Electric power steering machine with planetary gear transmission mechanism

Abstract

The utility model relates to the technical field of automobile steering systems, in particular to an electric power steering machine with a planetary gear transmission mechanism, which comprises a casing, a motor, a belt, a tie rod and the planetary gear transmission mechanism. The two ends of the planetary gear transmission mechanism are exposed out of the shell and are respectively connected with a transverse pull rod. Compared with the prior art, ball screw transmission is replaced by planetary gear transmission, the planetary gear transmission coefficient is high, the friction coefficient is small, the rack transmission efficiency is improved, and the overall steering performance and bearing capacity of the steering engine are enhanced; the number of parts is reduced, the cost is reduced, and cost reduction and efficiency improvement of enterprises are facilitated; the production line rhythm is increased, and the production efficiency is improved; the overall weight is reduced, lightweight design is facilitated, disassembly and assembly are convenient, and maintainability and replaceability are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile steering systems, in particular to an electric power steering machine with a planetary gear transmission mechanism. Background Art

[0002] With the rapid development of electric vehicles and passenger cars, the performance and noise requirements of the steering gear of the vehicle are getting higher and higher. As a steering gear that can provide high rack force and high performance, the parallel axis electric power steering gear has increasingly strict control over the performance of the transmission mode.

[0003] The existing parallel-axis electric power steering gear adopts ball screw transmission. The ball screw has many parts, which increases the weight of the steering gear and reduces the production line cycle. It is difficult to meet the lightweight development needs of electric vehicles and the company's goal of reducing costs and increasing efficiency.

[0004] Therefore, it is necessary to design an electric power steering machine with a planetary gear transmission mechanism to improve the rack transmission efficiency while reducing the number of parts, so as to reduce the weight of the steering machine and increase the production line cycle. Summary of the invention

[0005] The purpose of the utility model is to overcome the deficiencies of the prior art and provide an electric power steering machine with a planetary gear transmission mechanism, which improves the rack transmission efficiency while reducing the number of parts, thereby achieving the purpose of reducing the weight of the steering machine and increasing the production line cycle.

[0006] In order to achieve the above-mentioned purpose, the utility model is an electric power steering machine with a planetary gear transmission mechanism, including a housing, a motor, a belt, a tie rod, and a planetary gear transmission mechanism. The planetary gear transmission mechanism is located inside the housing, and the planetary gear transmission mechanism and the driving shaft of the motor are connected by a belt. The two ends of the planetary gear transmission mechanism are exposed outside the housing and are respectively connected to a tie rod.

[0007] The planetary gear transmission mechanism includes a rack, a connecting piece, a limit plate, a gear, a gear pulley, and a ball bearing. Both ends of the gear pulley are covered with limit plates, and both ends of the rack pass through the through holes on the surface of the limit plate. A cross rod is installed on the end of the rack. The two ends of the gear are respectively assembled to the two limit plates by connecting pieces. The outer surface of the gear is meshed with the rack and the inner surface of the gear pulley. The outer surface of the gear pulley is covered with a belt, and the gear pulley is connected to the housing by a ball bearing.

[0008] The connecting piece is a bolt.

[0009] There are four gears.

[0010] The inner ring of the ball bearing is interference fit with the gear pulley, and the outer ring of the ball bearing is interference fit with the housing.

[0011] The gear-type pulley is provided with a lubricating oil storage space inside.

[0012] Compared with the prior art, the utility model adopts planetary gear transmission instead of ball screw transmission. The planetary gear has a high transmission coefficient and a small friction coefficient, which improves the rack transmission efficiency and enhances the overall steering performance and carrying capacity of the steering gear; reduces the number of parts and reduces costs, which is beneficial to enterprises to reduce costs and increase efficiency; increases the production line rhythm and improves production efficiency; reduces the overall weight, which is beneficial to lightweight design, and is easy to disassemble and assemble, thereby improving maintainability and replaceability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the utility model.

[0014] Figure 2 It is an axonometric view of the planetary gear transmission mechanism of the utility model.

[0015] Figure 3 It is an exploded view of the planetary gear transmission mechanism of the utility model.

[0016] Figure 4 It is a cutaway view of the planetary gear transmission mechanism of the utility model. DETAILED DESCRIPTION

[0017] The utility model is now further described with reference to the accompanying drawings.

[0018] See also Figure 1~Figure 4 The utility model is an electric power steering machine with a planetary gear transmission mechanism, including a housing, a motor, a belt, a tie rod, and a planetary gear transmission mechanism. The planetary gear transmission mechanism 2 is located inside the housing 1, and the planetary gear transmission mechanism 2 is connected to the driving shaft of the motor 3 by a belt 4. The two ends of the planetary gear transmission mechanism 2 are exposed outside the housing 1 and are respectively connected to a tie rod 5.

[0019] The planetary gear transmission mechanism 2 includes a rack 21, a connecting member 22, a limit plate 23, a gear 24, a gear pulley 25, and a ball bearing 26. The two ends of the gear pulley 25 are covered with the limit plates 23. The two ends of the rack 21 pass through the through holes on the surface of the limit plates 23. The ends of the rack 21 are installed with transverse tie rods 5. The two ends of the gear 24 are respectively assembled to the two limit plates 23 by connecting members 22. The gear 24 is meshed with the outer surface of the rack 21 and the inner surface of the gear pulley 25. The outer surface of the gear pulley 25 is sleeved with a belt 4. The gear pulley 25 is connected to the housing 1 by a ball bearing 26.

[0020] Preferably, the connecting member 22 is a bolt. There are four gears 24.

[0021] In order to facilitate the rotation of the gear pulley 25 inside the housing 1 , the inner ring of the ball bearing 26 is interference fit with the gear pulley 25 , and the outer ring of the ball bearing 26 is interference fit with the housing 1 .

[0022] The gear pulley 25 is provided with a lubricating oil storage space inside so as to fill the gear 24 with lubricating oil, thereby reducing the noise coefficient and being beneficial to the NVH performance.

[0023] In order to further reduce the weight, the planetary gear transmission mechanism 2 can be made of aluminum. According to calculations, the aluminum planetary gear transmission mechanism can reduce the weight of the steering gear by about 10%.

[0024] When assembling the planetary gear transmission mechanism 2, first assemble the four gears 24 on a limit plate 23, then adjust the pre-assembled gears 24 and assemble them on the rack 21, then put the gear pulley 25 on the outside of the four gears 24 and inject lubricating oil; after assembling another limit plate 23, assemble the ball bearing 26 to the outside of the gear pulley 25.

[0025] When the utility model is working, the torque sensor calculates how much power the motor needs through the torque manually input by the steering wheel, and then the motor 3 starts to rotate to generate torque, and the torque is transmitted to the planetary gear transmission mechanism 2 through the belt 4. The planetary gear transmission mechanism 2 converts the circular motion into the lateral motion of the rack 21, so that the tie rod 5 moves left and right, thereby completing the steering of the car.

[0026] When the planetary gear transmission mechanism 2 is working, after the gear pulley 25 receives the torque of the motor 3 transmitted by the belt 4, the gear pulley 25 rotates, thereby driving the gear 24 to rotate. Under the rotation of the gear 24, the rack 21 moves laterally, thereby converting the torque of the motor 3 into the lateral movement of the rack 21, completing the force transmission.

[0027] The utility model adopts planetary gear transmission to replace ball screw transmission. The planetary gear has a high transmission coefficient and a small friction coefficient, which improves the rack transmission efficiency and enhances the overall steering performance and carrying capacity of the steering gear; reduces the number of parts and reduces costs, which is beneficial to enterprises to reduce costs and increase efficiency; increases the production line rhythm and improves production efficiency; reduces the overall weight, which is beneficial to lightweight design, and is easy to disassemble and assemble, thereby improving maintainability and replaceability.

Claims

1. An electric power steering machine with a planetary gear transmission mechanism, comprising a housing, a motor, a belt, a tie rod, and a planetary gear transmission mechanism, Features: The planetary gear transmission mechanism (2) is located inside the housing (1), and the planetary gear transmission mechanism (2) is connected to the drive shaft of the motor (3) by a belt (4). Both ends of the planetary gear transmission mechanism (2) are exposed outside the housing (1) and are respectively connected to a tie rod (5). The planetary gear transmission mechanism (2) comprises a rack (21), a connecting piece (22), a limit plate (23), a gear (24), a gear pulley (25), and a ball bearing (26). The two ends of the gear pulley (25) are covered with the limit plates (23). The two ends of the rack (21) pass through the through holes on the surface of the limit plates (23). The end of the rack (21) is mounted with a tie rod (5). The two ends of the gear (24) are respectively assembled on the two limit plates (23) by using the connecting piece (22). The gear (24) meshes with the outer surface of the rack (21) and the inner surface of the gear pulley (25). The outer surface of the gear pulley (25) is sleeved with a belt (4). The gear pulley (25) is connected to the housing (1) by using a ball bearing (26).

2. An electric power steering machine with a planetary gear transmission mechanism according to claim 1, Features: The connecting piece (22) is a bolt.

3. The electric power steering machine with a planetary gear transmission mechanism according to claim 1, Features: There are four gears (24).

4. The electric power steering machine with a planetary gear transmission mechanism according to claim 1, Features: The inner ring of the ball bearing (26) is interference fit with the gear pulley (25), and the outer ring of the ball bearing (26) is interference fit with the housing (1).

5. The electric power steering machine with a planetary gear transmission mechanism according to claim 1, Features: The gear-type pulley (25) is provided with a lubricating oil storage space inside.

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