Spiral bevel gear with novel laser welding structure

Abstract

A spiral bevel gear with a novel laser welding structure comprises a spiral bevel gear body, an exhaust groove structure is arranged at the bottom of the spiral bevel gear body and is an annular groove, a non-coplanar structure is arranged on the inner ring side of the exhaust groove structure, and a groove structure is arranged on the outer ring side of the exhaust groove structure. And a welding area structure is arranged on the outer side of the crevasse structure. According to the spiral bevel gear with the novel laser welding structure, the light weight effect is greatly improved, and reinforcing ribs are reduced, so that the transmission resistance is reduced, the oil consumption of an engine is reduced, and the transmission efficiency is also improved.

Description

Technical Field

[0001] The utility model belongs to the field of automatic processing technology for new energy vehicle parts, and particularly relates to a novel laser welding structure for connecting a spiral bevel gear and a main reduction case. Background Art

[0002] The traditional connection method between a gear and a main reduction case is bolt connection, which has many processes, requires drilling and is equipped with bolt connection, has a large overall weight, and has disadvantages such as large oil stirring resistance due to bolt protrusion and stiffeners.

[0003] In order to solve the problem of weight reduction and improve the transmission efficiency, the structure has been optimized, and an advanced technical process of laser welding connection has been adopted.

[0004] Laser beam welding (LBW for short) is a highly precise welding method that uses a laser beam with a high energy density as a heat source. It is a new welding technology that has been applied and gradually developed with the development of laser technology. Since the ruby laser was applied to welding technology in the mid-1960s of the last century, the laser welding technology has experienced more than 40 years of development history.

[0005] In the automotive industry, it is mostly used for welding parts such as passenger car final drives and electric vehicles. Since the parts of commercial vehicles are subject to large torques, large vehicle bodies and loads, the differential needs to be batch-applied only after strength verification and actual measurement through tests.

[0006] The integrated structure of differential gear welding replaces the traditional bolted structure, and can achieve the goal of weight reduction. Weight reduction is an important topic and direction in the current automotive industry. The welded structure can achieve weight reduction, reduce weight, save assembly bolts, have small oil resistance, small oil temperature rise, and the gear is not prone to pitting corrosion, etc.

[0007] When welding a gear and a differential case, welding deformation is one of the main control points. Welding deformation will cause deviation of the gear meshing position, resulting in vehicle installation failure.

[0008] In addition, the existing spiral bevel gears also have the following defects:

[0009] 1. Bulky structure: The differential is an important part of the vehicle's main reduction assembly, mainly composed of a differential, a passive gear and some bearing parts. In the traditional mode, the differential (differential reduction case) and the passive gear are connected by bolts. Due to reasons such as many processing and assembly processes, thread processing, bolt use, relatively thick thread wall thickness design and strengthened structure in the bolt area, the volumes of the differential reduction case and the gear are designed to be relatively large, and the structure is bulky.

[0010] 2. Large oil resistance: There are many protruding bolts on the assembly structure of the differential housing, and multiple reinforcing ribs are designed at the bolt holes. When the vehicle runs at high speed, the protruding bolts and reinforcing ribs are likely to agitate the lubricating oil in the main reducer, increasing the rotational resistance, resulting in an increase in engine fuel consumption and oil temperature, and a decrease in transmission efficiency. Summary of the Invention

[0011] The technical problem to be solved by the present invention is: how to improve the poor gear assembly accuracy caused by welding deformation problems, and provide a spiral bevel gear with a new laser welding structure.

[0012] The technical solution of the present invention is specifically as follows:

[0013] A spiral bevel gear with a new laser welding structure includes a spiral bevel gear body. An exhaust groove structure is provided at the bottom of the spiral bevel gear body. The exhaust groove structure is an annular groove. A non-coplanar structure is provided on the inner ring side of the exhaust groove structure, and a groove structure is provided on the outer ring side of the exhaust groove structure. A welding area structure is provided outside the groove structure.

[0014] A two-dimensional code sticking position is provided below the side of the spiral bevel gear body.

[0015] The spiral bevel gear body is a special-shaped structure and is made of carburizing steel 22CrMoH.

[0016] The right differential housing and the left differential housing are welded to the spiral bevel gear body. When the end face of the left differential housing fits with the end face of the spiral bevel gear body, a welding gap is left, and the welding gap is 0.15 mm.

[0017] The groove size of the groove structure is 5 mm * 0.6 mm, and the depth of the groove size accounts for 5 / 6.

[0018] The welding area structure adopts a spatial distance of 9.5 mm.

[0019] The beneficial effect of the present invention is: The spiral bevel gear with a new laser welding structure has greatly improved lightweight effect and reduced reinforcing ribs. Therefore, the transmission resistance is reduced, the engine fuel consumption is lowered, and the transmission efficiency is also improved. Brief Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is an assembly drawing of the gear and the differential housing of the present invention;

[0022] Figure 3 It is the welding position and the exhaust groove of the present invention;

[0023] Figure 4 It is a drawing of the groove size of the present invention;

[0024] Figure 5 This is the welding alignment diagram of the present utility model. Specific embodiments

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0026] As Figure 1 shown, a spiral bevel gear with a novel laser welding structure includes a spiral bevel gear body 5. An exhaust groove structure 1 is provided at the bottom of the spiral bevel gear body 5. The exhaust groove structure 1 is an annular groove. A non-coplanar structure 3 is provided on the inner ring side of the exhaust groove structure 1. A groove structure 2 is provided on the outer ring side of the exhaust groove structure 1. A welding area structure 4 is provided outside the groove structure 2.

[0027] Further, a two-dimensional code sticking position 8 is provided below the side surface of the spiral bevel gear body 5.

[0028] Further, it is not appropriate for the exhaust groove structure 1 to be too large or too small. An overly large exhaust groove causes a decrease in strength, and it is difficult to ensure a too small exhaust groove in the previous processes (heat treatment + machining). During the heat treatment process, an anti-seepage coating also needs to be applied at the exhaust groove, and there should be no carburized layer with a high carbon content on the surface of the workpiece during welding.

[0029] Further, the spiral bevel gear body 5 is a special-shaped structure and is made of carburizing steel 22CrMoH.

[0030] Further, as Figure 2 、 Figure 3 、 Figure 4 shown, when the spiral bevel gear body 5 is assembled, a right differential case 6 and a left differential case 7 are welded on the spiral bevel gear body 5. In this way, a groove structure 2 needs to be reserved during welding of the special-shaped material, and the differential case material is QT-500. The groove structure 2 determines the feeding speed and wire filling speed of the laser welding torch. Taking the laser weld depth (weld width) of 6 mm as an example, that is, the penetration depth can reach 6 mm deep, and the groove size is 5 mm * 0.6 mm. See Figure 4 , the alignment requirements can be seen in Figure 5, the depth of the groove size accounts for 5 / 6. Through force analysis of this groove size and weld depth, the torque that can be withstood is 163,169.5 (N·m). The output torque of the driven gear is 40,000 (N·m), and a static torque coefficient of 1.8 times is required, which is equal to 72,000 (N·m). The designed torque under this groove is greater than the output torque of the driven gear, theoretically meeting the requirements. When designing the drawing, if the groove size changes, it will affect the wire feeding speed, wire filling amount during welding, and the torque borne by the workpiece.

[0031] Furthermore, in the welding area structure 4, a space for the welding torch to enter and a space for wire filling of the welding wire should be reserved. The design of this product is a space distance of 9.5 mm, as shown in Figure 4 . When the gear is heat-treated, the press quenching process is used, and the press quenching die should take this distance into account.

[0032] Furthermore, after welding, there will inevitably be deformation in the spiral bevel gear body 5. It was found during testing that when the end face of the left differential housing 7 and the end face of the spiral bevel gear body 5 are fitted, there is a certain welding gap, which is beneficial for releasing welding deformation, and it is designed as a non-coplanar structure 3. The welding gap is generally optimally reserved at 0.15 mm. When there is no gap, during cooling after welding, the tensile stress is large, resulting in tooth deformation, and the gear meshing area shifts, which is not suitable for vehicle installation.

[0033] The specific steps and process of laser welding of the present utility model are as follows: laser cleaning → press fitting → induction heating → laser welding → ultrasonic testing → end face runout testing.

[0034] During the design, factors such as welding strength, stress release, and welding deformation were fully considered. After the welding samples were completed, static torque test strength tests were carried out and all passed the tests.

[0035] The above are only the preferred embodiments of the present utility model. It should be pointed out that for those skilled in the art, without departing from the overall concept of the present utility model, several changes and improvements can still be made, and these should also be regarded as the protection scope of the present utility model.

Claims

1. A spiral bevel gear with a novel laser welding structure, characterized in that: It includes a spiral bevel gear body (5), and an exhaust groove structure (1) is provided at the bottom of the spiral bevel gear body (5). The exhaust groove structure (1) is an annular groove. A non-coplanar structure (3) is provided on the inner ring side of the exhaust groove structure (1), and a bevel structure (2) is provided on the outer ring side of the exhaust groove structure (1). A welding area structure (4) is provided on the outer side of the bevel structure (2).

2. A spiral bevel gear with a novel laser welding structure according to claim 1, characterized in that: A two-dimensional code pasting position (8) is provided below the side surface of the spiral bevel gear body (5).

3. A spiral bevel gear with a novel laser welding structure according to claim 1, characterized in that: The spiral bevel gear body (5) is a special-shaped structure and is made of carburizing steel 22CrMoH.

4. A spiral bevel gear with a novel laser welding structure according to claim 1, characterized in that: A right differential case (6) and a left differential case (7) are welded on the spiral bevel gear body (5). When the end surface of the left differential case (7) is in contact with the end surface of the spiral bevel gear body (5), a welding gap is left, and the welding gap is 0.15 mm.

5. A spiral bevel gear with a novel laser welding structure according to claim 1, characterized in that: The bevel size of the bevel structure (2) is 5 mm * 0.6 mm, and the depth of the bevel size accounts for 5 / 6.

6. A spiral bevel gear with a novel laser welding structure according to claim 1, characterized in that: The welding area structure (4) adopts a space distance of 9.5 mm.

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