A double gear assembly and gear box

Abstract

The utility model discloses a duplex gear assembly and gear box, it includes: duplex gear, bearing, gear shaft. Among them, duplex gear is along duplex gear's axial direction, is equipped with first center hole and second center hole, first center hole and second center hole coaxial and through -going arrangement. Bearing is located in second center hole, and bearing includes inner ring and outer ring, and the inner wall of second center hole is with the outer ring interference fit. Gear shaft penetrates first center hole and inner ring in proper order, and is equipped with the gap between gear shaft and first center hole, and is with inner ring interference fit. The utility model can solve the problem of axial excursion of the duplex gear of existing.

Description

Technical Field

[0001] This utility model relates to the field of gear transmission technology, and in particular to a double gear assembly and gearbox. Background Technology

[0002] In gearbox transmissions, double gears are one of the core components for achieving multi-stage speed changes. Currently, double gears are mainly connected to the gearbox housing via a shaft, with the shaft fixed to the housing and the double gears and shaft having a clearance fit. In this method, a certain axial clearance must be maintained between the double gears and the housing to ensure free rotation of the double gears. However, this also makes the double gears prone to axial movement during operation, causing collisions between the double gears or shaft and the gearbox. This not only impacts the gearbox and accelerates wear but also leads to increased meshing noise and decreased transmission accuracy. The movement is particularly pronounced when subjected to axial loads.

[0003] Therefore, in order to address the problem of axial movement of existing double gears, there is an urgent need for a double gear assembly and gearbox that can provide axial positioning. Utility Model Content

[0004] The purpose of this invention is to solve the problem of axial movement in existing double gears.

[0005] To solve the above-mentioned technical problems, this utility model discloses a double gear assembly, comprising: a double gear, wherein the double gear has a first central hole and a second central hole along the axial direction of the double gear; the first central hole and the second central hole are coaxial and interconnected; a bearing, wherein the bearing is disposed in the second central hole, the bearing comprising an inner ring and an outer ring, the outer ring being interference-fitted with the inner wall of the second central hole; a gear shaft, wherein the gear shaft passes through the first central hole and the inner ring in sequence; a gap is provided between the gear shaft and the first central hole, and the gear shaft is interference-fitted with the inner ring.

[0006] By employing the above technical solution, the inner ring of the bearing is fixedly connected to the gear shaft through an interference fit; simultaneously, the outer ring of the bearing is fixedly connected to the double gear through an interference fit between the outer ring and the inner wall of the second central hole. In other words, by interfering with both the bearing and the gear shaft and the double gear, and because the inner and outer rings are relatively stationary in the axial direction, a constraint is formed between the gear shaft and the double gear in the axial direction, preventing axial movement of the double gear relative to the gear shaft when it rotates. The clearance between the gear shaft and the first central hole allows for free rotation of the double gear relative to the gear shaft, reducing wear on both the double gear and the gear shaft.

[0007] According to another specific embodiment of the present invention, a double gear assembly is disclosed, further comprising: a bushing, the bushing being disposed within the first central hole and sleeved on the gear shaft. The bushing has a first wall and a second wall, the second wall being interference-fitted with the inner wall of the first central hole, and the first wall being clearance-fitted with the gear shaft; along the axial direction of the double gear, the bushing and the bearing are spaced apart.

[0008] By adopting the above technical solution, a bushing is set in the first central hole, and the bushing can be made of a more wear-resistant material than the double gear shaft, thereby concentrating wear on the replaceable bushing, improving the service life of the double gear and reducing maintenance costs.

[0009] According to another specific embodiment of the present invention, a double gear assembly is disclosed, wherein lubricating grease is provided in the gap between the gear shaft and the bushing.

[0010] By adopting the above technical solution, lubricating grease is placed between the gear shaft and the bushing, reducing the motion resistance and friction loss when the two rotate relative to each other.

[0011] According to another specific embodiment of the present invention, a double gear assembly is disclosed. A needle roller bearing is provided in the gap between the bushing and the gear shaft. The needle roller bearing includes a sleeve and a plurality of needle rollers. The sleeve has a plurality of mounting grooves along its circumference. The needle rollers are correspondingly disposed in the mounting grooves and are in rolling contact with the sleeve. The sleeve has an inner surface and an outer surface. Along the radial direction of the sleeve, the needle rollers protrude from both the inner and outer surfaces of the sleeve. The sleeve is sleeved on the gear shaft. The portion of the needle rollers protruding from the outer surface of the sleeve rolls in contact with the first wall, and the portion of the needle rollers protruding from the inner surface of the sleeve rolls in contact with the gear shaft.

[0012] By adopting the above technical solution, a needle roller bearing is set between the bushing and the gear shaft. A part of the needle roller protrudes from the needle roller bearing and rolls in contact with the bushing, while the other part of the needle roller protrudes from the needle roller bearing and rolls in contact with the gear shaft. This changes the original sliding friction between the gear shaft and the bushing into rolling friction, thereby reducing frictional resistance and frictional loss.

[0013] According to another specific embodiment of the present invention, a double gear assembly is disclosed, wherein a transition hole is provided between the first central hole and the second central hole, the transition hole being coaxial with and communicating with the first central hole and the second central hole; the diameter of the transition hole is larger than the inner diameter of the outer ring and smaller than the outer diameter of the outer ring.

[0014] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a double gear assembly, wherein the transition hole is a tapered hole.

[0015] By employing the above technical solution, a coaxial through-hole is provided between the first and second center holes. The diameter of the through-hole is larger than the inner diameter of the bearing's outer ring but smaller than its outer diameter. This difference in size between the through-hole and the outer ring forms a limiting surface, which effectively blocks the bearing's outer ring, thus effectively locking it in place and further limiting the bearing's upward movement, preventing axial runout. The through-hole has a tapered structure, smoothly connecting the walls of the first and second center holes.

[0016] According to another specific embodiment of the present invention, a double gear assembly is disclosed, wherein both ends of the gear shaft are provided with chamfers.

[0017] By adopting the above technical solution, chamfers are set at both ends of the gear shaft to facilitate assembly and prevent damage to the ends of the gear shaft during assembly.

[0018] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a double gear assembly, wherein the second central hole has a protrusion on the inner wall at the end away from the first central hole, and the protrusion abuts against the bottom surface of the outer ring.

[0019] By adopting the above technical solution, a protrusion is set in the second center hole, and the protrusion abuts against the bottom surface of the outer ring of the bearing, which further limits the bearing and prevents the bearing from moving downward axially during operation.

[0020] The present invention also discloses a gearbox, which includes at least the double gear assembly and housing as described in any of the above embodiments. The double gear assembly is located inside the housing, and one end of the gear shaft in the double gear assembly is fixedly connected to the housing. Along the axial direction, the double gear and the housing are spaced apart. Attached Figure Description

[0021] Figure 1 This invention provides a front view of a double gear assembly after assembly.

[0022] Figure 2 Show Figure 1 The cross-sectional view of the bushing-equipped double gear assembly shown along the AA direction. Figure 1 ;

[0023] Figure 3 An exploded view of the double gear assembly with bushing of this utility model is shown. Figure 1 ;

[0024] Figure 4 Show Figure 1 The cross-sectional view of the double gear assembly containing needle roller bearings along the AA direction is shown. Figure 2 ;

[0025] Figure 5 An exploded view of the double gear assembly containing needle roller bearings according to this invention is shown. Figure 2 ;

[0026] Figure 6 A perspective view of a needle roller bearing according to an embodiment of the present invention is shown;

[0027] Figure 7 This diagram shows an assembly schematic of the gearbox according to an embodiment of the present invention.

[0028] Figure label:

[0029] Double gear assembly 100;

[0030] Double gear 110; First center hole 111; Second center hole 112; Limiting surface 1121; Transition hole 113; Protrusion 114;

[0031] Bearing 120; Outer ring 121; Bottom surface 1211; Inner ring 122;

[0032] Gear shaft 130; Chamfer 131;

[0033] Bushing 140; First wall 141; Second wall 142;

[0034] Needle roller bearing 150; sleeve 151; mounting groove 1511; inner surface 1512; outer surface 1513; needle roller 152;

[0035] Gearbox 200;

[0036] Casing 210. Detailed Implementation

[0037] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0038] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0040] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0041] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0042] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0043] For ease of subsequent description, the X direction is first defined by way of example in this application embodiment. For example... Figure 1As shown, the X direction is the axial direction of the double gear 110, the B direction is the positive direction of the axial direction, and the D direction is the negative direction of the axial direction.

[0044] refer to Figure 1 , Figure 2 , Figure 3 This application provides a double gear assembly 100, including: a double gear 110, a bearing 120, and a gear shaft 130. The double gear 110 is positioned along its axial direction (…). Figure 1 In the X direction, a first central hole 111 and a second central hole 112 are provided; the first central hole 111 and the second central hole 112 are coaxial and interconnected. A bearing 120 is disposed in the second central hole 112, and the bearing 120 includes an inner ring 122 and an outer ring 121, with the outer ring 121 having an interference fit with the inner wall of the second central hole 112. A gear shaft 130 passes through the first central hole 111 and the inner ring 122 in sequence; a gap is provided between the gear shaft 130 and the first central hole 111, and it has an interference fit with the inner ring 122.

[0045] The inner ring 122 of the bearing 120 is fixedly connected to the gear shaft 130 through an interference fit between the gear shaft 130 and the inner ring 122 of the bearing 120; simultaneously, the outer ring 121 of the bearing 120 is fixedly connected to the double gear 110 through an interference fit between the outer ring 121 of the bearing 120 and the inner wall of the second central hole 112. That is, through the interference fit between the bearing 120 and both the gear shaft 130 and the double gear 110, the inner ring 122 and the outer ring 121 are relatively stationary in the axial direction, thus constraining the gear shaft 130 and the double gear 110 in the axial direction. This prevents the double gear 110 from axially moving relative to the gear shaft 130 when it rotates relative to the gear shaft 130. The clearance between the gear shaft 130 and the first central hole 111 allows the double gear 110 to rotate freely relative to the gear shaft 130, reducing wear on both the double gear 110 and the gear shaft 130.

[0046] refer to Figure 2 In this embodiment, the aperture d of the first central hole 111 is... Figure 2 The diameter of the hole (as shown in d) is smaller than that of the second central hole 112 (which is the same as the outer diameter of the outer ring 121, as shown in d). Figure 2 (As shown in c). In some possible embodiments, the diameter d of the first central hole 111 can be greater than or equal to the diameter of the second central hole 112, as long as it can ensure that the gear shaft 130 rotates within the first central hole 111, and is not limited in this application.

[0047] refer to Figure 1 , Figure 2In this embodiment, a transition hole 113 is provided between the first central hole 111 and the second central hole 112. The transition hole 113 is coaxial with and passes through the first central hole 111 and the second central hole 112; the diameter b of the transition hole 113 is... Figure 2 (As shown in b) is greater than the inner diameter a of the outer ring 121. Figure 2 As shown in Figure a), and smaller than the outer diameter c of the outer ring 121 ( Figure 2 As shown in Figure c). In this embodiment, the transition hole 113 is a tapered hole, and the diameter of the transition hole 113 is along the positive direction of the axial direction ( Figure 1 The diameter of the transition hole 113 gradually decreases in the direction of B. In some possible embodiments, the diameter of the transition hole 113 may also decrease in the opposite direction to the axial direction. Figure 1 (Central D direction).

[0048] By providing a coaxial through-hole 113 between the first central hole 111 and the second central hole 112, and the diameter b of the through-hole 113 being larger than the inner diameter a of the outer ring 121 of the bearing 120 but smaller than the outer diameter c of the outer ring 121, a limiting surface 1121 is formed through the size difference between the through-hole 113 and the outer ring 121. This limiting surface 1121 can block the outer ring 121 of the bearing 120, effectively locking the outer ring 121, and further limiting the bearing 120 in the positive axial direction, preventing the bearing 120 from axially moving in the B direction. This design is simple and reliable. The through-hole 113 adopts a tapered structure, smoothly connecting the hole walls of the first central hole 111 and the second central hole 112. In this embodiment, the double gear 110 is integrally formed, and the use of the tapered through-hole 113 also facilitates demolding.

[0049] refer to Figure 1 , Figure 2 In this embodiment, along the axial direction ( Figure 1 In the X direction), the height of the transition hole 113 is e ( Figure 2 As shown in the figure (e), where e>0.

[0050] By limiting the height of the transition hole 113, the resulting internal space provides the necessary buffer space for the rolling elements inside the bearing 120 to move up and down during operation. In the axial direction, it ensures that the bearing 120 and the first central hole 111 are in a non-contact state, reducing the friction between them.

[0051] refer to Figure 2In this embodiment, the inner wall of the second central hole 112 at the end away from the first central hole 111 has an annular protrusion 114, which abuts against the bottom surface 1211 of the outer ring 121. In this embodiment, the annular protrusion 114 is inverted, specifically, the diameter of the protrusion 114 gradually increases along direction B, serving as a guide for the installation of the bearing 120. Simultaneously, the upper surface along direction B is flat, fitting against the bottom surface 1211 of the outer ring 121. In this embodiment, the annular protrusion 114 abuts against the bottom surface 1211 of the outer ring 121 but does not contact the inner ring 122. This both limits the positioning of the bearing 120 and facilitates its installation.

[0052] By providing an annular protrusion 114 within the second central hole 112, and having the annular protrusion 114 abut against the bottom surface 1211 of the outer ring 121, the bearing 120 is further limited, preventing the bearing 120 from reversing axially during operation. Figure 1 The movement (in the direction of D).

[0053] In some possible implementations, the shape of the protrusion 114 may include, but is not limited to, a ring shape, as long as it can serve a limiting function. For example, it may be a strip protrusion, a dot protrusion, a beveled protrusion, etc.

[0054] refer to Figure 1 , Figure 3 In this embodiment, chamfers 131 are provided at both ends of the gear shaft 130 along the axial direction. By providing chamfers 131 at both ends of the gear shaft 130, assembly is facilitated and damage to the ends of the gear shaft 130 is prevented during assembly.

[0055] refer to Figure 2 , Figure 3 In this embodiment, a double gear assembly 100 further includes a bushing 140. The bushing 140 is disposed within a first central hole 111 and sleeved on the gear shaft 130. The bushing 140 has a first wall 141 and a second wall 142. In this embodiment, the first wall 141 is the inner wall of the bushing 140, and the second wall 142 is the outer wall of the bushing 140. The second wall 142 is interference-fitted with the inner wall of the first central hole 111, and the first wall 141 is clearance-fitted with the gear shaft 130. Along the axial direction of the double gear 110, the bushing 140 and the bearing 120 are spaced apart. For example, the bushing 140 needs to be made of a wear-resistant material, such as wear-resistant materials like alloys or engineering plastics.

[0056] By providing a bushing 140 within the first central hole 111, the distance between the gear shaft 130 and the first central hole 111 is further reduced, thereby further limiting the radial movement of the gear shaft 130. Furthermore, the bushing 140 can be made of a more wear-resistant material than the shaft of the double gear 110, thus concentrating wear on the replaceable bushing 140, increasing the service life of the double gear 110 body, and reducing maintenance costs.

[0057] refer to Figure 2 , Figure 3 In this embodiment, lubricating grease is provided in the gap between the gear shaft 130 and the bushing 140. In some possible implementations, the lubricating substance provided includes, but is not limited to, lubricating grease, as long as it serves a lubricating function, such as: solid lubricant, lubricating oil, grease, self-lubricating composite material, etc.

[0058] By providing lubricating grease between the gear shaft 130 and the bushing 140, the motion resistance and friction loss during relative rotation between the two are reduced.

[0059] For ease of subsequent description, the Y direction is first defined by example in this application embodiment. For example... Figure 4 As shown, the Y direction is the radial direction of sleeve 151.

[0060] refer to Figure 4 , Figure 5 , Figure 6 In this embodiment, a needle roller bearing 150 is provided in the gap between the bushing 140 and the gear shaft 130. The needle roller bearing 150 includes a sleeve 151 and a plurality of needle rollers 152. The sleeve 151 is provided with a plurality of mounting grooves 1511 along the circumferential direction. The needle rollers 152 are correspondingly disposed in the mounting grooves 1511 and are in rolling connection with the sleeve 151. The sleeve 151 has an inner surface 1512 and an outer surface 1513 along the radial direction of the sleeve 151. Figure 4 In the Y direction, the needle roller 152 protrudes from both the inner surface 1512 and the outer surface 1513 of the sleeve 151. The sleeve 151 is fitted onto the gear shaft 130. The portion of the needle roller 152 protruding from the outer surface 1513 of the sleeve 151 rolls in contact with the first wall 141, and the portion of the needle roller 152 protruding from the inner surface 1512 of the sleeve 151 rolls in contact with the gear shaft 130. Rolling contact between the needle roller 152 and the gear shaft 130 is sufficient; in some possible embodiments, the needle roller 152 may not protrude from the outer surface 1513 of the sleeve 151. For example, the sleeve 151 is directly press-fitted with the first wall 141, and the portion of the needle roller 152 protruding from the inner surface 1512 of the sleeve 151 rolls in contact with the gear shaft 130. In some possible embodiments, the needle roller bearing 150 can be fixed in the bushing 140 by means of a snap ring, retaining ring (not shown in the figure), etc.

[0061] In this embodiment, the height of the needle roller bearing 150 is equal to the height of the bushing 140 along the axial direction. Exemplarily, the height of the needle roller bearing 150 is not limited as long as it can roll in contact with both the bushing 140 and the gear shaft 130. In some possible implementations, the height of the rolling bearing 120 may be less than or greater than the height of the bushing 140.

[0062] By setting a needle roller bearing 150 between the bushing 140 and the gear shaft 130, a portion of the needle roller 152 protruding from the needle roller bearing 150 makes rolling contact with the bushing 140, and another portion of the needle roller 152 protruding from the needle roller bearing 150 makes rolling contact with the gear shaft 130, the original sliding friction between the gear shaft 130 and the bushing 140 is changed to rolling friction, which reduces frictional resistance and reduces frictional loss.

[0063] refer to Figure 7 This application provides a gearbox 200, which includes a double gear assembly 100 and a housing 210 as described in any of the above embodiments. The double gear assembly 100 is located inside the housing 210. One end of the gear shaft 130 in the double gear assembly 100 is fixedly connected to the housing 210. Along the axial direction, the double gear 110 is spaced apart from the housing 210 and can rotate relative to the housing 210.

[0064] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A double gear assembly, characterized in that, include: The double gear has a first center hole and a second center hole along its axial direction; the first center hole and the second center hole are coaxial and interconnected. A bearing is disposed in the second central hole. The bearing includes an inner ring and an outer ring, and the outer ring is interference-fitted with the inner wall of the second central hole. The gear shaft passes through the first central hole and the inner ring in sequence; there is a gap between the gear shaft and the first central hole, and it is interference-fitted with the inner ring.

2. The double gear assembly as described in claim 1, characterized in that, Also includes: A bushing is disposed in the first central hole and sleeved on the gear shaft; the bushing has a first wall and a second wall, the second wall is interference-fitted with the inner wall of the first central hole, and the first wall is clearance-fitted with the gear shaft; Along the axial direction of the double gear, the bushing is spaced apart from the bearing.

3. The double gear assembly as described in claim 2, characterized in that, The gap between the gear shaft and the bushing is filled with lubricating grease.

4. The double gear assembly as described in claim 2, characterized in that, A needle roller bearing is provided in the gap between the bushing and the gear shaft. The needle roller bearing includes a sleeve and a plurality of needle rollers. The sleeve has a plurality of mounting grooves along the circumference. Each needle roller is correspondingly disposed in the mounting groove and is tactilely connected to the sleeve. The sleeve has an inner surface and an outer surface. Along the radial direction of the sleeve, the needle roller protrudes from both the inner surface and the outer surface of the sleeve. The sleeve is fitted onto the gear shaft, and the portion of the needle roller protruding from the outer surface rolls in contact with the first wall, while the portion of the needle roller protruding from the inner surface rolls in contact with the gear shaft.

5. The double gear assembly as described in claim 1, characterized in that, A transition hole is provided between the first central hole and the second central hole, and the transition hole is coaxial with and passes through the first central hole and the second central hole; The diameter of the transition hole is larger than the inner diameter of the outer ring and smaller than the outer diameter of the outer ring.

6. The double gear assembly as described in claim 5, characterized in that, The transition hole is a tapered hole.

7. The double gear assembly as described in claim 1, characterized in that, Along the axial direction, both ends of the gear shaft are chamfered.

8. The double gear assembly as described in claim 1, characterized in that, The second central hole has a protrusion on its inner wall at the end away from the first central hole, and the protrusion abuts against the bottom surface of the outer ring.

9. A gearbox, characterized in that, include: The double gear assembly as claimed in any one of claims 1 to 8; The housing contains the double gear assembly, one end of the gear shaft in the double gear assembly is fixedly connected to the housing, and the double gear is spaced apart from the housing along the axial direction.

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