A rocker shaft power-assisted circulating ball electric power steering

Abstract

The invention relates to a car power steering device, including a steering device body, the steering device body, including a screw nut assembly, a transmission shaft worm gear assembly connected to the screw nut assembly, and a worm transmission assembly connected to the transmission shaft worm gear assembly; the transmission shaft worm gear assembly includes a worm gear shaft, on which a fan-shaped gear connected to the screw nut assembly is arranged; the worm gear arranged on the worm gear shaft is connected to a driving motor that provides power to the car power steering device through the worm transmission assembly; the screw nut assembly includes a steering screw, on which a steering nut meshing with the fan-shaped gear is mounted, the inner wall of the steering nut and the tooth groove of the steering screw form a channel for rolling steel balls, and the steering nut is provided with a conduit connected to the channel. Through the car power steering device of the invention, the steering device in the scheme has a more flexible arrangement and is more suitable for large and heavy-loaded vehicles.

Description

Technical Field

[0001] The invention patent relates to a rocker shaft power-assisted circulating ball electric power steering gear. Background Art

[0002] The electric power steering system appeared in the late 1980s. In the rapid development of electronics, the electric power steering system, as a representative of mechatronics, combines motors with electronic devices. While satisfying the driver's need for easy operation and applicability, it also improves the driver's grasp of the road feel and has a positive improvement on the car's driving system. The electric power steering system of the car is composed of an electronic control servo system installed on the basis of a mechanical steering gear (mostly a gear rack type for cars). The system is mainly composed of sensors, controllers and actuators. The energy of its motor comes from the on-board battery. The controller analyzes the signals of each sensor, issues control instructions according to a certain control strategy and wheel status, and transmits current to the motor when the vehicle is turning and returning to the center, realizing power assistance and return control, improving the steering performance of the gas car, assisting the driver to complete the steering operation, and making the steering light, sensitive and stable. Therefore, the design of the electric power steering device plays an extremely important role in the system. However, at present, in my country's electric power steering system, there is a lack of steering devices that are better suitable for high power consumption and large steering assistance requirements in heavy-duty trucks and commercial new energy buses with large tonnage. Summary of the invention

[0003] The purpose of the present invention is to provide an automobile power steering device that is more suitable for trucks with larger tonnage and commercial new energy buses. The automobile power steering device of the present invention comprises: a screw nut assembly, a transmission shaft worm gear assembly drivingly connected to the screw nut assembly, and a worm transmission assembly drivingly connected to the transmission shaft worm gear assembly;

[0004] The transmission shaft worm gear assembly includes a worm gear shaft, on which a sector gear connected to a screw nut assembly is disposed; the worm gear disposed on the worm gear shaft is connected to a drive motor that provides power to the vehicle power steering device through a worm transmission assembly;

[0005] The screw-nut assembly comprises a steering screw, on which a steering nut meshing with the sector gear is mounted, an inner wall of the steering nut and a tooth groove of the steering screw form a channel for the steel ball to roll, and a conduit communicating with the channel is provided on the steering nut;

[0006] The worm transmission assembly includes a worm, which is meshed with the worm wheel. A first gear is provided at one end of the worm, and the first gear is meshed with a second gear; the second gear is connected to a drive motor through a reducer with a planetary gear train arranged inside.

[0007] Through the automobile power steering device of the present invention, the screw nut assembly, the transmission shaft worm gear assembly and the worm transmission assembly are adopted, so that the steering device in the scheme has a more flexible arrangement mode, is more suitable for large heavy-duty vehicles, fills the gap of the electric power steering device in this area, and is more suitable for use in large vehicles. It is green and efficient, and also improves the comfort of the driver's operation during driving. The automobile power steering device has high transmission efficiency. The output of the motor is decelerated and torque-increased by the reduction mechanism, and drives the worm gear mechanism to generate a large steering assist. At the same time, since the electric power steering system does not rely on the engine and has no hydraulic oil pipe, it is not sensitive to cold weather and can work even at minus 40°C, so it provides a fast cold start. Because the system does not start preheating, it also saves energy. Without using a hydraulic oil pump, the parasitic energy loss of the engine is avoided, the fuel economy is improved, and all aspects of the needs of large automobile steering devices are met.

[0008] Specifically, the planetary gear train of the reducer is a double planetary gear set, and the drive motor outputs torque to the second gear through the planet carrier of the double planetary gear set.

[0009] The present invention adopts a double planetary gear set that can achieve a larger transmission ratio. Its input torque is transmitted to the large gear in the double planetary gear through the sun gear, and then transmitted to the sun gear by the planet carrier. The sun gear and the planet gear are meshed, and then the planet carrier outputs torque and speed, which are finally transmitted to the worm, and the worm is meshed with the worm wheel.

[0010] Specifically, the double planetary gear set includes a first planetary gear train and a second planetary gear train; the planet carrier of the first planetary gear train is drivingly connected to the sun gear of the second planetary gear train, and is used to transmit torque to the sun gear of the second planetary gear train through the planet carrier of the first planetary gear train; the sun gear of the first planetary gear train is drivingly connected to the drive motor, and is used to receive torque, and the planet carrier of the second planetary gear train is drivingly connected to the second gear.

[0011] Specifically, the arrangement direction of the first planetary gear train and the second planetary gear train is the same as the extension direction of the worm.

[0012] Specifically, the automobile power steering gear also includes a steering gear housing main body assembly, which includes a steering gear housing main body for accommodating a screw nut assembly, a drive shaft worm gear assembly, and a worm transmission assembly. The steering gear housing main body includes a housing main body, a side cover and a gear cover that are detachable and sealed from the housing main body.

[0013] Specifically, the side cover is sealed with the shell body through a side cover sealing gasket, and the side cover is fixed to the shell body through bolts; the gear cover is sealed with the shell body through a sealing gasket, and the gear cover is fixed to the shell body through screws.

[0014] Specifically, the steering screw is arranged in parallel with the worm gear shaft.

[0015] Specifically, the extending direction of the worm wheel shaft is arranged at a right angle to the extending direction of the worm.

[0016] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present invention are used to assist in understanding the present invention. The contents provided in the drawings and their related descriptions in the present invention can be used to explain the present invention, but do not constitute improper limitations on the present invention. In the drawings:

[0018] Figure 1 It is a schematic diagram of the internal structure of the automobile power steering device of the present invention;

[0019] Figure 2 It is a schematic diagram of the internal structure of the automobile power steering device of the present invention;

[0020] Figure 3 It is a structural schematic diagram of a screw and nut assembly of an automobile power steering device of the present invention;

[0021] Figure 4 It is a front view of the automobile power steering device of the present invention without the housing body, the side cover and the sealing gasket;

[0022] Figure 5 It is a schematic diagram of the main view of the automobile power steering device of the present invention

[0023] Figure 6 It is the invention of the schematic diagram of the car power steering reducer;

[0024] Figure 7 is a schematic top view of an automobile power steering device of the present invention;

[0025] Figure 8 It is a half-section view of the front view of the automobile power steering device of the present invention; DETAILED DESCRIPTION

[0026] The present invention is described clearly and completely below in conjunction with the accompanying drawings. A person skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0027] The technical solutions and technical features provided in each part of the present invention, including the following description, may be combined with each other if there is no conflict.

[0028] In addition, the embodiments of the present invention involved in the following description are generally only a part of the embodiments of the present invention, rather than all the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] About the terms and units in the present invention: The term "comprises" and any variations thereof in the description and claims of the present invention and related parts are intended to cover non-exclusive inclusions.

[0030] Reference Figure 1-8 , an automobile power steering device, comprising the following parts: a screw nut assembly 100, a transmission shaft worm gear assembly 200 drivingly connected to the screw nut assembly 100, and a worm transmission assembly 300 drivingly connected to the transmission shaft worm gear assembly 200;

[0031] The transmission shaft worm gear assembly 200 includes a worm gear shaft 28, on which a sector gear 12 connected to a screw nut assembly 100 is disposed; the worm wheel 15 disposed on the worm gear shaft 28 is connected to a drive motor 10 providing power to the vehicle power steering device through a worm transmission assembly 300;

[0032] The screw-nut assembly 100 includes a steering screw 16, on which a steering nut 17 meshing with the sector gear 12 is mounted, and an inner wall of the steering nut 17 and a tooth groove of the steering screw 16 form a channel for the steel ball 20 to roll, and a guide tube 24 communicating with the channel is provided on the steering nut 17;

[0033] The worm transmission assembly 300 includes a worm 5, which is meshed with the worm wheel 15. A first gear 14 is provided at one end of the worm 5, and the first gear 14 is meshed with a second gear 21; the second gear 21 is connected to the drive motor 10 through a reducer with a planetary gear train arranged inside. The steering screw 16 is arranged parallel to the worm wheel shaft 28. The extension direction of the worm wheel shaft 28 is arranged at a right angle to the extension direction of the worm 5.

[0034] The power steering device for automobiles has high transmission efficiency. The output of the motor is decelerated and torque-increased by the speed reduction mechanism, and then drives the worm gear mechanism to generate large steering assistance. At the same time, since the electric power steering system does not rely on the engine and has no hydraulic oil pipe, it is not sensitive to cold weather and can work even at minus 40 degrees Celsius, so it provides a fast cold start. Because the system does not start preheating, it also saves energy. Without using a hydraulic oil pump, the parasitic energy loss of the engine is avoided, the fuel economy is improved, and all aspects of the needs of large automobile steering devices are met.

[0035] The planetary gear train of the reducer is a double planetary gear set, and the drive motor 10 outputs the torque to the second gear 21 through the planet carrier of the double planetary gear set.

[0036] The double planetary gear set includes a first planetary gear train 7 and a second planetary gear train 8; the planet carrier of the first planetary gear train 7 is drivingly connected to the sun gear of the second planetary gear train 8, and is used to transmit torque to the sun gear of the second planetary gear train 8 through the planet carrier of the first planetary gear train 7; the sun gear of the first planetary gear train 7 is drivingly connected to the drive motor 10 for receiving torque, and the planet carrier of the second planetary gear train 8 is drivingly connected to the second gear 21. The arrangement direction of the first planetary gear train 7 and the second planetary gear train 8 is the same as the extension direction of the worm 5.

[0037] The automotive power steering system presents a set of relatively high-quality solutions. The large input torque is reduced by planetary gears with a larger transmission ratio, so that the steering gear in the solution has a more flexible layout and is more suitable for large and heavy-loaded vehicles. It fills the gap in electric power steering and is more suitable for use in large vehicles. It is green and efficient while also enhancing the driver's comfort during driving.

[0038] The automotive power steering device also includes a steering gear housing main body assembly including a steering gear housing main body 1 for accommodating a screw nut assembly 100, a transmission shaft worm gear assembly 200, and a worm transmission assembly 300. The steering gear housing main body includes a housing main body 1, a side cover 2 and a gear cover 3 that are detachable and sealed from the housing main body. The housing main body 1 and the side cover 2 form a worm cavity 27 for accommodating a worm 5. The side cover 2 is sealed with the housing main body through a side cover sealing gasket, and the side cover is fixed to the housing main body through bolts; the gear cover is sealed with the housing main body through a sealing gasket, and the gear cover is fixed to the housing main body through screws.

[0039] Specifically, the side cover 2 is fixedly connected to the shell body 1 by screws. The side cover 2 seals the connection between the worm shaft 28 and the side cover 2 through a skeleton oil seal 3 (60×85×12). At the same time, the other end of the worm shaft 28 is constrained by the shell body 1 to roll with the solid outer ring needle roller bearing 4. The four-point contact ball bearing constrained by the clamping nut 9 (M42) at the end of the worm shaft 28 is limited in the shell body 1, and the worm 5 is constrained by surface contact with the worm tooth surface of the worm shaft 28. One end of the worm 5 is constrained and connected to the tapered roller bearing 26 through a clamping screw plug (M72), and another tapered roller bearing 26 is symmetrically arranged at the other end. The end of the worm 5 is connected to the first gear 14 by a clamping retaining ring 18, and the bolt 19 is fixed to the clamping retaining ring 18. The gear 14 is then vertically contacted with the second gear 21 according to the transmission requirements. The two gears are protected by the gear cover seal 22 and the gear cover 23. The second gear 21 is then connected to the drive motor 10 through the skeleton oil seal 13 (45×70×12). The fan-shaped gear at one end of the worm shaft 28 close to the physical outer ring needle bearing 4 contacts the steering nut 17 in the screw nut assembly 100. The steering nut 17 is connected to the steering screw by the guide tube 24 and the guide tube clamp 25 with M5×8 screws. One end of the steering screw is fixed by the eccentric sleeve 6 by the locking ring and the clamping screw plug (M72), and the other end is connected to the upper cover assembly 11 through the bearing.

[0040] When in use, the torque sensor installed on the steering shaft continuously measures the torque signal on the steering shaft as the steering wheel is operated, so that the signal and the vehicle speed signal are simultaneously input to the electronic control unit. The electronic control unit determines the magnitude and direction of the power-assist torque based on the input signal, that is, determines the magnitude and direction of the electric motor current, and adjusts the magnitude of the steering auxiliary power. The torque of the drive motor is decelerated and increased by the electromagnetic clutch through the reducer, and then loaded on the steering mechanism of the car, so that it obtains a steering force that is adapted to the working conditions of the car.

[0041] The electronic control unit (ECU) determines the rotation direction and optimal power torque of the motor according to the signals output by each sensor, sends control signals to the motor and clutch, and controls the rotation of the DC motor through the power drive circuit. After the output of the motor is decelerated and torque-increased by the reduction mechanism, a two-stage planetary reducer with a larger transmission ratio is used, and the worm gear transmission is used to reduce the input torque. At the same time, on the basis of the recirculating ball structure, the transmission efficiency of the transmission system is increased. This automotive power steering device has a more flexible layout and has the possibility and practical demand for application in large special vehicles.

[0042] Those skilled in the art will be able to implement the present invention based on these descriptions. Based on the above content of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

Claims

1. Automobile power steering gear, characterized in that: It includes a screw-nut assembly, a transmission shaft worm gear assembly drivingly connected to the screw-nut assembly, and a worm transmission assembly drivingly connected to the transmission shaft worm gear assembly; The transmission shaft worm gear assembly includes a worm gear shaft, on which a sector gear connected to a screw nut assembly is disposed; the worm gear disposed on the worm gear shaft is connected to a drive motor that provides power to the vehicle power steering device through a worm transmission assembly; The screw-nut assembly comprises a steering screw, on which a steering nut meshing with the sector gear is mounted, an inner wall of the steering nut and a tooth groove of the steering screw form a channel for the steel ball to roll, and a conduit communicating with the channel is provided on the steering nut; The worm transmission assembly includes a worm, which is meshed with the worm wheel. A first gear is provided at one end of the worm, and the first gear is meshed with a second gear; the second gear is connected to a drive motor through a reducer with a planetary gear train arranged inside.

2. The automotive power steering device according to claim 1, characterized in that: The planetary gear train of the reducer is a double planetary gear set, and the drive motor outputs torque to the second gear through the planet carrier of the double planetary gear set.

3. The automotive power steering device according to claim 2, characterized in that: The double planetary gear set includes a first planetary gear train and a second planetary gear train; the planet carrier of the first planetary gear train is drivingly connected to the sun gear of the second planetary gear train, and is used to transmit torque to the sun gear of the second planetary gear train through the planet carrier of the first planetary gear train; the sun gear of the first planetary gear train is drivingly connected to the drive motor for receiving torque, and the planet carrier of the second planetary gear train is drivingly connected to the second gear.

4. The automotive power steering device according to claim 3, characterized in that: The arrangement direction of the first planetary gear train and the second planetary gear train is the same as the extension direction of the worm.

5. The automotive power steering device according to claim 1, characterized in that: The automobile power steering gear also includes a steering gear housing main body component, which includes a steering gear housing main body for accommodating a screw nut assembly, a transmission shaft worm gear assembly, and a worm transmission assembly. The steering gear housing main body includes a housing main body, a side cover and a gear cover that are detachable and sealed from the housing main body.

6. The automotive power steering device according to claim 5, characterized in that: The side cover is sealed with the shell body through a side cover sealing gasket, and the side cover is fixed to the shell body through bolts; the gear cover is sealed with the shell body through a sealing gasket, and the gear cover is fixed to the shell body through screws.

7. The automotive power steering device according to claim 1, characterized in that: The steering screw is arranged parallel to the worm gear shaft.

8. The automotive power steering device according to claim 1, characterized in that: The extending direction of the worm wheel shaft is arranged at a right angle to the extending direction of the worm.

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