Intermediate shaft gear assembly and speed reducer

Abstract

The utility model provides an intermediate shaft gear assembly and a speed reducer, the intermediate shaft gear assembly is used for the speed reducer of a vehicle, and the intermediate shaft gear assembly comprises an intermediate shaft, a first gear, a second gear and an annular buffer part. The first gear is pressed on the intermediate shaft; the second gear is pressed on the intermediate shaft, the second gear is arranged on one side of the first gear in the axial direction of the intermediate shaft, and the addendum circle radius of the second gear is smaller than that of the first gear; the annular buffering piece is connected between the first rim of the first gear and the second rim of the second gear in an abutting mode in the axial direction, and the annular buffering piece is used for relieving press-fitting impact transmitted to the second gear by the first gear in the axial direction. In this way, the manufacturing difficulty and manufacturing cost of the intermediate shaft gear assembly can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of reducers of new energy vehicles, and in particular to an intermediate shaft gear assembly and a reducer. BACKGROUND

[0002] In the current field of new energy vehicles, in order to transmit smoothly, gears are mostly helical gears. The intermediate shaft gear assembly is an important transmission assembly in the reducer of a new energy vehicle. In the intermediate shaft gear assembly, the intermediate shaft gear needs to bear not only radial force and circumferential force but also axial force when meshing, and a backup safety factor is considered in the design. The interference amount required between the intermediate shaft gear and the intermediate shaft is large. The existing assembly process of the intermediate shaft gear assembly has a large influence on the helix angle deviation of the intermediate shaft pinion, resulting in a large manufacturing cost and difficulty of the intermediate shaft gear assembly. CONTENT OF THE UTILITY MODEL

[0003] The present application provides an intermediate shaft gear assembly for a reducer of a vehicle. The intermediate shaft gear assembly comprises an intermediate shaft, a first gear, a second gear and an annular buffer. The first gear is press-fitted on the intermediate shaft. The second gear is press-fitted on the intermediate shaft, and is arranged on one side of the first gear along the axial direction of the intermediate shaft. The addendum circle radius of the second gear is smaller than that of the first gear. The annular buffer is abutted between the first rim of the first gear and the second rim of the second gear along the axial direction, and is used to alleviate the press-fitting impact of the first gear transmitted to the second gear along the axial direction.

[0004] In some embodiments, the second rim extends a buffer portion protruding relative to the gear teeth of the second gear along the axial direction, and the buffer portion serves as the annular buffer.

[0005] In some embodiments, the buffer portion comprises a first annular portion and a second annular portion. One end of the first annular portion along the axial direction is abutted with the first rim, and the other end is connected with the second annular portion. One end of the second annular portion along the axial direction, which is away from the first annular portion, is connected with the second rim. In the radial direction of the intermediate shaft, the first outer circle diameter of the first annular portion is greater than the second outer circle diameter of the second annular portion.

[0006] In some embodiments, the width dimension of the first annular portion along the axial direction is greater than or equal to 3mm.

[0007] In some embodiments, the width dimension of the second annular portion along the axial direction is greater than or equal to 2mm.

[0008] In some embodiments, the second outer circle diameter is smaller than the dedendum circle diameter of the second gear.

[0009] In some embodiments, the ratio of the width dimension of the first annular portion along the axial direction to the width dimension of the second annular portion along the axial direction is greater than or equal to 1 and less than or equal to 1.5.

[0010] In some embodiments, the first rim is provided with a first assembly hole matched with the intermediate shaft, and the second rim is provided with a second assembly hole matched with the intermediate shaft, and the radial dimension of the first assembly hole is equal to that of the second assembly hole.

[0011] In some embodiments, the first gear is a disc gear structure, and the second gear is a shaft gear structure.

[0012] The application also provides a speed reducer comprising the intermediate shaft gear assembly described in any of the above embodiments.

[0013] The intermediate shaft gear assembly provided by the application is used in a speed reducer of a vehicle, and comprises an intermediate shaft, a first gear, a second gear and an annular buffer. The first gear is press-fitted on the intermediate shaft, and the second gear is press-fitted on the intermediate shaft and arranged on one side of the first gear along the axial direction of the intermediate shaft. The addendum circle radius of the second gear is smaller than that of the first gear. The annular buffer is abutted between the first rim of the first gear and the second rim of the second gear along the axial direction, and is used to reduce the press-fitting impact of the first gear transmitted to the second gear along the axial direction. During the press-fitting process, the annular buffer can reduce the press-fitting impact of the first gear transmitted to the second gear along the axial direction, in other words, the annular buffer plays a role of force relief during the press-fitting process, so that the press-fitting force transmitted from the first gear to the second gear can be reduced, thereby effectively reducing the influence of the press-fitting process on the helix angle deviation of the second gear. Therefore, during gear grinding, the gear precision of the second gear can be directly ground according to the required value in the drawing, and only the effective gear precision of the second gear needs to be ensured, without considering the influence of press-fitting on the gear precision. In other words, by arranging the annular buffer between the first gear and the second gear, the press-fitting test is not required before the gear grinding of the second gear, thereby effectively reducing the manufacturing difficulty of the second gear, and further effectively reducing the manufacturing difficulty and cost of the intermediate shaft gear assembly. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a structural schematic view of an embodiment of the intermediate shaft gear assembly of the application;

[0015] Figure 2 is Figure 1 is an enlarged structural schematic view of the partial A of the intermediate shaft gear assembly shown in FIG. 1. DETAILED DESCRIPTION

[0016] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of the present application.

[0017] The terms "first", "second" in the present application are only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited. In addition, the terms "include" and "have" and any variations thereof are intended to cover exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units not listed, or optionally also includes other steps or units inherent to the process, method, product or device.

[0018] As shown in Figure 1 The present application provides an intermediate shaft 100 gear assembly 10 for a reducer of a vehicle, wherein the intermediate shaft 100 gear assembly 10 of the present application is mainly applied to the reducer of a new energy vehicle, of course, in other embodiments, the intermediate shaft 100 gear assembly 10 can also be applied to the reducer in other technical fields, which will not be described in detail here, and the intermediate shaft 100 gear assembly 10 of the present application will be described mainly in the application of the reducer of a new energy vehicle.

[0019] The intermediate shaft 100 gear assembly 10 comprises: an intermediate shaft 100, a first gear 300, a second gear 200 and an annular buffer 400. The first gear 300 is press-fitted on the intermediate shaft 100; the second gear 200 is press-fitted on the intermediate shaft 100, and the second gear 200 is arranged on one side of the first gear 300 along the axial direction x1 of the intermediate shaft 100, and the addendum circle radius of the second gear 200 is smaller than that of the first gear 300; the annular buffer 400 abuts between the first rim (not marked in the figure) of the first gear 300 and the second rim (not marked in the figure) of the second gear 200 along the axial direction x1, and the annular buffer 400 is used to reduce the press-fitting impact of the first gear 300 transmitted to the second gear 200 along the axial direction x1.

[0020] Specifically, the addendum circle radius of the second gear 200 is smaller than the addendum circle radius of the first gear 300, which can be understood that the second gear 200 is a smaller intermediate shaft 100 pinion in the intermediate shaft 100 gear assembly 10 relative to the first gear 300, and the first gear 300 is a larger intermediate shaft 100 gear in the intermediate shaft 100 gear assembly 10 relative to the second gear 200. Wherein, in this paper, the area between the root circle of the gear and the hole wall of the assembly hole of the gear is the rim of the gear (in this paper, the rim of the first gear 300 is called the first rim, and the rim of the second gear 200 is called the second rim).

[0021] The first gear 300 and the second gear 200 can be connected with the intermediate shaft 100 by interference fit to realize torque transmission. In the field of new energy vehicles, in order to transmit smoothly, helical gears are often used for gears, and the intermediate shaft gears (including the first gear 300 and the second gear 200) not only need to bear radial force and circumferential force when meshing, but also bear additional axial x1 force, and the backup safety factor is considered in design, and the interference amount required between the first gear 300 and the intermediate shaft 100 is large. When the first gear 300 and the intermediate shaft 100 are press-fitted, the first gear 300 will bear a large press-fitting force and deform, especially the helix angle deviation of the second gear 200, which may change by a certain amount after the press-fitting process and be out of tolerance, resulting in assembly scrap. In order to avoid the influence of the interference fit press-fitting of the first gear 300 and the intermediate shaft 100 on the helix angle deviation of the second gear 200, the existing process must be subjected to a "press-fitting test" before the gear grinding of the second gear 200. A large amount of data is collected and summarized for the change of the helix angle deviation of the second gear 200 before and after press-fitting, and a "change amount" is obtained. Then, according to the "change amount", the gear grinding process of the second gear 200 is "pre-adjusted and corrected" to ensure that the helix angle deviation of the second gear 200 meets the requirements after the press-fitting process. The "press-fitting test" not only increases the cost investment and wastes resources, but also prolongs the production time and affects the delivery schedule. The "change amount" data collection and summary of "pre-adjustment and correction" is limited, and in mass production, due to the fact that the deformation range cannot be completely covered during actual production, there may still be out-of-tolerance, resulting in scrap of the intermediate shaft 100 gear assembly 10.

[0022] In this embodiment, an annular buffer 400 is provided between the first gear 300 and the second gear 200. The annular buffer 400 abuts between the first rim and the second rim. During the pressing process, the annular buffer 400 can reduce the pressing impact transmitted from the first gear 300 to the second gear 200 along the axial direction x1. In other words, during the pressing process, the annular buffer 400 plays a force-relieving role, which can reduce the pressing force transmitted from the first gear 300 to the second gear 200, thereby effectively reducing the impact of the pressing process on the helix angle deviation of the second gear 200. Based on this, during gear grinding, the gear precision of the second gear 200 can be directly ground according to the drawing requirements, and it is only necessary to ensure the effective gear precision of the second gear 200. There is no need to consider the impact of press fitting on the gear precision. In other words, by setting an annular buffer 400 between the first gear 300 and the second gear 200, it is not necessary to conduct a "press fitting test" before grinding the second gear 200, thereby effectively reducing the manufacturing difficulty of the second gear 200, and thus effectively reducing the manufacturing difficulty and cost of the intermediate shaft 100 gear assembly 10, and thus effectively reducing the manufacturing difficulty and cost of the reducer.

[0023] like Figure 1 and Figure 2 As shown, in some embodiments, the annular buffer 400 can be integrally formed with the second gear 200 as part of the second gear 200. Specifically, a buffer portion 410 is provided that protrudes from the second gear rim along the axial direction x1 relative to the teeth of the second gear 200, and the buffer portion 410 serves as the annular buffer 400.

[0024] like Figure 2 As shown, in some embodiments, the buffer portion 410 includes a first annular portion 420 and a second annular portion 430. One end of the first annular portion 420 along the axial direction x1 abuts against the first wheel rim, and the other end is connected to the second annular portion 430. The end of the second annular portion 430 along the axial direction x1 away from the first annular portion 420 is connected to the second wheel rim. In the radial direction of the intermediate shaft 100, the first outer diameter of the first annular portion 420 is larger than the second outer diameter of the second annular portion 430. In other words, the first outer diameter of the first annular portion 420 is larger than the second outer diameter of the second annular portion 430. This can be understood as the second annular portion 430 being recessed relative to the first annular portion 420 in the radial direction (radial direction of the second gear 200). This forms a groove structure 440 with a force-relieving effect between the first annular portion 420 and the second rim, making the axial x1 buffering effect of the buffer portion 410 more obvious. This effectively reduces the pressing force transmitted from the first gear 300 to the second gear 200, thereby effectively reducing the influence of the pressing process on the helix angle deviation of the second gear 200.

[0025] In some embodiments, the first annular portion 420 has a width dimension L1 along the axial direction x1 greater than or equal to 3 mm. Specifically, the first annular portion 420 is machined by a machining process, and the width dimension L1 of the first annular portion 420 along the axial direction x1 is set to be greater than or equal to 3 mm, for example, 3 mm, 4 mm, 5 mm, etc. In this way, the deformation of the gear tooth 200 can be effectively reduced.

[0026] In some embodiments, the second annular portion 430 has a width dimension L2 along the axial direction x1 greater than or equal to 2 mm. Specifically, the second annular portion 430 can be machined by a machining process, and the width dimension of the second annular portion 430 along the axial direction x1 is set to be greater than or equal to 2 mm, for example, 2 mm, 3 mm, 4 mm, 5 mm, etc. In this way, the machining difficulty of the second annular portion 430 can be effectively reduced.

[0027] In some embodiments, the ratio of the width dimension L1 of the first annular portion 420 along the axial direction x1 to the width dimension L2 of the second annular portion 430 along the axial direction x1 is greater than or equal to 1 and less than or equal to 1.5.

[0028] In some embodiments, the second outer diameter is less than the dedendum diameter of the second gear 200. Specifically, the second outer diameter is the maximum radial dimension of the second annular portion 430. Since the second annular portion 430 is directly connected to the second rim, if the second outer diameter is greater than or equal to the dedendum diameter, the pressing force transmitted by the second annular portion 430 will directly act on the gear tooth of the second gear 200, which will increase the probability of deformation of the gear tooth of the second gear 200 during the pressing process. Therefore, the second outer diameter is set to be less than the dedendum diameter of the second gear 200, which can effectively reduce the probability of deformation of the gear tooth of the second gear 200 during the pressing process.

[0029] In some embodiments, the first rim is provided with a first assembly hole (not labeled in the figure) matched with the intermediate shaft 100, and the second rim is provided with a second assembly hole (not labeled in the figure) matched with the intermediate shaft 100. The radial dimension of the first assembly hole is equal to the radial dimension of the second assembly hole. Specifically, the radial dimension of the first assembly hole is equal to the radial dimension of the second assembly hole, which can effectively reduce the machining difficulty of the intermediate shaft 100.

[0030] In some embodiments, the first gear 300 is a disc gear structure, and the second gear 200 is a shaft gear structure. The first gear 300 being a disc gear structure can be understood as the gear tooth of the first gear 300 being a disc gear structure, and the second gear 200 being a shaft gear structure can be understood as the gear tooth of the second gear 200 being a shaft gear structure.

[0031] Optionally, the first gear 300 and the second gear 200 can be matched with the intermediate shaft 100 by means of a spline interference fit or an outer circle interference fit.

[0032] The application also provides a speed reducer, which comprises the intermediate shaft 100 gear assembly 10 described in any of the above embodiments.

[0033] In summary, the intermediate shaft 100 gear assembly 10 provided by the application is provided with the annular buffer 400 between the first gear 300 and the second gear 200, the annular buffer 400 abuts between the first rim and the second rim, during the pressing process, the annular buffer 400 can slow down the pressing impact of the first gear 300 transmitted to the second gear 200 along the axial direction x1, in other words, during the pressing process, the annular buffer 400 plays a role in force relief, which can reduce the pressing force transmitted by the first gear 300 to the second gear 200, thereby effectively reducing the influence of the pressing process on the spiral angle deviation of the second gear 200. Based on this, during gear grinding, the gear precision of the second gear 200 can be directly ground according to the required value of the drawing, and only the effective gear precision of the second gear 200 needs to be ensured, without considering the influence of the pressing fit on the gear precision, in other words, by arranging the annular buffer 400 between the first gear 300 and the second gear 200, it is not necessary to perform the “pressing test” before the gear grinding of the second gear 200, thereby effectively reducing the manufacturing difficulty of the second gear 200, and further effectively reducing the manufacturing difficulty and manufacturing cost of the intermediate shaft 100 gear assembly 10.

[0034] It is worth noting that the drawings in the present application are only used to show the structural relationship and connection relationship of the utility model product, and do not limit the specific structural size of the utility model product.

[0035] The above is only the embodiment of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the protection range of the utility model patent.

Claims

1. An intermediate shaft gear assembly characterized by, A decelerator for a vehicle, the intermediate shaft gear assembly comprising: an intermediate shaft; a first gear press-fitted to the intermediate shaft; a second gear press-fitted to the intermediate shaft, the second gear being disposed on one side of the first gear along an axial direction of the intermediate shaft, a tip circle radius of the second gear being smaller than a tip circle radius of the first gear; a ring-shaped buffer abutting between a first rim of the first gear and a second rim of the second gear along the axial direction, the ring-shaped buffer being configured to mitigate press-fitting impact of the first gear transmitted to the second gear along the axial direction.

2. The intermediate shaft gear assembly of claim 1, wherein, the second rim is provided with a buffer portion protruding along the axial direction relative to a tooth of the second gear, the buffer portion serving as the ring-shaped buffer.

3. The intermediate shaft gear assembly of claim 2, wherein, the buffer portion comprises a first ring-shaped portion and a second ring-shaped portion, one end of the first ring-shaped portion abutting the first rim along the axial direction and the other end connected to the second ring-shaped portion, one end of the second ring-shaped portion connected to the second rim and the other end away from the first ring-shaped portion along the axial direction, wherein, along a radial direction of the intermediate shaft, a first outer circle diameter of the first ring-shaped portion is greater than a second outer circle diameter of the second ring-shaped portion.

4. The intermediate shaft gear assembly of claim 3, wherein, a width dimension of the first ring-shaped portion along the axial direction is greater than or equal to 3mm.

5. The intermediate shaft gear assembly of claim 3, wherein, a width dimension of the second ring-shaped portion along the axial direction is greater than or equal to 2mm.

6. The intermediate shaft gear assembly of claim 3, wherein, the second outer circle diameter is smaller than a dedendum circle diameter of the second gear.

7. The intermediate shaft gear assembly of claim 3, wherein, a ratio of the width dimension of the first ring-shaped portion along the axial direction to the width dimension of the second ring-shaped portion along the axial direction is greater than or equal to 1 and less than or equal to 1.

5.

8. The intermediate shaft gear assembly of claim 1, wherein, the first rim is provided with a first fitting hole configured to cooperate with the intermediate shaft, and the second rim is provided with a second fitting hole configured to cooperate with the intermediate shaft, a radial dimension of the first fitting hole being equal to a radial dimension of the second fitting hole.

9. The intermediate shaft gear assembly of claim 1, wherein, the first gear is a disc gear, and the second gear is a shaft gear.

10. A speed reducer characterized by, an intermediate shaft gear assembly according to any one of claims 1-9.

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