CN220639997U - Electric steering gear of electric cylinder structure suitable for heavy-duty vehicle type - Google Patents

Abstract

The utility model belongs to the technical field of automobile manufacturing, and relates to an electric steering gear of an electric cylinder structure suitable for a heavy-duty vehicle type, which comprises: the utility model adopts the belt with high transmission efficiency and the planetary reduction mechanism, reduces power consumption, adopts the ball screw with high bearing capacity, thereby realizing intelligent driving functions such as active correction and the like, and realizing electric power assisted steering in unmanned intelligent driving mode in the future development and vehicle driving process.

Description

Electric steering gear of electric cylinder structure suitable for heavy-duty vehicle type

Technical Field

The utility model belongs to the technical field of automobile manufacturing, and relates to an electric steering gear with an electric cylinder structure suitable for a heavy-duty automobile type.

Background

Along with the rapid development of new energy automobiles, the electric steering matched with the new energy automobiles has the advantages of energy conservation, environmental protection, intellectualization and the like. Electric power steering apparatuses, which are not only limited to passenger vehicles but also to commercial vehicles, have been widely used nowadays.

However, when the worm and gear structure transmits torque, most of the engagement contact surfaces are in sliding friction, so that the torque transmission efficiency is low, and the worm wheel applied to steering at present basically adopts materials such as nylon and plastic, so that under the constraint of a certain vehicle space range, the conventional worm and gear structure has difficulty in meeting the requirements of output torque and durability of passenger cars or light trucks with a front axle of more than 3 t. Accordingly, there is a need for an electric power steering apparatus that has higher torque transmission efficiency to solve the above-described problems.

Disclosure of Invention

The technical scheme adopted for solving the technical problems is as follows: an electric power steering apparatus of an electric cylinder structure suitable for a heavy duty vehicle type, comprising: the motor-ECU, the planetary reduction mechanism, the belt pulley transmission mechanism, the ball screw and the ball head pull rod are coaxially and fixedly connected with a sun gear of the planetary reduction mechanism, an output shaft of a planet wheel of the planetary reduction mechanism is coaxially and fixedly connected with a driving wheel of the belt pulley transmission mechanism, a driven wheel of the belt pulley transmission mechanism is coaxially and fixedly connected with the ball screw, a cylindrical nut sleeve is sleeved on the ball screw, one end of the nut sleeve is fixedly connected with a cylindrical thrust sleeve, one end of the thrust sleeve, far from the nut sleeve, is hinged with the ball head pull rod, and one end of the ball head pull rod, far from the thrust sleeve, is connected to the vehicle steering mechanism; the power torque of the motor-ECU is transmitted to a driving wheel of a belt pulley transmission mechanism after the speed and the torque are increased through a sun wheel of a planetary reduction mechanism, the driving wheel transmits the power torque to the ball screw through a tensioned belt and a driven wheel which is coaxially and fixedly connected with the ball screw through secondary speed and the torque increase, and the ball screw converts the power torque into a linear driving force through a nut sleeve and a thrust sleeve and transmits the linear driving force to a ball head pull rod so as to provide steering power for steering a vehicle;

the rotating shaft of the motor-ECU output shaft is parallel to the rotating shaft of the ball screw, the sun wheel is meshed with the planet wheel through a gear, the periphery of the planet wheel is also meshed with an outer gear ring, the radius of the driving wheel is smaller than that of the driven wheel, the driving wheel is in belt transmission connection with the driven wheel, the inner ring of the nut sleeve is meshed with the outer circumference of the ball screw through a roller, the diameter of the inner ring of the thrust sleeve is larger than that of the outer circumference of the ball screw, and the ball screw, the nut sleeve and the thrust sleeve are coaxial with the rotating shaft; the rotation shaft of the motor-ECU output shaft is parallel to the rotation shaft of the ball screw, so that the whole structure of the electric steering gear is more compact, and the installation space is smaller.

Preferably, the electric steering gear is also provided with a displacement sensor, the displacement sensor is used for monitoring the telescopic position state of the ball head pull rod in real time, and the displacement sensor is electrically connected to the motor-ECU; the displacement sensor with large measuring range and high precision is adopted, so that the closed-loop control of the steering gear can be realized, the telescopic position of the ball head pull rod can be monitored in real time, the inaccuracy of belt transmission can be made up, and the safety and the operability of the whole vehicle can be improved.

Preferably, the bearing of the driving wheel is fixedly connected to the shell of the electric steering gear through a waist-shaped hole; the belt tensioning force is adjusted by adjusting the axial distance between the driving wheel and the driven wheel by adopting the eccentric bearing and the waist-shaped hole on the shell, and the belt tensioning device is simple and compact in structure and strong in adjustability.

More preferably, the two ends of the ball screw are fixedly connected to the shell of the electric steering gear through bearings.

More preferably, the outer circumference of the joint of the thrust sleeve and the ball head pull rod is further wrapped with a cylindrical flexible telescopic sealing sleeve which can axially stretch, one end of the telescopic sealing sleeve is fixed on the shell, and the other end of the telescopic sealing sleeve is fixedly sleeved on the outer circumference of the ball head pull rod; the telescopic sealing sleeve is used for sealing an internal mechanical transmission part, so that dust and moisture are prevented from entering the ball screw through gaps of the ball head pull rod, the thrust sleeve and the shell, and the transmission efficiency and the transmission safety are affected.

More preferably, the telescopic sealing sleeve is fixedly connected to the shell through a cylindrical rear cover, an annular boss is arranged on the cylindrical inner ring of the rear cover, the inner diameter of the boss is larger than the outer diameter of the ball screw, the inner diameter of the boss is smaller than the outer diameter of the thrust sleeve, and the boss and the ball screw are coaxial; the boss realizes that the nut sleeve runs to the limit position and mechanically limits, and the whole vehicle is prevented from turning to transition, so that the damage of parts of the whole vehicle is avoided.

The beneficial effects of the utility model are as follows:

1. the utility model adopts the electric power steering, and can realize intelligent driving functions such as active alignment, lane keeping, automatic parking, active steering and the like.

2. The utility model adopts the belt, the planetary reduction mechanism and the ball screw mechanism with high torque transmission efficiency to reduce power loss and pollution, improve steering output capability and meet the steering requirement of heavy-duty vehicles.

3. The utility model adopts the eccentric bearing and the shell waist-shaped hole to adjust the tension of the belt, and has simple and compact structure.

4. The utility model adopts the displacement sensor with large measuring range and high precision, can realize the closed-loop control of the steering gear, and improves the safety and the operability of the whole vehicle.

5. The utility model adopts the inner and outer pull rod ball head structure, can output thrust and has high space freedom degree, and can realize displacement deflection of the wheels in the large-angle steering process.

6. In future development, the utility model combines the sensors at other positions of the vehicle and the vehicle ECU signals to realize the electric power steering of the unmanned intelligent driving mode.

Drawings

Fig. 1 is a perspective view of an electric power steering apparatus of an electric cylinder structure suitable for a heavy-duty vehicle type;

FIG. 2 is a front cross-sectional view;

FIG. 3 is an enlarged partial view of the pulley end of FIG. 2;

FIG. 4 is an enlarged partial view of the ball screw end of FIG. 2;

FIG. 5 is a schematic diagram of a pulley side end face;

fig. 6 is a top perspective view.

In the figure: 1. a motor-ECU; 2. a planetary reduction mechanism; 3. a pulley transmission mechanism; 4. a ball screw; 5. a ball head pull rod; 6. a sun gear; 7. a planet wheel; 8. a driving wheel; 9. driven wheel; 10. a nut sleeve; 11. a thrust sleeve; 12. an outer ring gear; 13. a displacement sensor; 14. a waist-shaped hole; 15. a housing; 16. an expansion seal sleeve; 17. a rear cover; 18. a boss.

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 6, an electric power steering apparatus of an electric cylinder structure suitable for a heavy duty vehicle type, includes: the motor-ECU 1, the planetary reduction mechanism 2, the belt pulley transmission mechanism 3, the ball screw 4 and the ball head pull rod 5, wherein an output shaft of the motor-ECU 1 is coaxially and fixedly connected with a sun wheel 6 of the planetary reduction mechanism 2, an output shaft of a planet wheel 7 of the planetary reduction mechanism 2 is coaxially and fixedly connected with a driving wheel 8 of the belt pulley transmission mechanism 3, a driven wheel 9 of the belt pulley transmission mechanism 3 is coaxially and fixedly connected with the ball screw 4, a cylindrical nut sleeve 10 is sleeved on the ball screw 4, one end of the nut sleeve 10 is fixedly connected with a cylindrical thrust sleeve 11, one end of the thrust sleeve 11, far away from the nut sleeve 10, is hinged with the ball head pull rod 5, and one end of the ball head pull rod 5, far away from the thrust sleeve 11, is connected to a vehicle steering mechanism; the power torque of the motor-ECU 1 is transmitted to a driving wheel 8 of the belt pulley transmission mechanism 3 after being decelerated and torque-increased through a sun wheel 6 of the planetary reduction mechanism 2, the driving wheel 8 transmits the power torque to the ball screw 4 through a tensioned belt and a driven wheel 9 which is coaxially and fixedly connected with the ball screw 4 through secondary deceleration and torque-increase, and the ball screw 4 converts the power torque into linear driving force through a nut sleeve 10 and a thrust sleeve 11 and transmits the linear driving force to a ball head pull rod 5 so as to provide steering power for steering a vehicle;

the rotation shaft of the output shaft of the motor-ECU 1 is parallel to the rotation shaft of the ball screw 4, the sun wheel 6 is meshed with the planet wheel 7 by a gear, the outer periphery of the planet wheel 7 is also meshed with an outer gear 12 by a gear, the radius of the driving wheel 8 is smaller than that of the driven wheel 9, the driving wheel 8 is in belt transmission connection with the driven wheel 9, the inner ring of the nut sleeve 10 is meshed with the outer circumference of the ball screw 4 by a roller, the diameter of the inner ring of the thrust sleeve 11 is larger than the outer circumference of the ball screw 4, and the ball screw 4, the nut sleeve 10 and the thrust sleeve 11 are coaxial with the rotation shaft; the rotation axis of the output shaft of the motor-ECU 1 is parallel to the rotation axis of the ball screw 4 so that the overall structure of the electric power steering apparatus is more compact and the installation space is smaller.

Further, the electric steering gear is also provided with a displacement sensor 13, the displacement sensor 13 is used for monitoring the telescopic position state of the ball head pull rod 5 in real time, and the displacement sensor 13 is electrically connected to the motor-ECU 1; the displacement sensor 13 with large measuring range and high precision is adopted, so that closed-loop control of the steering gear can be realized, the telescopic position of the ball head pull rod 5 can be monitored in real time, the inaccuracy of belt transmission can be made up, and the safety and operability of the whole vehicle can be improved.

Further, the bearing of the driving wheel 8 is fixedly connected to a shell 15 of the electric steering gear through a waist-shaped hole 14; the belt tensioning force is adjusted by adjusting the axial distance between the driving wheel 8 and the driven wheel 9 by adopting the eccentric bearing and the waist-shaped hole 14 on the shell 15, the structure is simple and compact, and the adjustability is strong.

Further, both ends of the ball screw 4 are fixedly connected to the housing 15 of the electric power steering apparatus through bearings.

Further, the outer circumference of the joint of the thrust sleeve 11 and the ball head pull rod 5 is further wrapped with a cylindrical flexible telescopic sealing sleeve 16 which can axially stretch, one end of the telescopic sealing sleeve 16 is fixed on the shell 15, and the other end of the telescopic sealing sleeve 16 is fixedly sleeved on the outer circumference of the ball head pull rod 5; the telescopic sealing sleeve 16 is used for sealing an internal mechanical transmission part and preventing dust and moisture from entering the ball screw 4 from the gap between the ball head pull rod 5 and the thrust sleeve 11 as well as between the ball head pull rod and the shell 15, thereby influencing transmission efficiency and transmission safety.

Further, the telescopic sealing sleeve 16 is fixedly connected to the shell 15 through a cylindrical rear cover 17, an annular boss 18 is arranged on the cylindrical inner ring of the rear cover 17, the inner diameter of the boss 18 is larger than the outer diameter of the ball screw 4, the inner diameter of the boss 18 is smaller than the outer diameter of the thrust sleeve 11, and the boss 18 and the ball screw 4 are coaxial; the boss 18 realizes mechanical limit of the nut sleeve 10 when the nut sleeve runs to the limit position, and avoids the whole vehicle steering transition to cause the damage of the whole vehicle parts.

Examples

The purpose of this embodiment is to: under the current technical conditions, based on the fact that the existing heavy-duty commercial vehicle type does not have a mature electric steering scheme, the scheme of the electric steering system suitable for the heavy-duty vehicle type is provided, and the scheme can be matched with a line control sensing unit, a VCU (virtual control Unit) and a sensor unit of the vehicle, so that advanced functions such as lane keeping, automatic parking and automatic steering can be realized.

The embodiment achieves the above object through the following technical scheme:

on the basis of the existing electric cylinder, a set of motor-ECU 1, a planetary reduction mechanism 2, a displacement sensor 13 and an inner ball head pull rod 5 which are in accordance with the safety of steering function are added. The device consists of a motor-ECU 1, a planetary reduction mechanism 2, a belt pulley transmission mechanism 3, an eccentric bearing, a belt shell, a shell 15, a ball screw 4 (or a planetary screw), a thrust sleeve 11, an inner ball head pull rod 5, an outer ball head pull rod 5, a rear cover 17, a displacement sensor 13, a wire harness assembly and the like. The belt and planetary reduction mechanism with high torque transmission efficiency is adopted, motor torque is amplified and transmitted to the ball screw 4 (or the planetary screw), the ball screw 4 (or the planetary screw) converts the torque into push-pull force, the push-pull force acts on the inner and outer ball head pull rods 5, the pull rods are output to wheels of the whole vehicle, the steering of the wheels is realized, and the push-pull force and the steering speed of the steering system can completely cover the steering requirements of all commercial vehicle types by adopting the proper power motor-ECU 1. The output end of the motor is connected to the input end of the planetary gear through an inner pin key and an outer pin key, and the pin key shaft is matched with the input end of the planetary gear through a coating process, so that a gap can be eliminated, and abnormal sound can be avoided; the motor is connected with an outer gear ring of the planetary gear mechanism through threads, the output end of a planetary gear of the planetary reduction mechanism is connected with a small belt wheel shaft of the belt through a spline, the outer spline also eliminates a gap between the planetary gear mechanism and the small belt wheel shaft through a coating process, abnormal sound is avoided, the outer gear ring 12 of the planetary gear mechanism is connected with the shell 15 through a waist-shaped hole 14, the small belt wheel shaft carrying the small belt wheel of the belt is fixed on the shell 15 through an eccentric bearing, the center distance of the belt is adjusted by combining the eccentric bearing with the waist-shaped hole 14, and the belt is tensioned; the large belt pulley is pressed on a screw shaft of the ball screw 4 (or the planetary screw), a bearing on the screw is a main bearing, the constraint screw is fixed, the axial force and the lighter radial force of the ball screw 4 (or the planetary screw) are born, six guide grooves are designed at the contact part of the shell 15 and the screw nut sleeve 10, the nut sleeve 10 is circumferentially constrained to rotate, the effective stroke and the thrust of the nut sleeve 10 are ensured, a limit boss is designed in one section of inner circle of the shell 15 according to the system requirement, the tail screw of the shell 15 is connected with a rear cover 17 of the limit boss 18, the mechanical limit of the two ends of the nut sleeve 10 when the two ends of the nut sleeve travel to the limit position is realized, and the whole vehicle is prevented from turning transition and damage to parts of the whole vehicle; the nut sleeve 10 is in threaded connection with the thrust sleeve 11, the thrust sleeve 11 outputs to the ball head of the inner pull rod, the thrust sleeve 11 is in threaded connection with the nut sleeve 10 and the ball head of the inner pull rod, and a locking ring is assembled for axial locking fit; the tail end of the rear cover 17 is provided with an extensible and contractible telescopic sealing sleeve 16 for sealing an internal mechanical transmission part and an internal and external ball head pull rod structure at the output end, so that any position of a pull rod of a wheel in the steering process can be adjusted; the displacement sensor 13 is assembled to the shell 15 and is tightly connected with the nut sleeve 10, the connector interface connection wire harness feeds back the position state of the steering gear to the ECU, the whole vehicle VCU transmits a vehicle speed signal and the whole vehicle state to the ECU, the steering and intelligent driving functions are realized, and the stroke is controlled in a closed loop mode.

The mounting implementation mode of the electric cylinder steering gear is as follows:

1. the screw, the nut, the steel ball, the lock nut c and the thrust sleeve 11 are assembled into the ball screw 4 assembly.

2. The ball screw assembly 4, the ball screw left end bearing, the bearing washer, the ball screw right end bearing, the locking nut b, the locking nut a, the locking ring a and the displacement sensor 13 are fixedly assembled in the shell 15, and then the displacement sensor 13 is assembled on the surface of the shell 15 by screws to form the ball screw shell assembly.

3. The output end of the belt pulley transmission mechanism 3 is pressed on a screw rod of the ball screw shell assembly, the belt pulley of the belt pulley transmission mechanism 3 is pressed on a belt input shaft, the belt input shaft is fixed on the shell through an eccentric bearing and a bearing retainer ring, the input end flat belt of the belt pulley transmission mechanism 3 is assembled on the belt input shaft provided with the belt pulley, the bearing outer ring of the eccentric bearing is adjusted, the center distance of the belt is adjusted to adjust the tension of the belt, and after the tension of the belt is adjusted, the eccentric bearing is fixed on the shell 15 through the riveting process circumference of the shell 15, and the belt shell is installed on the shell 15 through screws to form the belt ball screw shell assembly.

4. An output shaft of the planetary reduction mechanism 2 assembly is connected with a belt input shaft through an internal spline and an external spline, an external gear ring 12 is mounted on a shell 15 through a waist round hole through a screw, a planetary gear output shaft is fixed by a bearing of the planetary reduction mechanism 2 assembly, and the planetary gear output shaft is connected with a planetary gear of the planetary reduction mechanism to form a planetary belt ball screw shell assembly.

5. The motor-ECU 1 is matched and connected with a shaft pin key of a sun gear 5 of the planetary reduction mechanism 2 to form a power unit assembly.

6. The inner ball head pull rod 5 is connected to the thrust sleeve 11 of the power unit assembly through threads, a locking nut d is installed, an expansion sealing sleeve 16 is installed, and finally the outer ball head pull rod 5 and the locking nut e are sequentially connected.

7. And connecting interfaces at two ends of the wire harness with an interface end of the displacement sensor 13 and a sensor signal interface end of the motor-ECU 1 respectively to finish the installation of the electric cylinder steering device assembly.

8. The electric cylinder steering assembly is mounted to the whole vehicle floor through mounting holes in the housing 15, and the whole vehicle VCU can wire and the power wire are connected to the harness interface of the motor-ECU 1.

In the running process of the vehicle, when the vehicle needs to turn, signals sent by a whole vehicle VCU or a road feel feedback unit are transmitted to a motor ECU1 of the electric cylinder steering gear, the motor ECU1 controls the current of the motor according to the speed signals of the whole vehicle, so that the motor drives the planetary transmission mechanism to transmit power to the belt pulley transmission mechanism 3, then the power is transmitted to the screw rod and the screw rod through the steel ball, the power is transmitted to the steel ball, the steel ball is transmitted to the nut, the rotation torque is converted into thrust to be transmitted to the ball head pull rod 5, the thrust is transmitted to the wheel knuckle arm through the ball head pull rod 5, the vehicle turns, and the ball head pull rod 5 can adapt to the space angle position in the wheel turning process.

In summary, the utility model provides an electric power steering gear applied to a medium-heavy truck type, which sequentially decelerates and increases torque through a motor-ECU, a planetary reduction mechanism, a belt pulley transmission mechanism, a ball screw and a ball head pull rod, and converts torque into linear pushing force to be transmitted to the ball head pull rod so as to provide steering power for steering a vehicle, so that the torque transmission efficiency of an electric power steering system on the medium-heavy truck type is higher, and the electric power steering gear 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. An electric power steering apparatus of an electric cylinder structure suitable for a heavy duty vehicle type, comprising: the novel steering device comprises a motor-ECU (1), a planetary reduction mechanism (2), a belt pulley transmission mechanism (3), a ball screw (4) and a ball head pull rod (5), wherein an output shaft of the motor-ECU (1) is coaxially and fixedly connected with a sun gear (6) of the planetary reduction mechanism (2), an output shaft of a planet wheel (7) of the planetary reduction mechanism (2) is coaxially and fixedly connected with a driving wheel (8) of the belt pulley transmission mechanism (3), a driven wheel (9) of the belt pulley transmission mechanism (3) is coaxially and fixedly connected with the ball screw (4), a cylindrical nut sleeve (10) is sleeved on the ball screw (4), one end of the nut sleeve (10) is fixedly connected with a cylindrical thrust sleeve (11), one end of the thrust sleeve (11), far away from the nut sleeve (10), is hinged with the ball head pull rod (5), and one end of the ball head pull rod (5), far away from the thrust sleeve (11), is connected to a steering mechanism of a vehicle.

The motor-ECU (1) output shaft's rotation axis is parallel with the rotation axis of ball (4), sun gear (6) are gear engagement with planet wheel (7), the periphery of planet wheel (7) still gear engagement has outer ring gear (12), the radius of action wheel (8) is less than the radius of driven wheel (9), action wheel (8) belt drive connection is from driving wheel (9), the outer circumference of ball (4) is passed through in the inner circle of nut cover (10), the inner circle diameter of thrust cover (11) is greater than the outer circumference diameter of ball (4), nut cover (10), thrust cover (11) are with the rotation axis.

2. An electric power steering apparatus of an electric cylinder structure suitable for a heavy duty vehicle type according to claim 1, characterized in that a displacement sensor (13) is further provided on the electric power steering apparatus, the displacement sensor (13) is used for monitoring the telescopic position state of the ball head tie rod (5) in real time, and the displacement sensor (13) is electrically connected to the motor-ECU (1).

3. The electric power steering apparatus of an electric cylinder structure suitable for a heavy duty vehicle type according to claim 1, characterized in that the bearing of the driving wheel (8) is fixedly connected to the housing (15) of the electric power steering apparatus through a waist-shaped hole (14).

4. An electric power steering apparatus of an electric cylinder structure adapted to a heavy duty vehicle type according to claim 3, wherein both ends of the ball screw (4) are fixedly connected to a housing (15) of the electric power steering apparatus through bearings.

5. The electric steering gear with the electric cylinder structure suitable for the heavy-duty vehicle type according to claim 4, wherein the outer circumference of the joint of the thrust sleeve (11) and the ball head pull rod (5) is further wrapped with a cylindrical flexible telescopic sealing sleeve (16) which can stretch along the axial direction, one end of the telescopic sealing sleeve (16) is fixed on the shell (15), and the other end of the telescopic sealing sleeve (16) is fixedly sleeved on the outer circumference of the ball head pull rod (5).

6. The electric steering gear with the electric cylinder structure suitable for the heavy-duty vehicle type according to claim 5, characterized in that the telescopic sealing sleeve (16) is fixedly connected to the shell (15) through a cylindrical rear cover (17), an annular boss (18) is arranged on the cylindrical inner ring of the rear cover (17), the inner diameter of the boss (18) is larger than the outer diameter of the ball screw (4), the inner diameter of the boss (18) is smaller than the outer diameter of the thrust sleeve (11), and the boss (18) and the ball screw (4) are coaxial.