CN113734273A - Steering gear, steering system and vehicle of vehicle - Google Patents

Abstract

The invention discloses a vehicle steering gear, a steering system and a vehicle, wherein the vehicle steering gear comprises a screw rod, a motion assembly and an output shaft, the motion assembly comprises an inner shell and a roller, the inner shell is arranged around the periphery of the screw rod, two axial ends of the screw rod penetrate out of the inner shell, the roller is positioned between the inner peripheral wall of the inner shell and the outer peripheral wall of the screw rod, two axial ends of the roller are respectively and rotatably connected with the inner shell, the outer peripheral wall of the roller is spaced from the inner peripheral wall of the inner shell, the roller is in threaded fit with the screw rod, under the condition that the screw rod rotates, the roller rotates to drive the motion assembly to move in the axial direction of the screw rod, and the motion assembly moves to drive the output shaft to rotate. The steering gear of the vehicle has high bearing capacity, can be used under the condition of heavy load, and has the advantages of simple structure, convenient processing and assembly, low cost and convenient use.

Description

Steering gear, steering system and vehicle of vehicle

Technical Field

The invention relates to the field of automobiles, in particular to a steering gear and a steering system of a vehicle and the vehicle.

Background

In the related art, some steering gears are provided with a recirculating ball type ball screw structure to achieve power transmission, and some steering gears are provided with a planetary roller screw structure to achieve power transmission. The ball screw structure of the recirculating ball type transfers load by means of point contact of the balls with the screw and the nut, so that the bearing capacity is limited, and the ball screw structure is difficult to use under heavy load. The rolling element of the planetary roller screw between the nut and the screw is a threaded roller, when the screw rotates, the threaded roller not only rotates around the axis of the screw, but also revolves around the axis of the screw, the planetary roller screw has high bearing capacity, however, in the structure, in order to ensure that the threaded roller can accurately rotate and revolve, the nut is also provided with parts such as an inner gear ring, a retainer, a snap spring and the like which are matched with the threaded roller, so that the whole structure has a plurality of parts, which causes inconvenience in production and processing, and in the assembly, the threaded roller needs to be ensured to be accurately matched with the screw, the threaded roller needs to be matched with the nut, and simultaneously, the threaded roller needs to be meshed with the inner gear rings at two ends, the assembly is complex, the difficulty is high, and the structure is difficult to be widely applied.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, a first object of the present invention is to provide a steering gear for a vehicle, which has high load-bearing capacity, simple structure, and is easy to manufacture and assemble.

A second object of the present invention is to provide a steering system including the above-described steering gear.

A third object of the present invention is to provide a vehicle including the steering system described above.

A steering gear of a vehicle according to an embodiment of the present invention includes: a lead screw; a motion assembly, the motion assembly comprising: the inner shell is arranged around the periphery of the screw rod, two axial ends of the screw rod penetrate out of the inner shell, the roller is located between the inner peripheral wall of the inner shell and the outer peripheral wall of the screw rod, the two axial ends of the roller are respectively and rotatably connected with the inner shell, the outer peripheral wall of the roller is spaced from the inner peripheral wall of the inner shell, the roller is in threaded fit with the screw rod, and under the condition that the screw rod rotates, the roller rotates to drive the motion assembly to move in the axial direction of the screw rod; and an output shaft, the motion assembly moving to drive the output shaft to rotate.

According to the vehicle steering device, the two axial ends of the roller are respectively rotatably connected with the inner shell, the outer peripheral wall of the roller is spaced from the inner peripheral wall of the inner shell, and the roller is in threaded fit with the screw rod, so that when the screw rod rotates, the roller can not only rotate around the axis of the roller but also move along the axis direction of the screw rod, and further the roller can drive the inner shell to move when rotating, and therefore the rotation of the screw rod can be finally converted into the movement of the motion assembly.

In some embodiments of the present invention, the roller is provided in plurality, and the plurality of rollers are arranged at intervals in a circumferential direction of the screw.

In some embodiments of the invention, the rollers are connected at both axial ends to the inner shell by a first bearing assembly.

In some embodiments of the present invention, the first bearing assembly includes a first bearing, the roller includes a cylindrical portion and connecting portions provided at both axial ends of the cylindrical portion, the cylindrical portion is threadedly engaged with the lead screw, and the first bearing is fitted over the connecting portions and connected to the inner housing for bearing a radial load.

In some embodiments of the invention, the inner shell comprises: a body, both axial sides of which are open; and the two end covers are respectively arranged on two open sides of the body, the end covers are provided with avoidance openings and mounting openings, two ends of the lead screw respectively pass through the avoidance openings and penetrate out of the inner shell, and the mounting openings are internally provided with first bearings.

In some embodiments of the invention, the first bearing assembly comprises a second bearing disposed between the axial ends of the cylindrical portion and the corresponding end caps for carrying axial loads.

In some embodiments of the invention, the first bearing is a needle bearing and the second bearing is a flat thrust bearing.

In some embodiments of the present invention, the device further comprises a housing, the lead screw and the moving assembly are located in the housing, and a second bearing assembly is arranged between both axial ends of the lead screw and the inner wall surface of the housing, and the second bearing assembly can bear axial load and/or radial load.

In some embodiments of the present invention, the screw shaft is provided with a limiting member at each of two axial ends thereof, the limiting member is configured to be annular and is sleeved on the screw shaft, the housing includes two first side wall surfaces oppositely disposed in the axial direction of the screw shaft, and the second bearing assembly includes a third bearing, the third bearing is sleeved on the screw shaft and abuts between the limiting member and the first side wall surface adjacent to the limiting member.

In some embodiments of the invention, the second bearing assembly comprises a fourth bearing sleeved over the stop and radially abutting the inner wall of the housing.

In some embodiments of the invention, the third bearing is a flat thrust bearing and the fourth bearing is a needle bearing.

A steering system according to an embodiment of the present invention includes: the steering gear is the steering gear; the steering control mechanism is connected with the input shaft; and the steering transmission mechanism is connected with an output shaft of the steering gear.

According to the steering system provided by the embodiment of the invention, as the two axial ends of the roller of the steering gear are respectively and rotatably connected with the inner shell, the outer peripheral wall of the roller is spaced from the inner peripheral wall of the inner shell, and the roller is in threaded fit with the screw rod, when the screw rod rotates, the roller can not only rotate around the axis of the roller but also move along the axis direction of the screw rod, and further the roller can drive the inner shell to move when rotating, so that the rotation of the screw rod can be finally converted into the movement of the motion assembly.

According to the embodiment of the invention, the vehicle comprises the steering system.

According to the vehicle provided by the embodiment of the invention, the two axial ends of the roller of the steering gear are respectively rotatably connected with the inner shell, the outer peripheral wall of the roller is spaced from the inner peripheral wall of the inner shell, and the roller is in threaded fit with the screw rod, so that when the screw rod rotates, the roller can not only rotate around the axis of the roller but also move along the axis direction of the screw rod, and further the roller can drive the inner shell to move when rotating, and therefore, the rotation of the screw rod can be finally converted into the movement of the motion assembly.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a cross-sectional view of a diverter according to an embodiment of the present invention;

FIG. 2 is a schematic view of the motion assembly portion of FIG. 1;

FIG. 3 is an exploded view of a portion of a motion assembly according to an embodiment of the present invention;

fig. 4 is a schematic view of the location of the screw in fig. 1.

Reference numerals:

a steering gear 100;

a housing 1; a second step portion 11; a first sidewall surface 111; a third step portion 12;

an input shaft 2; a shaft body 21; a torsion bar 22;

a power assembly 3; a motor 31; a drive assembly 32;

a lead screw 4; a stopper 41;

a moving assembly 5; an inner shell 51; a body 511; a rack portion 5111; an end cap 512; an escape opening 5121; a mounting opening 5122; a first stepped portion 5123; a roller 52; a cylindrical portion 521; a connecting portion 522;

a first bearing assembly 6; a first bearing 61; a second bearing 62;

a second bearing assembly 7; a third bearing 71; a fourth bearing 72;

an output shaft 8; the wheel tooth portion 81;

the detection element 9.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

A steering gear 100, a steering system, and a vehicle of a vehicle according to an embodiment of the present invention will be described below with reference to the drawings, in which the steering gear 100 mainly functions to appropriately convert a steering torque and a steering angle from a steering wheel and output them to a tie rod mechanism, thereby steering the vehicle. The steering gear 100 has many kinds, and in the following description, the steering gear 100 is taken as an example to explain, and the electric power steering gear directly provides the steering power by the motor, compared with a hydraulic power steering gear, the electric power steering gear is more convenient to operate and control, and does not need to be provided with an oil pump, an oil pipe and other components, so the structure is more compact, the occupied space is small, and the pollution problem caused by hydraulic oil leakage does not exist.

As shown in fig. 1 and 2, a steering gear 100 of a vehicle according to an embodiment of the present invention includes a lead screw 4, a moving assembly 5, and an output shaft 8.

As shown in fig. 2, the moving assembly 5 includes an inner housing 51 and rollers 52, the inner housing 51 is disposed around the outer periphery of the screw rod 4, and two axial ends (for example, left and right ends) of the screw rod 4 penetrate through the inner housing 51, the rollers 52 are located between the inner peripheral wall of the inner housing 51 and the outer peripheral wall of the screw rod 4, two axial ends (for example, left and right ends) of the rollers 52 are respectively rotatably connected with the inner housing 51, the outer peripheral wall of the rollers 52 is spaced apart from the inner peripheral wall of the inner housing 51, the rollers 52 are in threaded engagement with the screw rod 4, under the condition that the screw rod 4 rotates, the rollers 52 move to drive the moving assembly 5 to move in the axial direction of the screw rod 4, the moving assembly 5 moves to drive the output shaft 8 to rotate, wherein the output shaft 8 is adapted to be connected with a drop arm of the vehicle, and thus when the output shaft 8 rotates, the drop arm can be driven by the output shaft 8 to swing so as to achieve steering of the vehicle.

Specifically, for example, referring to fig. 2, the roller 52 is mounted on the inner housing 51 and can rotate around its own axis relative to the inner housing 51, the outer peripheral wall of the roller 52 is provided with threads and can be in threaded engagement with the screw 4, and since the outer peripheral wall of the roller 52 is spaced from the inner peripheral wall of the inner housing 51, the inner peripheral wall of the inner housing 51 does not interfere with the relative movement between the roller 52 and the screw 4, so that when the screw 4 rotates, the roller 52 not only rotates around its own axis, but also moves along the axial direction of the screw 4, and the roller 52 moves to drive the inner housing 51 to move, thereby finally converting the rotation of the screw 4 into the movement of the motion assembly 5.

In the related art, some steering gears are provided with a recirculating ball type ball screw structure to achieve power transmission, and some steering gears are provided with a planetary roller screw structure to achieve power transmission. The ball screw structure of the recirculating ball type uses rolling of balls to convert rotation of a screw into movement of a nut, and since the balls transmit load through point contact with the screw and the nut, the ball screw has limited bearing capacity and is difficult to use under heavy load. The rolling element of the planet roller screw between the nut and the screw is a thread roller which is matched with the screw thread and the nut thread, when the screw rotates, the thread roller not only rotates around the self axis, but also revolves around the screw axis to finally drive the nut to move, compared with the roller screw, the load transmission element of the planet roller screw is a thread roller which is typically in line contact, thereby being capable of providing rated dynamic load and static load higher than those of the ball screw, so that the planet roller screw has high bearing capacity, but in the structure, in order to ensure that the thread roller can accurately rotate and revolve, parts such as an inner gear ring, a retainer, a snap spring and the like which are matched with the thread roller are also required to be arranged on the nut, so that the whole structure has a plurality of parts, which causes inconvenient production and processing, and when in assembly, the thread roller is required to be accurately matched with the screw, the structure is matched with the nut, and simultaneously needs to be meshed with the inner gear rings at two ends, so that the structure is complex to assemble and high in difficulty, and is difficult to widely apply.

Based on the above situation, the applicant creatively designs a steering gear 100 of a vehicle, the steering gear 100 is provided with a screw 4, a roller 52 and an inner shell 51, wherein the roller 52 is arranged between the inner peripheral wall of the inner shell 51 and the outer peripheral wall of the screw 4 and is connected with the inner shell 51 in a rotating way, the outer peripheral wall of the roller 52 is spaced from the inner peripheral wall of the inner shell 51, the roller 52 is in threaded fit with the screw 4, so that when the screw 4 rotates, the roller 52 does not revolve around the axis of the screw 4, only rotates around the axis of the roller, and simultaneously moves along the axis direction of the screw 4, and then the inner shell 51 can be driven to move, therefore, compared with a circulating ball type ball screw, because the device still adopts the linear contact of the roller 52 and the screw 4 to transmit load, the bearing capacity is high, the device can be used under heavy load, and compared with a planetary ball screw, the device does not need to use an internally toothed ring gear, The retainer, the snap spring and other components, and the inner peripheral wall of the inner shell 51 do not need to be processed with threads, so the structure is simple, the processing and the assembly are convenient, the cost is low, and the use is convenient.

According to the steering gear 100 of the vehicle of the embodiment of the invention, as the two axial ends of the roller 52 are respectively rotatably connected with the inner shell 51, the outer peripheral wall of the roller 52 is spaced from the inner peripheral wall of the inner shell 51, and the roller 52 is in threaded fit with the screw rod 4, when the screw rod 4 rotates, the roller 52 not only rotates around the self axis, but also moves along the axial direction of the screw rod 4, and further the roller 52 moves to drive the inner shell 51 to move, so that the rotation of the screw rod 4 can be finally converted into the movement of the movement assembly 5.

In some embodiments of the present invention, as shown in fig. 3, the number of the rollers 52 is multiple (for example, six), and the multiple rollers 52 are arranged at intervals along the circumferential direction of the screw 4, so that the load-bearing capacity of the steering gear 100 can be further improved. In the description of the present invention, "a plurality" means two or more.

In some embodiments of the present invention, as shown in fig. 2, both axial ends (e.g., left and right ends) of the rollers 52 are connected to the inner housing 51 by the first bearing assembly 6, so that the rollers 52 can be rotatably connected to the inner housing 51, and the structure is simple and easy to implement.

Of course, the present invention is not limited thereto, and in other embodiments, the rollers 52 may be connected to the inner shell 51 in a rotating manner through other structures.

In some embodiments of the present invention, the first bearing assembly 6 can withstand axial and radial loads, thereby allowing the rollers 52 to operate stably under more complex loading conditions (e.g., multiple loads, heavy loads), which in turn facilitates increased load carrying capability of the steering gear 100.

In some embodiments of the present invention, the first bearing assembly 6 may be a tapered roller bearing or an angular contact ball bearing. Both the tapered roller bearing and the angular ball bearing can simultaneously bear axial load and radial load, and during actual assembly, the tapered roller bearing or the angular ball bearing is generally used in pairs, that is, the tapered roller bearing or the angular ball bearing can be respectively arranged at the two axial ends of the roller 52. In specific application, a tapered roller bearing or an angular contact ball bearing meeting requirements can be selected according to the size of the borne load.

In some embodiments of the present invention, as shown in fig. 2 and 3, the first bearing assembly 6 includes the first bearing 61, the roller 52 includes a cylindrical portion 521 and connecting portions 522 disposed at two axial ends of the cylindrical portion 521, the cylindrical portion 521 is in threaded fit with the lead screw 4, and the first bearing 61 is sleeved on the connecting portions 522 and connected to the inner shell 51 for bearing radial load, so that the radial load bearing capability of the moving assembly 5 can be improved.

Specifically, for example, referring to fig. 2 and 3, the column 521 and the connecting portion 522 of the roller 52 are both cylindrical structures, wherein the column 521 and the connecting portion 522 are coaxially arranged, the diameter of the column 521 is larger than that of the connecting portion 522, a thread which can be engaged with the lead screw 4 is arranged on the outer peripheral wall of the column 521, the first bearings 61 are respectively sleeved on the connecting portions 522 on the left and right sides of the column 521, and the first bearings 61 are detachably connected with the inner shell 51, so that the structure is simple, and the assembly and disassembly are convenient.

In some embodiments of the present invention, as shown in fig. 2 and 3, the inner shell 51 includes a body 511 and two end covers 512, two axial sides of the body 511 are open, the two end covers 512 are respectively disposed on two open sides of the body 511, the end covers 512 are provided with an avoiding opening 5121 and a mounting opening 5122, two ends of the lead screw 4 respectively pass through the avoiding opening 5121 and penetrate out of the inner shell 51, and the mounting opening 5122 is provided with a first bearing 61 therein, so that the structure is simple and the mounting is convenient.

In some embodiments of the present invention, the body 511 is an annular structure, the body 511 defines a cavity which is open at two axial sides, and the body 511 is disposed coaxially with the lead screw 4, so that the structure is simple.

In some embodiments of the present invention, end cap 512 is removably coupled to body 511, thereby facilitating removal of end cap 512 from body 511.

In practice, there are many ways in which end cap 512 may be removably coupled to body 511. For example, the end cap 512 is detachably connected to the body 511 by a fastener, specifically, the fastener may be a bolt, wherein the end cap 512 is provided with a through hole, the body 511 is provided with a threaded hole, and the bolt passes through the through hole and is threadedly engaged with the threaded hole, thereby firmly fixing the end cap 512 to the body 511.

In some embodiments of the present invention, as shown in fig. 2, one end of the mounting opening 5122 close to the cylindrical portion 521 is provided with a first stepped portion 5123, and one axial end of the first bearing 61 abuts against the first stepped portion 5123, so that the first stepped portion 5123 can limit the first bearing 61, and the first bearing 61 can be conveniently mounted.

In some embodiments of the present invention, as shown in fig. 2, the first bearing assembly 6 includes the second bearings 62, and the second bearings 62 are provided between both axial ends of the cylindrical portion 521 and the corresponding end caps 512 for bearing the axial load, whereby the ability of the moving assembly 5 to bear the axial load can be improved. Compared with a tapered roller bearing or an angular contact ball bearing, the structural form of adopting two bearings to respectively bear axial load and radial load is more beneficial to reducing the overall structural size of the moving component 5 and improving the bearing capacity of the moving component 5. Because the bearing is a standard component, under the condition of meeting the bearing capacity of both axial load and radial load, the size of the selected tapered roller bearing or angular contact ball bearing is larger, which results in that the sizes of the roller 52 and the inner shell 51 which are matched with the bearing need to be correspondingly increased, so that the size of the steering gear 100 is further increased, the installation is inconvenient, and under the condition of being assembled on the roller 52 with the same size, the bearing capacity of the motion assembly 5 in the matching mode of the first bearing 61 and the second bearing 62 is higher than that in the mode of the tapered roller bearing or the angular contact ball bearing.

In a specific application, for the roller 52, since the diameter of the cylindrical portion 521 is larger than that of the connecting portion 522, a step portion may be formed at a connecting position of the cylindrical portion 521 and the connecting portion 522, so as to facilitate the position limitation of the second bearing 62. In actual assembly, for example, the first bearings 61 on both sides are respectively mounted in the mounting holes 5122 of the corresponding end covers 512, one of the end covers 512 is mounted on the body 511 by using bolts, then the second bearings 62 are respectively sleeved on the connecting portions 522 on both sides of the roller 52, then the connecting portion 522 on one side of the roller 52 is inserted into the first bearing 61 of the end cover 512 mounted on the body 511, then the connecting portion 522 on the other side of the roller 52 is inserted into the first bearing 61 of the other end cover 512, finally the other end cover 512 is mounted on the body 511 by using bolts, and after assembly, the screw rod 4 is screwed in, so that the assembly process is simple and convenient.

In some embodiments of the present invention, the first bearing 61 is a needle bearing, and the second bearing 62 is a flat thrust bearing, thereby providing a simple structure and facilitating assembly.

It should be noted that, in practical applications, the second bearing 62 is not limited to a thrust ball bearing or a thrust roller bearing, and may be selected according to practical requirements.

In some embodiments of the present invention, as shown in fig. 1 and 2, the inner housing 51 is provided with a rack portion 5111, the output shaft 8 is provided with a toothed portion 81, and the rack portion 5111 cooperates with the toothed portion 81 to form a rack and pinion engagement, so that when the inner housing 51 moves, the output shaft 8 can be driven to rotate by the cooperation of the rack portion 5111 and the toothed portion 81, and the structure is simple and convenient to implement.

In practical application, because the output shaft 8 is connected with the drop arm, the output shaft 8 does not need to rotate 360 degrees in the process of realizing vehicle steering, the wheel tooth part 81 does not need to be arranged into a whole circle gear pattern, and the wheel tooth part is arranged into a sector gear structure as shown in fig. 1 according to practical requirements, so that the material cost can be saved.

In some embodiments of the present invention, as shown in fig. 1 and 4, the steering gear 100 further comprises a housing 1, the lead screw 4 and the moving assembly 5 are located in the housing 1, and a second bearing assembly 7 is provided between both axial ends (e.g., left and right ends) of the lead screw 4 and an inner wall surface of the housing 1, so that the lead screw 4 can be connected to the housing 1 for rotation through the second bearing assembly 7, wherein the second bearing assembly 7 can bear axial load and/or radial load. Specifically, the second bearing unit 7 capable of bearing axial load, or the second bearing unit 7 capable of bearing both axial load and radial load can be selected according to the actual load condition.

In some embodiments of the present invention, the second bearing assembly 7 can bear axial load and radial load, so that the lead screw 4 can still work stably under more complicated load conditions (e.g. multiple loads and heavy loads), which is favorable for further improving the bearing capacity of the steering gear 100.

In some embodiments of the invention, the second bearing assembly 7 may be a tapered roller bearing or an angular contact ball bearing. The tapered roller bearings or the angular contact ball bearings can bear axial loads and radial loads at the same time, and during actual assembly, the tapered roller bearings or the angular contact ball bearings are generally used in pairs, namely, the tapered roller bearings or the angular contact ball bearings can be arranged at the two axial ends of the lead screw 4 respectively. In specific application, a tapered roller bearing or an angular contact ball bearing meeting requirements can be selected according to the size of the borne load.

In some embodiments of the present invention, as shown in fig. 4, the two axial ends of the lead screw 4 are respectively provided with a limiting member 41, the limiting members 41 are configured to be annular and are sleeved on the lead screw 4, the housing 1 includes two first side wall surfaces 111 oppositely arranged in the axial direction (for example, the left-right direction) of the lead screw 4, the second bearing assembly 7 includes a third bearing 71, the third bearing 71 is sleeved on the lead screw 4 and is abutted between the limiting member 41 and the first side wall surface 111 adjacent to the limiting member 41, so that the limiting member 41 is arranged to limit the third bearing 71, and facilitate the installation of the third bearing 71, where the third bearing 71 is used for bearing radial load.

Further, referring to fig. 4, the housing 1 is provided with a second stepped portion 11, and a wall surface of the second stepped portion 11 facing the stopper 41 in the axial direction of the screw 4 is a first side wall surface 111, so that the structure is simple and the implementation is easy.

In a specific application, the third bearing 71 is a plane thrust bearing, so that a large radial load can be borne, and the structure is simple and convenient to mount. In actual assembly, the third bearing 71 is a thrust ball bearing or a thrust roller bearing, which is not limited herein and can be selected according to actual requirements.

In some embodiments of the present invention, the position-limiting member 41 is detachably connected to the screw rod 4, so as to facilitate the assembling and disassembling of the position-limiting member 41 and the screw rod 4.

In practice, there are many ways in which end cap 512 may be removably coupled to body 511. For example, the stopper 41 is screwed or keyed to the screw 4.

In some embodiments of the present invention, as shown in fig. 4, the second bearing assembly 7 includes a fourth bearing 72, and the fourth bearing 72 is sleeved on the retaining member 41 and radially abutted against the inner wall of the housing 1, so that the retaining member 41 is further provided to retain the fourth bearing 72, thereby facilitating the installation of the fourth bearing 72, where the fourth bearing 72 is used for bearing radial load.

It should be noted that, the fourth bearing 72 is selectively sleeved on the limiting member 41, because in a specific application, under a condition of meeting a stress requirement, from the viewpoint of saving cost and reducing the overall weight, a lead screw 4 structure with a small diameter may be selected, and the inner diameter of the fourth bearing 72 meeting a load requirement may be relatively large, so that the fourth bearing 72 may be selectively sleeved on the limiting member 41 after the limiting member 41 is disposed, and the type selection of the lead screw 4 may not be affected.

Further, referring to fig. 4, the housing 1 is provided with a third step portion 12, a wall surface of the third step portion 12 facing the stopper 41 in the radial direction of the screw 4 is a second side wall surface, and the outer peripheral wall of the fourth bearing 72 abuts against the second side wall surface, so that the structure is simple and the implementation is convenient.

In a specific application, the fourth bearing 72 is a needle bearing, so that a large radial load can be borne, and the fourth bearing is simple in structure and convenient to mount. Compared with a tapered roller bearing or an angular contact ball bearing, the mode of combining the third bearing 71 and the fourth bearing 72 to respectively bear the axial load and the radial load is more beneficial to reducing the overall structural size of the steering gear 100 and improving the bearing capacity of the steering gear 100. Because the bearing is a standard component, under the condition that the bearing capacity of the bearing can meet the bearing capacity of an axial load and the bearing capacity of a radial load, the size of the selected tapered roller bearing or angular contact ball bearing is larger, which causes the sizes of the lead screw 4 and the shell 1 which are matched with the bearing to be correspondingly increased, so that the size of the steering gear 100 is further increased, the installation is inconvenient, and under the condition that the steering gear 100 is assembled on the lead screw 4 with the same size, the bearing capacity of the steering gear 100 in the matching mode of the third bearing 71 and the fourth bearing 72 is higher than that of the steering gear in the mode of the tapered roller bearing or the angular contact ball bearing.

In some embodiments of the present invention, as shown in fig. 1, the steering gear 100 further includes an input shaft 2 and a power assembly 3, and the input shaft 2 and the power assembly 3 are respectively located at both axial sides of the lead screw 4 and are connected to the lead screw 4, so that the structure is simple. Specifically, the input shaft 2 is adapted to be connected to a steering wheel of a vehicle to transmit a steering force from the steering wheel to the steering gear 100, and the power assembly 3 is adapted to drive the lead screw 4 to rotate.

In some embodiments of the present invention, as shown in fig. 1, the power assembly 3 includes a motor 31 and a transmission assembly 32, and the transmission assembly 32 is connected to the motor 31 and the lead screw 4, respectively, so that the power of the motor 31 can be transmitted to the lead screw 4 after being transmitted by the transmission assembly 32.

Since the steering gear 100 requires more output torque than output motion during actual vehicle steering, the transmission assembly 32 is usually a speed reducing mechanism in practical applications, so that the torque finally transmitted to the lead screw 4 by the motor 31 can be increased.

Specifically, the speed reducing mechanism may be a first-stage speed reducing mechanism, a second-stage speed reducing mechanism, and the like, and the type of the speed reducing mechanism may be a planetary gear speed reducing mechanism, a worm and gear speed reducing mechanism, and the like, which may be selected according to actual requirements, and the invention is not limited thereto.

In some embodiments of the present invention, as shown in fig. 1, the steering gear 100 further comprises a detecting element 9, the detecting element 9 is used for detecting the torque and/or the rotation angle of the input shaft 2 and generating a detecting signal, the detecting element 9 is adapted to transmit the detecting signal to a control mechanism of the vehicle so that the control mechanism can control the power assembly 3 to work according to the detecting signal, and therefore the steering gear 100 can provide the power assisting force for the steering of the vehicle.

In a specific application, the detecting element 9 may be a sensor, for example, and according to the actual control requirement, a sensor may be provided to detect the torque of the input shaft 2, or detect the rotation angle of the input shaft 2, or detect the torque and the rotation angle of the input shaft 2, and the control mechanism may be an ECU (electronic control unit) of the vehicle, for example.

In some embodiments of the present invention, as shown in fig. 1, the input shaft 2 includes a shaft body 21 and a torsion bar 22, a portion of the shaft body 21 extends out of the housing 1, a remaining portion of the shaft body 21 is disposed in the housing 1, the shaft body 21 is rotatable relative to the housing 1, wherein a sensor is disposed on a portion of the shaft body 21 located in the housing 1, a mounting through hole extending along an axial direction thereof and having both ends open is disposed on the shaft body 21, the torsion bar 22 is inserted into the mounting through hole and partially extends out of the mounting through hole, a portion of the torsion bar 22 located in the mounting through hole is connected to the shaft body 21, and a portion of the torsion bar 22 extending out of the mounting through hole is connected to the lead screw 4.

Specifically, referring to fig. 1, the portion of the shaft body 21 extending out of the housing 1 is usually provided with splines so that the shaft body 21 can be splined to a connection column of a steering wheel to transmit a steering force from the steering wheel, the torsion bar 22 is fixedly connected to the shaft body 21 by a latch, and the torsion bar 22 is splined to the first bevel gear, so that when the shaft body 21 is rotated by the steering force from the steering wheel, the shaft body 21 rotates the torsion bar 22 due to the fixed connection of the torsion bar 22 to the shaft body 21 by the latch, and the torsion bar 22 is twisted due to the force, and the torsion bar 22 rotates the lead screw 4 due to the splined connection of the torsion bar 22 to the lead screw 4. In this process, the sensor can detect the torque and/or the rotation angle of the input shaft 2 by detecting the torque and/or the rotation angle of the torsion bar 22, and the sensor can generate a detection signal and transmit the detection signal to the ECU of the vehicle, so that the ECU can control the operation of the motor 31 according to the detection signal, for example, control the current and the rotation speed of the motor 31, and further can adjust the torque of the motor 31 so that the steering gear 100 can provide a proper steering assistance force. The related detection and control processes are well known to those skilled in the art and will not be described in detail herein.

The steering system according to the embodiment of the present invention includes a steering gear 100, a steering mechanism and a steering transmission mechanism, the steering gear 100 is the steering gear 100 described above, the steering mechanism is connected to the input shaft 2, and the steering transmission mechanism is connected to the output shaft 8 of the steering gear 100. Wherein the steering operation mechanism is adapted to transmit power of a driver turning a steering wheel to the steering gear 100 through the input shaft 2, and the steering transmission mechanism is adapted to transmit power of the steering gear 100 to the steered wheels to steer the steered wheels.

According to the steering system of the embodiment of the invention, as the two axial ends of the roller 52 of the steering gear 100 are respectively rotatably connected with the inner shell 51, the outer peripheral wall of the roller 52 is spaced from the inner peripheral wall of the inner shell 51, and the roller 52 is in threaded fit with the screw rod 4, when the screw rod 4 rotates, the roller 52 not only rotates around the self axis, but also moves along the axial direction of the screw rod 4, and further the roller 52 moves to drive the inner shell 51 to move, so that the rotation of the screw rod 4 can be finally converted into the movement of the movement assembly 5.

According to the embodiment of the invention, the vehicle comprises the steering system.

According to the vehicle of the embodiment of the invention, as the two axial ends of the roller 52 of the steering gear 100 are respectively rotatably connected with the inner shell 51, the outer peripheral wall of the roller 52 is spaced from the inner peripheral wall of the inner shell 51, and the roller 52 is in threaded fit with the screw rod 4, when the screw rod 4 rotates, the roller 52 not only rotates around the self axis, but also moves along the axial direction of the screw rod 4, and further the roller 52 moves to drive the inner shell 51 to move, so that the rotation of the screw rod 4 can be finally converted into the movement of the movement assembly 5.

In the description of the present invention, it is to be understood that the terms "left", "right", "inner", "outer", "axial", "circumferential", "radial", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, "the first feature" and "the second feature" may include one or more of the features. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description herein, references to the description of the terms "some embodiments," "alternative embodiments," or the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (13)

1. A steering gear for a vehicle, comprising:

a lead screw;

a motion assembly, the motion assembly comprising: the inner shell is arranged around the periphery of the screw rod, two axial ends of the screw rod penetrate out of the inner shell, the roller is located between the inner peripheral wall of the inner shell and the outer peripheral wall of the screw rod, the two axial ends of the roller are respectively and rotatably connected with the inner shell, the outer peripheral wall of the roller is spaced from the inner peripheral wall of the inner shell, the roller is in threaded fit with the screw rod, and under the condition that the screw rod rotates, the roller rotates to drive the motion assembly to move in the axial direction of the screw rod; and

an output shaft, the motion assembly moving to drive the output shaft to rotate.

2. The steering gear for a vehicle according to claim 1, wherein the roller is plural, and plural rollers are arranged at intervals in a circumferential direction of the screw shaft.

3. The vehicle steering gear according to claim 1, wherein both axial ends of the roller are connected to the inner housing by a first bearing assembly.

4. The vehicle steering gear according to claim 3, wherein the first bearing assembly comprises a first bearing, the roller comprises a column portion and connecting portions provided at both axial ends of the column portion, the column portion is threadedly engaged with the lead screw, and the first bearing is fitted over the connecting portions and connected to the inner housing for bearing a radial load.

5. The steering gear for a vehicle according to claim 4, wherein the inner casing includes:

a body, both axial sides of which are open; and

the two end covers are respectively arranged on two open sides of the body, an avoiding opening and a mounting opening are formed in the end covers, two ends of the lead screw respectively pass through the avoiding opening and penetrate out of the inner shell, and the first bearing is arranged in the mounting opening.

6. The vehicle steering gear according to claim 4, wherein the first bearing assembly includes a second bearing provided between both axial ends of the column portion and the corresponding end caps for bearing an axial load.

7. The vehicle steering gear according to claim 6, wherein the first bearing is a needle bearing and the second bearing is a flat thrust bearing.

8. The vehicle steering gear according to claim 1, further comprising a housing, wherein the lead screw and the moving assembly are located in the housing, and a second bearing assembly is provided between both axial ends of the lead screw and an inner wall surface of the housing, and the second bearing assembly can bear axial load and/or radial load.

9. The vehicle steering device according to claim 8, wherein the screw shaft is provided at both axial ends thereof with stoppers, respectively, the stoppers are configured in a ring shape and are fitted over the screw shaft, the housing includes two first side wall surfaces disposed opposite to each other in the axial direction of the screw shaft, and the second bearing assembly includes a third bearing fitted over the screw shaft and abutting between the stoppers and the first side wall surfaces adjacent to the stoppers.

10. The vehicle steering gear according to claim 9, wherein the second bearing assembly includes a fourth bearing that is sleeved over the retainer and radially abuts against an inner wall of the housing.

11. The vehicle steering gear according to claim 10, wherein the third bearing is a flat thrust bearing and the fourth bearing is a needle bearing.

12. A steering system, comprising:

a diverter according to any one of claims 1 to 11;

the steering control mechanism is connected with the input shaft; and

and the steering transmission mechanism is connected with an output shaft of the steering gear.

13. A vehicle characterized by comprising the steering system of claim 12.

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