Gearbox

Abstract

The utility model relates to a gear box, which comprises a transmission shaft (1) extending along the axial direction; the bevel gear (2) is arranged on the transmission shaft; a bearing (3) rotatably supporting the propeller shaft and positioned adjacent to the bevel gear, the bearing having a bearing end face facing the bevel gear; a contact (4) arranged around the drive shaft between the bearing and the bevel gear; wherein the bevel gear has a plurality of teeth, each tooth extending from a proximal tooth end face (5) close to the bearing to a distal tooth end face away from the bearing, an axial side surface of the contact facing the bearing being in contact with a bearing end face of the bearing, the other axial side surface, facing the bevel gear, of the contact piece makes contact with the multiple near-side tooth end faces of the multiple teeth, and the contact area of the contact piece making contact with the bearing end face is larger than the total contact area of the contact piece making contact with the multiple near-side tooth end faces. The contact piece is arranged between the bearing and the bevel gear, so that the risk of tooth damage of the bevel gear can be reduced.

Description

Technical Field

[0001] The utility model relates to a gearbox. Background Art

[0002] In the application of a gearbox using bevel gear transmission, the bevel gear usually needs to occupy a relatively large internal space. In the case where the internal space of the gearbox is limited, instead of the solution of assembling a separate bevel gear on the transmission shaft, the bevel gear can be directly formed on the transmission shaft, that is, the bevel gear and the transmission shaft are formed as a whole, so that the teeth of the bevel gear are as close as possible to the axis of the transmission shaft to save radial space. Moreover, in order to adapt to the limited axial space, the bearing that supports the rotation of the transmission shaft can be directly axially abutted against the teeth of the bevel gear. Since the bearing is in direct contact with the teeth of the bevel gear, the axial force of the bearing will be directly transmitted to the teeth of the bevel gear, causing excessive pressure on these tooth surfaces of the bevel gear and being easily damaged.

[0003] Therefore, it is necessary to design an improved gearbox to solve the above one or more technical defects. Summary of the Utility Model

[0004] To overcome at least one defect of the prior art, the utility model provides a gearbox capable of reducing the pressure exerted by the bearing on the tooth surface of the bevel gear.

[0005] According to one aspect of the utility model, there is provided a gearbox, which includes:

[0006] A transmission shaft extending axially;

[0007] A bevel gear provided on the transmission shaft;

[0008] A bearing rotatably supporting the transmission shaft and positioned adjacent to the bevel gear, the bearing having a bearing end face facing the bevel gear;

[0009] A contact member disposed around the transmission shaft between the bearing and the bevel gear;

[0010] Wherein, the bevel gear has a plurality of teeth, each tooth extending from a proximal tooth end face close to the bearing to a distal tooth end face away from the bearing, an axially one-side surface of the contact member facing the bearing contacts the bearing end face of the bearing, an axially the other-side surface of the contact member facing the bevel gear contacts the plurality of proximal tooth end faces of the plurality of teeth, and the contact area of the contact member contacting the bearing end face is larger than the total contact area of the contact member contacting the plurality of proximal tooth end faces.

[0011] According to one embodiment, the shapes of the axially one-side surface and the axially the other-side surface of the contact member respectively conform to the shapes of the bearing end face and the proximal tooth end face.

[0012] According to one embodiment, the contact member is formed as a flat member, and the axially one-side surface and the axially the-other-side surface of the contact member are flat surfaces respectively.

[0013] According to one embodiment, the contact member is an elastic annular member with an opening, and the annular member extends continuously in the circumferential direction to its opposite two ends to form the opening.

[0014] According to one embodiment, the annular member is disposed in a groove on the outer surface of the transmission shaft, and the groove extends around the transmission shaft in the circumferential direction of the transmission shaft.

[0015] According to one embodiment, the groove is a groove with a U-shaped cross-section, which has bearing-side side walls and tooth-side side walls opposite to each other along the axis, the bearing-side side walls and the tooth-side side walls are flat surfaces respectively, and are coplanar with the bearing end face and the proximal tooth end face respectively.

[0016] According to one embodiment, the contact member is a rigid support ring, and the support ring is formed into a complete circular ring and is mounted on the outer surface of the transmission shaft.

[0017] According to one embodiment, the projection of the proximal tooth end face of the tooth on the plane where the bearing end face is located along the axis of the transmission shaft at least partially overlaps with the projection of the bearing end face on the plane.

[0018] According to one embodiment, the projection of the proximal tooth end face of the tooth on the plane where the bearing end face is located along the axis of the transmission shaft is completely covered by the projection of the bearing end face on the plane.

[0019] According to one embodiment, the gearbox has at least one of the following features:

[0020] The transmission shaft and the bevel gear are integrally formed;

[0021] The bevel gear is located at the axial end of the transmission shaft;

[0022] The teeth of the bevel gear are straight teeth, helical teeth or spiral teeth;

[0023] The proximal tooth end face of the tooth is formed as a flat surface extending in the radial direction of the transmission shaft;

[0024] The bearing is a rolling bearing or a sliding bearing; and

[0025] The bearing end face of the bearing is formed as a flat surface extending in the radial direction of the transmission shaft.

[0026] According to the gearbox of the present utility model, by providing an additional contact member between the bearing and the bevel gear, compared with directly contacting the proximal tooth end face of each tooth of the bevel gear with the bearing end face of the bearing, the contact area between the bearing and the adjacent component can be increased, thereby reducing the pressure borne by the tooth surface of the bevel gear, reducing the risk of its damage, and extending the service life of the bevel gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Specific details of various embodiments according to the present utility model are illustrated in the drawings and the following description. Based on these descriptions and illustrations, other features and advantages of the present utility model will be apparent.

[0028] Figure 1 FIG. is a schematic cross-sectional view of a transmission shaft and a bevel gear in a gearbox according to an embodiment of the present utility model.

[0029] Figure 2 FIG. is a schematic cross-sectional view of a transmission shaft and a bevel gear in a gearbox according to another embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Specific embodiments and their variations according to the present utility model will be described in detail below with reference to the drawings.

[0031] For the sake of convenience of description, in this text, spatial relative terms such as "inner", "outer", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", etc. are used to define the various components and their connection relationships. However, this is not restrictive. When the placement orientation of the components changes, these spatial relative relationships can also be reversed or changed without affecting the protection scope of the present utility model.

[0032] Figure 1 FIG. is a schematic cross-sectional view of a transmission shaft and a bevel gear in a gearbox according to an embodiment of the present utility model.

[0033] As Figure 1 shown, the gearbox includes a transmission shaft 1 disposed within a housing (not shown). The transmission shaft 1 extends axially and has an outer surface 10 that extends axially and circumferentially. A bevel gear 2 is provided, for example, at one axial end of the transmission shaft 1. The transmission shaft 1 and the bevel gear 2 are rotatably supported by two bearings 3, one of the bearings 3 ( Figure 1 the right bearing in Figure 1 is disposed close to the bevel gear 2, and the other bearing (

[0034] The bearing 3 can be a rolling bearing such as a cylindrical roller bearing, a tapered roller bearing, a ball bearing, etc., or can be a sliding bearing or other types of bearings. The bearing 3 has a bearing end face 30 facing the bevel gear 2, and this bearing end face 30 will transmit the axial force and is designed to contact the contact member 4 described later. Although Figure 1 and Figure 2 it is shown that the inner ring of the bearing 3 contacts the contact member 4, however, it is conceivable that it can also be the outer ring of the bearing 3 that contacts the contact member 4.

[0035] In Figure 1 the illustrated example, the bevel gear 2 is formed by machining teeth on the outer surface 10 of the end of the transmission shaft 1. That is, the transmission shaft 1 and the bevel gear 2 are integrally formed. However, it is conceivable that the bevel gear 2 can also be a separate component assembled to the transmission shaft 1, for example, the synchronous rotation of the two is achieved through structures such as splines between the transmission shaft 1 and the bevel gear 2.

[0036] The bevel gear 2 has a plurality of teeth, and each tooth extends from the proximal tooth end close to the bearing 3 to the distal tooth end far from the bearing 3. Preferably, the proximal tooth end face 5 of the proximal tooth end is formed as a flat surface and advantageously extends radially along the transmission shaft 1 (i.e., perpendicular to the axis of the transmission shaft 1) to increase the contact area with the contact member 4 that will be described later. To adapt to the limited space within the gearbox, the proximal tooth end face 5 of the teeth of the bevel gear 2 can be designed to be as close as possible to the axis of the transmission shaft 1, so that it is axially opposite to the adjacent bearing end face 30. That is, the projection of the proximal tooth end face 5 of the teeth along the axial direction of the transmission shaft 1 on the plane where the bearing end face 30 is located at least partially overlaps with the projection of the bearing end face 30 on the said plane, or is completely covered by the projection of the bearing end face 30 so as to be closest to the transmission shaft. Additionally, the bevel gear 2 can be a spur gear, a helical gear or a spiral gear. Correspondingly, the teeth of the bevel gear 2 can be formed as straight teeth, helical teeth or spiral teeth.

[0037] A contact member 4 is provided between the mutually facing bearing end face 30 and the proximal tooth end face 5 of the bevel gear teeth. The contact member 4 is an annular member that extends circumferentially around the transmission shaft 1. The axially one side surface of the contact member 4 facing the bearing 3 contacts the bearing end face 30, and the axially opposite other side surface of the contact member 4 facing the bevel gear 2 contacts the plurality of proximal tooth end faces 5 of the plurality of teeth of the bevel gear 2. The contact area of the contact member 4 contacting the bearing end face 30 is larger than the total contact area of the contact member 4 contacting the plurality of proximal tooth end faces 5 of the plurality of teeth, that is, the sum of the contact areas contacting all the proximal tooth end faces 5.

[0038] Preferably, the shapes of the axially one-side surface and the axially other-side surface of the contact member 4 can be formed to conform to the shapes of the bearing end face 30 and the proximal tooth end face 5 in contact therewith, that is, the shapes of the corresponding surfaces complementarily fit with each other to maximize the contact area between the contact member 4 and the bearing end face 30 and the proximal tooth end face 5. For example, when both the bearing end face 30 and the proximal tooth end face 5 are formed as flat surfaces and extend radially along the transmission shaft 1 (i.e., perpendicular to the axis of the transmission shaft 1), the axially one-side surface and the axially other-side surface of the contact member 4 are also correspondingly formed as flat surfaces and extend radially along the transmission shaft 1, so that the contact member 4 is formed in a flat shape.

[0039] The contact member 4 can be elastic, so that it is not necessary to adopt a complete ring shape, but a ring shape with an opening can be adopted. The opening is formed by the opposite ends of the contact member 4 that continuously extend circumferentially, so that the contact member 4 forms a substantially C-shaped shape, for example Figure 1 the snap ring shown. Of course, the elastic contact member 4 can also be formed in a complete ring shape.

[0040] The elastic contact member 4 can be arranged in the groove 6 on the outer surface 10 of the transmission shaft 1. The groove 6 extends circumferentially around the transmission shaft 1 and is adjacent to the proximal tooth end face 5 of the teeth of the bevel gear 2. The groove 6 can be formed as a groove 6 with a U-shaped cross-section, and the two opposite side walls of the groove 6 can be respectively formed to conform to the shapes of the two opposite axially side surfaces of the contact member 4. For example, when the two axially side surfaces of the contact member 4 are formed as flat surfaces extending radially along the transmission shaft 1, the two opposite side wall surfaces of the groove 6 are also formed as flat surfaces extending radially along the transmission shaft 1. Advantageously, the tooth-side side wall of the groove 6 closer to the proximal tooth end face 5 of the bevel gear tooth is coplanar with the proximal tooth end face 5 of the bevel gear tooth, so that the axially other-side surface of the contact member 4 not only contacts the proximal tooth end face 5 of the bevel gear tooth, but also contacts the tooth-side side wall of the groove 6, so as to increase the contact area of the contact member 4 on the bevel gear side with a very compact axial structure. Similarly advantageously, the bearing-side side wall of the groove 6 closer to the bearing 3 is coplanar with the bearing end face 30, so that the axially one-side surface of the contact member 4 not only contacts the bearing end face 30, but also contacts the bearing-side side wall of the groove 6, so as to increase the contact area of the contact member 4 on the bearing side with a very compact axial structure.

[0041] Although it is described above that the two opposite side walls of the groove 6 are formed as flat surfaces and are respectively coplanar with the proximal tooth end face 5 of the bevel gear tooth and the bearing end face 30, however, the present application is not limited thereto, and the shape and position of the groove 6 can also be changed as needed, as long as the two axially side surfaces of the contact member 4 arranged in the groove 6 can respectively contact the bearing end face 30 and the proximal tooth end face 5 of the bevel gear tooth.

[0042] During installation as Figure 1When the elastic contact member 4 shown is involved, the two open ends of the elastic contact member 4 can be pulled outwards, and the contact member 4 can be placed around the transmission shaft 1 in the groove 6 of the transmission shaft 1. When the pulling stops, the contact member 4 can recover to its original state by virtue of its own elastic force and thus be clamped on the transmission shaft 1 in the groove 6. Thereby, the material consumption of the contact member 4 can be reduced and the cost can be lowered.

[0043] In addition, although the contact member 4 is described above as being installed in the groove 6 of the transmission shaft 1, it can be conceived that the elastic contact member 4 can also be directly installed on the surface of the transmission shaft 1, thereby avoiding machining the groove 6 on the surface of the transmission shaft 1.

[0044] Figure 2 is a schematic cross-sectional view showing the cooperation between the transmission shaft 1 and the bevel gear 2 in the gearbox according to another embodiment of the present invention. The difference between this embodiment and Figure 1 the embodiment shown is that the contact member 4 is replaced by a rigid support ring from an elastic annular member, and instead of being located in the groove 6 on the outer surface 10 of the transmission shaft 1, the support ring is directly located on the outer surface 10 of the transmission shaft 1.

[0045] As Figure 2 shown, the support ring is also formed in an annular shape. Different from the Figure 1 open annular member shown, this support ring is a complete circular ring without any opening, so as to contact the bearing end face 30 and the proximal tooth end face 5 of the bevel gear teeth in the entire circumference, thereby increasing the contact area therebetween. However, the support ring can also be formed in a shape with an opening to reduce the material consumption.

[0046] The two axial side surfaces of the support ring can be respectively formed to conform to the shapes of the contacted bearing end face 30 and the proximal tooth end face 5. For example, when both the bearing end face 30 and the proximal tooth end face 5 are formed as flat surfaces extending radially along the transmission shaft 1, the two axial side surfaces of the support ring are also formed as flat surfaces, so as to maximize the contact area contacting the bearing end face 30 and the proximal tooth end face 5 of the bevel gear teeth. The inner diameter size of the support ring is preferably designed such that the support ring has a clearance fit or an interference fit with the transmission shaft 1 to reduce the potential stress caused by the cooperation with the transmission shaft 1 and lower the risk of fracture.

[0047] According to the installation space requirements in the gearbox, the above-mentioned elastic contact members 4 such as snap rings and the rigid contact members 4 such as support rings can be provided with one or more, or they can also be arranged in combination with each other.

[0048] By arranging a contact member 4 between the bearing 3 and the bevel gear 2, the contact area between the bearing 3 and the adjacent components can be increased compared with the case where the proximal tooth end face 5 of each tooth directly contacts the end face 30 of the bearing. According to the formula P = F / S, where P is the pressure acting on the proximal tooth end face 5 of the tooth of the bevel gear 2, F is the axial force transmitted by the bearing 3, and S is the contact area between the bearing 3 and the adjacent components. When the contact area S between the bearing 3 and the adjacent components is increased, the pressure P acting on the tooth of the bevel gear 2 by the axial force of the bearing 3 via the contact member 4 is reduced. For example, for a bevel gear 2 with a large transmission ratio, the pressure P value can be significantly reduced to 25% of the original value by arranging an additional contact member 4, thereby reducing the risk of damage to the tooth of the bevel gear 2 and extending the service life of the bevel gear 2.

[0049] In addition, since the pressure applied to the tooth of the bevel gear 2 is reduced, the diameter of the transmission shaft 1 can be designed to be smaller, so that a larger transmission ratio can be achieved with a thinner shaft, and the transmission ratio of the gearbox can be increased, expanding the application range of the gearbox.

[0050] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above specific structures, but covers various deformations and equivalent features. Those skilled in the art can make various changes without departing from the protection scope of the present invention.

Claims

1. A gearbox, characterized in that, The gearbox includes: a transmission shaft (1) extending axially; a bevel gear (2) provided on the transmission shaft (1); a bearing (3) rotatably supporting the transmission shaft (1) and positioned adjacent to the bevel gear (2), the bearing having a bearing end face (30) facing the bevel gear; a contact member (4) disposed around the transmission shaft (1) between the bearing (3) and the bevel gear (2); wherein the bevel gear (2) has a plurality of teeth, each tooth extending from a proximal tooth end face (5) close to the bearing (3) to a distal tooth end face away from the bearing (3), an axially one-side surface of the contact member (4) facing the bearing (3) contacts the bearing end face (30) of the bearing (3), an axially the other-side surface of the contact member (4) facing the bevel gear (2) contacts the plurality of proximal tooth end faces (5) of the plurality of teeth, and a contact area of the contact member (4) contacting the bearing end face (30) is larger than a total contact area of the contact member (4) contacting the plurality of proximal tooth end faces (5).

2. The gearbox according to claim 1, wherein, Shapes of the axially one-side surface and the axially the other-side surface of the contact member (4) respectively conform to shapes of the bearing end face (30) and the proximal tooth end face (5).

3. The gearbox according to claim 2, characterized in that, The contact member (4) is formed as a flat member, and the axially one-side surface and the axially the other-side surface of the contact member (4) are respectively flat surfaces.

4. The gearbox according to any one of claims 1-3, characterized in that The contact member (4) is an elastic annular member having an opening, and the annular member extends circumferentially continuously to its opposite two ends to form the opening.

5. The gearbox according to claim 4, wherein The annular member is disposed in a groove (6) on an outer surface (10) of the transmission shaft (1), and the groove (6) extends around the transmission shaft (1) in the circumferential direction of the transmission shaft (1).

6. The gearbox according to claim 5, characterized in that, The groove (6) is a groove (6) having a U-shaped cross section, which has a bearing-side side wall and a tooth-side side wall opposite to each other axially, and the bearing-side side wall and the tooth-side side wall are respectively flat surfaces and are coplanar with the bearing end face (30) and the proximal tooth end face (5) respectively.

7. The gearbox according to any one of claims 1-3, characterized in that, The contact member (4) is a rigid support ring, and the support ring is formed as a complete circular ring and is mounted on the outer surface (10) of the transmission shaft (1).

8. The gearbox according to any one of claims 1 to 3, characterized in that, A projection of the proximal tooth end face (5) of the tooth on a plane where the bearing end face (30) is located axially along the transmission shaft (1) at least partially overlaps a projection of the bearing end face (30) on the plane.

9. The gearbox according to claim 8, characterized in that, A projection of the proximal tooth end face (5) of the tooth on a plane where the bearing end face (30) is located axially along the transmission shaft (1) is completely covered by a projection of the bearing end face (30) on the plane.

10. The gearbox according to any one of claims 1-3, characterized in that, The gearbox has at least one of the following features: the transmission shaft (1) and the bevel gear (2) are integrally formed; the bevel gear (2) is located at an axial end of the transmission shaft (1); teeth of the bevel gear (2) are straight teeth, helical teeth or spiral teeth; the proximal tooth end face (5) of the tooth is formed as a flat surface extending radially along the transmission shaft (1); The bearing (3) is a rolling bearing or a sliding bearing; and The bearing end face (30) of the bearing (3) is formed as a flat surface extending in the radial direction of the transmission shaft (1).

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