Electric power steering gear driven by planetary roller screw
By using electric power steering gear driven by planetary roller screw in heavy commercial vehicles, the wear problem of traditional worm gear and worm reduction transmission mechanism is solved, and the electric power steering system with high torque output and good stability is achieved, satisfying the heavy commercial use Car steering demand.
Patent Information
- Application Number
- CN202421181503.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-28
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-05-28
AI Technical Summary
The traditional worm gear and worm reduction transmission mechanism wears due to friction transmission, resulting in increased clearance and increased delay, making it difficult to meet the high torque steering needs of heavy commercial vehicles.
Electric power steering gear driven by planetary roller screws, including a power assist motor, a planetary roller reduction transmission mechanism and a power-end pulley reduction transmission mechanism, torque amplification is achieved through screw studs and roller nut racks, replacing the traditional hydraulics Steering system.
It realizes a pure electric drive steering system with high structural stability, low noise, and easy to assemble and adjust, improves torque output and transmission efficiency, reduces wear, and meets the high torque steering needs of heavy-duty commercial vehicles.
Smart Images
Figure CN222224247U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of automobile steering, in particular to an electric power steering device driven by a planetary roller screw. Background Art
[0002] Traditional heavy-duty commercial vehicles generally use a recirculating ball hydraulic power steering gear, which is driven by the engine to drive the hydraulic oil pump to provide steering power. Because the steering of the wheels requires a large torque under the influence of the vehicle's own weight, a reduction mechanism is provided between the auxiliary motor and the steering shaft to increase the torque. Conventional gear reduction mechanisms need to change the gear ratio. When a large torque state is required, a large number of gears need to be superimposed. Therefore, many use worm gears to achieve a large reduction ratio to increase the torque.
[0003] At present, the traditional worm gear reduction transmission mechanism will wear because the worm gear mainly relies on the friction transmission between the side of the worm wheel teeth and the spiral side of the worm. That is, there is a gap between the worm gear and the worm. When the steering is switched, the gap will cause the worm to idle until the worm contacts the worm wheel again to drive, and the gap between the worm and the worm wheel will further increase. As the worm and the worm wheel wear, the delay will continue to increase. Therefore, there is an urgent need for an electric power steering with a planetary roller screw drive to solve the above problems. Utility Model Content
[0004] 1. Technical issues to be solved
[0005] In view of the shortcomings of the prior art, the utility model provides an electric power steering device with a planetary roller screw drive, which has the advantages of replacing a hydraulic steering system, etc., and solves the problem of wear in traditional worm gear reduction transmission mechanisms because the worm gear mainly relies on the friction transmission between the side of the worm gear teeth and the spiral side of the worm.
[0006] (II) Technical solution
[0007] The utility model provides a technical solution to the above-mentioned technical problems as follows: an electric power steering device with a planetary roller screw drive, comprising a shell, a power-assisting motor is fixedly mounted on the side wall of the shell, a power-assisting controller is mounted on the top of the power-assisting motor, a power-assisting end pulley reduction transmission mechanism is mounted on the output shaft of the power-assisting motor, a planetary roller reduction transmission mechanism is mounted inside the shell, a gear fan transmission member is mounted inside the shell and is transmission-connected to the planetary roller reduction transmission mechanism, the planetary roller reduction transmission mechanism comprises a screw stud rotatably connected to the inside of the shell, a cylindrical screw shaft assembly is mounted on the top of the screw stud, a roller nut rack is mounted outside the screw stud, a roller wheel cover is mounted inside the roller nut rack, a roller transmission connected to the screw stud is rotationally connected inside the roller wheel cover.
[0008] The beneficial effects of the utility model are:
[0009] The electric power steering device with planetary roller screw drive can replace the hydraulic steering system and realize the steering of the pure electric drive steering system. It has good structural stability, low noise, easy assembly, and easy adjustment operation.
[0010] On the basis of the above technical solution, the present invention can also be improved as follows.
[0011] Furthermore, a sensor housing is fixedly connected to the top of the housing, and a steering wheel mechanical connection spline is rotatably connected to the interior of the sensor housing.
[0012] Furthermore, a sensor support cover is installed inside the sensor housing, and a torque angle sensor is installed inside the sensor support cover.
[0013] Furthermore, the cylindrical screw shaft assembly includes a torsion bar assembled inside the screw stud, and the outside of the torsion bar is equipped with an input shaft spline.
[0014] Furthermore, a lower end shell is fixedly connected to the bottom of the shell, and a bearing is assembled at the connection between the lower end shell and the screw rod stud.
[0015] Furthermore, the power-assisting end pulley reduction transmission mechanism includes a first synchronous pulley fixedly connected to the output shaft of the power-assisting motor, the external transmission of the first synchronous pulley is connected with a synchronous belt, the bottom of the screw stud is fixedly connected with a second synchronous pulley, and the end of the synchronous belt away from the first synchronous pulley is transmission-connected to the second synchronous pulley. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of the structure of the utility model;
[0017] Figure 2 This is a cross-sectional view of the structure of the utility model;
[0018] Figure 3 It is a structural schematic diagram of the belt pulley reduction transmission mechanism at the power-assisting end of the utility model;
[0019] Figure 4 It is a structural schematic diagram of the planetary roller reduction transmission mechanism in the utility model;
[0020] Figure 5 This is a schematic diagram of the structure of the roller nut rack in the utility model;
[0021] Figure 6 It is a schematic diagram of the structure of the roller in the utility model;
[0022] Figure 7 It is a structural schematic diagram of the cylindrical screw shaft assembly in the utility model.
[0023] In the figure: 1. Steering wheel mechanical connection spline; 2. Torque angle sensor; 3. Power-assist controller; 4. Power-assist motor; 6. Gear fan transmission; 7. Housing; 9. Power-assist end pulley reduction transmission mechanism; 10. Planetary roller reduction transmission mechanism; 11. First synchronous pulley; 12. Synchronous belt; 13. Second synchronous pulley; 14. Cylindrical screw shaft assembly; 15. Roller wheel cover; 16. Roller; 17. Roller nut rack; 18. Torsion bar; 19. Input shaft spline; 20. Screw stud; 21. Sensor support cover; 22. Sensor housing; 23. Bearing; 24. Lower end housing. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0025] In the embodiment, Figure 1-4 An electric power steering device with planetary roller screw drive is provided. The utility model comprises a housing 7, a power motor 4 is fixedly mounted on the side wall of the housing 7, a power controller 3 is mounted on the top of the power motor 4, a power end pulley reduction transmission mechanism 9 is mounted on the output shaft of the power motor 4, a planetary roller reduction transmission mechanism 10 is mounted inside the housing 7, and a gear fan transmission member 6 is mounted inside the housing 7 and is transmission-connected to the planetary roller reduction transmission mechanism 10;
[0026] The planetary roller reduction transmission mechanism 10 includes a screw stud 20 rotatably connected to the inside of the housing 7, a cylindrical screw shaft assembly 14 is assembled on the top of the screw stud 20, a roller nut rack 17 is assembled on the outside of the screw stud 20, a roller wheel cover 15 is assembled inside the roller nut rack 17, and a roller 16 that is rotatably connected to the screw stud 20 for transmission is assembled inside the roller wheel cover 15.
[0027] In this embodiment, in actual use, the number of roller wheel covers 15 is two, and the planetary roller reduction transmission mechanism 10 is composed of the roller wheel cover 15 and the roller 16 installed between the roller nut rack 17 and the screw stud 20, the bosses at both ends of the roller 16 are installed in the holes of the roller wheel cover 15, and the roller wheel cover 15 is tightly installed on the two end surfaces of the roller nut rack 17 with interference fit, and the assembly is completed.
[0028] In this embodiment, in actual use, compared with the traditional worm gear reduction transmission mechanism steering system, a set of planetary roller screw transmission mechanism is added to realize two-level torque conversion, which greatly improves the torque required for vehicle rotation. Compared with the traditional worm gear reduction transmission mechanism, a large amount of installation space is saved, the power assistance strength is increased, and the transmission efficiency is increased.
[0029] The top of the housing 7 is fixedly connected with a sensor housing 22 , the interior of the sensor housing 22 is rotatably connected with a steering wheel mechanical connection spline 1 , the interior of the sensor housing 22 is equipped with a sensor support cover 21 , and the interior of the sensor support cover 21 is equipped with a torque angle sensor 2 .
[0030] The cylindrical screw shaft assembly 14 includes a torsion bar 18 assembled inside the screw stud 20. The outside of the torsion bar 18 is equipped with an input shaft spline 19. The input shaft spline 19 is used in conjunction with the steering wheel mechanical connection spline 1. The cylindrical screw shaft assembly 14 is to press the torsion bar 18 into the upper end hole of the screw stud 20, and then the input shaft spline 19 is inserted into the torsion bar 18. The spline is tightly fixed by drilling and pressing pins. The assembly of this assembly is completed, and the assembly accuracy is controlled by a certain size.
[0031] A lower housing 24 is fixedly connected to the bottom of the housing 7 , and a bearing 23 is assembled at the connection between the lower housing 24 and the screw stud 20 .
[0032] The power-assisting end pulley reduction transmission mechanism 9 includes a first synchronous pulley 11 fixedly connected to the output shaft of the power-assisting motor 4, the external transmission connection of the first synchronous pulley 11 is connected with a synchronous belt 12, the bottom of the screw stud 20 is fixedly connected with a second synchronous pulley 13, and the end of the synchronous belt 12 away from the first synchronous pulley 11 is connected with the second synchronous pulley 13 for transmission.
[0033] The power-assisting motor 4 outputs a certain speed and torque, and uses the small wheel to drive the large wheel to amplify the torque and reduce the speed. The second synchronous pulley 13 drives the screw stud 20 to rotate, and the screw stud 20 links the roller 16, and the roller nut rack 17 moves up and down. The roller 16 drives the lower roller nut rack 17 to amplify the thrust again, and the roller nut rack 17 meshes with the gear fan transmission 6 to convert the thrust into torque and output it to the upper connecting rod to complete the steering.
[0034] Among them, by replacing the traditional worm gear reduction transmission mechanism with a pulley reduction transmission mechanism, the transmission ratio can be better met, and after conversion, the product can provide corresponding sufficient torque to achieve driving steering.
[0035] Working principle:
[0036] According to the hand force input on the steering wheel, the torque angle sensor 2 receives the signal, and the information is input into the power-assisting controller 3. The power-assisting controller 3 calculates and transforms the output electrical signal to the power-assisting motor 4. The power-assisting motor 4 itself outputs the corresponding torque and speed due to the rotation of the voltage and current. The torque is amplified by the power-assisting end pulley reduction transmission mechanism 9, and then further amplified by the planetary roller reduction transmission mechanism 10 to the gear fan transmission member 6 to output the corresponding steering torque. The end of the gear fan transmission member 6 is connected to the swing arm connecting rod, and the rod is connected to the wheel to realize the steering driving function.
[0037] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.
[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. An electric power steering device with planetary roller screw drive, comprising a housing (7), characterized in that: A power-assisting motor (4) is fixedly mounted on the side wall of the housing (7); a power-assisting controller (3) is mounted on the top of the power-assisting motor (4); a power-assisting end pulley reduction transmission mechanism (9) is mounted on the output shaft of the power-assisting motor (4); a planetary roller reduction transmission mechanism (10) is mounted inside the housing (7); and a gear fan transmission member (6) is mounted inside the housing (7) and is transmission-connected to the planetary roller reduction transmission mechanism (10); The planetary roller reduction transmission mechanism (10) comprises a screw stud (20) rotatably connected to the inside of a housing (7); a cylindrical screw shaft assembly (14) is mounted on the top of the screw stud (20); a roller nut rack (17) is mounted on the outside of the screw stud (20); a roller wheel cover (15) is mounted on the inside of the roller nut rack (17); and a roller (16) rotatably connected to the inside of the roller wheel cover (15) and connected to the screw stud (20).
2. The electric power steering device with planetary roller screw drive according to claim 1, characterized in that: The top of the housing (7) is fixedly connected to a sensor housing (22), and the interior of the sensor housing (22) is rotatably connected to a steering wheel mechanical connection spline (1).
3. The electric power steering device with planetary roller screw drive according to claim 2, characterized in that: A sensor support cover (21) is mounted inside the sensor housing (22), and a torque angle sensor (2) is mounted inside the sensor support cover (21).
4. The electric power steering device with planetary roller screw drive according to claim 1, characterized in that: The cylindrical screw shaft assembly (14) comprises a torsion bar (18) which is assembled inside a screw stud (20), and an input shaft spline (19) is assembled outside the torsion bar (18).
5. The electric power steering device with planetary roller screw drive according to claim 1, characterized in that: The bottom of the housing (7) is fixedly connected to a lower housing (24), and a bearing (23) is mounted at the connection between the lower housing (24) and the screw stud (20).
6. The electric power steering device with planetary roller screw drive according to claim 1, characterized in that: The boost end pulley reduction transmission mechanism (9) comprises a first synchronous pulley (11) fixedly connected to the output shaft of the boost motor (4); the first synchronous pulley (11) is externally transmission-connected with a synchronous belt (12); the bottom of the screw stud (20) is fixedly connected with a second synchronous pulley (13); and one end of the synchronous belt (12) away from the first synchronous pulley (11) is transmission-connected with the second synchronous pulley (13).