Electric drive gearbox assembly positioned with stepped bore

Abstract

An electric drive gearbox assembly positioned by a stepped hole, specifically comprising a first housing (1), a second housing (2) and a positioning pin (3), a first positioning hole (4) provided on a connecting surface of the first housing, and a second positioning hole (5) corresponding to the first positioning hole provided on the second housing, the first housing and the second housing being positioned and connected by the first positioning hole, the second positioning hole and the positioning pin, the first positioning hole and / or the second positioning hole being a stepped hole, the stepped hole including a guide portion (4-1) close to an opening of the hole and an engagement portion (4-2) remote from the opening, the hole diameter of the guide portion being larger than the hole diameter of the engagement portion, and the guide portion being for guiding the positioning pin to enter the engagement portion. In this electric drive gearbox assembly, the first housing can be pre-positioned when attached to the second housing, and during pre-positioning, the first housing can be radially adjusted relative to the second housing, facilitating positioning and attachment of the first housing and promoting the realization of automatic, batch assembly of the electric drive assembly.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to a Chinese patent application filed with the China Patent Office on January 4, 2022, bearing application number 202210002945.1 and title "Electric Drive Gearbox Assembly Positioned by Stepped Bore," the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to the technical field of electric drive assemblies, and more particularly to stepped bore positioned electric drive gearbox assemblies. [Background technology]

[0003] With the continuous development of the automobile industry, people have higher and higher requirements for the structural layout of the gearbox (transmission) and the entire automobile power system, and in order to make the axial dimension of the power assembly more compact, the power assembly often adopts an integral shaft structure supported by multiple bearings. And the housings of the power assembly are usually positioned and connected by locating pins and locating holes, and in the process of mounting one housing assembly with the outer ring and rollers of the bearing mounted on another housing assembly with the inner ring of the bearing mounted on, there is no sufficient offset space between the locating pins and locating holes, so the rollers of the bearing and the inner ring of the bearing are pressed against each other during the mounting process, resulting in scratches on the raceway surface of the bearing, which in turn affects the performance and life of the bearing and the entire power system.

[0004] In response to this, a conventional patent (application number 202110202229.3) entitled "Box Assembly for Electric Drive Power Transmission System Positioned by Step Pin and Method for Installing the Same" proposes providing a step pin to prevent the occurrence of damage to the raceway surface of the bearing caused by pressing between the inner ring of the bearing and the roller of the bearing. However, since the structures of both ends of the step pin are different, when performing batch installation via the step pin between the first housing and the intermediate housing, it is easy for the end of the step pin to be installed in reverse, resulting in an invalid installation and ultimately affecting the efficiency of the installation. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE DISCLOSURE In view of the above problems, the present invention discloses an electric drive gearbox assembly positioned with a stepped bore to eliminate or at least partially solve the above problems. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention employs the following technical solutions.

[0007] The present invention provides an electric drive gearbox assembly positioned with a stepped hole, the electric drive gearbox assembly including a first housing, a second housing, and a positioning pin; a first positioning hole is provided on a connection surface of the first housing, a second positioning hole corresponding to the first positioning hole is provided on the second housing, and the first housing and the second housing are positioned and connected by the first positioning hole, the second positioning hole and the positioning pin, The first positioning hole and / or the second positioning hole is a stepped hole, which includes a guide portion close to the hole opening and an engagement portion far from the hole opening, the hole diameter of the guide portion being larger than the hole diameter of the engagement portion, and the guide portion being intended to guide the positioning pin into the engagement portion.

[0008] Furthermore, the hole diameter of the engagement portion in the stepped hole is equal to the diameter of the positioning pin, or the engagement portion and the positioning pin are fitted together by an interference fit.

[0009] Furthermore, the outer surface of the positioning pin is provided with an axially disposed ventilation groove.

[0010] Furthermore, the first housing and / or the second housing are provided with a ventilation hole, and the ventilation hole communicates with the engagement portion.

[0011] Furthermore, the end of the positioning pin is provided with a direction guide inclined surface or a direction guide arc surface.

[0012] Furthermore, the stepped hole further includes a directional guide portion provided between the guide portion and the engagement portion, and the directional guide portion is for directional guidance of the entry of the positioning pin from the guide portion to the engagement portion.

[0013] Furthermore, the electric drive gearbox assembly further includes a power shaft, one end of the power shaft being supportably connected to the first housing via a first bearing and an intermediate position of the power shaft being supportably connected to the second housing via a second bearing.

[0014] Furthermore, an inner ring of the first bearing is fixedly connected to the power shaft, and an outer ring of the first bearing is fixedly connected to the first housing.

[0015] Furthermore, in the stepped hole, the gap between the guide portion and the positioning pin satisfies the condition that a radial space is maintained between any two of the inner ring of the first bearing, the outer ring of the first bearing, and the roller of the first bearing during the installation process in which more than half of the axial direction of the roller of the first bearing enters the raceway of the inner ring of the first bearing.

[0016] Furthermore, in the stepped hole, the axial lengths of the guide portion and the engagement portion are determined in accordance with the axial dimensions of the first bearing, the first housing, and the power shaft. Effect of the Invention

[0017] The advantages and beneficial effects of the present invention are as follows: In the electric drive gearbox assembly of the present invention, the first positioning hole on the first housing and / or the second positioning hole on the second housing are provided as stepped holes, so that the preliminary positioning of the first and second housings between the guide portion of the stepped hole and the positioning pin can be realized, and the first housing can be adjusted in the radial direction relative to the second housing during the preliminary positioning, facilitating the positioning and installation of the first and second housings. In addition, since both ends of the positioning pin can be engaged with the first positioning hole and the second positioning hole, no invalid installation occurs during the installation and positioning of the first positioning hole and the second positioning hole by the positioning pin, which promotes the realization of automatic and batch assembly of the electric drive assembly. [Brief description of the drawings]

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. In addition, like reference numerals refer to like parts throughout the drawings. [Figure 1]FIG. 1 is an axial cross-sectional view of an electric drive gearbox assembly according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a cross-sectional view of an initial position of a first bearing installation process of an electric drive gearbox assembly in accordance with a first embodiment of the present invention. [Diagram 3] 1 is a cross-sectional view showing the state in which a positioning pin begins to enter an engagement portion of a first positioning hole during the installation process of a first bearing of an electric drive gearbox assembly in Example 1 of the present invention. FIG. [Figure 4] FIG. 11 is a cross-sectional view showing the roller of the first bearing fully inserted into the raceway of the inner ring during the installation process of the first bearing of the electric drive gearbox assembly in the first embodiment of the present invention. [Diagram 5] FIG. 11 is an axial cross-sectional view of an electric drive gearbox assembly in a second embodiment of the present invention. [Figure 6] FIG. 11 is a cross-sectional view showing the state in which the positioning pin begins to enter the engagement portion of the first positioning hole during the installation process of the first bearing of the electric drive gearbox assembly in the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In order to make the objectives, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the described embodiments are only some embodiments of the present invention, and are not all embodiments. All other embodiments obtained by those skilled in the art without creative efforts based on the embodiments of the present invention are within the protection scope of the present invention.

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, technical solutions according to various embodiments of the present invention

[0021] [Example 1] This embodiment provides an electric drive gearbox assembly positioned by a stepped hole, and as shown in Figures 1 to 4, the electric drive gearbox assembly includes a first housing 1, a second housing 2 and a positioning pin 3. Among them, the radial cross section of the positioning pin 3 may be a circle, a regular polygon, or other shapes.

[0022] Specifically, a first positioning hole 4 is provided on the connection surface of the first housing 1 where the connection with the second housing 2 is formed, and the specific number and positions of the first positioning holes 4 can be adjusted as necessary. The second housing 2 is provided with a second positioning hole 5 corresponding to the first positioning hole 4. The first housing 1 and the second housing 2 are positioned and connected by the first positioning hole 4, the second positioning hole 5 and the positioning pin 3, that is, both ends of the positioning pin 3 are inserted into the first positioning hole 4 and the second positioning hole 5, respectively, to realize relative fixation of the first housing 1 and the second housing 2.

[0023] Among them, the first positioning hole 4 is a stepped hole, specifically including a guide portion 4-1 close to the hole opening and an engagement portion 4-2 far from the hole opening, the hole diameter of the guide portion 4-1 being larger than the hole diameter of the engagement portion 4-2, and the guide portion 4-1 is for guiding the positioning pin 3 to enter the engagement portion 4-2. It is preferable that there is an interference fit between the second positioning hole 5 and the positioning pin 3. In this way, when the first housing 1 and the second housing 2 are attached via the positioning pin 3, one end of the positioning pin 3 is first inserted into the second positioning hole 5, and then the other end of the positioning pin 3 is inserted into the guide portion 4-1 in the first positioning hole 4, thereby realizing preliminary positioning of the positioning pin 3 and the first positioning hole 4, i.e., preliminary positioning of the first housing 1 and the second housing 2 is realized. At this time, since there is a radial gap between the positioning pin 3 and the guide portion 4-1, the first housing 1 can be adjusted radially relative to the second housing 2, and when the end of the positioning pin 3 enters the engagement portion 4-2 from the guide portion 4-1 in the first positioning hole 4, radial positioning of the first housing 1 and the second housing 2 is realized.

[0024] Of course, in other embodiments, the second positioning hole may be a stepped hole and the first positioning hole may be a straight hole, or both the first positioning hole and the second positioning hole may be stepped holes.

[0025] In summary, in the electric drive gearbox assembly of this embodiment, the first positioning hole on the first housing and / or the second positioning hole on the second housing are provided as stepped holes, so that the radial gap between the guide portion of the stepped hole and the positioning pin can be utilized to realize preliminary positioning of the first housing and the second housing, and during preliminary positioning, the first housing can be adjusted radially relative to the second housing, facilitating positioning and installation of the first housing and the second housing. In addition, since both ends of the positioning pin can be engaged with the first positioning hole and the second positioning hole, ineffective installation does not occur during installation and positioning of the first positioning hole and the second positioning hole by the positioning pin, and installation efficiency is improved, which promotes the realization of automatic and batch-wise assembly of the electric drive assembly.

[0026] In this embodiment, the hole diameter of the engagement part in the stepped hole is equal to the diameter of the locating pin, and the matching installation can improve the accuracy after the first housing and the second housing are installed, and can effectively prevent the structural loosening and abnormal noise of the electric drive gearbox assembly caused by long-term vibration. Of course, in other embodiments, the engagement part and the locating pin may be interference-fitted to further realize a strong fixed connection between the first housing and the second housing.

[0027] Furthermore, an axially arranged ventilation groove is provided on the outer surface of the positioning pin, and when the end of the positioning pin enters the engagement portion from the guide portion, gas between the positioning pin and the engagement portion is discharged through the ventilation groove, allowing the positioning pin to enter the engagement portion smoothly.

[0028] In this embodiment, the first positioning hole further includes a direction guide portion provided between the guide portion and the engagement portion, and the direction guide portion is for guiding the direction of entry of the positioning pin from the guide portion to the engagement portion. This makes it easier for the end of the positioning pin to enter the engagement portion from the guide portion more accurately, improving the efficiency of installation.

[0029] In this embodiment, as shown in Figures 1 to 4, the electric drive gearbox assembly further includes a power shaft 6, one end of which is supported and connected to the first housing 1 via a first bearing 7, and an intermediate position of the power shaft 6 is supported and connected to the second housing 2 via a second bearing 8.

[0030] Among them, the inner ring 7-1 of the first bearing is fixedly connected to the power shaft 6, the outer ring 7-2 of the first bearing is fixedly connected to the first housing 1, and the roller 7-3 of the first bearing is fixed to the outer ring 7-2 of the first bearing.

[0031] Furthermore, in the first positioning hole, the gap between the guide portion and the positioning pin satisfies the condition that a radial space is maintained between any two of the inner ring of the first bearing, the outer ring of the first bearing, and the roller of the first bearing during the installation process in which more than half of the axial direction of the roller in the first bearing enters the raceway of the inner ring of the first bearing.

[0032] In the first positioning hole, the axial lengths of the guide portion and the engagement portion are determined according to the axial dimensions of the first bearing, the first housing, and the power shaft. Specifically, the axial length of the guide portion is set to a length such that, when the end of the positioning pin is inserted into the leading or middle portion of the guide portion, the outer ring of the first bearing, the rollers of the first bearing, and the inner ring of the first bearing are positioned at the start of installation, and when the end of the positioning pin is inserted to the end of the guide portion, at least half of the rollers of the first bearing are inserted into the inner ring slideway of the first bearing. The axial length of the engagement portion is set to a length such that, when the end of the positioning pin is fully inserted into the engagement portion, the remaining part of the rollers of the first bearing are inserted completely into the raceway of the inner ring of the first bearing.

[0033] In this embodiment, when the first housing 1 and the second housing 2 are attached to each other, as shown in FIG. 2, when the end of the positioning pin 3 is inserted into the guide portion 4-1, the first bearing 7 is in the attached position and there is a radial gap between the positioning pin 3 and the guide portion 4-1, so that the first housing 1 can be adjusted radially relative to the second housing 2. Furthermore, sufficient radial space is secured between the inner ring 7-1 of the first bearing and the roller 7-3 of the first bearing, making it easy to adjust the two radially and preventing the occurrence of scratches due to rubbing between the inner ring 7-1 of the first bearing and the roller 7-3 of the first bearing. As shown in Figure 3, when at least half of the axial direction of the roller 7-3 of the first bearing has entered the raceway of the inner ring of the first bearing, the end of the positioning pin 3 begins to enter the engagement portion 4-2, and when the end of the positioning pin 3 is inserted into the engagement portion 4-2, as shown in Figure 4, the roller 7-3 of the first bearing has completely entered the raceway of the inner ring of the first bearing, i.e., the installation of the first bearing 7 is completed.

[0034] By providing the first positioning hole as a stepped hole, a stepped fit between the positioning pin and the stepped hole is realized, which can prevent scratches on the raceway surface of the inner ring of the first bearing caused by the inner ring of the first bearing and the rollers of the first bearing being pressed against each other during the installation process of the first housing and the second housing, and further improves the service life of the first bearing and the electric drive gearbox assembly.

[0035] [Example 2] 5 and 6, the difference from the first embodiment is that the inner ring 7-1 of the first bearing is fixedly connected to the power shaft 6, the outer ring 7-2 of the first bearing is fixedly connected to the first housing 1, and the roller 7-3 of the first bearing is fixed to the inner ring 7-1 of the first bearing. In this case, a separate type cylindrical roller bearing may be selected as the first bearing to be used.

[0036] [Example 3] A difference from Example 1 is that in this Example, the design of the ventilation groove is omitted. Also, when both the first positioning hole and the second positioning hole are stepped holes, both the first housing and the second housing are provided with ventilation holes, which communicate with the engagement portion, and when the positioning pin enters the engagement portion, the ventilation holes allow gas between the positioning pin and the engagement portion to be exhausted, so that the positioning pin can smoothly enter the engagement portion. When only the first positioning hole is a stepped hole, the ventilation hole is provided in the first housing, and when only the second positioning hole is a stepped hole, the ventilation hole is provided in the second housing.

[0037] [Example 4] The difference from the first embodiment is that the end of the positioning pin in this embodiment is provided with a direction guide slope or a direction guide arc surface, which makes it easier for the positioning pin to enter the engagement part from the guide part, and reduces the difficulty of installation.

[0038] The above is merely a specific embodiment of the present application, and under the above teaching of the present application, those skilled in the art can make other improvements or modifications based on the above embodiments. Those skilled in the art should understand that the above specific description is for better interpreting the object of the present invention, and the protection scope of the present application is based on the protection scope of the claims. [Explanation of symbols]

[0039] 1...first housing, 2...second housing, 3...positioning pin, 4...first positioning hole, 4-1...guide portion, 4-2...engagement portion, 5...second positioning hole, 6...power shaft, 7...first bearing, 7-1...inner ring of first bearing, 7-2...outer ring of first bearing, 7-3...roller of first bearing, 8...second bearing.

Claims

1. 1. An electric drive gearbox assembly located with a stepped hole, the electric drive gearbox assembly including a first housing, a second housing, and a location pin; a first positioning hole is provided on a connection surface of the first housing, a second positioning hole corresponding to the first positioning hole is provided on the second housing, and the first housing and the second housing are positioned and connected by the first positioning hole, the second positioning hole and the positioning pin, The electric drive gearbox assembly, characterized in that the first positioning hole and / or the second positioning hole are stepped holes, the stepped holes including a guide portion close to a hole opening and an engagement portion far from the hole opening, the hole diameter of the guide portion being larger than the hole diameter of the engagement portion, and the guide portion being for guiding the positioning pin to enter the engagement portion.

2. 2. The electric drive gearbox assembly according to claim 1, wherein a hole diameter of the engagement portion of the stepped hole is equal to a diameter of the positioning pin, or the engagement portion and the positioning pin are fitted together by an interference fit.

3. 3. The electric drive gearbox assembly of claim 2, wherein the locating pin has an outer surface with axially disposed ventilation grooves.

4. The electric drive gearbox assembly according to claim 2, characterized in that the first housing and / or the second housing are provided with a ventilation hole, the ventilation hole communicating with the engagement portion.

5. The electric drive gearbox assembly according to claim 1, characterized in that the end of the positioning pin is provided with a direction guide bevel or a direction guide arc surface.

6. 2. The electric drive gearbox assembly according to claim 1, wherein the stepped hole further includes a directional guide portion provided between the guide portion and the engagement portion, the directional guide portion being for directional guidance of the entry of the positioning pin from the guide portion to the engagement portion.

7. 7. An electric drive gearbox assembly as claimed in any one of claims 1 to 6, further comprising a power shaft, one end of the power shaft being supportably connected to the first housing via a first bearing and an intermediate position of the power shaft being supportably connected to the second housing via a second bearing.

8. 8. The electric drive gearbox assembly of claim 7, wherein an inner ring of the first bearing is fixedly connected to the power shaft and an outer ring of the first bearing is fixedly connected to the first housing.

9. In the stepped hole, the gap between the guide portion and the positioning pin is 9. The electric drive gearbox assembly according to claim 8, characterized in that during an installation process in which more than half of the axial portion of the rollers of the first bearing enters the raceway of the inner ring of the first bearing, a radial space is maintained between any two of the inner ring of the first bearing, the outer ring of the first bearing, and the rollers of the first bearing.

10. 9. The electric drive gearbox assembly according to claim 8, wherein the axial lengths of the guide portion and the engagement portion in the stepped hole are determined according to the axial dimensions of the first bearing, the first housing, and the power shaft.

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