Connecting and assembling structure of lower shell in small-space design layout positioning of P-EPS

Abstract

The utility model relates to a connecting and assembling structure of a lower shell in P-EPS design layout positioning in a small space, which belongs to the technical field of automobile electric steering gears and comprises a locking bolt, a middle shell, a lower shell, a gear shaft clamping ring, an input shaft and gear shaft combination, an O-shaped ring and a main stress bearing. The input shaft and gear shaft combination is assembled in the axial direction, a shaft shoulder of the input shaft and gear shaft combination is positioned to the end face of the main stress bearing, and the gear shaft clamping ring is sleeved with the input shaft and gear shaft combination. According to the connecting and assembling structure of the lower shell in the small-space design layout positioning of the P-EPS and the connecting and assembling structure of the lower shell in the small-space design layout positioning of the P-EPS, the axial height proportion of the P-EPS is reduced, the space layout of the P-EPS in a limited chassis of a whole vehicle is facilitated, and the space layout efficiency of the P-EPS is improved. The attached planes of the middle shell and the lower shell do not collide and contact to cause plane relative movement in the operation stress process, bending deformation of the torsion bar caused by the influence of axial force is avoided, and the assembly characteristic can be guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of automobile electric steering gear, specifically to a kind of connection and assembly structure of P-EPS in small space design layout positioning middle and lower shell. BACKGROUND

[0002] Electric power steering system is a kind of power steering system directly relying on motor to provide auxiliary torque, compared with traditional hydraulic power steering system HPS, EPS system has many advantages.EPS is mainly composed of torque sensor, speed sensor, motor, speed reduction mechanism and electronic control unit (ECU) etc.

[0003] The existing automobile electric steering gear assembly, the main bearing positioning of the torque direction input by driver generally adopts the mode that bearing is completely assembled to middle shell, collar is pressed riveting, nut is locked to carry out axial positioning, but this assembly mode has several problems: 1, bearing is completely assembled to middle shell, and the height direction of middle shell is thickened to envelope multiple assembly parts, which is not conducive to the compact space layout of whole vehicle, and increases the difficulty of scheme design.2, collar pressing riveting is only for the structure of torsion bar without axial stress component, P-EPS needs torsion bar to collect torsion signal, so collar pressing riveting will cause deformation of torsion bar.3, main bearing is completely assembled to middle shell, and middle shell stop is used as connecting structure, stress conduction is all in middle shell, and lower shell is relatively weak, middle and lower shell is prone to mispositioning due to deformation in running stress process, relative movement of middle and lower shell connection place of fitting plane causes collision and contact, and relative slip friction noise problem of bolt connection surface of middle and lower shell is caused.Fixing connection mode that bearing is completely assembled to middle shell and axial stress pressing riveting gear shaft collar is not conducive to the space design and performance of product. UTILITY MODEL CONTENTS

[0004] In view of the defects of prior art, the utility model provides a kind of connection and assembly structure of P-EPS in small space design layout positioning middle and lower shell, with the advantages of reducing the axial height proportion of P-EPS, the fitting plane of middle shell and lower shell will not collide and contact in running stress process and preventing torsion bar deformation, solves the problems of not conducive to the compact space layout of whole vehicle, collar pressing riveting will cause deformation of torsion bar and relative slip friction noise problem of bolt connection surface of middle and lower shell.

[0005] In order to achieve the above object, the utility model provides the following technical scheme: a kind of connection and assembly structure of P-EPS in small space design layout positioning lower shell, including locking bolt, middle shell, lower shell, gear shaft collar, input shaft gear shaft combination, O-ring and main force bearing, the main force bearing is pressed into middle shell assembly cavity, input shaft gear shaft combination is assembled from axial, input shaft gear shaft combination shoulder positioning is to the end surface of main force bearing, gear shaft collar is sleeved into input shaft gear shaft combination, with the end surface of main force bearing, gear shaft collar plastic deformation fills into the clamping groove of input shaft gear shaft combination, the main force bearing is fastened and locked positioning to axial inner ring, main force bearing outer ring is assembled O-ring, main force bearing is positioned and assembled into lower shell with stop, and middle shell and lower shell are fixed by locking bolt.

[0006] Further, the input shaft gear shaft combination includes a gear shaft, the outer surface of the gear shaft is provided with a worm gear combination, the surface of the gear shaft is provided with a support bearing, the outer side of the support bearing is provided with a partition plate, the inner wall of the gear shaft is provided with a needle bearing, and the inner side of the needle bearing is provided with an output shaft.

[0007] Further, the torsion bar is connected with the output shaft as a whole through a positioning pin, the outer side of the output shaft is provided with a sensor, and the top end of the output shaft is connected with a rubber plug.

[0008] Further, the sensor is a torque sensor.

[0009] Further, the overall width of the middle shell and the lower shell to the main force bearing is 2 / 5 of the distribution ratio of the shell assembly depth.

[0010] Further, the gear shaft collar is clamped into the clamping groove of the input shaft gear shaft combination in a radial riveting positioning mode.

[0011] Further, the middle shell cavity depth tolerance size is-0.08 to-0.10mm, the lower shell cavity depth tolerance size is-0.08 to-0.10mm, and the width tolerance size of the main force bearing 7 is 0 to-0.02mm.

[0012] Further, after the middle shell and the lower shell are fixed, there is a gap of 0.16-0.18mm between the middle shell and the lower shell.

[0013] Further, the number of locking bolts is three, which are evenly distributed on the outer side of the middle shell and the lower shell and fixed.

[0014] Compared with the prior art, the technical scheme of the present application has the following advantages:

[0015] 1. The P-EPS is connected and assembled in the small space design layout positioning of the lower shell, through the reasonable distribution proportion of the overall width of the main force bearing of the middle shell and the lower shell in the assembly depth of the shell, the axial height proportion of the P-EPS is reduced, which is beneficial to the space layout of the P-EPS in the limited chassis of the whole vehicle.

[0016] 2. The P-EPS is connected and assembled in the small space design layout positioning of the lower shell, through the reasonable gap value between the middle shell and the lower shell, the fitting plane of the middle shell and the lower shell can not be collided and contacted to cause relative movement of the plane in the running stress process within the error range of the machining of the shell, such as flatness and perpendicularity.

[0017] 3. The P-EPS is connected and assembled in the small space design layout positioning of the lower shell, through the radial force extrusion of the gear shaft collar by the spin riveting process, the plastic deformation of the gear shaft collar fills into the clamping groove of the input shaft gear shaft combination, the bending deformation of the torsion bar caused by the axial force is avoided, and the assembly characteristics can be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 It is the middle and lower shell positioning and assembling part section view of the utility model bearing;

[0019] Fig. 2 It is the input shaft gear shaft combination structure schematic view of the utility model;

[0020] Fig. 3 It is the middle shell and lower shell bolt positioning layout schematic view of the utility model;

[0021] Fig. 4 It is the main view of the electric power steering gear assembly of the utility model.

[0022] In the drawing: 1 locking bolt, 2 middle shell, 3 lower shell, 4 gear shaft collar, 5 input shaft gear shaft combination, 6 O-ring, 7 main force bearing, 8 rubber plug, 9 output shaft, 10 positioning pin, 11 torsion bar, 12 sensor, 13 needle bearing, 14 supporting bearing, 15 partition plate, 16 worm gear combination, 17 gear shaft. DETAILED DESCRIPTION

[0023] The technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the utility model.

[0024] Please refer to Figs. 1 to 4The P-EPS in the embodiment is used for connecting and assembling the lower shell in small space design layout positioning, and comprises locking bolts 1, a middle shell 2, a lower shell 3, a gear shaft collar 4, an input shaft gear shaft assembly 5, an O-ring 6 and a main load bearing 7, wherein the main load bearing 7 is pressed into the assembly cavity of the middle shell 2, the input shaft gear shaft assembly 5 is assembled from the axial direction, the shaft shoulder of the input shaft gear shaft assembly 5 is positioned to the end surface of the main load bearing 7, the gear shaft collar 4 is sleeved into the input shaft gear shaft assembly 5, the gear shaft collar 4 is clamped into the clamping groove of the input shaft gear shaft assembly 5 in the radial direction by the spin riveting positioning mode, and is supported on the end surface of the main load bearing 7, the gear shaft collar 4 is plastically deformed and filled into the clamping groove of the input shaft gear shaft assembly 5, thereby fastening, locking and positioning the inner ring of the main load bearing 7, the outer ring of the main load bearing 7 is assembled with the O-ring 6, the main load bearing 7 is positioned and assembled into the lower shell 3 in the stop position, and the middle shell 2 and the lower shell 3 are fixed by the locking bolts 1.

[0025] The input shaft gear shaft assembly comprises a gear shaft 17, a worm wheel assembly 16 mounted on the outer surface of the gear shaft 17, a support bearing 14 mounted on the surface of the gear shaft 17, a partition plate 15 mounted on the outer side of the support bearing 14, a needle bearing 13 mounted on the inner wall of the gear shaft 17, an output shaft 9 mounted on the inner side of the needle bearing 13, a torsion bar 11 arranged in the output shaft 9, the bottom end of the torsion bar 11 being pressed into the gear shaft 17, the torsion bar 11 being connected with the output shaft 9 as a whole through a positioning pin 10, a sensor 12 arranged on the outer side of the output shaft 9, and a rubber plug 8 connected to the top end of the output shaft 9, the sensor 12 being a torque sensor.

[0026] The torsion bar 11 of the P-EPS is used for receiving and transmitting the torque signal of the driver's twisted steering wheel, the torsion bar 11 is connected with the output shaft 9 as a whole through the positioning pin 10 after being pressed into the gear shaft 17, there is a gap of 0.3 between the end surface of the input shaft 9 and the gear shaft 17, which is beneficial to the torsional deformation of the torsion bar 11 and does not cause friction. If the gear shaft collar 4 for fixing the main load bearing 7 adopts the axial direction press riveting positioning mode, the torsion bar 11 is bent and deformed under the influence of the axial force. However, the gear shaft collar 4 adopts the radial direction spin riveting positioning mode, the torsion bar 11 is not affected at all, and the assembly characteristics can be ensured.

[0027] The overall width of the middle shell 2 and the lower shell 3 to the main load bearing 7 is 2 / 5 in the distribution ratio of the shell assembly depth, which can realize reliable support and positioning of the main load bearing 7 in the shell, does not affect the carrying capacity and service life of the main load bearing 7, and reduces the design space of the bearing assembly position of the middle shell 2 and the lower shell 3. At the same time, the gear shaft collar 4 occupies the blank space area of the lower shell 3, which maximally reduces the axial height space proportion of the P-EPS, and is beneficial to the space layout of the P-EPS in the limited chassis of the whole vehicle.

[0028] The middle shell 2 type cavity depth tolerance size is -0.08 to -0.10 mm, the lower shell 3 type cavity depth tolerance size is -0.08 to -0.10 mm, the width tolerance size of the main force bearing 7 is 0 to -0.02 mm, the number of locking bolts 1 is three, which are uniformly distributed on the outside of the middle shell 2 and the lower shell 3 and fixed, after the middle shell 2 and the lower shell 3 are fixed, there is a gap of 0.16-0.18 mm between the middle shell 2 and the lower shell 3, the main force bearing 7 is proportionally distributed in the middle shell 2 and the lower shell 3, and the torsional force borne by the main force bearing 7 is transmitted to the middle shell 2 and the lower shell 3 at the same time when steering, so as to ensure that the vibration of the shell is the same frequency, and the reasonable gap value between the middle shell 2 and the lower shell 3 can ensure that the error range of the machining of the shell, such as flatness and perpendicularity, the fitting plane of the middle shell 2 and the lower shell 3 will not cause relative movement of the plane caused by collision and contact during operation, especially the abnormal sound caused by relative friction after durability of the shell.

[0029] In summary, the above-mentioned embodiments have the following advantages:

[0030] The reasonable distribution proportion of the overall width of the main force bearing 7 in the shell assembly depth of the middle shell 2 and the lower shell 3 is 2 / 5, which can realize reliable support and positioning of the main force bearing 7 in the shell, and at the same time does not affect the carrying capacity and service life of the main force bearing 7. The maximum reduction of the axial height space ratio of P-EPS is beneficial to the space layout of P-EPS in the limited chassis of the whole vehicle.

[0031] The bearing assembly depth tolerance of the middle shell 2 is (-0.08 / -0.10) mm, the bearing assembly depth tolerance of the lower shell 3 is (-0.08 / -0.10) mm, and after the three locking bolts 1 are tightened, there will be a gap of (0.16-0.18) mm between the middle shell 2 and the lower shell 3. The reasonable gap value between the middle shell 2 and the lower shell 3 can ensure that the error range of the machining of the shell, such as flatness and perpendicularity, the fitting plane of the middle shell 2 and the lower shell 3 will not cause relative movement of the plane caused by collision and contact during operation, especially the abnormal sound caused by relative friction after durability of the shell.

[0032] The input shaft gear shaft combination 5 with the torsion bar 11 is designed, when the gear shaft collar 4 fixing the main force bearing 7 is assembled, the radial direction riveting fastening mode is adopted, which avoids the bending deformation of the torsion bar 11 caused by the axial force, and can ensure the assembly characteristics.

[0033] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and implementations, it is to be understood that the terminology used is for the purpose of descriptive clarity and that it is intended to be limited only by the words recited in the appended claims. The scope of the present application shall be limited only by the claims.

[0034] While the embodiments of the present application have been shown and described with respect to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the application. Therefore, the scope of the application should not be limited by the embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A connection and assembly structure for the lower housing of a P-EPS in a small space design layout, comprising a locking bolt (1), a middle housing (2), a lower housing (3), a gear shaft retaining ring (4), an input shaft gear shaft assembly (5), an O-ring (6), and a main load-bearing bearing (7), characterized in that: The main force bearing (7) is pressed into the assembly cavity of the middle shell (2), the input shaft gear shaft assembly (5) is assembled from the axial direction, the shaft shoulder of the input shaft gear shaft assembly (5) is positioned to the end face of the main force bearing (7), the gear shaft collar (4) is sleeved into the input shaft gear shaft assembly (5) and abuts against the end face of the main force bearing (7), the gear shaft collar (4) is plastically deformed and filled into the clamping groove of the input shaft gear shaft assembly (5), the main force bearing (7) is fastened, locked and positioned to the axial inner ring, the outer ring of the main force bearing (7) is assembled with the O-shaped ring (6), the main force bearing (7) is positioned and assembled into the lower shell (3) through the stop opening, and the middle shell (2) and the lower shell (3) are fixed through the locking bolts (1).

2. The connecting and assembling structure of the lower housing in the small space design layout positioning of a P-EPS according to claim 1, characterized in that: The input shaft gear shaft assembly comprises a gear shaft (17), a worm wheel assembly (16) is mounted on the outer surface of the gear shaft (17), a support bearing (14) is mounted on the surface of the gear shaft (17), a partition plate (15) is mounted on the outer side of the support bearing (14), a needle bearing (13) is mounted on the inner wall of the gear shaft (17), an output shaft (9) is mounted on the inner side of the needle bearing (13), and a torsion bar (11) is arranged in the output shaft (9).

3. The connecting and assembling structure of the lower housing in the small space design layout positioning of a P-EPS according to claim 2, characterized in that: The torsion bar (11) is connected with the output shaft (9) as a whole through a positioning pin (10), a sensor (12) is arranged on the outer side of the output shaft (9), and a rubber plug (8) is connected to the top end of the output shaft (9).

4. The connecting and assembling structure of the lower housing in the small space design layout positioning of a P-EPS according to claim 3, characterized in that: The sensor (12) is a torque sensor.

5. The connecting and assembling structure of the lower housing in the small space design layout positioning of a P-EPS according to claim 1, characterized in that: The overall width of the middle shell (2) and the lower shell (3) to the main force bearing (7) is 2 / 5 of the assembly depth of the shell.

6. The connecting and assembling structure of the lower housing in the small space design layout positioning of a P-EPS according to claim 1, characterized in that: The gear shaft collar (4) is clamped into the clamping groove of the input shaft gear shaft assembly (5) in a radial riveting positioning mode.

7. The connecting and assembling structure of the lower housing in the small space design layout positioning of a P-EPS according to claim 1, characterized in that: The tolerance size of the cavity depth of the middle shell (2) is -0.08 to -0.10 mm, the tolerance size of the cavity depth of the lower shell (3) is -0.08 to -0.10 mm, and the width tolerance size of the main force bearing (7) is 0 to -0.02 mm.

8. The connecting and assembling structure of the lower housing in the small space design layout positioning of a P-EPS according to claim 7, characterized in that: After the middle shell (2) and the lower shell (3) are fixed, there is a gap of 0.16-0.18 mm between the middle shell (2) and the lower shell (3).

9. The connecting and assembling structure of the lower housing in the small space design layout positioning of a P-EPS according to claim 1, characterized in that: The number of locking bolts (1) is three, which are evenly distributed on the outer sides of the middle shell (2) and the lower shell (3) and fixed.

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