A worm and gear gap adjusting structure for an electric power steering system

Abstract

The utility model discloses a kind of worm and worm gear clearance adjusting structure for electric power steering system, it is related to automobile steering system technical field, it aims at solving the problem of pre-tightening force difficult to balance in prior art, assembly complex, poor adaptability, the technical scheme used is, including base, support body and needle roller bearing, the support body is slidably connected on the base, the support body is installed in the end of the worm through the needle roller bearing, spiral spring and diaphragm spring are also installed on the base, the elastic force of the spiral spring exerts radial tension on the support body, so that the worm and the worm gear keep zero-gap engagement, the diaphragm spring elastically supports the support body, adopt spiral spring and diaphragm spring cooperation, traditional adjusting pin structure is saved, without clearance adjustment in assembly process, shorten assembly time, improve production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of automotive steering system technology, specifically to a worm gear clearance adjustment structure for an electric steering system. Background Technology

[0002] With the increasing prevalence of automotive electronics, electric power steering (EPS) is well-suited to the development of electric vehicles, meeting the automotive industry's needs for assisted intelligent driving and autonomous driving technologies. The motor-driven worm gear transmission is the mainstream structure in EPS products, including C-EPS, P-EPS, DP-EPS, and R-EPS. Even commercial vehicles use worm gear transmissions in their electric power steering systems. Due to manufacturing tolerances, a certain clearance is required between the worm gears for smooth meshing and transmission; this clearance is adjusted using a clearance adjustment mechanism.

[0003] Chinese patent CN216045224U discloses a worm gear clearance adjustment mechanism. The technical solution adopted is that a worm gear and a worm are meshed with each other. One end of the worm is coaxially connected to the output shaft of the power motor. A bearing bushing is provided between the bearing at the other end of the worm and the reducer housing. A leaf spring is snapped on the outer wall of the bearing bushing. The radial deformation of the leaf spring drives the worm to always be close to the worm gear for effective meshing.

[0004] While the aforementioned technical solutions effectively reduce the internal friction between the worm gear and worm and significantly decrease the wear of the worm gear and worm, they still have the following drawbacks: During installation, the preload of the blade spring needs to be adjusted by changing the pressing displacement and depth of the adjusting pin. Excessive preload will result in insufficient worm gear clearance and increased friction, making assembly difficult and accelerating wear; insufficient preload will fail to resist reverse impacts, easily causing collision noises. Furthermore, some mechanisms require adjusting the preload using adjusting pins, increasing assembly complexity and reducing production efficiency. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the existing defects and provide a worm gear clearance adjustment structure for an electric steering system, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, this utility model discloses a worm gear clearance adjustment structure for an electric steering system. The technical solution includes a worm gear and a worm, wherein the worm gear and the worm mesh with each other, one end of the worm is equipped with a ball bearing, and the other end is equipped with a clearance adjustment mechanism. It also includes a base, a support body, and a needle roller bearing. The support body is slidably connected to the base and is mounted on the end of the worm gear via the needle roller bearing. A helical spring and a diaphragm spring are also installed on the base. The elastic force of the helical spring applies a radial tension to the support body, keeping the worm gear and the worm wheel in zero-clearance meshing. The diaphragm spring provides elastic support to the support body. The use of a helical spring and a diaphragm spring eliminates the need for a traditional adjusting pin structure, eliminating the need for clearance adjustment during assembly, shortening assembly time, and improving production efficiency.

[0007] As a preferred embodiment of this utility model, the base has a mounting groove in the middle, and the support body is slidably connected in the mounting groove.

[0008] As a preferred technical solution of this utility model, the base is also provided with a slot, which is connected to the mounting slot, and the diaphragm spring is inserted into the slot. Under heavy load or impact, the high-stiffness diaphragm spring provides damping force through elastic support, and works with the helical spring to resist the impact, avoid gap generation, and ensure stability under harsh working conditions.

[0009] As a preferred technical solution of this utility model, the support body is further provided with extensions on both sides, and the extensions are provided with lugs connected to the helical spring. Under light load or normal turning, the low-stiffness helical spring pulls the support body by tensile force, so that the worm and worm wheel maintain zero clearance meshing, reducing internal friction and transmission noise.

[0010] As a preferred embodiment of this utility model, the base is further provided with an arc-shaped groove for accommodating the helical spring, and the two ends of the helical spring are provided with hooks that are compatible with the hanging ears.

[0011] Compared with the prior art, the beneficial effects of this utility model are: by using a combination of a helical spring and a diaphragm spring, this utility model eliminates the traditional adjusting pin structure, eliminates the need for gap adjustment during assembly, shortens assembly time, and improves production efficiency; Under light loads or normal steering, the low-stiffness helical spring pulls the support body through tensile force, keeping the worm and worm wheel engaged with zero clearance, reducing internal friction and transmission noise; under heavy loads or impacts, the high-stiffness diaphragm spring provides damping force through elastic support, working in conjunction with the helical spring to resist impacts, avoid clearance, and ensure stability under harsh working conditions. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the present invention in use; Figure 2 This is a schematic diagram of the structure of this utility model; Figure 3 This is an exploded view of the present invention.

[0013] In the diagram: 1. Worm gear; 2. Worm; 3. Ball bearing; 4. Base; 5. Diaphragm spring; 6. Support body; 7. Helical spring; 8. Needle roller bearing; 41. Arc groove; 42. Mounting groove; 43. Card slot; 61. Extension; 62. Hanging ear; 71. Hook. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example 1

[0015] like Figures 1 to 3 As shown, this utility model discloses a worm gear clearance adjustment structure for an electric steering system. The technical solution adopted includes a worm gear 1 and a worm 2, wherein the worm gear 1 and the worm 2 are meshed, and a ball bearing 3 is installed at one end of the worm 2 and a clearance adjustment mechanism is installed at the other end. It also includes a base 4, a support body 6, and a needle roller bearing 8, with the support body 6 slidably connected to the base 4. The base 4 has a mounting groove 42 in the middle, and the support 6 is slidably connected in the mounting groove 42 and can slide along the extension direction of the mounting groove 42.

[0016] The base 4 has an arc-shaped groove 41 and a slot 43. The arc-shaped groove 41 is used to accommodate the helical spring 7. The two ends of the helical spring 7 are provided with hooks 71, which are connected to the lugs 62 on the extensions 61 on both sides of the support body 6 respectively. After assembly, the helical spring 7 is in a stretched state, and its elastic force pulls the support body 6 radially, so that the worm 2 always moves closer to the worm wheel 1, maintaining zero-backlash meshing.

[0017] The slot 43 is connected to the mounting slot 42. The diaphragm spring 5 is inserted into the slot 43, with its middle part abutting against the support body 6 and its two ends fixed to the base 4, forming an elastic support for the support body 6. When the support body 6 is impacted and slides away from the worm gear 1, the diaphragm spring 5 bends and deforms, generating a reverse elastic force to resist the impact.

[0018] The working principle of this utility model: In the initial state and during normal steering, the tension of the helical spring 7 causes the support body 6 to drive the worm 2 to press against the worm wheel 1, eliminating meshing clearance, ensuring smooth transmission, and reducing noise.

[0019] After the worm gear 1 and worm 2 wear down, the elastic restoring force of the helical spring 7 drives the support body 6 to slide, causing the worm 2 to move closer to the worm gear 1, automatically compensating for the gap caused by wear.

[0020] When subjected to a large impact or heavy load, the support body 6 compresses the diaphragm spring 5. The high stiffness of the diaphragm spring 5 provides sufficient damping force, which works together with the helical spring 7 to prevent the worm 2 from moving away from the worm wheel 1, avoid the generation of backlash, and ensure stable transmission.

[0021] The circuits and mechanical connections involved in this utility model are common practices used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments. They are common knowledge.

[0022] Components not described in detail in this article are existing technologies.

[0023] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A worm gear clearance adjustment structure for an electric steering system, comprising a worm gear (1) and a worm (2), wherein the worm gear (1) and the worm (2) are meshed, and a ball bearing (3) is installed at one end of the worm (2) and a clearance adjustment mechanism is installed at the other end; characterized in that It also includes a base (4), a support body (6) and a needle roller bearing (8). The support body (6) is slidably connected to the base (4). The support body (6) is mounted on the end of the worm (2) through the needle roller bearing (8). A helical spring (7) and a diaphragm spring (5) are also installed on the base (4). The elastic force of the helical spring (7) applies a radial tension to the support body (6) so that the worm (2) and the worm wheel (1) maintain zero clearance meshing. The diaphragm spring (5) provides elastic support to the support body (6).

2. The worm gear backlash adjustment structure for an electric power steering system according to claim 1, characterized by: The base (4) has an installation groove (42) in the middle part, and the support (6) is slidably connected in the installation groove (42).

3. The worm-gear backlash adjustment structure for an electric power steering system according to claim 2, characterized by: The base (4) is also provided with a slot (43), which is connected to the mounting slot (42), and the diaphragm spring (5) is inserted into the slot (43).

4. The worm gear backlash adjustment structure for an electric power steering system according to claim 1, characterized by: The support (6) is also provided with extensions (61) on both sides, and the extensions (61) are provided with lugs (62) that are connected to the helical spring (7).

5. The worm and gear backlash adjustment structure for an electric power steering system according to claim 4, characterized by: The base (4) is also provided with an arc-shaped groove (41) for accommodating the helical spring (7). The two ends of the helical spring (7) are also provided with hooks (71) that are compatible with the hanging ears (62).

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