Axial welding differential mechanism

Abstract

The utility model relates to the technical field of differential mechanisms, in particular to an axial welding differential mechanism. Comprising a differential shell, an exhaust groove and an exhaust hole, the differential shell and a gear ring are welded together through a welding seam, the exhaust groove is composed of a gear ring rectangular groove and a differential shell oval transition circular bead, after optimization, the phenomenon of stress concentration at the position of a circular bead of the exhaust groove is reduced, the probability that a welding connector loses efficacy in work is reduced, larger axial force can be borne, and the service life of the welding connector is prolonged. Compared with an original structure, the differential shell is fewer in machining face and higher in production efficiency, the exhaust groove structure does not need to independently machine a rectangular groove in the differential shell relative to the original structure, then existing structure optimization can be conducted, the original welding position of the improved structure is not changed, the structural size of a welding connector cannot be increased, and under the same load bearing condition, the machining efficiency of the differential shell is greatly improved. Load generated when a welding seam is loaded is reduced, the axial bearing capacity of a welding connector is improved, meanwhile, the machining face of the welding connector is reduced, and the production efficiency of the welding differential mechanism is improved.

Description

Technical Field

[0001] This utility model relates to the field of differential technology, and in particular to an axially welded differential. Background Technology

[0002] As a crucial component in automobiles for achieving differential speeds between drive wheels and transmitting power, the differential, with the evolving trends in automotive engineering, demands are for lighter weight and smaller size while maintaining the same strength requirements. Currently, welded differentials are a good solution. Given the company's existing axial laser-welded differentials (such as...), Figure 1 As shown), their welded joint structures all have the following problems: 1. The differential shell venting groove structure is of the rectangular groove type. Stress is more likely to concentrate at the rounded corners of this structure, especially when the axial force is directed to the left. Figure 1 1. (In the direction indicated by the arrow) The entire axial force is borne by the welded area, which poses a certain risk of failure under large axial loads; 2. This structure cannot have too large a fillet unless the axial length of the welded joint is increased, which would increase the weight of the differential, making it counterproductive; 3. Although this welding structure can be reversed, with the weld area on the right and the press-fit area on the left, which can improve the stress on the fillet of the exhaust groove to some extent, this structure will reduce the welding space, which may cause the laser beam to come into contact with the non-welded surface of the differential shell. It is also extremely unfavorable for the arrangement of welding fixtures and anti-spatter fixtures. Utility Model Content

[0003] The purpose of this utility model is to provide an axially welded differential, which aims to optimize the existing structure. The improved structure does not change the original welding position and does not increase the structural size of the welded joint. Under the same load conditions, it reduces the load on the weld and improves the axial bearing capacity of the welded joint. At the same time, it reduces the machining surface of the welded joint and improves the production efficiency of the welded differential.

[0004] To achieve the above objectives, this utility model provides an axially welded differential, including a differential housing, wherein the differential housing and the gear ring are welded together by a weld seam;

[0005] The toothed ring press-fit surface and the differential housing press-fit surface are connected together by an interference fit, working together to ensure the centering of the toothed ring and to bear radial loads;

[0006] The axial positioning surface of the differential housing is in axial contact with the positioning step of the gear ring.

[0007] It also includes exhaust channels and exhaust ports;

[0008] The exhaust groove is used to store the gas generated during welding, accommodate weld collapse, and release the stress generated during welding. The exhaust hole is used to expel the gas generated during welding, reduce defects, and balance the gas pressure in the exhaust groove.

[0009] The exhaust groove is composed of a rectangular groove on a gear ring and an elliptical transition shoulder on a differential shell.

[0010] The weld seam serves to connect the differential shell and the gear ring, and also bears a certain load.

[0011] The differential housing is used to receive the torque transmitted from the gear ring and transmit it to the half shaft to drive the wheel, and also serves as a carrier for the gear ring and the inner cavity parts.

[0012] The gear ring is used to transmit torque, change the magnitude of torque, and change the direction of rotation.

[0013] The differential housing axial positioning surface and the gear ring positioning step work together to restrict the axial displacement of the gear ring, while also bearing part of the axial force generated when the differential is working.

[0014] This utility model discloses an axially welded differential. The improved structure significantly reduces stress concentration at the rounded corners of the exhaust groove, lowering the probability of weld joint failure during operation. Furthermore, the improved structure can withstand greater axial forces. Compared to the original structure, the differential housing has fewer machined surfaces, resulting in higher production efficiency. The exhaust groove of the improved structure consists of a rectangular groove on the gear ring and an elliptical transition shoulder on the differential housing. Compared to the original structure, it does not require separate machining of the rectangular groove on the differential housing, thus enabling optimization of the existing structure. The original welding position remains unchanged and the structural dimensions of the weld joint are not increased. Under the same load conditions, the load on the weld is reduced, improving the axial bearing capacity of the weld joint. At the same time, the number of machined surfaces of the weld joint is reduced, improving the production efficiency of the welded differential. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0016] Figure 1 This is a schematic diagram of the differential in the current technology.

[0017] Figure 2 This is a schematic diagram of the overall structure of the axially welded differential of this utility model.

[0018] Figure 3 This is a simulation comparison chart of the structure of this utility model and the structure of existing technology.

[0019] Figure 1In the middle: 1-Differential shell, 2-Exhaust groove, 3-Weld, 4-Gear ring, 5-Gear ring rectangular groove, 6-Differential shell rectangular groove transition fillet, 7-Gear ring press-fit surface, 8-Differential shell press-fit surface, 9-Differential shell axial positioning surface, 10-Gear ring positioning step, 11-Differential shell contact surface, 12-Gear ring contact surface, 13-Exhaust hole, 14-Differential shell rectangular groove.

[0020] Figure 2 In the middle: 20-differential shell, 21-vent groove, 22-weld, 23-gear ring, 24-gear ring rectangular groove, 25-differential shell elliptical transition shoulder, 26-gear ring press-fit surface, 27-differential shell press-fit surface, 28-differential shell axial positioning surface, 29-gear ring positioning step, 30-vent hole. Detailed Implementation

[0021] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0022] like Figure 2 As shown, this utility model provides an axially welded differential, comprising a differential housing 20, an exhaust groove 21, and an exhaust port 30. The differential housing 20 is welded to the gear ring 23 via a weld seam 22. The gear ring press-fit surface 26 and the differential housing press-fit surface 27 are connected together via an interference fit. The exhaust groove 21 is formed by a rectangular groove 24 of the gear ring and an elliptical transition shoulder 25 of the differential housing. This solution optimizes the existing structure. The improved structure retains the original welding position and does not increase the structural dimensions of the welded joint. Under the same load conditions, it reduces the load on the weld seam, improves the axial load-bearing capacity of the welded joint, and reduces the machining surface of the welded joint, thus improving the production efficiency of the welded differential. It is understood that the aforementioned solution can optimize the structure of existing differentials and achieve better performance.

[0023] In this embodiment, the differential shell 20 and the gear ring 23 are welded together by weld 22. The improved structure can withstand greater axial force at the welded area. Figure 1 On the left, the end faces of shell 1 and gear ring 4 are flush, while the right side is stepped. Stepped structures are prone to stress concentration, making the right side relatively weaker. When the axial load is to the left ( Figure 1 (Arrow direction), the stress is very high at the right-side transition fillet. Original structure ( Figure 1 The intermediate shell 1 is subjected to a leftward ( Figure 1 When the axial force (in the direction of the arrow) is borne entirely by the weld seam 3 area, the improved structure's leftward axial force is mainly borne by the differential shell axial positioning surface 28. This results in a smaller leftward axial force on the weld area, and the stress on the left differential shell rectangular groove transition fillet 6 will also be smaller.

[0024] The toothed ring press-fit surface 26 and the differential shell press-fit surface 27 are connected together by an interference fit, which together ensures the centering of the toothed ring 23 and bears radial load; the interference fit connection has good stability.

[0025] The axial positioning surface 28 of the differential shell is in axial contact with the positioning step 29 of the gear ring;

[0026] The venting groove 21 is used to store gases generated during welding, accommodate weld collapse, and release stress generated during welding. The venting hole 30 is used to expel gases generated during welding, reduce defects, and balance the gas pressure within the venting groove 21. The improved structure significantly reduces stress concentration at the rounded corners of the venting groove 21. (Relevant data can be found...) Figure 3 ( Figure 3 The top left side shows the original structural data under the prior art, and the top right side shows the data of the improved structure of this application. This reduces the probability of welded joint failure during operation, the stress concentration factor of the improved structure is smaller, and the right-side fillet does not need to be considered. Figure 1 The right side of the rectangular groove transition fillet is 6 (for the intermediate shell), so the left fillet can be designed to be larger. In addition, the elliptical transition has a better stress relief effect than the fillet transition. In order to further reduce stress concentration, the elliptical transition is adopted, and the elliptical processing is also relatively easy.

[0027] The exhaust groove 21 is formed by the rectangular groove 24 of the gear ring and the elliptical transition shoulder 25 of the differential shell. In the improved structure, the exhaust groove 21 is composed of the rectangular groove 24 of the gear ring and the elliptical transition shoulder 25 of the differential shell, which eliminates the need to separately machine the rectangular groove 14 on the differential shell 1 compared to the original structure.

[0028] Secondly, the weld 22 serves to connect the differential shell 20 and the gear ring 23, and also bears a certain load.

[0029] Then, the differential housing 20 is used to receive the torque transmitted from the gear ring 23 and transmit it to the half shaft, thereby driving the wheel, and at the same time serving as a carrier for the gear ring 23 and the inner cavity parts.

[0030] Furthermore, the gear ring 23 is used to transmit torque, change the magnitude of torque, and change the direction of rotation.

[0031] Finally, the differential housing axial positioning surface 28 and the gear ring positioning step 29 work together to restrict the axial displacement of the gear ring 23, while bearing part of the axial force brought about by the differential during operation.

[0032] When using the axially welded differential of this utility model, the assembly is performed first. Then, when the car is in motion, the power generated by the prime mover is transmitted to the main reduction gear through the intermediate transmission system. Considering factors such as load, high speed, and NVH, helical gears are generally used as the main reduction gears. However, helical gear transmission will inevitably generate circumferential force, radial force, and axial force.

[0033] Circumferential force is transmitted to the differential housing 20 through the gear ring 23 and the weld 22. Radial force is mainly transmitted to the differential housing 20 through the circumferential contact surface between the gear ring 23 and the differential housing 20. The axial force changes direction simultaneously when the differential rotates forward and backward, resulting in different effects on the welded structure.

[0034] When the axial force is to the left ( Figure 1 or Figure 2 (indicating direction), for Figure 1 In the original structure, the axial force was entirely borne by weld 3 and transferred to the differential shell 1. The transition fillet 6 of the differential shell rectangular groove in differential shell 1 would be subjected to significant tensile stress under this condition. For the present application... Figure 2 With the improved structure, the axial force is mainly transmitted to the differential housing 20 through the positioning step 29 of the gear ring and the axial positioning surface 28 of the differential housing. Most of the axial force is borne by the axial positioning surface 28 of the differential housing, and the tensile stress acting on the rounded corner of the exhaust groove 21 will be very small.

[0035] When the axial force is directed to the right Figure 1 The stress effect of the original structure and Figure 2 The improved structure is similar. And... Figure 2 With the improved structure, in this state, the weld 22 also bears all the axial force, but the effect of the force is different. The rounded corner of the exhaust groove 21 is mainly subjected to compressive stress.

[0036] In conclusion, Figure 1 The original structure is more suitable for situations where the axial force is to the right; when the force is reversed, the fillet of exhaust groove 2 is subjected to tensile stress. This application Figure 2 The improved structure is suitable for cases where the axial force is to the left; in the opposite direction, the rounded corners of the exhaust groove 21 are subjected to compressive stress. Often, the compressive strength of a material is greater than its tensile strength, therefore compared to… Figure 1 The original structure has a better load-bearing capacity.

[0037] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. An axial welded differential, comprising a differential case, characterized in that: the differential case and the ring gear are welded together by a weld joint; the ring gear press-fit surface and the differential case press-fit surface are connected together by an interference fit, which together ensure the centring of the ring gear and bear radial loads; the differential case axial positioning surface and the ring gear positioning step axially contact each other; it further comprises an exhaust groove and an exhaust hole; the exhaust groove is used to store the gas generated during welding, accommodate the weld joint, release the stress generated during welding, and the exhaust hole is used to exhaust the gas generated during welding, reduce defects, and balance the air pressure in the exhaust groove; the exhaust groove is composed of a ring gear rectangular groove and a differential case elliptical transition shoulder.

2. The axial welded differential of claim 1, characterized in that: the weld joint serves to connect the differential case and the ring gear and simultaneously bears a certain load.

3. The axial welded differential of claim 1, characterized in that: the differential case is used to receive the torque transmitted by the ring gear and transmit it to the half shaft, thereby driving the wheels, and at the same time serves as a carrier for the ring gear and the inner cavity parts.

4. The axial welded differential of claim 1, characterized in that: the ring gear is used to transmit torque, change the size and direction of torque.

5. The axially welded differential of claim 1 wherein : the differential case axial positioning surface and the ring gear positioning step jointly limit the axial displacement of the ring gear, while bearing part of the axial force during differential operation.

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