CN219969767U - Pure electric power steering gear for commercial medium and heavy truck - Google Patents

Abstract

The utility model belongs to the technical field of automobile manufacturing, and relates to a pure electric power steering gear for a commercial medium-heavy truck, which comprises an input shaft, a torsion bar, a torque rotation angle sensor, a first worm, a first motor, a worm wheel, a second worm, a second motor, a roller screw, a sector gear, a rocker shaft, a nut and a shell; the utility model uses the whole vehicle storage battery as a power source, completely abandons a hydraulic system, perfectly solves the problems of high energy consumption, easy leakage and environment unfriendly hydraulic steering system, and can improve the cost of the system due to the reduction of the parts of the hydraulic system, so that the arrangement and matching of the steering system on the whole vehicle are easier, the structural strength is effectively improved, and the electric power steering system can be applied to medium-heavy truck types.

Description

Pure electric power steering gear for commercial medium and heavy truck

Technical Field

The utility model belongs to the technical field of automobile manufacturing, and relates to a pure electric power steering gear for a commercial medium-heavy truck.

Background

With the rapid development of the automobile industry, the intelligent driving technology is developed, an electric power steering system (EPS) is widely used on passenger cars, and in recent years, the electric power steering on light new energy commercial vehicles is gradually standard, but because the load of a steering shaft of a medium-heavy truck is large, the strength of structural members such as worm gears, ball screws and the like of the conventional electric power steering system is limited, and the conventional electric power steering system cannot be matched; at present, most of medium and heavy truck types still use traditional recirculating ball hydraulic steering gears, and the hydraulic steering gears have the defects of high energy consumption, easy leakage, unfriendly environment, poor resilience, heavy low-speed steering, floating high-speed steering, poor steering hand feeling and the like due to the self structural reasons, and the hydraulic steering gears cannot communicate with the whole truck, so that the functions of speed-following power assistance, multi-mode steering, lane keeping, crosswind compensation and the like cannot be realized, the driving labor intensity of a driver is high, and the driver is easy to fatigue; in addition, some middle-heavy truck type electro-hydraulic steering systems are applied, namely, a set of electric power assisting system is overlapped on the basis of the hydraulic steering system, so that the communication with the whole vehicle can be realized, the functions of speed-following power assisting, steering in multiple modes, lane keeping, side wind compensation and the like are realized, but the hydraulic system is not completely abandoned, the defects of high energy consumption, easy leakage, unfriendly environment and the like exist, the steering system cannot provide full power when the hydraulic pressure fails, the hand feeling is heavy, risks are easy to generate, and in addition, the matching cost is greatly improved due to the fact that a set of electric power assisting system is added.

The existing pure hydraulic steering gear, electromechanical circulating ball steering gear and electro-hydraulic steering gear have the following different defects, and the specific defects are as follows:

1. the conventional electric power steering system cannot be directly matched and applied to medium-heavy truck types due to the limited strength of structural members such as worm gears, ball screws and the like;

2. at present, most of medium and heavy truck types still use traditional recirculating ball hydraulic steering gears, and the hydraulic steering gears have the defects of high energy consumption, easy leakage, unfriendly environment, poor resilience, heavy low-speed steering, floating high-speed steering, poor steering hand feeling and the like due to the self structural reasons, and the hydraulic steering gears cannot communicate with the whole truck, so that the functions of speed-following power assisting, multi-mode steering, lane keeping, crosswind compensation and the like cannot be realized, the driving labor intensity of a driver is high, and the driver is easy to fatigue.

3. In part, the electro-hydraulic steering system is applied to a heavy truck, namely, a set of electric power assisting system is overlapped on the basis of the hydraulic steering system, so that the functions of speed-following power assistance, steering in multiple modes, lane keeping, crosswind compensation and the like are realized although the communication with the whole truck can be realized, but the hydraulic system is not completely abandoned, the defects of high energy consumption, easy leakage, unfriendly environment and the like exist, and when the hydraulic pressure fails, the steering system cannot provide full power, so that the hand feeling becomes heavy and the risk is easy to generate, and in addition, the matching cost is greatly improved by adding a set of electric power assisting system.

How to realize the turning of the medium-heavy truck commercial vehicle to the pure electric state becomes an urgent need for the turning of the current commercial vehicle. The pure electric steering gear with large torque and high bearing capacity is researched, and is a necessary path for the development of steering electrodynamic properties of commercial vehicles. Therefore, a new electric power steering apparatus is urgently needed to solve the above-described problems.

Disclosure of Invention

The technical scheme adopted for solving the technical problems is as follows: a purely electric power steering gear for a commercial medium and heavy truck, comprising: the device comprises an input shaft, a torsion bar, a torque rotation angle sensor, a first worm, a first motor, a worm wheel, a second worm, a second motor, a roller screw, a sector gear, a rocker shaft, a nut and a shell; one end of the input shaft stretches into the shell, one end of the input shaft, which is positioned outside the shell, is connected with the steering column of the whole vehicle and synchronously rotates, one end of the input shaft, which is positioned inside the shell, is coaxially and fixedly connected with the upper end of a torsion bar, the lower end of the torsion bar is coaxially and fixedly connected with the upper end of a roller screw, the roller screw is sleeved with a worm wheel, a driving end bearing and a driven end bearing in sequence from top to bottom, the roller screw is positioned on the outer circumference between the driving end bearing and the driven end bearing, an inner hole of a connecting nut is screwed on the outer circumference of the roller screw, a rack which is in the same direction with the axial direction of the input shaft is arranged on the outer side wall of the nut, the rack is meshed with a sector gear, the sector gear is sleeved and fixed on a rocker shaft, and the outer rings of the driving end bearing and the driven end bearing are fixedly connected with the inner wall of the shell;

the first motor and the second motor respectively drive a first worm and a second worm, and the first worm and the second worm are respectively meshed with the worm wheel; the stator of the torque angle sensor is fixedly connected with the outer circumference of the input shaft, the rotor of the torque angle sensor is fixedly connected with the outer circumference of the roller screw rod, the torque angle sensor is electrically connected to the vehicle-mounted ECU, the torque angle sensor outputs the detected torque and angle electric signals to the vehicle-mounted ECU, and the first motor and the second motor are respectively electrically connected to the vehicle-mounted ECU;

the double-worm is simultaneously meshed with the worm wheel, and the double-motor double-worm speed-reducing torque-increasing mechanism can effectively reduce acting force simultaneously acting on a single tooth of the worm wheel, so that the module and the size of the worm wheel and the worm can be reduced, the space size of the steering gear assembly can be effectively reduced, and the whole vehicle space arrangement is facilitated; when the double-motor power assisting system effectively improves the safety of the system and works normally, the two sets of motors respectively provide 50% of power assisting output, and when one motor fails, the other motor still can provide 50% of power assisting, so that the emergency steering assisting function is ensured, and the driving safety is improved.

Preferably, the first motor and the second motor are respectively provided with a first motor controller and a second motor controller, and the first motor controller and the second motor controller are respectively and electrically connected to the vehicle-mounted ECU.

Preferably, the first worm and the second worm are respectively positioned at two symmetrical positions of the worm wheel and meshed with the worm wheel; the double worms are symmetrically distributed to engage the worm wheel, so that the stress of the worm wheel is more uniform, and compared with the two worms which are respectively arranged at two ends of the roller screw, the worm wheel is omitted, the axial stability is better, and the radial stress is smaller.

More preferably, the first motor and the second motor are arranged side by side in the same direction, rated power of the first motor and rated power of the second motor are the same, and rotation shafts of the first worm and the second worm are perpendicular to rotation shafts of the roller screw rods.

Preferably, the driving end bearing and the driven end bearing are tapered roller bearings, the driving end bearing and the driven end bearing are reversely pressed at two ends of the roller screw, and the reversely pressed bearings can more effectively offset the axial stress of the roller screw.

Preferably, a mounting hole is formed in the outer portion of the shell for loading the steering gear.

The beneficial effects of the utility model are as follows:

1. the utility model provides an electric power steering device applied to a medium-heavy truck type, which takes a whole truck storage battery as a power source, completely abandons a hydraulic system, perfectly solves the problems of high energy consumption, easy leakage and unfriendly environment of the hydraulic power steering system, and can improve the cost of the system due to the reduction of the parts of the hydraulic system, the arrangement and the matching of the steering system on the whole truck are easier, and the structural strength is effectively improved, so that the electric power steering system can be applied to the medium-heavy truck type.

2. The utility model adopts the pure electric steering gear, so that the driving assistance functions such as speed-following assistance, steering multimode, lane keeping, crosswind compensation, automatic parking and the like are easy to realize, the driving experience of drivers and passengers can be effectively improved, the driving labor intensity of the drivers is reduced, the safety of the system is effectively improved by the design of the double-motor assistance system, and when one motor fails, the other motor can still provide 50% assistance, the emergency steering assistance function is ensured, and the driving safety is improved.

3. According to the utility model, the worm wheel is meshed with the double worm from the left side and the right side, the acting force acting on a single tooth of the worm wheel at the same time can be effectively reduced by reducing the speed and the torque of the double worm, so that the module and the size of the worm wheel and the worm can be reduced, the space size of the steering gear assembly can be effectively reduced, the space arrangement of the whole automobile is facilitated, and compared with the bilateral symmetrical arrangement of the double worm at the same end, the two worms are respectively arranged at the two ends of the roller screw, so that not only is one turbine omitted, but also the axial stability is better, and the radial stress is smaller.

Drawings

FIG. 1 is a perspective view of the internal engagement of a purely electric power steering gear for a commercial medium and heavy truck;

FIG. 2 is a schematic diagram of operation;

fig. 3 is a schematic perspective view of an external structure.

In the figure: 1. an input shaft; 2. a torsion bar; 3. a torque rotation angle sensor; 4. a first worm; 5. a first motor; 6. a worm wheel; 7. a second worm; 8. a second motor; 9. a roller screw; 10. sector gears; 11. a rocker shaft; 12. a nut; 13. a housing; 14. a driving end bearing; 15. a driven end bearing; 16. a rack; 17. a first motor controller; 18. a second motor controller; 19. and (5) mounting holes.

Detailed Description

The following description of the related art will be made apparent to, and is not intended to limit the scope of, the embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1 to 3, a pure electric power steering gear for a commercial medium and heavy truck includes: an input shaft 1, a torsion bar 2, a torque rotation angle sensor 3, a first worm 4, a first motor 5, a worm wheel 6, a second worm 7, a second motor 8, a roller screw 9, a sector gear 10, a rocker shaft 11, a nut 12 and a housing 13; one end of the input shaft 1 stretches into the shell 13, one end of the input shaft 1, which is positioned outside the shell 13, is connected with a steering column of the whole vehicle and synchronously rotates, one end of the input shaft 1, which is positioned inside the shell 13, is coaxially and fixedly connected with the upper end of the torsion bar 2, the lower end of the torsion bar 2 is coaxially and fixedly connected with the upper end of the roller screw 9, the roller screw 9 is sleeved and fixedly connected with the worm wheel 6, the driving end bearing 14 and the driven end bearing 15 from top to bottom in sequence, the roller screw 9 is positioned on the outer circumference between the driving end bearing 14 and the driven end bearing 15, the inner hole of the connecting nut 12 is screwed and rotated, a rack 16 which is in the same direction as the axial direction of the input shaft 1 is arranged on the outer side wall of the nut 12, the rack 16 is meshed with the sector gear 10, the sector gear 10 is sleeved and fixed on the rocker shaft 11, and the outer rings of the driving end bearing 14 and the driven end bearing 15 are fixedly connected with the inner wall of the shell 13;

the first motor 5 and the second motor 8 respectively drive the first worm 4 and the second worm 7, and the first worm 4 and the second worm 7 are respectively meshed with the worm wheel 6; the stator of the torque rotation angle sensor 3 is fixedly connected with the outer circumference of the input shaft 1, the rotor of the torque rotation angle sensor 3 is fixedly connected with the outer circumference of the roller screw 9, the torque rotation angle sensor 3 is electrically connected to the vehicle-mounted ECU, the torque rotation angle sensor 3 outputs the detected torque and rotation angle electric signals to the vehicle-mounted ECU, and the first motor 5 and the second motor 8 are respectively electrically connected to the vehicle-mounted ECU;

the double-worm is simultaneously meshed with the worm wheel 6, and the double-motor double-worm speed-reducing torque-increasing mechanism can effectively reduce acting force simultaneously acting on a single tooth of the worm wheel 6, so that the module and the size of the worm wheel 6 and the worm can be reduced, the space size of the steering gear assembly can be effectively reduced, and the whole vehicle space arrangement is facilitated; when the double-motor power assisting system effectively improves the safety of the system and works normally, the two sets of motors respectively provide 50% of power assisting output, and when one motor fails, the other motor still can provide 50% of power assisting, so that the emergency steering assisting function is ensured, and the driving safety is improved.

Further, the first motor 5 and the second motor 8 are respectively provided with a first motor controller 17 and a second motor controller 18, and the first motor controller 17 and the second motor controller 18 are respectively electrically connected to the vehicle-mounted ECU.

Further, the first worm 4 and the second worm 7 are respectively positioned at two symmetrical positions of the worm wheel 6 and meshed with the worm wheel 6; the double worms are symmetrically distributed to engage the worm wheel 6, so that the stress of the worm wheel 6 is more uniform, and compared with the two worms which are respectively arranged at two ends of the roller screw 9, the two worm wheels are not only saved, but also the axial stability is better, and the radial stress is smaller.

Furthermore, the first motor 5 and the second motor 8 are arranged side by side in the same direction, the rated power of the first motor 5 and the rated power of the second motor 8 are the same, and the rotating shafts of the first worm 4 and the second worm 7 are perpendicular to the rotating shaft of the roller screw 9.

Further, the driving end bearing 14 and the driven end bearing 15 are tapered roller bearings, the driving end bearing 14 and the driven end bearing 15 are reversely pressed at two ends of the roller screw 9, and the reversely pressed bearings can more effectively offset the axial stress of the roller screw 9.

Further, a mounting hole 19 is formed outside the housing 13 for loading the steering gear.

Examples

In the embodiment, the electric power steering gear mainly comprises a torque rotation angle sensing mechanism, two sets of worm and gear speed reducing mechanisms, a motor controller and a mechanical circulating ball system.

As shown in fig. 2, when the driver turns the steering wheel, the steering torque is applied to the steering system through the input shaft 1, the corresponding torsion bar 2 generates torsion deformation, the deformation angle is detected by the torque angle sensor 3 and converted into an electric signal, the electric signal is transmitted to two motor controllers, the motor controllers supply power through the whole vehicle storage battery and receive the whole vehicle signal (vehicle speed, engine state and the like) through the CAN line, the two motor controllers respectively calculate the current power-assisted demand according to the current vehicle speed, the steering torque and the like, the two motor controllers control the motor to output the power-assisted torque, the torque is jointly overlapped on the worm wheel 6 through the two worms, the worm wheel 6 is fixedly connected with the ball screw 9, the ball screw 9 converts the rotary motion of the worm wheel 6 into the axial translation of the nut 12, the torque overlapped on the worm wheel 6 is converted into the axial thrust on the rack 16 of the nut 12, the rack 16 on the nut 12 is meshed with the toothed sector wheel 10 fixedly connected with the rocker shaft 11, the axial thrust on the rack 16 is converted into the rotary torque on the rocker shaft 11, the axial translation of the rocker shaft 11 is converted into the rotary motion around the axis of the self axis, and the wheel link mechanism pushes the wheel link mechanism to transmit the torque to the wheel link mechanism, and the steering swing steering is realized. When the electric vehicle is in normal operation, the two sets of motors respectively provide 50% of power-assisted output, and when one set of motor power-assisted fails, the other set of motor still can provide 50% of power-assisted output, so that the emergency steering requirement of the whole vehicle can be met, and the driving safety of the whole vehicle is effectively improved.

As shown in FIG. 1, the power-assisted torque of the two sets of motors is transmitted by the two worms and then acts on different tooth parts of the same worm wheel 6, so that compared with the scheme of providing power assistance by adopting a single motor and a single worm, the power-assisted worm wheel has the advantages that acting force acting on a single tooth of the worm wheel 6 can be effectively reduced, the module and the size of the worm wheel can be reduced, the space size of the steering gear assembly can be effectively reduced, and the whole vehicle space arrangement is facilitated. The tooth back side of the ball screw 9 is designed to be round and is designed to be in small clearance fit with the shell, when the tooth is acted by a large radial partial force, the screw generates slight deflection, the outer circle of the tooth back of the nut 12 contacts with the inner cavity of the shell to form an effective support, the radial force acting on the screw of the ball screw 9 can be effectively reduced, the service life of the ball screw 9 can be effectively prolonged, the reliability of the whole system is further improved, and otherwise, the size of the ball screw is required to be greatly increased to bear the corresponding radial force without damage.

As shown in fig. 3, the steering gear installation and arrangement form is consistent with that of a traditional medium-heavy truck hydraulic circulating ball steering gear, so that the electric steering gear can be easily matched under the condition that the mechanical structure of the whole automobile is not changed. The schematic diagram only shows the situation that the double motor and the worm gear reduction mechanism are positioned at the upper end of the circulating ball steering gear, if the space arrangement is needed, the double motor and the worm gear reduction mechanism can also be arranged at the lower end of the circulating ball steering gear, meanwhile, according to the whole car space arrangement, the motor controller can also rotate around the axis of the input shaft to be arranged in any direction, and the space arrangement space of the whole car can be flexibly matched.

The embodiment has the advantages that the whole vehicle storage battery is used as a power source, the hydraulic system is completely abandoned, the problems of high energy consumption, easiness in leakage and environment unfriendly of the hydraulic steering system are perfectly solved, the cost of the system can be improved due to the reduction of components of the hydraulic system, the installation and arrangement form of the steering device is consistent with that of a traditional medium-heavy truck hydraulic circulating ball steering device, the electric steering device can be easily matched under the condition that the whole vehicle mechanical structure is not changed, the arrangement and matching of the steering system on the whole vehicle are easier, and the driving auxiliary functions such as speed-following assistance, steering multiple modes, lane keeping, crosswind compensation and automatic parking are easy to realize due to the pure electric steering device, so that the driving experience of drivers and passengers can be effectively improved, and the driving labor intensity of the drivers is reduced.

Due to the design of the double-motor power-assisted system, when the safety of the system is effectively improved and the system works normally, 50% of power-assisted output is respectively provided by the two sets of motors, and when one motor fails, 50% of power assistance can still be provided by the other motor, so that an emergency steering auxiliary function is ensured, and the driving safety is improved.

The double-motor double-worm speed reducing mechanism can effectively reduce acting force simultaneously acting on a single tooth of the worm gear, so that the module and the size of the worm gear can be reduced, the space size of the steering gear assembly can be effectively reduced, and the space arrangement of the whole vehicle is facilitated.

The tooth back side of the ball screw is designed to be round and is designed to be in small clearance fit with the shell, when the tooth is acted by a large radial partial force, the screw generates slight deflection deformation, the outer circle of the tooth back of the nut is contacted with the inner cavity of the shell to form effective support, so that the radial force acting on the ball screw can be effectively reduced, the service life of the ball screw mechanism can be effectively prolonged, the reliability of the whole system is further improved, otherwise, the size of the ball screw is required to be greatly increased to bear the corresponding radial force without damage.

According to the space arrangement requirement, the double motors and the worm and gear speed reducing mechanism can be arranged at the upper end of the circulating ball steering gear and the lower end of the circulating ball steering gear, and meanwhile, the motor controller can also rotate around the axis of the input shaft to be arranged in any direction, so that the space of the whole vehicle arrangement can be flexibly matched.

In the present embodiment, the ECU: electronic Control Unit electronic controller unit.

In summary, the utility model provides the electric power steering device applied to the medium-heavy truck type, the electric power steering device takes the whole vehicle storage battery as a power source, the hydraulic system is completely abandoned, the problems of high energy consumption and easy leakage of the hydraulic steering system and unfriendly environment are perfectly solved, and the cost of the system can be improved due to the reduction of the parts of the hydraulic system, the arrangement and the matching of the steering system on the whole vehicle are easier, the structural strength is effectively improved, and the electric power steering system can be applied to the medium-heavy truck type, so that the utility model has wide application prospect.

It is emphasized that: the above embodiments are merely preferred embodiments of the present utility model, and the present utility model is not limited in any way, and any simple modification, equivalent variation and modification made to the above embodiments according to the technical substance of the present utility model still fall within the scope of the technical solution of the present utility model.

Claims (6)

1. A purely electric power steering gear for a commercial medium and heavy truck, comprising: the device comprises an input shaft (1), a torsion bar (2), a torque rotation angle sensor (3), a first worm (4), a first motor (5), a worm wheel (6), a second worm (7), a second motor (8), a roller screw (9), a sector gear (10), a rocker shaft (11), a nut (12) and a shell (13);

one end of the input shaft (1) stretches into the shell (13), one end of the input shaft (1) positioned outside the shell (13) is connected with a whole steering column and synchronously rotates, one end of the input shaft (1) positioned inside the shell (13) is coaxially and fixedly connected with the upper end of the torsion bar (2), the lower end of the torsion bar (2) is coaxially and fixedly connected with the upper end of the roller screw (9), the roller screw (9) is sleeved and fixedly connected with the worm wheel (6), a driving end bearing (14) and a driven end bearing (15) from top to bottom in sequence, the roller screw (9) is positioned on the outer circumference between the driving end bearing (14) and the driven end bearing (15) and is in threaded rotation connection with an inner hole of the nut (12), the outer side wall of the nut (12) is provided with a rack (16) which is coaxial with the axial direction of the input shaft (1), the rack (16) is meshed with the fan gear (10), the fan gear (10) is sleeved and fixedly connected with the worm wheel (6), and the outer ring of the driving end bearing (14) is fixedly connected with the inner ring of the driving end bearing (15) of the shell (13);

the first motor (5) and the second motor (8) respectively drive the first worm (4) and the second worm (7), and the first worm (4) and the second worm (7) are respectively meshed with the worm wheel (6); the torque rotation angle sensor (3) is characterized in that a stator of the torque rotation angle sensor (3) is fixedly connected with the outer circumference of the input shaft (1), a rotor of the torque rotation angle sensor (3) is fixedly connected with the outer circumference of the roller screw (9), the torque rotation angle sensor (3) is electrically connected to the vehicle-mounted ECU, the torque rotation angle sensor (3) outputs electric signals of detected torque and rotation angle to the vehicle-mounted ECU, and the first motor (5) and the second motor (8) are respectively electrically connected to the vehicle-mounted ECU.

2. The pure electric power steering gear for the commercial medium and heavy truck according to claim 1, wherein a first motor controller (17) and a second motor controller (18) are respectively arranged on the first motor (5) and the second motor (8), and the first motor controller (17) and the second motor controller (18) are respectively electrically connected to an on-vehicle ECU.

3. The pure electric power steering gear for a commercial medium and heavy truck according to claim 1, wherein the first worm (4) and the second worm (7) are respectively positioned at two symmetrical positions of the worm wheel (6) and meshed with the worm wheel (6).

4. The pure electric power steering gear for the commercial medium and heavy truck according to claim 3, wherein the first motor (5) and the second motor (8) are arranged side by side in the same direction, rated power of the first motor (5) and rated power of the second motor (8) are the same, and rotation shafts of the first worm (4) and the second worm (7) are perpendicular to rotation shafts of the roller screw rods (9).

5. The pure electric power steering gear for the commercial medium and heavy truck according to claim 1, wherein the driving end bearing (14) and the driven end bearing (15) are tapered roller bearings, and the driving end bearing (14) and the driven end bearing (15) are reversely pressed at two ends of the roller screw (9).

6. A purely electric power-assisted steering for a commercial medium and heavy truck according to claim 1, characterized in that the housing (13) is provided externally with mounting holes (19) for steering loading.