Reducer housing and reducer

Abstract

The present application discloses a reducer housing and reducer, which relates to the technical field of automobile parts, and includes a housing, wherein the housing is provided with a mounting cavity and a mounting opening connected to the mounting cavity, wherein two mounting seats are provided in the mounting cavity, and the two mounting seats are respectively provided with mounting holes, wherein the axes of the two mounting holes coincide with each other, and each mounting hole penetrates the housing along the axis in a direction away from the other mounting hole; when the intermediate shaft system passes through the mounting opening and enters the mounting cavity, the mounting hole is used for the intermediate shaft bearing to be installed from the outside of the housing to one axial end of the intermediate shaft. By providing two mounting holes, and making each mounting hole penetrate the housing along the axis, the intermediate shaft bearing can be installed from the outside of the mounting hole, and the intermediate shaft system as a whole can be installed in the mounting cavity first, so that the intermediate shaft system can be installed in the mounting cavity with a higher coaxiality, and the NVH performance of the reducer as a whole can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of automobile parts, and more specifically, to a reducer housing and a reducer. Background Art

[0002] The reducer plays a huge role in the process of automobile power transmission. When the engine output power remains unchanged, the speed can be reduced to obtain greater torque and thus greater driving force.

[0003] The reducer housing in the automobile often adopts an integral structure. During the assembly process of the existing integral structure, it is necessary to install a shaft system with an intermediate shaft, which includes an intermediate shaft, a primary driven gear and a secondary driving gear. Since the overall size of the primary driven gear is relatively large and both ends of the intermediate shaft need to cooperate with the intermediate shaft bearing, the primary driven gear cannot be installed into the installation cavity in the reducer housing as a whole with the intermediate shaft, but needs to be installed separately. The traditional installation method is to first install the primary driven gear into the installation cavity, and then press the intermediate shaft axially from the side so that the intermediate shaft and the primary driven gear are coaxially fixed. However, there is a major defect in this method. Since the intermediate shaft is pressed into the center hole of the primary driven gear from the side, it is usually necessary to apply several tons of pressure to press the intermediate shaft into the primary driven gear and the intermediate shaft bearing. In this way, it is difficult to ensure the coaxiality between the intermediate shaft and the primary driven gear and the intermediate shaft bearing, resulting in poor NVH performance of the reducer as a whole, which needs to be improved. Summary of the invention

[0004] In order to improve the overall NVH performance of the reducer, the present application provides a reducer housing and a reducer.

[0005] The present application provides a reducer housing and a reducer, which adopt the following technical solutions:

[0006] A reducer housing, comprising a housing, the housing being provided with a mounting cavity and a mounting opening communicating with the mounting cavity, the mounting opening being used for the intermediate shaft system to pass through, the mounting cavity being used for accommodating the intermediate shaft system, two mounting seats being provided in the mounting cavity, the two mounting seats being respectively provided with mounting holes for mounting the intermediate shaft bearing, the axes of the two mounting holes being coincident with each other, and each mounting hole penetrating the housing along the axis in a direction away from the other mounting hole;

[0007] When the intermediate shaft system passes through the installation opening and enters the installation cavity, the installation hole is used for the intermediate shaft bearing to be installed from the outside of the housing to one axial end of the intermediate shaft.

[0008] Through the above technical scheme, two mounting holes are provided, and each mounting hole passes through the shell along the axis, so that the intermediate shaft bearing can be axially installed into the mounting hole from the outside of the shell, and then the intermediate shaft bearing does not need to be assembled before the intermediate shaft system, but after the intermediate shaft system is installed in the installation cavity, the intermediate shaft bearing is pressed into the two mounting holes from the two outsides of the shell respectively, so that the two intermediate shaft bearings are matched with the two ends of the intermediate shaft. Since the intermediate shaft system can be directly installed at one time, the intermediate shaft system can be integrally formed or pressed before the outside, so that the intermediate shaft system can be installed in the installation cavity with higher coaxiality and intermediate shaft system accuracy, thereby improving the overall NVH performance of the reducer.

[0009] Optionally, at least one of the mounting seats is provided with a through groove, and the through groove opening on each mounting seat is arranged toward the other mounting seat. The through groove is located on the side of the mounting hole close to the mounting opening, and the through groove completely penetrates the mounting seat from the mounting opening to the mounting hole and is connected with the mounting hole. The through groove is used for the intermediate shaft to pass through.

[0010] Through the above technical solution, the through groove is provided, so that when the intermediate shaft is installed into the installation cavity, the axis of the intermediate shaft and the axis of the installation hole can be kept parallel, and the intermediate shaft can be installed into the installation cavity without an inclination angle. After entering the installation cavity, the position of the intermediate shaft system is adjusted axially, so that the two ends of the intermediate shaft can be respectively extended into the two installation holes, thereby improving the convenience of installing the intermediate shaft into the installation cavity;

[0011] Furthermore, since the intermediate shaft can be installed in the installation cavity without tilting an angle, the installation cavity structure can be arranged more compactly, and the adjustment space of the overall structure is larger, and the adaptability is better.

[0012] Optionally, both mounting seats are provided with a through groove.

[0013] Through the above technical solution, through grooves are provided on both mounting seats, making it more convenient to install the intermediate shaft.

[0014] Optionally, the housing is further provided with two output shaft bearing seats, the distribution direction between the two output shaft bearing seats is parallel to the distribution direction of the two mounting seats, and the mounting opening is provided between the two output shaft bearing seats;

[0015] Each of the output shaft bearing seats comprises a first splicing seat and a second splicing seat, wherein the first splicing seat is fixed to the housing, the second splicing seat is connected to the first splicing seat by bolts, the first splicing seat is provided with a first splicing half hole, the second splicing seat is provided with a second splicing half hole, and the first splicing half hole and the second splicing half hole are spliced ​​into an output bearing hole for installing the output shaft bearing;

[0016] The two through grooves are respectively connected to the two first splicing half holes.

[0017] Through the above technical solution, two through grooves are set to be connected with the two first splicing half holes respectively, and the two ends of the intermediate shaft can enter the installation cavity through the through grooves connected with the two first splicing half holes, so that the positions of the two first splicing seats can be consistent with the two installation seats. The position adjustment space of the two first splicing seats is relatively large, allowing the overall structural design of the shell to be more compact and reduce the overall volume of the shell.

[0018] Optionally, the two mounting seats and the two first splicing seats are integrally formed with the shell.

[0019] Through the above technical solution, the housing, two mounting seats, and two first splicing seats are all formed in one piece. The coaxiality between the two mounting holes and the coaxiality between the two output bearing holes can be controlled during the processing of the housing. Compared with the later assembly method, the coaxiality of the two mounting holes and the coaxiality of the two output bearing holes processed in one piece are higher, which can effectively improve the coaxiality of the intermediate shaft system after installation and the coaxiality of the output shaft after installation, thereby improving the overall NVH performance of the reducer.

[0020] A reducer, comprising any of the reducer housings described above;

[0021] It also includes an intermediate shaft system and two intermediate shaft bearings, wherein the intermediate shaft system is located in the mounting cavity, and the two intermediate shaft bearings are respectively mounted in two mounting holes;

[0022] The intermediate shaft system comprises a primary driven gear, a secondary driving gear and an intermediate shaft which are coaxially arranged, and two ends of the intermediate shaft are coaxially connected to two intermediate shaft bearings respectively.

[0023] Through the above technical solution, the overall NVH performance of the reducer is improved.

[0024] Optionally, the diameter of the mounting hole is larger than the diameter of the tooth top circle of the secondary driving gear.

[0025] Through the above technical solution, the diameter of the mounting hole is set to be larger than the tooth top circle diameter of the secondary driving gear. When the intermediate shaft bearing is not installed in place, the secondary driving gear can be pushed axially so that the secondary driving gear is pushed into the mounting hole. During the process of the secondary driving gear being pushed into the mounting hole, the intermediate shaft bearings in the two mounting holes will also be pushed out, which facilitates the removal of the intermediate shaft bearing and the intermediate shaft system from the housing, thereby improving the convenience of removing the intermediate shaft system and the intermediate shaft bearing.

[0026] Optionally, the axial length of each intermediate shaft bearing is smaller than the axial depth of any mounting hole;

[0027] An oil seal cover is coaxially embedded in each mounting hole. The two oil seal covers are respectively located on two sides of two intermediate shaft bearings that are away from each other. The oil seal covers are used to cover the mounting holes.

[0028] Through the above technical solution, an oil seal cover is provided to improve the sealing performance of the intermediate shaft bearing when it is installed in the installation hole;

[0029] And because the axial length of each intermediate shaft bearing is smaller than the axial depth of any mounting hole, a certain space is left outside the mounting hole, which is convenient for the tooling used to eject the intermediate shaft bearing to enter the mounting hole for rapid positioning.

[0030] Optionally, two ends of the intermediate shaft are respectively flush with two end surfaces of two intermediate shaft bearings that are away from each other.

[0031] Through the above technical scheme, during the press-fitting process of the intermediate shaft bearing and the intermediate shaft, the inner ring and the outer ring of the intermediate shaft bearing can be press-fitted synchronously in the axial direction, effectively avoiding the axial relative displacement of the inner ring and the outer ring of the intermediate shaft bearing due to the asynchronous press-fitting of the inner ring and the outer ring during the press-fitting process, thereby reducing the damage of the intermediate shaft bearing during the installation process and improving the yield rate of the overall assembly of the reducer.

[0032] In summary, the present application includes at least one of the following beneficial technical effects:

[0033] (1) By setting two mounting holes, and making each mounting hole penetrate the housing along the axis, the intermediate shaft bearing can be installed from the outside of the mounting hole, and then the intermediate shaft system as a whole can be installed in the mounting cavity first, and then the intermediate shaft bearings at both ends can be installed. Compared with the traditional installation method of first installing the primary driven gear and then installing the intermediate shaft, the installation method of first processing the intermediate shaft system on the outside and then installing it as a whole in the mounting cavity can better ensure a higher coaxiality and intermediate shaft system accuracy, and effectively improve the overall NVH performance of the reducer;

[0034] (2) By providing the through groove, when the intermediate shaft system is installed into the installation cavity as a whole, the axis of the intermediate shaft can be kept parallel to the axis of the installation hole and the intermediate shaft can be installed into the installation cavity without tilting the intermediate shaft. Moreover, the intermediate shaft system only needs to adjust the axial position when entering the installation cavity, thereby improving the convenience of installing the intermediate shaft system into the installation cavity;

[0035] (3) By arranging the housing, the two mounting seats, and the two first splicing seats to be integrally formed, the coaxiality between the two mounting holes and the coaxiality between the two output bearing holes can be controlled during the processing of the housing. Compared with the later assembly method, the coaxiality of the two mounting holes and the coaxiality of the two output bearing holes processed in one piece are higher, which can effectively improve the coaxiality of the intermediate shaft system after installation and the coaxiality of the output shaft after installation, and further improve the overall NVH performance of the reducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the reducer housing structure of this embodiment.

[0037] Figure 2 It is a schematic cross-sectional view of the reducer housing structure of this embodiment.

[0038] Figure 3 Schematic diagram of the overall structure of the reducer of this embodiment.

[0039] Figure 4 It is a schematic cross-sectional view of the overall structure of the reducer of this embodiment.

[0040] Figure numerals: 1. housing; 2. input cavity; 3. mounting cavity; 4. input hole; 5. mounting opening; 6. mounting seat; 7. mounting hole; 8. through groove; 9. output shaft bearing seat; 91. first splicing seat; 92. second splicing seat; 10. output bearing hole; 101. first splicing half hole; 102. second splicing half hole; 11. input shaft system; 111. input shaft; 112. primary driving gear; 12. input shaft bearing; 13. intermediate shaft system; 131. intermediate shaft; 132. primary driven gear; 133. secondary driving gear; 14. intermediate shaft bearing; 15. oil seal cover. DETAILED DESCRIPTION

[0041] The present application is further described in detail below in conjunction with the accompanying drawings.

[0042] An embodiment of the present application discloses a reducer housing.

[0043] Reference Figure 1 and Figure 2 , including a housing 1, the housing 1 is provided with an input chamber 2 and a mounting chamber 3 which are connected to each other, the input chamber 2 is used to install an input shaft 111 and a primary driving gear 112 fixed on the input shaft 111, and the mounting chamber 3 is used to install an intermediate shaft system 13. An input hole 4 connected to the input chamber 2 is provided on the side wall of the housing 1. The housing 1 is also provided with a mounting opening 5 connected to the mounting chamber 3, and the mounting opening 5 is located at one end of the mounting chamber 3 away from the input chamber 2.

[0044] Reference Figure 2 Two mounting seats 6 are integrally arranged in the mounting cavity 3 . The two mounting seats 6 are respectively located on two opposite inner walls of the mounting cavity 3 , and the distribution direction of the two mounting seats 6 is parallel to the axial direction of the input hole 4 .

[0045] Reference Figure 2Each mounting seat 6 is provided with a mounting hole 7, and the axial direction of each mounting hole 7 is arranged parallel to the axial direction of the input hole 4, and the axes of the two mounting holes 7 coincide. Each mounting hole 7 completely penetrates the housing 1 along the axial direction, so that the outer side of the housing 1 is connected with the mounting cavity 3 through the mounting hole 7.

[0046] Reference Figure 2 , through grooves 8 are respectively opened at the opposite ends of the two mounting seats 6, and the through grooves 8 on each mounting seat 6 are arranged between the mounting hole 7 and the mounting opening 5. Each through groove 8 passes through the mounting seat 6 from the mounting opening 5 to the mounting hole 7, so that the two through grooves 8 are respectively connected to the two mounting holes 7.

[0047] Reference Figure 1 and Figure 2 The housing 1 is provided with two output shaft bearing seats 9, and the two output shaft bearing seats 9 are located at one end of the mounting cavity 3 away from the input cavity 2. The distribution direction between the two output shaft bearing seats 9 is arranged parallel to the distribution direction of the two mounting seats 6. The mounting opening 5 is arranged between the two output shaft bearing seats 9.

[0048] Reference Figure 1 and Figure 2 Each output shaft bearing seat 9 includes a first splicing seat 91 and a second splicing seat 92. The first splicing seat 91 is integrally formed with the housing 1, and the second splicing seat 92 is fixed to the first splicing seat 91 by bolts. A first splicing half hole 101 is provided at one end of the first splicing seat 91 away from the housing 1, and a second splicing half hole 102 is provided on the second splicing seat 92 to match the first splicing half hole 101. The first splicing half hole 101 and the second splicing half hole 102 are spliced ​​together to form an output bearing hole 10. The axial direction of the output bearing hole 10 is parallel to the axial direction of the mounting hole 7. The output bearing hole 10 is used for mounting the output shaft bearing.

[0049] Reference Figure 1 and Figure 2 The first splicing seat 91 axially away from one end of the input hole 4 is formed by the mounting seat 6 axially away from one end of the input hole 4 extending out of the housing 1 in the direction close to the mounting opening 5. The first splicing seat 91 axially close to one end of the input hole 4 and the mounting seat 6 axially close to one end of the input hole 4 are staggered in the axial direction. The spacing between the two first splicing seats 91 is greater than the spacing between the two mounting seats 6. The two through grooves 8 penetrate the inner hole walls of the two first splicing half holes 101 respectively.

[0050] The embodiment of the present application also discloses a reducer.

[0051] Reference Figure 3 and Figure 4 An input shaft system 11 is installed in the input cavity 2, and an intermediate shaft system 13 is installed in the installation cavity 3.

[0052] Reference Figure 3 and Figure 4 The input shaft system 11 includes an input shaft 111 and a primary driving gear 112 coaxially fixed with the input shaft 111. The input shaft 111 bearing is coaxially installed in the input hole 4. The input shaft 111 is coaxially connected with the input shaft 111 bearing. One end of the input shaft 111 extends to the outside of the housing 1 through the input hole 4. The top circle diameter of the primary driving gear 112 is smaller than the diameter of the input hole 4. In the actual installation process, the input shaft system 11 can be pressed into the input cavity 2 from the input hole 4 along the axial direction as a whole.

[0053] Reference Figure 3 and Figure 4 The intermediate shaft system 13 includes an intermediate shaft 131 and a primary driven gear 132 and a secondary driving gear 133 coaxially fixed to the intermediate shaft 131. An intermediate shaft bearing 14 is coaxially installed in each mounting hole 7, and the two ends of the intermediate shaft 131 are coaxially connected to the two intermediate shaft bearings 14 respectively. The secondary driving gear 133 is axially located on the side close to the input hole 4, and the tooth top circle diameter of the secondary driving gear 133 is smaller than the diameter of the mounting hole 7. The primary driven gear 132 is axially located on the side away from the input hole 4, and the primary driven gear 132 is meshed with the primary driving gear 112. The number of teeth of the primary driven gear 132 is greater than the number of teeth of the primary driving gear 112, and the tooth top circle diameter of the primary driven gear 132 is greater than the tooth top circle diameter of the primary driving gear 112.

[0054] Reference Figure 3 and Figure 4 , the axial length of the intermediate shaft 131 is less than or equal to the distance between the bottoms of the two through grooves 8, and the diameter of the intermediate shaft 131 is less than or equal to the distance between the opposite side walls of the through grooves 8. The distance between the two ends of the primary driven gear 132 and the secondary driving gear 133 that are away from each other is less than the distance between the opposite ends of the two mounting seats 6. Therefore, in the actual installation process, the two ends of the intermediate shaft 131 can directly enter the two mounting holes 7 through the two through grooves 8 respectively, and the primary driven gear 132 and the secondary driving gear 133 can enter the mounting cavity 3 together with the intermediate shaft 131, thereby improving the convenience of installing the intermediate shaft system 13 into the mounting cavity 3.

[0055] Reference Figure 3 and Figure 4 The end faces of the two intermediate shaft bearings 14 that face away from each other are flush with the axial ends of the intermediate shaft 131. The axial length of each intermediate shaft bearing 14 is less than the axial depth of the mounting hole 7. And the spacing between the end faces of the two intermediate shaft bearings 14 that face away from each other is less than the spacing between the outermost sides of the two mounting holes 7. When the intermediate shaft bearing 14 needs to be removed from the mounting hole 7, one end of the outer side of the mounting hole 7 can be inserted into the tooling used to eject the intermediate shaft bearing 14 to facilitate the positioning of the tooling.

[0056] Reference Figure 3 and Figure 4 An oil seal cover 15 is embedded in each mounting hole 7 . The two oil seal covers 15 are respectively located on two sides of the two intermediate shaft bearings 14 that are away from each other. The oil seal covers 15 are used to cover the mounting holes 7 to improve the sealing performance of the mounting holes 7 .

[0057] Reference Figure 3 and Figure 4 The steps for installing the intermediate shaft system 13 and the intermediate shaft bearing 14 are as follows: first, install the intermediate shaft system 13 as a whole from the installation opening 5, so that the two ends of the intermediate shaft 131 respectively enter the two installation holes 7 through the two through grooves 8, so that the intermediate shaft system 13 as a whole enters the installation cavity 3, and then press the two intermediate shaft bearings 14 axially into the two installation holes 7 from the outside of the two installation holes 7, so that the two intermediate shaft bearings 14 are coaxially connected to the two ends of the intermediate shaft 131 respectively.

[0058] Reference Figure 3 and Figure 4 Since the intermediate shaft system 13 can be directly integrated into the installation cavity 3, the intermediate shaft 131, the first-stage driven gear 132 and the second-stage driving gear 133 can be directly integrated or press-fitted externally before being installed into the installation cavity 3. After the intermediate shaft system 13 is processed externally so that the intermediate shaft system 13 has a higher coaxiality and intermediate shaft system accuracy as a whole, it can be installed into the cavity of the installation cavity 3 to improve the overall NVH performance of the reducer.

[0059] Reference Figure 3 and Figure 4 Since the output shaft bearing seat 9 is formed by splicing the first splicing seat 91 and the second splicing seat 92, and the inner hole walls of the two first splicing half holes 101 are respectively connected to the two through grooves 8, before installing the intermediate shaft system 13, the two second splicing seats 92 can be removed from the two first splicing seats 91 respectively, so that the two ends of the intermediate shaft 131 can enter the two through grooves 8 respectively. Therefore, in the actual design process, even if the two output shaft bearing seats 9 are not axially offset from the two mounting seats 6, the two second splicing seats 92 can be removed so that the intermediate shaft system 13 can enter the mounting cavity 3, meeting the size requirement of the mounting opening 5 required for the intermediate shaft system 13 to enter the mounting cavity 3. Therefore, the housing 1 as a whole can be set more compactly according to actual needs, and the volume of the housing 1 as a whole will not be increased.

[0060] Reference Figure 3 and Figure 4Since the two intermediate shaft bearings 14 are respectively installed into the mounting hole 7 from the outside of the two mounting holes 7, each intermediate shaft bearing 14 can be press-fitted by an integrated press-fitting method, that is, the inner ring and the outer ring of the intermediate shaft bearing 14 are synchronously pressed into the mounting hole 7 along the axial direction. Compared with the traditional installation method of first installing the intermediate shaft bearing 14 into the mounting hole 7 and then press-fitting the intermediate shaft 131, the installation method of synchronously pressing the inner ring and the outer ring of the intermediate shaft bearing 14 along the axial direction causes less damage to the intermediate shaft bearing 14, and the stability and precision of the intermediate shaft bearing 14 after being installed into the mounting hole 7 and matched with the intermediate shaft 131 are higher.

[0061] The working principle of this embodiment is: two mounting holes 7 are set to pass through the shell 1 along the axis, and a mounting opening 5 and two through grooves 8 are set, so that the intermediate shaft system 13 can be installed in the mounting cavity 3 in an integrated manner, without the need to first install the primary driven gear 132 and then press the intermediate shaft system 13 from the side. Furthermore, when the intermediate shaft system 13 is installed in the mounting cavity 3 and cooperates with the two intermediate shaft bearings 14, the coaxiality between the intermediate shaft system 13 and the two intermediate shaft bearings 14 is higher, thereby improving the overall NVH performance.

[0062] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A reducer housing, comprising a housing (1), characterized in that: The housing (1) is provided with a mounting cavity (3) and a mounting opening (5) connected to the mounting cavity (3); the mounting opening (5) is used for allowing an intermediate shaft system (13) to pass through; the mounting cavity (3) is used for accommodating the intermediate shaft system (13); two mounting seats (6) are provided in the mounting cavity (3); the two mounting seats (6) are respectively provided with mounting holes (7) for mounting intermediate shaft bearings (14); the axes of the two mounting holes (7) coincide with each other; each mounting hole (7) penetrates the housing (1) along the axis in a direction away from the other mounting hole (7); When the intermediate shaft system (13) passes through the installation opening (5) and enters the installation cavity (3), the installation hole (7) is used for the intermediate shaft bearing (14) to be installed from the outside of the housing (1) to one axial end of the intermediate shaft (131); At least one of the mounting seats (6) is provided with a through groove (8), the through groove (8) on each mounting seat (6) is arranged to face the other mounting seat (6), the through groove (8) is located on a side of the mounting hole (7) close to the mounting opening (5), the through groove (8) completely penetrates the mounting seat (6) from the mounting opening (5) to the mounting hole (7) and is connected to the mounting hole (7), and the through groove (8) is used for allowing the intermediate shaft (131) to pass through; The two mounting seats (6) are both provided with a through slot (8); The housing (1) is further provided with two output shaft bearing seats (9), the distribution direction between the two output shaft bearing seats (9) is parallel to the distribution direction of the two mounting seats (6), and the mounting opening (5) is provided between the two output shaft bearing seats (9); Each of the output shaft bearing seats (9) comprises a first splicing seat (91) and a second splicing seat (92), wherein the first splicing seat (91) is fixed to the housing (1), and the second splicing seat (92) is connected to the first splicing seat (91) by bolts, the first splicing seat (91) is provided with a first splicing half hole (101), and the second splicing seat (92) is provided with a second splicing half hole (102), and the first splicing half hole (101) and the second splicing half hole (102) are spliced ​​to form an output bearing hole (10) for mounting the output shaft bearing; The two through grooves (8) are respectively connected to the two first splicing half holes (101).

2. A reducer housing according to claim 1, characterized in that: The two mounting seats (6) and the two first splicing seats (91) are integrally formed with the shell (1).

3. A reducer, characterized in that: A reducer housing comprising any one of claims 1 to 2; It also includes an intermediate shaft system (13) and two intermediate shaft bearings (14), wherein the intermediate shaft system (13) is located in the mounting cavity (3), and the two intermediate shaft bearings (14) are respectively mounted in two mounting holes (7); The intermediate shaft system (13) comprises a primary driven gear (132), a secondary driving gear (133) and an intermediate shaft (131) which are coaxially arranged, and two ends of the intermediate shaft (131) are coaxially connected to two intermediate shaft bearings (14) respectively.

4. A reducer according to claim 3, characterized in that: The diameter of the mounting hole (7) is greater than the diameter of the tooth top circle of the secondary driving gear (133).

5. A reducer according to claim 4, characterized in that: The axial length of each intermediate shaft bearing (14) is smaller than the axial depth of any mounting hole (7); An oil seal cover (15) is coaxially embedded in each mounting hole (7), and the two oil seal covers (15) are respectively located on two sides of two intermediate shaft bearings (14) that are away from each other. The oil seal covers (15) are used to cover the mounting holes (7).

6. A reducer according to claim 4, characterized in that: The two ends of the intermediate shaft (131) are respectively flush with two end surfaces of the two intermediate shaft bearings (14) that are away from each other.

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