore, the shaft may be provided with a blind hole in a radially central portion of the third axial portion, the blind hole starting from an axial end of the shaft.
[0016] Furthermore, the shaft can have an axial stop at the opposite end and can be inserted into the hub up to this stop, so that the connection between shaft and hub is also improved in this axial direction.
[0017] According to a second aspect, the present invention relates to a method for producing such a shaft-hub assembly, the method comprising the following steps: providing a hub, the hub being provided with an axially extending opening, wherein the opening comprises: a first axial portion having a substantially constant cross-section; a second axial portion, the second axial portion starting from the first axial portion and substantially expanding from a first cross-section corresponding to the cross-section of the first axial portion to a larger second cross-section; and a third axial portion having a substantially constant cross-section; providing a shaft having a substantially constant first cross-section, the first cross-section corresponding to the cross-section of the first axial portion of the opening, wherein the shaft has a toothed or corrugated profile on its outer side, and the opening of the hub has a complementary profile at least in its first axial portion; and deforming the shaft by pressing the third axial portion of the shaft into the material of the hub so as to form a second portion and a third portion corresponding to the second axial portion of the opening, wherein the third portion of the shaft has a cross-section larger than the third axial cross-section of the hub.
[0018] By means of this method, a shaft-hub assembly according to the invention having the advantages described above can be produced in a simple and effective manner.
[0019] According to the invention, before the two components are connected here, only the first axial portion of the opening of the hub can have a complementary profile, while the second and third axial portions are free of such a profile.
[0020] Furthermore, the deformation step here can be performed by applying axial punching or pressing. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Additional features and advantages of the present invention will become more apparent from the following description of its embodiments when considered together with the accompanying drawings. In detail, in the accompanying drawings:
[0022] Figure 1a and Figure 1b shows a hub of a shaft-hub assembly according to the invention before and after being connected to a corresponding shaft;
[0023] Figure 2a to Figure 2c shows a shaft of a shaft-hub assembly according to the invention before being connected to a hub, and shows the shaft of a shaft-hub assembly according to the invention in two views after being connected to a hub; and
[0024] Figure 3a to Figure 3c The shaft-hub assembly is shown during connection of the shaft and the hub, and the shaft-hub assembly is shown in two views after connection of the shaft and the hub. DETAILED DESCRIPTION
[0025] exist Figure 1a and Figure 1b In the drawings, the hub of the shaft-hub assembly according to the invention is initially indicated by reference numeral 10 and is shown in two states, namely before and after being connected to a corresponding shaft, wherein in Figure 1b In the representation of , the representation of the axes is initially omitted for clarity.
[0026] Here, in the embodiment shown, the hub 10 can represent, for example, a clutch housing of a spindle drive. Here, the hub 10 can in particular be made of a relatively soft metal material or plastic material and comprises an opening 12 extending in the axial direction A, which extends through the entire body 10a of the hub 10. In addition, in Figure 1a As can be seen in FIG. 1 , the opening 12 comprises a first axial portion 12 a having a substantially constant cross section Q1 , wherein the wall of the opening in the first axial portion 12 a has a toothed or corrugated profile 14 .
[0027] Adjacent to this in the axial direction, the opening 12 also comprises a second axial portion 12b which, starting from the first axial portion 12a, expands from a first cross section Q1 corresponding to the cross section Q1 of the first axial portion 12a to a second, larger cross section Q2. Adjacent to this is a third axial portion 12c having a substantially constant cross section Q3 which is again larger than the second cross section Q2, thereby forming a step 12d between the second axial portion 12b and the third axial portion 12c. It can be seen that the second and third portions 12b and 12c and the step 12d do not have the toothed or corrugated profile 14 found in the first portion 12a.
[0028] refer to Figure 1bIt can now be seen that after the hub 10 has been connected to the shaft as shown in the figure below, a corresponding toothed or corrugated profile 14 has also been formed in the second and third parts 12b and 12c and the step 12d by pressing the corresponding parts of the shaft into the material of the hub 10, so that a friction and form-locking connection has been established between the two components.
[0029] exist Figure 2a to Figure 2c In FIG. 1 , a corresponding shaft 20 of a shaft-hub assembly according to the present invention is shown and generally indicated by the reference numeral 20. Figure 2a In the state, it is not connected to Figure 1a and Figure 1b The shaft 20 is still cylindrical in its axial upper region, with a substantially constant cross section Q1, wherein it has only on its outer side a toothed or corrugated profile 24 complementary to the opening of the hub 10. Furthermore, an axial stop 26 is provided in the axial lower region of the shaft 20, which limits the insertion of the shaft 20 in this direction into the opening 12 of the hub 10. On its axial upper side, the shaft 20 also has a blind hole 28 in the radial center portion.
[0030] exist Figure 2b and Figure 2c , the shaft 20 is now shown connected to Figure 1a and Figure 1b 1 , wherein, however, the representation of the hub 10 is initially omitted for reasons of visibility. Here, it can be seen that, after a corresponding deformation, the shaft 20 now comprises a first axial portion 22a in which the shaft 20 has a first constant cross section Q1, which corresponds to the cross section Q1 of the opening 12 of the hub 10 in its first portion 12a. Adjoining this in the axial direction is a second axial portion 22b, which expands in the axial direction starting from the first cross section Q1 to a larger second cross section Q2, while a third axial portion 22c further adjoins this second axial portion 22b and has a substantially constant third cross section Q3, which is larger than the second cross section Q2.
[0031] Finally, in Figure 3a to Figure 3c In the embodiment, the shaft-hub assembly 30 is shown in a state where the shaft 20 has been inserted into the opening 12 of the hub 10, but has not yet been deformed. As described above, in this state, Figure 3a A stop 26 (not shown) may limit the insertion of the shaft 20 in the axial direction A into the opening 12 of the hub 10 .
[0032] In addition, Figure 3b and Figure 3cIn the figure, the shaft-hub assembly 30 is shown in its final connected state in two views, in which it can be seen that a form locking and friction connection has been achieved between the hub 10 and the shaft 20 through the interaction of the separate axial portions of the two components, in particular the pressing of the third axial portion 22c of the shaft 20 into the material of the hub 10 in the region of its third portion 12c and the axial contact on the step 12d.
Claims
1. A shaft-hub assembly (30), comprising: - a hub (10) provided with an axially extending opening (12); and - a shaft (20) which is inserted into the opening (12) of the hub (10), The shaft (20) comprises at least the following parts: - a first axial portion (22a), in which the shaft (20) has a substantially constant cross section (Q1); and - a second axial portion (22b) which, starting from the first axial portion (22a), expands substantially from a first cross-section (Q1) corresponding to the cross-section (Q1) of the first axial portion (22a) to a second, larger cross-section (Q2); Characterized in that the shaft (20) further comprises a third axial portion (22c) which adjoins the second axial portion (22b) and has a substantially constant third cross section (Q3), which is the same as or larger than the second cross section (Q2) and which establishes a form-locking and frictional connection with the hub (10), and The third axial portion (22c) forms an axial end of the shaft (20), and the outer sides of the first to third axial portions (22a-22c) have corresponding toothed or corrugated profiles (24).
2. The shaft-hub assembly (30) according to claim 1, The third axial portion (22c) of the shaft (20) is pressed into the material of the hub (10).
3. The shaft-hub assembly (30) according to any one of the preceding claims, wherein the shaft (20) is formed of a harder material than the hub (10).
4. The shaft-hub assembly (30) according to claim 3, The shaft (20) is formed of a metal material, and the hub (10) is formed of a softer metal material or a plastic material.
5. The shaft-hub assembly (30) according to any one of the preceding claims, wherein a radial step (22d) is provided between the second axial portion (22b) and the third axial portion (22c) of the shaft (20).
6. The shaft-hub assembly (30) according to any one of the preceding claims, wherein the second axial portion (22b) expands substantially conically from the first axial portion (22a) to the third axial portion (22c).
7. The shaft-hub assembly (30) according to any one of the preceding claims, wherein the shaft (20) is provided with a blind hole (28) in a radial centre portion of the third axial portion.
8. The shaft-hub assembly (30) according to any one of the preceding claims, wherein the shaft (20) has an axial stop (26) and the shaft is inserted into the hub (20) up to the stop.
9. A method for producing a shaft-hub assembly (30) according to any one of the preceding claims, the method comprising the following steps: - providing a hub (10) provided with an axially extending opening (12), wherein the opening (12) comprises: o a first axial portion (12a) having a substantially constant cross section (Q1), a second axial portion (12b) which, starting from the first axial portion (12a), expands substantially from a first cross-section (Q1) corresponding to the cross-section (Q1) of the first axial portion (12a) to a second, larger cross-section (Q2); and o a third axial portion (12c) having a substantially constant cross-section (Q3); - providing a shaft (20) having a substantially constant first cross-section (Q1), said first cross-section corresponding to said cross-section (Q1) of said first axial portion (12a) of said opening (12); wherein the outer side of said shaft (20) has a toothed or corrugated profile (24), and said opening (12) of said hub (10) has a complementary profile (14) at least in said first axial portion (12a) of said opening; and - deforming the shaft (20) by pressing the third axial portion (22c) of the shaft (20) into the material of the hub (10) so as to form a second portion (22b) and a third portion (22c) corresponding to the second axial portion (12b) of the opening (12), wherein the third portion (22c) of the shaft (20) has a larger cross section (Q3) than the third axial cross section (Q3) of the hub (10).
10. The method according to the preceding claim, Wherein only the first axial portion (12a) of the opening (12) of the hub (10) has the complementary profile (14) when the first axial portion is provided, while the second axial portion (12b) and the third axial portion (12c) do not have this profile.
11. The method according to the preceding claim, The deformation The step is performed by applying axial punching or pressing.