Electric recirculating ball steering gear

Abstract

The utility model relates to an electric recirculating ball steering gear, and belongs to the technical field of automobile steering systems. Comprising a shell, an input shaft, a ball screw and a synchronous belt mechanism, the input shaft is movably installed on the shell, the ball screw is fixedly installed at one end of the input shaft in the shell, a ball nut is installed on the ball screw through a ball, a fan-shaped shaft is installed on the shell on one side of the ball nut, and the ball nut is meshed with the fan-shaped shaft. An upper worm gear and a lower worm gear are fixedly installed on the ball screw at intervals, an upper worm and a lower worm are installed on the shell on one side of the upper worm gear and one side of the lower worm gear respectively, the upper worm is meshed with the upper worm gear, the lower worm is meshed with the lower worm gear, and the upper worm and the lower worm are connected through a synchronous belt mechanism. A double-winding power-assisted motor is fixedly installed on the shell corresponding to the lower worm through a motor installation base, and a double-plate controller is installed on the double-winding power-assisted motor. The electric recirculating ball steering gear is compact in structure, small in size, long in service life, safe and reliable.

Description

Technical Field

[0001] The utility model relates to an electric circulating ball steering gear, belonging to the technical field of automobile steering systems. Background Art

[0002] With the development of intelligent technology in commercial vehicles, there is an urgent need to realize electrification and intelligence of steering systems and equip electric intelligent steering systems. At present, the commonly used solution for intelligent steering gears in commercial vehicles is electric recirculating ball steering gear. Electric recirculating ball intelligent steering gear adds a set of electric power-assisting mechanism on the basis of traditional mechanical recirculating ball steering gear to achieve intelligent control of output torque and steering angle, thereby meeting the intelligent driving needs of commercial vehicles.

[0003] For example, the Chinese patent publication number CN113811479A is titled as an automobile steering device, which includes a housing, the housing including a ball screw, a ball nut connected to the ball screw through balls, and a fan-shaped shaft meshed with the ball nut, an output shaft, the output shaft being connected to the ball screw; a reducer, the reducer including a worm gear connected to the output shaft and a first worm shaft and a second worm shaft meshed with the worm gear; and a motor, the motor being connected to the first worm shaft and the second worm shaft via a gear box, the first worm shaft and the second worm shaft being located on opposite sides of the worm gear, and the first worm shaft and the second worm shaft need to rotate in opposite directions respectively. The automobile steering device drives the first worm shaft and the second worm shaft to rotate in opposite directions by cooperating with the first gear, the second gear, the third gear and the fourth gear through the motor, and the first worm shaft and the second worm shaft simultaneously drive the worm gear to rotate, and the worm gear drives the output shaft to rotate synchronously.

[0004] Although the automobile steering device can assist in rotating the output shaft through the cooperation of a double worm, a single worm wheel and a gear set, it is limited by the installation space of the vehicle chassis. The gear set structure is large in size and will take up more space on the vehicle. On the other hand, the transmission structure of the double worm and single worm wheel can easily cause serious wear of the worm wheel's teeth, resulting in a short service life of the worm wheel and posing certain safety hazards. Therefore, it is necessary to improve it. Summary of the Invention

[0005] The purpose of the utility model is to provide an electric recirculating ball steering gear with compact structure, small size, long service life, safety and reliability.

[0006] The technical solution of the utility model is:

[0007] An electric recirculating ball steering gear comprises a housing, an input shaft, a ball screw and a synchronous belt mechanism, wherein the input shaft is movably mounted on the housing, a ball screw is fixedly mounted on one end of the input shaft in the housing, a ball nut is mounted on the ball screw through a ball, a sector shaft is mounted on the housing on one side of the ball nut, and the ball nut is meshed with the sector shaft, and is characterized in that an upper worm gear and a lower worm gear are fixedly mounted on the ball screw at intervals, an upper worm and a lower worm gear are respectively mounted on the housing on one side of the upper worm gear and the lower worm gear, the upper worm gear is meshed with the upper worm gear, the lower worm gear is meshed with the lower worm gear, the upper worm gear and the lower worm gear are connected by a synchronous belt mechanism, a double-winding power-assisting motor is fixedly mounted on the housing corresponding to the lower worm gear through a motor mounting seat, and the double-winding power-assisting motor is equipped with a double-board controller.

[0008] The synchronous belt mechanism includes an upper pulley, a lower pulley, a synchronous belt and a tensioner. The upper pulley is fixedly mounted on the upper worm, and the lower pulley is fixedly mounted on the lower worm. An eccentric disk is fixedly mounted on the shell on one side of the center of the upper pulley and the lower pulley by bolts. A tensioner is movably mounted on the eccentric disk through a bearing. A synchronous belt is mounted on the upper pulley and the lower pulley, and the tensioner is in contact with the outer side of the synchronous belt.

[0009] One end of the input shaft extends to the outside of the shell.

[0010] A shaft sleeve is sleeved on the ball screw between the upper worm gear and the lower worm gear.

[0011] One end of the worm is movably connected to the housing via a deep groove ball bearing, and one end of the worm is movably connected to the housing via a four-point angular contact ball bearing.

[0012] A torsion bar is arranged inside the input shaft, and a dual-chip four-channel torque angle sensor is mounted on the input shaft and the outer circle of the ball screw.

[0013] The beneficial effects of the present invention compared with the prior art are:

[0014] As the input shaft of the electric recirculating ball steering gear rotates synchronously with the steering wheel, the torsion bar in the input shaft undergoes torsional deformation, and the dual-chip four-channel torque angle sensor arranged on the input shaft and the ball screw sends the measured torque and angle signals to the dual-board controller. The dual-board controller controls the dual-winding power-assist motor to output appropriate power-assist torque to the lower worm gear based on the torque signal and angle signal and in combination with the vehicle speed signal, etc. Since the lower worm gear and the upper worm gear are connected by the upper pulley, the lower pulley and the synchronous belt, when the power-assist torque drives the lower worm gear to rotate, the upper worm gear rotates synchronously, and when the upper worm gear and the lower worm gear rotate synchronously, the upper worm gear drives the upper worm gear to rotate, and the lower worm gear drives the lower worm gear to rotate, thereby transmitting the power-assist torque of the dual-winding power-assist motor to the input shaft of the steering gear. The synchronous belt mechanism of the electric recirculating ball steering gear is compact in size, effectively reducing the space occupied by the vehicle. The synchronous belt mechanism can synchronously drive the upper worm and the lower worm to rotate synchronously, and the upper worm and the lower worm drive the upper worm wheel and the lower worm wheel to rotate, thereby transmitting the power assist torque to the ball screw and the input shaft. The double worm wheel and double worm structural design can reduce the wear of the worm wheel teeth while ensuring sufficient torque force, thereby extending the service life. At the same time, the dual-chip four-channel torque angle sensor, dual-board controller and dual-winding power assist motor adopted can enhance the redundant structure of steering safety. When one of the sensor chips or a controller or a motor winding fails, the other sensor chip or a controller or a motor winding can still provide steering assistance, thereby improving the steering safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a front view structural diagram of the utility model;

[0016] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure along the AA direction;

[0017] Figure 3 for Figure 1 Schematic diagram of the cross-sectional structure along the BB direction.

[0018] In the figure: 1. Housing; 2. Input shaft; 3. Ball screw; 4. Torsion bar; 5. Dual-chip four-channel torque angle sensor; 6. Sector shaft; 7. Upper worm gear; 8. Lower worm gear; 9. Upper worm; 10. Lower worm; 11. Deep groove ball bearing; 12. Four-point angular contact ball bearing; 13. Upper pulley; 14. Lower pulley; 15. Synchronous belt; 16. Tensioner; 17. Bolt; 18. Eccentric disk; 19. Bushing; 20. Dual-winding power-assisted motor; 21. Four-claw coupling; 22. Dual-board controller; 23. Motor mounting base. DETAILED DESCRIPTION

[0019] As attached Figure 1-3 shown

[0020] The electric recirculating ball steering gear includes a housing 1, an input shaft 2, a ball screw 3 and a synchronous belt mechanism. The input shaft 2 is movably mounted on the housing 1 via a bearing. A torsion bar 4 is disposed within the input shaft 2. A dual-chip four-channel torque angle sensor 5 (model: Valeo TAS 4+4) is mounted on the outer circumference of the input shaft 2 and the ball screw 3. The dual-chip four-channel torque angle sensor 5 is a commercially available component. During operation, if one of the sensor chips in the dual-chip four-channel torque angle sensor 5 fails, the other sensor chip can be used to normally control steering and improve vehicle steering safety.

[0021] A ball screw 3 is fixedly mounted on one end of the input shaft 2 in the housing 1, and the other end of the input shaft 2 extends to the outside of the housing 1. The input shaft 2 extending to the outside of the housing 1 is connected to the driver's steering wheel through a connecting arm (not shown). During operation, when the driver turns the steering wheel, the input shaft 2 will rotate synchronously with the steering wheel. When the input shaft 2 rotates, the torsion bar 4 undergoes torsional deformation. The dual-chip four-channel torque angle sensor 5 is connected to the torsion bar 4 through a rotation angle / displacement converter. When the torsion bar 4 is deformed, the dual-chip four-channel torque angle sensor 5 arranged on the input shaft 2 and the ball screw 3 sends the measured torque signal and rotation angle signal applied by the driver to the steering wheel to the dual-board controller 22.

[0022] A ball nut is mounted on the ball screw 3 via balls, and a sector shaft 6 is mounted on the housing 1 on one side of the ball nut. The ball nut is meshed with the sector shaft 6. During operation, when the ball screw 3 rotates, the ball screw 3 converts the rotational motion of the ball screw 3 into axial movement of the ball nut through the rolling of the balls. When the ball nut and the sector shaft 6 are meshed with each other, when the ball nut slides, the sector shaft 6 can rotate, so that the connecting rod (not shown) connected to the sector shaft 6 can be operated, and then the wheels can be steered through the connecting rod.

[0023] An upper worm gear 7 and a lower worm gear 8 are fixedly installed on the ball screw 3 at intervals. An upper worm gear 9 and a lower worm gear 10 are respectively mounted on the housing 1 on the same side of the upper worm gear 7 and the lower worm gear 8. One end of the upper worm gear 9 and the lower worm gear 10 are movably connected to the housing 1 through a deep groove ball bearing 11, and the other end of the upper worm gear 9 and the lower worm gear 10 are movably connected to the housing 1 through a four-point angular contact ball bearing 12. During operation, the upper worm gear 9 and the lower worm gear 10 can rotate in the housing 1.

[0024] The upper worm 9 is meshed with the upper worm wheel 7, and the lower worm 10 is meshed with the lower worm wheel 8. During operation, when the upper worm 9 rotates, it drives the upper worm wheel 7 to rotate synchronously, and when the lower worm 10 rotates, it drives the lower worm wheel 8 to rotate synchronously.

[0025] The upper worm 9 and the lower worm 10 are connected by a synchronous belt mechanism, which includes an upper pulley 13, a lower pulley 14, a synchronous belt 15 and a tensioning pulley 16. The upper pulley 13 is fixedly mounted on the upper worm 9, and the lower pulley 14 is fixedly mounted on the lower worm 10. An eccentric disk 18 is fixedly mounted on the housing 1 on one side of the center of the upper pulley 13 and the lower pulley 14 by a bolt 17. A tensioning pulley 16 is movably mounted on the eccentric disk 18 through a bearing. During operation, the tensioning pulley 16 can rotate relative to the eccentric disk 18. By adjusting the tightness of the bolt 17, the position of the eccentric disk 18 can be adjusted by rotating the bolt 17 as the axis, and then the bolt 17 is tightened to fix the eccentric disk 18. Thus, the tension of the synchronous belt 15 is adjusted by cooperating with the eccentric disk 18, the tensioning pulley 16 and the synchronous belt 15, so that the tension of the synchronous belt 15 meets the design requirements.

[0026] A synchronous belt 15 is mounted on the upper pulley 13 and the lower pulley 14 , and a tensioning wheel 16 is connected to the outer side of the synchronous belt 15 . When working, the tensioning wheel 16 is used to tension the synchronous belt 15 .

[0027] A shaft sleeve 19 is mounted on the ball screw 3 between the upper worm gear 7 and the lower worm gear 8 . During operation, the shaft sleeve 19 is used to limit the upper worm gear 7 and the lower worm gear 8 .

[0028] A dual-winding power-assisting motor 20 is fixedly mounted on the housing 1 corresponding to the lower worm 10 through a motor mounting base 23. The transmission shaft of the dual-winding power-assisting motor 20 is connected to the lower worm 10 through a four-claw coupling 21. The dual-winding power-assisting motor 20 is a commercially available component. A dual-board controller 22 (PLC model is TC334LP) is installed on the dual-board controller 22. The dual-board controller 22 is a commercially available component. The dual-board controller 22 is electrically connected to the dual-winding power-assisting motor 20 and the dual-chip four-channel torque angle sensor 5. When working, the dual-board controller 22 can control the dual-winding power-assisting motor 20 to output appropriate power-assisting torque to the lower worm 10 according to the torque signal and angle signal transmitted by the dual-chip four-channel torque angle sensor 5 and combined with the vehicle speed signal.

[0029] When the electric recirculating ball steering gear is working, when the driver turns the steering wheel, the input shaft 2 of the steering gear rotates synchronously with the steering wheel. At this time, the torsion bar 4 in the input shaft 2 undergoes torsional deformation, and the dual-chip four-channel torque angle sensor 5 set on the input shaft 2 and the ball screw 3 will measure the torque and angle applied by the driver to the steering wheel, and send the measured torque signal and angle signal to the dual-board controller 22. The dual-board controller 22 controls the dual-winding power-assisted motor 20 to output appropriate power-assisted torque to the lower worm 10 based on the torque signal and angle signal and in combination with the vehicle speed signal.

[0030] Since the lower worm 10 and the upper worm 9 are connected by the upper pulley 13, the lower pulley 14 and the synchronous belt 15, when the power-assist torque drives the lower worm 10 to rotate, the upper worm 9 rotates synchronously. When the upper worm 9 and the lower worm 10 rotate synchronously, the upper worm 9 drives the upper worm wheel 7 to rotate, and the lower worm 10 drives the lower worm wheel 8 to rotate, thereby transmitting the power-assist torque of the double-winding power-assist motor 20 to the input shaft 2 of the steering gear.

[0031] The synchronous belt mechanism of the electric recirculating ball steering gear is compact and can effectively reduce the space occupied by the vehicle. The synchronous belt mechanism can synchronously drive the upper worm 9 and the lower worm 10 to rotate synchronously. The upper worm 9 and the lower worm 10 drive the upper worm wheel 7 and the lower worm wheel 8 to rotate, thereby transmitting the power assist torque to the ball screw 3 and the input shaft 2. The double-worm wheel and double-worm structural design can reduce the wear of the worm wheel teeth while ensuring sufficient torque force, thereby extending the service life. At the same time, the dual-chip four-channel torque angle sensor 5, dual-board controller 22 and dual-winding power assist motor 20 adopted can enhance the redundant structure of steering safety. When one of the sensor chips or a controller or a motor winding fails, the other sensor chip or a controller or a motor winding can still provide steering assistance, thereby improving the steering safety of the vehicle.

Claims

1. An electric recirculating ball steering gear, comprising a housing (1), an input shaft (2), a ball screw (3) and a synchronous belt mechanism, wherein the housing (1) is movably mounted with the input shaft (2), one end of the input shaft (2) in the housing (1) is fixedly mounted with the ball screw (3), a ball nut is mounted on the ball screw (3) via a ball, a sector shaft (6) is mounted on the housing (1) on one side of the ball nut, and the ball nut is engaged with the sector shaft (6), characterized in that: An upper worm wheel (7) and a lower worm wheel (8) are fixedly installed on the ball screw (3) at intervals. An upper worm (9) and a lower worm (10) are respectively installed on the housing (1) on one side of the upper worm wheel (7) and the lower worm wheel (8). The upper worm (9) is engaged with the upper worm wheel (7), and the lower worm (10) is engaged with the lower worm wheel (8). The upper worm (9) and the lower worm (10) are connected by a synchronous belt mechanism. A double-winding power-assisting motor (20) is fixedly installed on the housing (1) corresponding to the lower worm (10) through a motor mounting seat (23). The double-winding power-assisting motor (20) is connected to the lower worm (10). A double-board controller (22) is installed on the outside of the double-winding power-assisting motor (20).

2. The electric recirculating ball steering gear according to claim 1, characterized in that: The synchronous belt mechanism comprises an upper pulley (13), a lower pulley (14), a synchronous belt (15) and a tensioning wheel (16), wherein the upper pulley (13) is fixedly mounted on the upper worm (9), and the lower pulley (14) is fixedly mounted on the lower worm (10), an eccentric disk (18) is fixedly mounted on the housing (1) on one side of the center of the upper pulley (13) and the lower pulley (14) by means of bolts (17), a tensioning wheel (16) is movably mounted on the eccentric disk (18) via a bearing, a synchronous belt (15) is mounted on the upper pulley (13) and the lower pulley (14), and the tensioning wheel (16) is in contact with the outer side of the synchronous belt (15).

3. The electric recirculating ball steering gear according to claim 1, characterized in that: One end of the input shaft (2) extends to the outside of the housing (1).

4. The electric recirculating ball steering gear according to claim 1, characterized in that: A shaft sleeve (19) is mounted on the ball screw (3) between the upper worm gear (7) and the lower worm gear (8).

5. The electric recirculating ball steering gear according to claim 1, characterized in that: One end of the worm is movably connected to the housing (1) via a deep groove ball bearing (11), and one end of the worm is movably connected to the housing (1) via a four-point angular contact ball bearing (12).

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