CN211844609U

CN211844609U - Planetary gear type pure electric power steering gear

Info

Publication number: CN211844609U
Application number: CN202020446996.XU
Authority: CN
Inventors: 杨亮终
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2020-11-03
Anticipated expiration: 2030-03-31

Abstract

The utility model provides a pure electric power assisted steering ware of planetary gear formula, including helping hand motor, cylindrical gear reduction mechanism, planetary gear reduction mechanism, worm and worm wheel reduction mechanism, turn to the output shaft, turn to input shaft, casing and torque sensor. The combined structure of the planetary gear reduction mechanism and the cylindrical gear reduction mechanism is adopted to reduce the speed and increase the torque of the power output of the power-assisted motor, so that the steering output shaft of the steering gear can output the torque and the rotating speed meeting the use requirement; the worm and worm gear transmission mechanism is used for transmitting the control torsion of a steering wheel and the reverse feedback of wheel steering resistance, the steering power assisting and steering control are two independent power transmission chains, the steering power assisting and the steering control output torque are finally converged on a steering output shaft to be superposed into the work output torque of a product, the limitation of the conventional electric power-assisted steering device in the application field of commercial vehicles is effectively solved, the commercial vehicles can have high efficiency, energy conservation and light steering, and the pure electric power-assisted steering device with good controllability is selected.

Description

Planetary gear type pure electric power steering gear

Technical Field

The utility model relates to a car steering part field, concretely relates to pure electric power assisted steering ware of planetary gear formula.

Background

The steering system of a vehicle is a series of special devices for changing or maintaining the driving direction of the vehicle, and functions to control the driving direction of the vehicle according to the intention of a driver. The performance of the steering system, which is one of the important systems in the whole vehicle construction, is directly related to the comfort, safety and energy consumption of the vehicle driving, and even influences the environment. The development of automobile steering systems has gone from simple mechanical steering, hydraulic power steering, to electro-hydraulic power steering, to the emergence of more energy-saving, better-handling electric power steering systems. Electric steering is a short term and is distinguished from electro-hydraulic steering. The former refers to an electric-only power steering system (i.e., EPS), and the latter refers to an electro-hydraulic steering system (i.e., EHPS). The electric hydraulic steering system is still hydraulic power-assisted steering in nature, the electric steering only needs a power supply without a hydraulic power source, and compared with the hydraulic power steering system, the electric hydraulic steering system omits a plurality of elements, does not have an oil pump, an oil pipe, a pressure flow control valve, an oil storage tank and the like required by the hydraulic system, has less parts, convenient arrangement and light weight. The electric power steering system does not adopt oil medium any more, has no liquid leakage loss, reduces the possibility of oil pollution and also improves the environment. Therefore, the electric vehicle steering system is rapidly popularized in recent years and is a development direction of an automobile power steering system in the future.

Electric power steering has been developed to address the drawbacks of hydraulic power steering, so those drawbacks of hydraulic power steering have all become an advantage for electric power steering. The electric power steering has a wide development prospect, is free of containing condensation, but can only be applied to the field of passenger vehicles and gradually developed and popularized, a traditional hydraulic power steering system is selected for a fuel commercial vehicle, and an electric hydraulic power steering system is selected for a new energy commercial vehicle, so that the reason is that a pure electric power steering gear suitable for commercial vehicles still does not exist in the market at present, and the commercial vehicle still has to select the traditional power steering system. Therefore, the application of the electric power steering in the field of commercial vehicles becomes the blank and pain point of the electric power steering development industry. As the steering gear used by the commercial vehicle is almost all of the recirculating ball type, a plurality of domestic research institutions and manufacturing enterprises modify and upgrade the existing recirculating ball type steering gear in various modes, after a hydraulic oil way power-assisted system is removed, the recirculating ball screw nut transmission mechanism bears great load, and after years of research and exploration, the recirculating ball type pure electric steering gear is still not provided with a mature product, has an unsatisfactory effect, and cannot output enough torque to meet the use requirements of medium and heavy commercial vehicles. The pure electric power steering of the commercial vehicle can meet the market demand and promote the technical progress of the industry, so that the research on the electric power steering system with large output torque for the commercial vehicle has important significance for the development of the automobile steering industry.

In a common mechanical transmission: the planetary gear speed reducing mechanism has the advantages that the planetary gear speed reducing mechanism has larger-area gear contact, uniform load of 360 degrees, and a plurality of gear surfaces can uniformly bear instant impact load together, so that the planetary gear speed reducing mechanism can bear higher torque impact and cannot be damaged or broken. The torque-volume ratio is higher, and the output torque can be very large; the disadvantage is that the single-stage reduction ratio is small, and the axial size of the mechanism is larger if the multiple stages are connected in series. The installation and arrangement of products are difficult; if the cylindrical gear speed reducing mechanism needs to bear large torque, the gear modulus and the radial size are large; the worm and worm gear speed reducing mechanism has the characteristics of compact structure and large single-stage speed reducing ratio; however, the worm wheel and the worm have sliding friction, so that the transmission efficiency is low, and the heat productivity of the mechanism is large during heavy load transmission.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a pure electric power assisted steering ware of planetary gear formula, arrange cylindrical gear reduction mechanism on the high-speed low torque transmission level of power assisted steering drive chain, arrange planetary gear reduction mechanism on the low-speed big torque transmission level of power assisted steering drive chain, worm and worm gear reduction mechanism is used for steering the light load transmission of controlling the drive chain; the pure electric power-assisted steering gear of the hydraulic oil way power-assisted system is removed by skillfully and accurately matching three types of transmission mechanisms of a planetary gear reduction mechanism, a worm and worm gear reduction mechanism and a cylindrical gear reduction mechanism; the steering control steering shaft and the power-assisted steering of the steering motor are two independent transmission chains, and the vehicle turning of the commercial vehicle can be completed by using a smaller steering wheel rotating angle; the worm and worm gear speed reducing mechanism is arranged between the primary speed reducing mechanism and the final speed reducing mechanism, so that the axial size of a product is greatly reduced. The utility model provides a plurality of technical effects that preferred technical scheme among a great deal of technical scheme can produce see the explanation below in detail.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a pure electric power assisted steering ware of planetary gear formula, its characterized in that: the steering device comprises a power-assisted motor, a cylindrical gear speed reducing mechanism, a planetary gear speed reducing mechanism, a worm and worm gear speed reducing mechanism, a shell, a steering output shaft, a steering input shaft and a torque sensor; wherein:

optionally or preferably, the power-assisted motor is arranged on one side of the shell and is fixedly connected with the shell; the cylindrical gear speed reducing mechanism is arranged in the shell and is movably connected with the power-assisted motor.

Alternatively or preferably, the planetary gear reduction mechanism is disposed inside the housing, and the planetary gear reduction mechanism includes a primary reduction mechanism and a final reduction mechanism.

Alternatively or preferably, the primary reduction mechanism is connected to the final reduction mechanism on one side and to the spur gear reduction mechanism on the other side.

Alternatively or preferably, one end of the steering output shaft is buried inside the housing and connected to the final reduction mechanism.

Optionally or preferably, one end of the steering output shaft is provided with a limiting structure for ensuring that the steering output shaft rotates around the axis.

Alternatively or preferably, the worm and worm gear speed reducing mechanism is arranged on the upper side of the final speed reducing mechanism, and the worm and worm gear speed reducing mechanism is arranged in the shell and connected with the final speed reducing mechanism; the steering input shaft is connected with the worm and gear speed reducing mechanism, the torque sensor is arranged on the side surface of the steering input shaft and connected with the steering input shaft, the cylindrical gear speed reducing mechanism is used as a high-speed low-torque transmission stage in the power-assisted steering transmission chain, and the planetary gear speed reducing mechanism is used as a low-speed high-torque transmission stage in the power-assisted steering transmission chain; a worm and worm gear speed reducing mechanism is used as a power transmission mechanism of a steering control transmission chain.

Optionally or preferably, a side cover a is arranged between the power-assisted motor and the shell, and the side cover a is fixedly connected with the shell; the side cover a is fixedly connected with the power-assisted motor.

Optionally or preferably, the cylindrical gear speed reducing mechanism comprises a cylindrical gear a, a cylindrical gear shaft and a cylindrical gear b, and a motor output shaft of the power-assisted motor is in gear meshing connection with the cylindrical gear a; a rubber cushion pad, a cover plate and a chuck are arranged between the cylindrical gear a and the cylindrical gear shaft, the chuck is L-shaped, and the cylindrical gear a and the cylindrical gear shaft are connected through the chuck; the rubber cushion pad is arranged at the right angle of the chuck and is pressed and fixed through the cover plate; one end of the side cover a is provided with a countersunk hole, and one end of the cylindrical gear shaft is arranged in the countersunk hole and is movably connected with the side cover a through a bearing; the cylindrical gear b is meshed with the other end of the cylindrical gear shaft and connected with the primary speed reducing mechanism; an inner end cover is arranged between the cylindrical gear speed reducing mechanism and the primary speed reducing mechanism, a through hole is formed in the lower side of the inner end cover, the other end of the cylindrical gear shaft is arranged in the through hole and movably connected with the inner end cover through a bearing, and the cylindrical gear a, the rubber cushion, the chuck and the cover plate form a flexible connecting mechanism.

Alternatively or preferably, the primary reduction mechanism includes an inner gear ring a, a planetary gear a and a planetary gear shaft, and the final reduction mechanism includes a sun gear; the planet gear a of the primary speed reducing mechanism is arranged in the inner gear ring a and is in meshed connection with the inner side of the inner gear ring a; the planet gear shafts are arranged between the planet gears a and are in meshed connection with the planet gears a; one end of the planet gear shaft is fixedly connected with the cylindrical gear b, and the other end of the planet gear shaft is embedded in the sun gear and connected with the sun gear through a needle bearing; the center of the planetary gear a is provided with a fixed shaft a, the planetary gear a is movably connected with the fixed shaft a through a bearing, and the fixed shaft a is fixedly connected with a planet carrier of the primary speed reducing mechanism.

Optionally or preferably, the final reduction mechanism further comprises a planet carrier left side plate, planet gears b, an inner gear ring b and a planet carrier right side plate, wherein the planet gears b are circumferentially and uniformly distributed between the inner gear ring b and the sun gear, are in meshed connection with the inner side of the inner gear ring b and are also in meshed connection with the outer side of the sun gear; a boss matched with the sun gear is arranged at one end of the steering output shaft embedded in the shell, and the boss is arranged in the sun gear and connected through a needle bearing; a fixed shaft b is arranged in the center of the planet gear b and is arranged between the left side plate and the right side plate of the planet carrier, and the two ends of the fixed shaft b are fixedly connected with the left side plate and the right side plate of the planet carrier respectively; the right end of the sun gear of the final stage speed reducing mechanism in the planetary gear speed reducing mechanism is fixedly connected with the primary speed reducing mechanism into a whole, and the two stages of speed reducing mechanisms are coaxially and serially connected, namely, the speed reducing mechanisms are an energy output shaft and an energy input shaft of the next stage speed reducing mechanism.

Optionally or preferably, the worm and worm wheel speed reducing mechanism comprises a worm wheel and a worm, and the worm is arranged above the worm wheel and is in meshed connection; both ends of the worm are provided with bearings a and movably connected through the bearings a; the worm wheel is fixedly connected with the right side plate of the planet carrier of the final-stage speed reducing mechanism through a screw; a positioning hole is formed in the worm wheel, and a cylindrical positioning pin is arranged in the positioning hole; the shell is provided with two threaded plugs, a slotted pan head screw is arranged between the threaded plugs and the shell, and the slotted pan head screw is fixedly connected with the shell; an angle limiting block is arranged outside the slotted pan head screw, the angle limiting block is coaxially matched with the slotted pan head screw, the worm wheel is of a sector tooth structure, and when the worm wheel swings left and right to a limit position, two side faces of the worm wheel are in contact with the angle limiting block, so that the worm wheel is limited by a stroke; the slotted pan head screw is arranged inside the angle limiting block, and a screw hole for screwing the oil plug threaded plug is formed in the center of the slotted pan head screw; the rotating angle range of a steering output shaft of a steering gear of a common commercial vehicle is plus or minus 45 degrees, and a raised clamping tenon of the angle limiting block is just embedded into a clamping groove corresponding to an inner gear ring b of a final-stage speed reducing mechanism and an inner gear ring a of a primary speed reducing mechanism when the angle limiting block is installed; the fixed angle limiting block can also play a role in fixing the inner gear ring of the planetary gear speed reducing mechanism, and can prevent the inner gear ring from rotating in the shell under the stress during the operation; when the device is installed, the shaft axis of the steering input shaft is not vertical usually, and the device has an inclination angle of about 70 degrees backwards. According to the installation arrangement, the height position of the threaded plug is just in the proper position for oil drainage and oil filling, and the two slotted pan head screws are designed to be hollow; the threaded plug can fix and strain the slotted pan head screw and has the function of an oil plug. In consideration of practical use requirements, the threaded plug at the oil filling port needs to be a ventilation oil plug with a ventilation function.

Optionally or preferably, an upper cover is arranged on the upper side of the shell, and the upper cover is fixedly connected with the shell through a screw; the steering input shaft is characterized by also comprising a steering input shaft, wherein one end of the steering input shaft penetrates through the upper cover and is embedded in one end of the worm, and the steering input shaft is connected with the worm through a needle bearing; the steering input shaft is movably connected with the upper cover through a bearing; a dustproof ring is arranged between the upper cover and the steering input shaft; the other end of the steering input shaft is provided with a through hole for mounting a cylindrical pin; the steering input shaft further comprises an elastic torsion bar, and the elastic torsion bar is arranged inside the steering input shaft and is fixedly connected with the worm; the other end of the worm is provided with a plug screw for positioning the worm; a bearing gland is arranged on the side surface of a bearing a at one end of the worm connected with the elastic torsion bar and is fixedly connected with the shell through a countersunk head screw; the torque sensor is arranged between the steering input shaft and the worm, and an oil seal structure for sealing is arranged between the worm and the bearing gland; a cable waterproof joint is arranged on the outer side surface of the shell and penetrates through the shell to be fixedly connected with the torque sensor; a sealing ring is arranged between the waterproof cable joint and the shell; the steering hand force from the steering wheel is elastically deformed through the cylindrical pin control torsion bar and is transmitted to the right side plate of the planet carrier of the final-stage speed reducing mechanism through the elastic torsion bar, the worm and the worm gear, the steering control torque is changed to be matched with the rotating speed of the steering power-assisted transmission through the worm and worm gear transmission mechanism according to the set transmission speed ratio, and the steering control torque and the steering power-assisted torque are superposed on a steering output shaft of the steering gear through the final-stage speed reducing mechanism to be coupled into the working torque output of a product; in the process, the torsional deformation amount of the elastic torsion bar can feed back the steering resistance of the wheel, the torque sensor can send out corresponding electric signals according to the deformation, and the controller controls the power-assisted motor to provide output torque with proper magnitude according to the received signals.

Alternatively or preferably, the limiting structure comprises a tapered roller bearing and a planar needle thrust bearing, or a tapered roller bearing and an angular contact thrust ball bearing; the plane thrust needle roller bearing is arranged between the shell and the side surface of the final-stage speed reducing mechanism; the thrust angular contact ball bearing is arranged between the shell and the upper side of the final-stage speed reducing mechanism; a side cover b is arranged on the side face of one end, connected with the steering output shaft, of the shell, and the side cover b is fixedly connected with the shell through a screw; an oil seal structure for sealing is arranged between the side cover b and a third step of the steering output shaft; the tapered roller bearing is arranged between the steering output shaft and the shell, and a thread tightening ring for tightening the steering output shaft and the tapered roller bearing is arranged at the third-stage step right angle of the steering output shaft; the steering output shaft is movably connected with the shell through a tapered roller bearing, the tapered roller bearing arranged on the shell is a main supporting piece of the steering output shaft, and the axial position of the steering output shaft of the steering gear is fixed by adopting threads and a tight ring.

Based on the technical scheme, the following technical effects can be generated:

the embodiment of the utility model provides a pair of pure electric power assisted steering ware of planetary gear formula is applicable to the pure electric power assisted steering ware of various light, medium and heavy passenger train and freight train. The utility model relates to a pure electric power assisted steering ware of planetary gear formula arranges cylindrical gear reduction gears on the high-speed low torque transmission level of power assisted steering transmission chain, arranges planetary gear reduction gears on the low-speed big torque transmission level of power assisted steering transmission chain, and worm gear reduction gears is used for the light load transmission of steering control transmission chain, through the ingenious accurate cooperation of planetary gear reduction gears, worm gear reduction gears and the three types of transmission mechanisms of cylindrical gear reduction gears, realizes removing the pure electric power assisted steering ware of hydraulic pressure oil circuit helping hand system; the steering control steering shaft and the power-assisted steering of the steering motor are two independent transmission chains, and the torque output by the steering control steering shaft and the torque output by the steering motor are fused at the tail ends of the respective transmission chains and do not interfere with each other, so that the utility model can realize that the vehicle of the commercial vehicle is turned by a smaller steering wheel rotating angle; the worm and worm gear speed reducing mechanism is arranged between the primary speed reducing mechanism and the final speed reducing mechanism, and the spatial position which is vacant in the shell of the steering gear but cannot be subtracted is ingeniously utilized, so that the axial size of a product is greatly reduced; the output shaft is not supported by bearings at both ends of the output shaft like a steering gear with other structures, and the device adopts a tapered roller bearing and a thread tightening ring to ensure the complete positioning of parts, increase the transmission stability of the mechanism and reduce noise and vibration.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a main sectional view of a planetary gear type pure electric power steering gear;

FIG. 2 is a radial cross-sectional view taken along the line A-A and at the location of FIG. 1;

FIG. 3 is a schematic structural view of a connecting mechanism for flexibly connecting a gear shaft and a gear in a cylindrical gear reduction mechanism;

FIG. 4 is a schematic view of a connection structure of an annular gear of a planetary transmission mechanism and an angle limiting block in a planetary gear type pure electric power steering gear;

FIG. 5 is a schematic view of an external structure of a planetary gear type pure electric power steering gear;

FIG. 6 shows A, B two embodiments of the present invention for mounting and positioning the steering output shaft relative to the housing;

in the figure: 1-a steering output shaft; 101-a boss; 2-oil sealing; 3-screwing and tightening the ring; 4-side cover b; 5-tapered roller bearings; 6-a shell; 7-plane thrust needle roller bearing; 8-final reduction gear; 801-planet carrier left side plate; 802-ring gear b; 803-sun gear; 804-planet carrier right side plate; 805-planet gear b; 806-fixed axis b; 9-a worm; 10-a worm gear; 11-a primary reduction mechanism; 1101-ring gear a; 1102-planetary gear a; 1103-planet gear shaft; 1104-fixed axis a; 12-inner end cap; 13-side cover a; 14-a booster motor; 1401-motor output shaft; 15-needle bearings; 16-cylindrical gear a; 17-cylindrical gear b; 18-a cover plate; 19-rubber cushion; 20-a chuck; 21-cylindrical gear shaft; 22-a threaded plug; 23-slotted pan head screws; 24-angle stoppers; 25-cylindrical locating pins; 26-a plug screw; 27-a bearing gland; 28-a torque sensor; 29-cable watertight joint; 30-upper cover; 31-a dust ring; 32-a steering input shaft; 33-an elastic torsion bar; 34-cylindrical pin; 35-bearing a; 36-thrust angular contact ball bearing.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The invention will be further described with reference to the accompanying drawings, but the scope of the invention is not limited to the following description.

As shown in fig. 1-6:

the utility model provides a planetary gear type pure electric power steering gear, which comprises a power-assisted motor 14, a cylindrical gear speed reducing mechanism, a planetary gear number reducing mechanism, a worm and worm gear speed reducing mechanism, a shell 6, a steering output shaft 1, a steering input shaft 32 and a torque sensor 28; wherein:

the power-assisted motor 14 is arranged on one side of the shell 6 and is fixedly connected with the shell 6; the cylindrical gear speed reducing mechanism is arranged in the shell 6 and is movably connected with the power-assisted motor 14; the planetary gear speed reduction mechanism is arranged inside the shell 6 and comprises a primary speed reduction mechanism 11 and a final speed reduction mechanism 8; one side of the primary speed reducing mechanism 11 is connected with the final speed reducing mechanism 8, and the other side of the primary speed reducing mechanism is connected with the cylindrical gear speed reducing mechanism; one end of the steering output shaft 1 is embedded in the shell 6 and is connected with the final-stage speed reducing mechanism 8; one end of the steering output shaft 1 is provided with a limiting structure which ensures that the steering output shaft 1 rotates around the axis; the worm and worm wheel speed reducing mechanism is arranged on the upper side of the final speed reducing mechanism 8, is arranged in the shell 6 and is connected with the final speed reducing mechanism 8; the steering input shaft 32 is connected with a worm and worm gear speed reducing mechanism, and the torque sensor 28 is arranged on the side surface of the steering input shaft 32 and connected with the steering input shaft 32; a cylindrical gear speed reducing mechanism is used as a high-speed low-torque transmission stage in the power-assisted steering transmission chain, and a planetary gear speed reducing mechanism is used as a low-speed high-torque transmission stage in the power-assisted steering transmission chain; a worm and worm gear speed reducing mechanism is used as a power transmission mechanism of a steering control transmission chain.

As an alternative embodiment, a side cover a13 is arranged between the booster motor 14 and the housing 6, and the side cover a13 is fixedly connected with the housing 6; the side cover a13 is fixedly connected with the booster motor 14.

As an alternative embodiment, the cylindrical gear speed reducing mechanism comprises a cylindrical gear a16, a cylindrical gear shaft 21 and a cylindrical gear b17, and a motor output shaft 1401 of the power-assisted motor 14 is in gear engagement with the cylindrical gear a 16; a rubber cushion pad 19, a cover plate 18 and a chuck 20 are arranged between the cylindrical gear a16 and the cylindrical gear shaft 21, the chuck 20 is L-shaped, and the cylindrical gear a16 is connected with the cylindrical gear shaft 21 through the chuck 20; the rubber cushion pad 19 is arranged at the right angle of the chuck 20 and is pressed and fixed by the cover plate 18; one end of the side cover a13 is provided with a countersunk hole, one end of the cylindrical gear shaft 21 is arranged in the countersunk hole and is movably connected with the side cover a13 through a bearing; the cylindrical gear b17 is meshed with the other end of the cylindrical gear shaft 21, and the cylindrical gear b17 is connected with the primary speed reducing mechanism 11; an inner end cover 12 is arranged between the cylindrical gear speed reducing mechanism and the primary speed reducing mechanism 11, a through hole is formed in the lower side of the inner end cover 12, the other end of the cylindrical gear shaft 21 is arranged in the through hole and movably connected with the inner end cover 12 through a bearing, and the cylindrical gear a16, the rubber cushion pad 19, the chuck 20 and the cover plate 18 form a flexible connecting mechanism.

As an alternative embodiment, the primary reduction mechanism 11 includes an annular gear a1101, a planetary gear a1102, and a planetary gear shaft 1103, and the final reduction mechanism 8 includes a sun gear 803; planetary gears a1102 of the primary speed reduction mechanism 11 are disposed inside ring gear a1101 and are in meshing connection with the inside of ring gear a 1101; the planet gear shaft 1103 is arranged between the planet gears a1102 and is in meshed connection with the planet gears a 1102; one end of the planetary gear shaft 1103 is fixedly connected with the cylindrical gear b17, and the other end of the planetary gear shaft 1103 is embedded in the sun gear 803 and connected with the sun gear 803 through a needle bearing 15; a fixed shaft a1104 is arranged at the center of the planetary gear a1102, the planetary gear a1102 and the fixed shaft a1104 are movably connected through a bearing, and the fixed shaft a1104 is fixedly connected with a planet carrier of the primary speed reduction mechanism 11.

As an alternative embodiment, the final reduction gear 8 further comprises a planet carrier left side plate 801, a planet gear b805, an inner gear b802 and a planet carrier right side plate 804, wherein the planet gears b805 are circumferentially and uniformly distributed between the inner gear b802 and the sun gear 803, and are in meshed connection with the inner side of the inner gear b802 and the outer side of the sun gear 803; one end of the steering output shaft 1 embedded in the shell 6 is provided with a boss 101 matched with the sun gear 803, and the boss 101 is arranged in the sun gear 803 and connected through a needle bearing 15; a fixed shaft b806 is arranged in the center of the planetary gear b805, the fixed shaft b806 is arranged between the planet carrier left side plate 801 and the planet carrier right side plate 804, and two ends of the fixed shaft b806 are fixedly connected with the planet carrier left side plate 801 and the planet carrier right side plate 804 respectively; in the planetary gear speed reducing mechanism, the right end of the sun gear 803 of the final speed reducing mechanism 8 is fixedly connected with the primary speed reducing mechanism 11 into a whole, and the two-stage speed reducing mechanisms are coaxially and serially connected, namely, an energy output shaft and an energy input shaft of the next-stage speed reducing mechanism.

As an alternative embodiment, the worm and worm wheel speed reducing mechanism comprises a worm wheel 10 and a worm 9, wherein the worm 9 is arranged above the worm wheel 10 and is in meshed connection; both ends of the worm 9 are provided with bearings a35 and movably connected through bearings a 35; the worm wheel 10 is fixedly connected with a right side plate 804 of the planet carrier of the final-stage speed reducing mechanism 8 through a screw; a positioning hole is formed in the worm wheel 10, and a cylindrical positioning pin 25 is arranged in the positioning hole; two threaded plugs 22 are arranged on the shell 6, slotted pan head screws 23 are arranged between the threaded plugs 22 and the shell 6, and the slotted pan head screws 23 are fixedly connected with the shell 6; an angle limiting block 24 is arranged outside the slotted pan head screw 23, the angle limiting block 24 is coaxially matched with the slotted pan head screw 23, the worm wheel 10 adopts a sector tooth structure, and when the worm wheel 10 swings left and right to a limit position, two side surfaces of the worm wheel are limited by a stroke when contacting the angle limiting block 24; the slotted pan head screw 23 is arranged inside the angle limiting block 24, and a screw hole for the oil plug threaded plug 22 is formed in the center of the slotted pan head screw 23; the rotation angle range of a steering output shaft 1 of a common commercial vehicle steering gear is plus or minus 45 degrees, and when an angle limiting block 24 is installed, a raised tenon of the angle limiting block is just embedded into a clamping groove corresponding to an inner gear ring b802 of a final-stage speed reducing mechanism 8 and an inner gear ring a1101 of a primary speed reducing mechanism 11; the fixed angle limiting block 24 can also play a role in fixing the inner gear ring of the planetary gear reduction mechanism, and can prevent the inner gear ring from rotating in the shell 6 under the stress during the operation; when the device is installed, the axis line of the steering input shaft is not in the vertical direction, an inclination angle of about 70 degrees backward is usually generated, the height position of the threaded plug 22 is just in a proper position for oil drainage and oil filling, and the two slotted pan head screws 23 are designed to be hollow; the threaded plug 22 can fix and tighten the slotted pan head screw 23 and has the function of an oil plug. Considering practical use requirements, the threaded plug 22 at the oil filling port needs to be a ventilation oil plug with a ventilation function.

As an alternative embodiment, an upper cover 30 is arranged on the upper side of the housing 6, and the upper cover 30 is fixedly connected with the housing 6 through screws; the steering input shaft 32 is embedded in one end of the worm 9 through the upper cover 30, and one end of the steering input shaft 32 is connected with the worm 9 through the needle bearing 15; the steering input shaft 32 is movably connected with the upper cover 30 through a bearing; a dustproof ring 31 is arranged between the upper cover 30 and the steering input shaft 32; the other end of the steering input shaft 32 is provided with a through hole for mounting a cylindrical pin 34; the steering input shaft 32 further comprises an elastic torsion bar 33, and the elastic torsion bar 33 is arranged inside the steering input shaft 32 and fixedly connected with the worm 9; the other end of the worm 9 is provided with a screw plug 26 for positioning the worm 9; a bearing gland 27 is arranged on the side surface of a bearing a35 at one end of the worm 9 connected with the elastic torsion bar 33, and the bearing gland 27 is fixedly connected with the shell 6 through a countersunk head screw; the torque sensor 28 is arranged between the steering input shaft 32 and the worm 9, and an oil seal (2) structure for sealing is arranged between the worm 9 and the bearing gland 27; a cable waterproof joint 29 is arranged on the outer side surface of the shell 6, and the cable waterproof joint 29 penetrates through the shell 6 and is fixedly connected with the torque sensor 28; a sealing ring is arranged between the cable waterproof connector 29 and the shell 6; the steering hand force from the steering wheel controls the torsion bar to elastically deform through the cylindrical pin 34, the torsion bar 33, the worm 9 and the worm wheel 10 are transmitted to the planet carrier right side plate 804 of the final-stage speed reducing mechanism 8, the steering control torque is changed to be matched with the rotation speed of the steering power-assisted transmission through the transmission mechanism of the worm 9 and the worm wheel 10 according to the set transmission speed ratio, and the steering control torque and the steering power-assisted torque are superposed on the steering output shaft 1 of the steering gear through the final-stage speed reducing mechanism 8 and are coupled into the working torque output of a product.

As an alternative embodiment, the restricting structure includes the tapered roller bearing 5 and the planar thrust needle bearing 7, or the tapered roller bearing 5 and the angular contact thrust ball bearing 36; the plane thrust needle roller bearing 7 is arranged between the shell 6 and the side surface of the final-stage speed reducing mechanism 8; the thrust angular contact ball bearing 36 is arranged between the shell 6 and the upper side of the final-stage speed reducing mechanism 8, 5 degrees of freedom of the steering output shaft 1 can be limited by the two schemes, and the steering output shaft 1 can only rotate around the axis; a side cover b4 is arranged on the side surface of one end of the shell 6 connected with the steering output shaft 1, and the side cover b4 is fixedly connected with the shell 6 through screws; an oil seal 2 structure for sealing is arranged between the side cover b4 and a third step of the steering output shaft 1; the tapered roller bearing 5 is arranged between the steering output shaft 1 and the shell 6, and a thread tightening ring 3 for tightening the steering output shaft 1 and the tapered roller bearing 5 is arranged at the third-stage step right angle of the steering output shaft 1; the steering output shaft 1 is movably connected with a shell 6 through a tapered roller bearing 5, the tapered roller bearing 5 arranged on the shell 6 is a main supporting piece of the steering output shaft 1, and the axial position of the steering output shaft 1 of the steering gear is fixed by adopting a threaded tightening ring 3.

The utility model discloses an in the embodiment, a working process of pure electric power assisted steering ware of planetary gear formula as follows: the output torque of the booster motor 14 passes through a motor output shaft 1401 of the booster motor, a cylindrical gear a16, a cylindrical gear shaft 21, a cylindrical gear b17 and a planet gear shaft 1103; the steering power-assisted torque is transmitted to the primary speed reducing mechanism 11 through the speed reduction and torque increase of the cylindrical gear speed reducing mechanism; the steering power-assisted torque is decelerated and torque-increased through a planetary gear speed reducing mechanism which is coaxially connected in series at two stages of a primary speed reducing mechanism 11 and a final speed reducing mechanism 8; the power-assisted steering torque is increased to the working torque required by the product and then is output through a steering output shaft 1 of the steering gear; the steering input shaft 32 receives the steering control torque from the steering wheel, and the steering control torque is transmitted to the planet carrier right side plate 804 of the final reduction gear 8 through the elastic torsion bar 33, the worm 9 and the worm wheel 10, the steering control torque is changed to be matched with the rotation speed of the steering power-assisted transmission through the worm and worm wheel transmission mechanism according to the set transmission speed ratio, and the steering control torque and the steering power-assisted torque are superposed on the steering output shaft 1 of the steering gear through the final reduction gear 8 and are coupled into the working torque output of the product. In the process, the elastic torsion bar 33 is torsionally deformed, the deformation amount of the elastic torsion bar can feed back the magnitude of the wheel steering resistance, the torque sensor 28 can send out corresponding electric signals according to the deformation, and the controller controls the power-assisted motor 14 to provide output torque with proper magnitude according to the received signals.

Claims

1. The utility model provides a pure electric power assisted steering ware of planetary gear formula which characterized in that: the device comprises a power-assisted motor (14), a cylindrical gear speed reducing mechanism, a planetary gear number reducing mechanism, a worm and worm gear speed reducing mechanism, a shell (6), a steering output shaft (1), a steering input shaft (32) and a torque sensor (28); wherein:

the power-assisted motor (14) is arranged on one side of the shell (6) and is fixedly connected with the shell (6); the cylindrical gear speed reducing mechanism is arranged in the shell (6) and is movably connected with the power-assisted motor (14); the planetary gear speed reducing mechanism is arranged in the shell (6) and comprises a primary speed reducing mechanism (11) and a final speed reducing mechanism (8); one side of the primary speed reducing mechanism (11) is connected with the final speed reducing mechanism (8), and the other side of the primary speed reducing mechanism is connected with the cylindrical gear speed reducing mechanism; one end of the steering output shaft (1) is embedded in the shell (6) and is connected with the final-stage speed reducing mechanism (8); one end of the steering output shaft (1) is provided with a limiting structure which ensures that the steering output shaft (1) rotates around the axis; the worm and worm wheel speed reducing mechanism is arranged on the upper side of the final speed reducing mechanism (8), is arranged in the shell (6) and is connected with the final speed reducing mechanism (8); the steering input shaft (32) is connected with the worm and gear speed reducing mechanism, and the torque sensor (28) is arranged on the side surface of the steering input shaft (32) and connected with the steering input shaft (32).

2. The planetary gear type pure electric power steering gear according to claim 1, characterized in that: a side cover a (13) is arranged between the power-assisted motor (14) and the shell (6), and the side cover a (13) is fixedly connected with the shell (6); the side cover a (13) is fixedly connected with the power-assisted motor (14).

3. The planetary gear type pure electric power steering gear according to claim 2, characterized in that: the cylindrical gear speed reducing mechanism comprises a cylindrical gear a (16), a cylindrical gear shaft (21) and a cylindrical gear b (17), and a motor output shaft (1401) of the power-assisted motor (14) is in gear meshing connection with the cylindrical gear a (16); a rubber cushion pad (19), a cover plate (18) and a chuck (20) are arranged between the cylindrical gear a (16) and the cylindrical gear shaft (21), the chuck (20) is L-shaped, and the cylindrical gear a (16) is connected with the cylindrical gear shaft (21) through the chuck (20); the rubber buffer cushion (19) is arranged at the right angle of the chuck (20) and is tightly pressed and fixed through the cover plate (18); one end of the side cover a (13) is provided with a countersunk hole, and one end of the cylindrical gear shaft (21) is arranged in the countersunk hole and is movably connected with the side cover a (13) through a bearing; the cylindrical gear b (17) is meshed with the other end of the cylindrical gear shaft (21), and the cylindrical gear b (17) is connected with the primary speed reducing mechanism (11); an inner end cover (12) is arranged between the cylindrical gear speed reducing mechanism and the primary speed reducing mechanism (11), a through hole is formed in the lower side of the inner end cover (12), and the other end of the cylindrical gear shaft (21) is arranged in the through hole and movably connected with the inner end cover (12) through a bearing.

4. The planetary gear type pure electric power steering gear according to claim 3, characterized in that: the primary reduction mechanism (11) includes an annular gear a (1101), a plurality of planetary gears a (1102), and planetary gear shafts (1103), and the final reduction mechanism (8) includes a sun gear (803); the planet gears a (1102) of the primary speed reducing mechanism (11) are arranged inside the ring gear a (1101) and are in meshed connection with the inner side of the ring gear a (1101); the planet gear shafts (1103) are arranged between the planet gears a (1102) and are in meshed connection with the planet gears a (1102); one end of the planet gear shaft (1103) is fixedly connected with the cylindrical gear b (17), and the other end of the planet gear shaft is embedded in the inner part of one side of the sun gear (803) and is connected with the sun gear through a needle bearing (15); the center of the planetary gear a (1102) is provided with a fixed shaft a (1104), the planetary gear a (1102) and the fixed shaft a (1104) are movably connected through a bearing, and the fixed shaft a (1104) is fixedly connected with a planet carrier of the primary speed reducing mechanism (11).

5. The planetary gear type pure electric power steering gear according to claim 4, characterized in that: the final-stage speed reducing mechanism (8) further comprises a planet carrier left side plate (801), a plurality of planet gears b (805), an inner gear ring b (802) and a planet carrier right side plate (804), wherein the planet gears b (805) are circumferentially and uniformly distributed between the inner gear ring b (802) and the sun gear (803), are in meshed connection with the inner side of the inner gear ring b (802), and are in meshed connection with the outer side of the sun gear (803); one end of the steering output shaft (1) embedded in the shell (6) is provided with a boss (101) matched with the sun gear (803), and the boss (101) is arranged in the sun gear (803) and connected through a needle bearing (15); the center of the planetary gear b (805) is provided with a fixed shaft b (806), the fixed shaft b (806) is arranged between the planet carrier left side plate (801) and the planet carrier right side plate (804), and two ends of the fixed shaft b (806) are fixedly connected with the planet carrier left side plate (801) and the planet carrier right side plate (804) respectively.

6. The planetary gear type pure electric power steering gear according to claim 5, characterized in that: the worm and worm wheel speed reducing mechanism comprises a worm wheel (10) and a worm (9), and the worm (9) is arranged above the worm wheel (10) and is in meshed connection; both ends of the worm (9) are provided with bearings a (35) and movably connected with the shell (6) through the bearings a (35); the worm wheel (10) is fixedly connected with a right side plate (804) of a planet carrier of the final-stage speed reducing mechanism (8) through a screw; a positioning hole is formed in the worm wheel (10), and a cylindrical positioning pin (25) is arranged in the positioning hole; two threaded plugs (22) are arranged on the shell (6), a slotted pan head screw (23) is arranged between the threaded plugs (22) and the shell (6), and the slotted pan head screw (23) is fixedly connected with the shell (6); an angle limiting block (24) is arranged outside the slotted pan head screw (23), and the angle limiting block (24) is coaxially matched with the slotted pan head screw (23); the slotted pan head screw (23) is arranged in the angle limiting block (24), and a through hole for the oil plug threaded plug (22) is formed in the center of the slotted pan head screw (23).

7. The planetary gear type pure electric power steering gear according to claim 6, characterized in that: an upper cover (30) is arranged on the upper side of the shell (6), and the upper cover (30) is fixedly connected with the shell (6) through screws; one end of the steering input shaft (32) penetrates through the upper cover (30) and is buried in the worm (9), and is connected with the worm (9) through a needle bearing (15); the steering input shaft (32) is movably connected with the upper cover (30) through a bearing; a dustproof ring (31) is arranged between the upper cover (30) and the steering input shaft (32); the other end of the steering input shaft (32) is provided with a through hole for mounting a cylindrical pin (34); the steering input shaft (32) further comprises an elastic torsion bar (33), and the elastic torsion bar (33) is arranged inside the steering input shaft (32) and is fixedly connected with one end of the worm (9); the other end of the worm (9) is provided with a screw plug (26) for positioning the worm (9); a bearing gland (27) is arranged on the side face of a bearing a (35) at one end of the worm (9) connected with the elastic torsion bar (33), and the bearing gland (27) is fixedly connected with the shell (6) through a sunk screw; the torque sensor (28) is arranged between the steering input shaft (32) and the worm (9), and an oil seal (2) structure for sealing is arranged between the worm (9) and the bearing gland (27); a cable waterproof joint (29) is arranged on the outer side surface of the shell (6), and the cable waterproof joint (29) penetrates through the shell (6) and is fixedly connected with the torque sensor (28); and a sealing ring is arranged between the cable waterproof connector (29) and the shell (6).

8. The planetary gear type pure electric power steering gear according to claim 1, characterized in that: the limiting structure comprises a tapered roller bearing (5) and a plane thrust needle bearing (7), or the tapered roller bearing (5) and a thrust angular contact ball bearing (36); the plane thrust needle roller bearing (7) is arranged between the shell (6) and the side surface of the final-stage speed reducing mechanism (8); the thrust angular contact ball bearing (36) is arranged between the shell (6) and the upper side of the final speed reducing mechanism (8); a side cover b (4) is arranged on the side face of one end, connected with the steering output shaft (1), of the shell (6), and the side cover b (4) is fixedly connected with the shell (6) through screws; the steering output shaft (1) is a four-stage stepped shaft, and an oil seal (2) structure for sealing is arranged between the side cover b (4) and a third-stage step of the steering output shaft (1); the tapered roller bearing (5) is arranged between the steering output shaft (1) and the shell (6), and a thread tightening ring (3) for tightening the steering output shaft (1) and the tapered roller bearing (5) is arranged at the third-stage step right angle of the steering output shaft (1); the steering output shaft (1) is movably connected with the shell (6) through a tapered roller bearing (5).