Gearbox of wheel excavator

Abstract

The utility model relates to a gearbox of an engineering vehicle, in particular to a gearbox of a wheel excavator, which comprises a box body and an output shaft arranged in the box body, and a reverse gear and a reverse synchronizer matched with the reverse gear are sleeved on the output shaft. By arranging the reverse gear synchronizer matched with the reverse gear, the gear of the gearbox can be engaged into the reverse gear when the wheel excavator is in a non-static state, the reverse gear is not prone to being damaged, and the fault rate is relatively low. The end face bearings are arranged on the two sides of the idle wheel, axial force borne by the idle wheel can be borne by the box body, abrasion caused by direct contact of the idle wheel and the box body can be effectively avoided, meanwhile, due to the fact that no radial acting force is generated when the end face bearings transmit the axial force, the radial force borne by the idle wheel shaft cannot be increased, and the service life of the idle wheel shaft is prolonged. The risk that the idler shaft is bent or broken is effectively reduced, and the failure rate is further reduced.

Description

Technical Field

[0001] This utility model relates to a transmission for engineering vehicles, and more particularly to a transmission for a wheeled excavator. Background Technology

[0002] A vehicle's powertrain typically includes a gearbox and a transmission. The gearbox usually comprises a gearbox housing, an output shaft housed within the gearbox housing, an idler shaft, a reverse gear mounted on the output shaft, and an idler wheel mounted on the idler shaft to enable the vehicle's reverse gear function. Since traditional vehicles are usually stationary before engaging reverse gear, traditional gearboxes typically do not have a synchronizer for the reverse gear. However, for wheeled excavators, due to their heavier weight, greater inertia, and frequent shifts between forward and reverse, it is difficult to ensure the vehicle is stationary during gear changes. This leads to the reverse gear being prone to damage and having a relatively high failure rate.

[0003] Furthermore, in traditional gearboxes, only a bushing is provided between the idler gear and the idler gear shaft. However, during use, the idler gear comes into end-face contact with the gearbox body due to axial force, which causes wear and affects its service life. For passenger cars, the impact of wear on the idler gear and gearbox body is relatively insignificant because the reverse gear is used relatively infrequently. However, for wheel excavators, the frequent use of reverse gear means that wear on the idler gear and gearbox body will affect the normal operation of the wheel excavator.

[0004] Chinese utility model patent CN211715723U describes a speed-changing transmission structure developed by the applicant. It includes a gearbox housing and an idler shaft disposed within the gearbox housing. Two opposing first bearings, capable of withstanding axial forces, are mounted on the idler shaft, with a gap between them. The same idler wheel is mounted on both first bearings, and the bearings are tapered roller bearings. By using two opposing tapered roller bearings to replace the idler wheel in bearing the axial force, the effect of axial force on the idler wheel is fundamentally eliminated, thereby eliminating wear on the gearbox housing caused by the axial force of the idler wheel. However, while the opposing tapered roller bearings can eliminate axial force, they also increase the radial force on the idler shaft, easily leading to bending or even breakage of the idler shaft.

[0005] In view of this, the applicant conducted an in-depth study of the results of the wheel excavator gearbox, which led to this case. Utility Model Content

[0006] The purpose of this invention is to provide a wheel excavator gearbox with a relatively low failure rate.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A wheel excavator gearbox includes a housing and an output shaft disposed within the housing. A reverse gear and a reverse synchronizer cooperating with the reverse gear are sleeved on the output shaft.

[0009] As an improvement of this utility model, it also includes an idler shaft located inside the housing and arranged parallel to the output shaft. A needle roller bearing is sleeved on the idler shaft, and an idler wheel that meshes with the reverse gear is sleeved on the needle roller bearing. Each side of the idler wheel abuts against an end face bearing sleeved on the idler shaft, and the side of each end face bearing away from the idler wheel directly or indirectly abuts against the housing.

[0010] As an improvement of this utility model, countersunk holes are respectively opened on both sides of the idler wheel, and each of the end face bearings is inserted into the corresponding countersunk hole.

[0011] As an improvement of this utility model, the housing has a first support and a second support, one end of the idler shaft is connected to the first support and the other end is connected to the second support, one of the end face bearings directly or indirectly abuts against the first support, and the other end face bearing directly or indirectly abuts against the second support.

[0012] As an improvement of this utility model, the first support or the second support is the side wall of the box body.

[0013] As an improvement of this utility model, one of the end face bearings is indirectly abutted against the first bracket or the second bracket by adjusting a shim.

[0014] As an improvement of this utility model, an adjusting bolt is spirally connected to the first bracket or the second bracket, and one end of the adjusting bolt abuts against the adjusting shim.

[0015] By adopting the above technical solution, this utility model has the following beneficial effects:

[0016] 1. By setting a reverse gear synchronizer that works with the reverse gear, the gearbox can be engaged in reverse gear when the excavator is not stationary, and the reverse gear is less likely to be damaged, resulting in a relatively low failure rate.

[0017] 2. By setting end face bearings on both sides of the idler wheel, the housing can bear the axial force on the idler wheel and effectively avoid wear caused by direct contact between the idler wheel and the housing. At the same time, since the end face bearings do not generate radial force when transmitting axial force, they will not increase the radial force on the idler wheel shaft, effectively reducing the risk of bending or breaking of the idler wheel shaft and further reducing the failure rate. Attached Figure Description

[0018] Figure 1This is a cross-sectional structural diagram of the gearbox for the wheeled excavator of this utility model;

[0019] Figure 2 This is a partial cross-sectional view of another location of the gearbox of the wheel excavator according to this utility model. Some parts are omitted in the figure.

[0020] The corresponding markings in the diagram are as follows:

[0021] 10-Box body; 11-First support;

[0022] 12 - Second support; 20 - Output shaft;

[0023] 21-Reverse gear; 22-Reverse synchronizer;

[0024] 23 - Second gear; 24 - Second gear synchronizer;

[0025] 30 - Idler shaft; 31 - Needle roller bearing;

[0026] 32 - Idler gear; 33 - End face bearing;

[0027] 34 - Adjusting shim; 40 - Input shaft. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 and Figure 2 As shown, this embodiment provides a wheel excavator gearbox, including a housing 10, an output shaft 20 disposed within the housing 10, and an idler shaft 30 disposed within the housing 10 and arranged parallel to the output shaft 20. Of course, the housing 10 is also provided with components such as an input shaft 40, which are common components of wheel excavator gearboxes. The structure of these components and their connection position relationships are the same as those of conventional wheel excavator gearboxes, and will not be described in detail here.

[0030] The focus of this embodiment is to improve the reverse gear transmission structure based on a conventional wheeled excavator gearbox. Specifically, a reverse gear 21 and a reverse synchronizer 22 that cooperate with the reverse gear 21 are mounted on the output shaft 20. The connection structure between the reverse gear 21 and the output shaft 20 is the same as that of a conventional wheeled excavator gearbox. This embodiment adds a reverse synchronizer 22 that cooperates with the reverse gear 21 to the conventional gearbox. The specific cooperation structure between the reverse synchronizer 22 and the reverse gear 21 is the same as the cooperation structure between the second gear 23 and the second synchronizer 24. This type of cooperation structure is widely used in various vehicle gearboxes and will not be described in detail here.

[0031] Preferably, a needle roller bearing 31 is fitted onto the idler shaft 30, and an idler wheel 32 that meshes with the reverse gear 21 is fitted onto the needle roller bearing 31. That is, in this embodiment, a needle roller bearing 31 is used instead of a traditional bushing to connect the idler wheel 32 and the idler shaft 30, resulting in better wear resistance. End face bearings 33 fitted onto the idler shaft 30 are respectively abutted on both sides of the idler wheel 32. The side of each end face bearing 33 away from the idler wheel 32 directly or indirectly abuts against the housing 10, thereby directly limiting the axial movement of the idler wheel 32 and separating the idler wheel 32 from the housing 10 to prevent collision and wear. Specifically, the housing 10 has a first support 11 and a second support 12, wherein the first support 11 or the second support 12 is a side wall of the housing 10. In this embodiment, the first support 11 is an integrally connected support to the inner cavity side wall of the housing 10, and the second support 12 is a side wall of the housing 10. One end of the idler shaft 30 is connected to the first support 11, and the other end is connected to the second support 12. One end face bearing 33 directly or indirectly abuts against the first support 11, and the other end face bearing directly or indirectly abuts against the second support 12. In this embodiment, one end face bearing 33 indirectly abuts against the first support 11 through an adjusting shim 34, and the other end face bearing 33... 3. The bearing 33 directly abuts against the second bracket 12. Alternatively, one end face bearing 33 can indirectly abut against the second bracket 12 via an adjusting shim 34, while the other end face bearing 33 directly abuts against the first bracket 11. Furthermore, an adjusting bolt (not shown in the figure) is spirally connected to either the first bracket 11 or the second bracket 12. Whether the adjusting bolt is on the first or second bracket 12 depends on which bracket 11 has the adjusting shim 34 abutting against it. One end of the adjusting bolt abuts against the adjusting shim 34, facilitating adjustment of the assembly clearance and avoiding the need to repeatedly replace adjusting shims 34 of different thicknesses, thus improving assembly efficiency. Of course, other structures can also be used to adjust the assembly clearance, such as the idler shaft and gearbox body connection structure disclosed in Chinese Utility Model Patent Publication No. CN216643033U.

[0032] Considering that the position between the two supports is relatively fixed, it is necessary to install the idler shaft 30 on the two supports and then fit each bearing onto the idler shaft 30. To facilitate installation, in this embodiment, countersunk holes are opened on both sides of the idler 32, and each end face bearing 33 is inserted into the corresponding countersunk hole (the outer diameter of the end face bearing 33 is smaller than the diameter of the corresponding countersunk hole). In this way, during assembly, each bearing can be pre-assembled on the idler 32 and then fitted onto the idler shaft 30 as a whole.

[0033] The present invention has been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the above embodiments. Those skilled in the art can make various modifications to the present invention based on the prior art, and these modifications all fall within the protection scope of the present invention.

Claims

1. A gearbox for a wheeled excavator, comprising a housing and an output shaft disposed within the housing, characterized in that, The output shaft is fitted with a reverse gear and a reverse synchronizer that cooperates with the reverse gear.

2. The wheel excavator gearbox as described in claim 1, characterized in that, It also includes an idler shaft located inside the housing and arranged parallel to the output shaft. A needle roller bearing is fitted on the idler shaft, and an idler wheel that meshes with the reverse gear is fitted on the needle roller bearing. Each side of the idler wheel abuts against an end face bearing fitted on the idler shaft, and the side of each end face bearing away from the idler wheel directly or indirectly abuts against the housing.

3. The wheel excavator gearbox as described in claim 2, characterized in that, The idler wheel has countersunk holes on both sides, and each end face bearing is inserted into the corresponding countersunk hole.

4. The wheel excavator gearbox as described in claim 2 or 3, characterized in that, The housing has a first support and a second support. One end of the idler shaft is connected to the first support and the other end is connected to the second support. One of the end face bearings directly or indirectly abuts against the first support, and the other end face bearing directly or indirectly abuts against the second support.

5. The wheel excavator gearbox as described in claim 4, characterized in that, The first support or the second support is the side wall of the box body.

6. The wheel excavator gearbox as described in claim 4, characterized in that, One of the end face bearings is indirectly abutted against the first bracket or the second bracket by adjusting a shim.

7. The wheel excavator gearbox as described in claim 6, characterized in that, An adjusting bolt is spirally connected to the first or second bracket, and one end of the adjusting bolt abuts against the adjusting shim.

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