Electric power steering column with middle shell

Abstract

The invention discloses an electric power steering column with a middle shell. The electric power steering column comprises an input and output shaft combination, a worm gear, a worm, a lower shell, the middle shell, an upper shell, a first bearing, a second bearing and a sensor assembly. The lower shell, the middle shell and the upper shell are sequentially connected in a clearance fit mode and fixed through bolts. The outer diameter of the worm gear is in meshed connection with the worm, and the worm gear and the worm are arranged in a first space formed by combining the lower shell and the middle shell; the input and output shaft combination is sequentially sleeved with a first bearing, a worm gear and a second bearing in the axial direction, and the input and output shaft combination is axially fixed through double nuts. The outer diameter of the first bearing is connected with the lower shell; and the outer diameter of the second bearing is connected with the middle shell. According to the electric power steering column, radial vibration generated by the input and output shaft combination when an automobile runs on an uneven road surface is effectively restrained, abnormal sound generated at the meshing position of the worm gear and the worm is avoided, and the comfort of a driver and passengers is improved.

Description

Technical Field

[0001] The invention relates to the technical field of automobile electric power steering systems, in particular to an electric power steering column with a middle housing. Background Art

[0002] The existing automobile electric steering column includes an upper shell and a lower shell, a plastic partition is arranged in the lower shell, a bearing is installed in the plastic partition, the plastic partition is interference-connected with the lower shell through an O-ring, and the inner hole of the bearing in the plastic partition is connected to the input-output shaft combination to support the input-output shaft combination. Since the plastic partition and the lower shell are softly connected through the O-ring, when the automobile is driving on an uneven road, it is impacted by the road surface, and the input-output shaft combination is prone to large radial vibration due to unstable support, thereby causing abnormal noise at the meshing point of the worm wheel and the worm, affecting the comfort of the driver and passengers. Summary of the invention

[0003] The main purpose of the present invention is to provide an electric power steering column with a middle housing, aiming to solve the above technical problems in the background technology.

[0004] To achieve the above object, the present invention provides an electric power steering column with a middle housing, comprising an input and output shaft assembly, a worm gear, a worm, a lower housing, a middle housing, an upper housing, a first bearing, a second bearing and a sensor assembly;

[0005] The lower shell, the middle shell and the upper shell are connected in sequence with clearance fit and fixed by bolts;

[0006] The outer diameter of the worm wheel is meshedly connected with the worm, and the worm wheel and the worm are arranged in a first space formed by the combination of the lower housing and the middle housing;

[0007] The sensor assembly is arranged in a second space formed by the combination of the middle shell and the upper shell;

[0008] The input-output shaft assembly is sleeved with the first bearing, the worm gear and the second bearing in sequence along the axial direction, and the input-output shaft assembly is axially fixed by a double nut;

[0009] The outer diameter of the first bearing is connected to the lower housing;

[0010] The outer diameter of the second bearing is connected to the middle housing.

[0011] Preferably, a slot for clamping the sensor assembly is provided on the middle shell.

[0012] Preferably, a buckle is provided on the sensor assembly, and the buckle is fixed in the slot.

[0013] Preferably, the middle shell comprises a bottom and an outer side connected to the bottom, and the outer side is provided with an opening adapted to the cable connector.

[0014] Preferably, an annular flange is provided on the circumference of the outer side, and the annular flange is provided with bolt mounting ear holes for mounting bolts.

[0015] Preferably, a bearing mounting hole is provided in the middle of the bottom, and a plurality of reinforcing ribs are provided on the back side of the bottom along the circumference of the bearing mounting hole.

[0016] Preferably, the lower housing is provided with a worm mounting cavity, and the worm is mounted in the worm mounting cavity.

[0017] Preferably, the input-output shaft combination includes an output shaft, a lower portion of an input shaft, an upper portion of an input shaft and a torsion bar; the output shaft is connected to the lower portion of the input shaft through the torsion bar, and the lower portion of the input shaft is connected to the upper portion of the input shaft; the inner hole of the first bearing and the inner hole of the second bearing are both clearance-matched with the output shaft.

[0018] Preferably, a combined pipe sleeve is installed at the front end of the upper shell, and an upper part of the input shaft is arranged inside the combined pipe sleeve.

[0019] Preferably, a motor and controller combination is mounted on the lower housing, and the motor and controller combination is connected to the worm.

[0020] The electric power steering column with a middle shell provided by the present invention has a middle shell arranged between a lower shell and an upper shell, and a second bearing installed on the middle shell and a first bearing installed on the lower shell are used to stably support the input and output shaft combination, so that when the automobile is driving on an uneven road surface, the input and output shaft combination will not have a large radial vibration, thereby avoiding the problem of abnormal noise generated at the meshing point of the worm wheel and the worm, and improving the comfort of the driver and passengers. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of an electric power steering column with a middle housing in one embodiment of the present invention;

[0023] Figure 2 for Figure 1A schematic cross-sectional view of an electric power steering column with a middle housing;

[0024] Figure 3 for Figure 2 A local enlarged schematic diagram of the middle A;

[0025] Figure 4 for Figure 1 Schematic diagram of the structure of the upper shell of the electric power steering column with the middle shell Figure 1 ;

[0026] Figure 5 for Figure 1 Schematic diagram of the structure of the upper shell of the electric power steering column with the middle shell Figure 2 ;

[0027] Figure 6 A schematic diagram of the structure of a sensor assembly in one embodiment of the present invention;

[0028] Figure 7 Schematic diagram of circumferential positioning of a sensor assembly in one embodiment of the present invention.

[0029] The serial numbers in the figure are as follows:

[0030] 1. Lower shell; 2. Middle shell; 201. Bottom; 202. Outer side; 203. Bearing mounting hole; 204. Slot; 205. Opening; 206. Reinforcement rib; 207. Annular flange; 3. Upper shell; 4. Input and output shaft combination; 401. Output shaft; 402. Lower part of input shaft; 403. Torsion bar; 404. Upper part of input shaft; 5. Worm gear; 6. Worm; 7. First bearing; 8. Second bearing; 9. Bolt; 10. Double nut; 11. Cable connector; 12. Sensor assembly; 121. Sensor body; 122. Sensor rotor; 123. Buckle; 13. Combined sleeve; 131. First sleeve; 132. Second sleeve; 14. Motor and controller combination. DETAILED DESCRIPTION

[0031] In order to better understand the above technical solution, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0032] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0033] It should be noted that, in the embodiments of the present invention, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the coordinate system shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] The present invention provides an electric power steering column with a middle housing, referring to Figure 1 , Figure 2 and Figure 3In one embodiment, the electric power steering column with a middle shell includes an input-output shaft combination 4, a worm wheel 5, a worm 6, a lower shell 1, a middle shell 2, an upper shell 3, a first bearing 7, a second bearing 8 and a sensor assembly 12; the lower shell 1, the middle shell 2 and the upper shell 3 are connected in sequence by clearance fit and fixed by bolts 9; the outer diameter of the worm wheel 5 is meshed with the worm 6, and the worm wheel 5 and the worm 6 are arranged in a first space formed by the combination of the lower shell 1 and the middle shell 2; the sensor assembly 12 is arranged in a second space formed by the combination of the middle shell 2 and the upper shell 3; the input-output shaft combination 4 is sequentially sleeved with the first bearing 7, the worm wheel 5 and the second bearing 8 along the axial direction, and the input-output shaft combination 4 is axially fixed by a double nut 10; the outer diameter of the first bearing 7 is connected to the lower shell 1; the outer diameter of the second bearing 8 is connected to the middle shell 2.

[0037] It can be understood that in the electric power steering column with a middle shell of this embodiment, the shell 2 is arranged between the lower shell 1 and the upper shell 3, and the middle shell 2 is matched with the lower shell 1 and the upper shell 3 with a small gap, and is fastened together by a number of bolts 9. At this time, the peripheral sides of the lower shell 1, the middle shell 2 and the upper shell 3 are all provided with bolt mounting ear holes with the same number as the bolts 9. Preferably, the gap value between the two shells is set between 0.01mm and 0.05mm. The number and installation position of the bolt mounting ear holes are set according to the needs. For example, when there are two bolt mounting ear holes, the two bolt mounting ear holes are symmetrically installed on the peripheral side of the shell; for another example, when there are three bolt mounting ear holes, the three bolt mounting ear holes are arranged at intervals on the peripheral side of the shell.

[0038] The lower housing 1 is interference-fitted with a first bearing 7, and the inner hole of the first bearing 7 is connected to the input-output shaft assembly 4. Preferably, one side of the lower housing 1 protrudes outward to form a first installation cavity for installing the first bearing 7, and a first through hole for installing the input-output shaft assembly 4 is opened in the middle of the first installation cavity.

[0039] The middle housing 2 is interference-fitted with a second bearing 8, and the inner hole of the second bearing 8 is connected to the input-output shaft assembly 4. Further, the interference between the housing and the bearing is set between 0.01 mm and 0.03 mm.

[0040] The lower housing 1 and the middle housing 2 cooperate with each other with a small gap to form a first space. A worm wheel 5 is arranged in the first space, and the inner hole of the worm wheel 5 is connected to the input-output shaft combination 4 , and the outer diameter of the worm wheel 5 is meshedly connected to the worm 6 .

[0041] The input-output shaft combination 4 can pass through the lower shell 1, the middle shell 2 and the upper shell 3, and is supported by the first bearing 7 and the second bearing 8, and then axially fixed by the double nut 10, so that the input-output shaft combination 4 is completely fixed in the entire shell formed by the lower shell 1, the middle shell 2 and the upper shell 3.

[0042] The sensor assembly 12 is preferably a torque and angle sensor for measuring the torque and the rotation angle of the electric power steering column.

[0043] In summary, in the electric power steering column with a middle shell of the present embodiment, a middle shell 2 is arranged between the lower shell 1 and the upper shell 3. The second bearing 8 installed on the middle shell 2 and the first bearing 7 installed on the lower shell 1 realize stable support for the input-output shaft combination 4, which effectively suppresses the radial vibration of the input-output shaft combination 4 when the car is driving on uneven roads, avoids abnormal noise at the meshing point of the worm wheel 5 and the worm 6, and is beneficial to improving the comfort of the driver and passengers.

[0044] As a preferred embodiment, based on Figure 1 The embodiment of the electric power steering column with a middle housing shown in FIG. Figure 4 and Figure 7 The middle shell 2 is provided with a slot 204 for clamping the sensor assembly 12 .

[0045] In this embodiment, a card slot 204 is provided on the side of the middle shell 2 facing the upper shell 3. The card slot 204 can be formed by splicing two concave platforms or can be integrally formed. The card slot 204 is used to clamp the sensor assembly 12 to achieve circumferential positioning of the sensor assembly 12.

[0046] As a preferred embodiment, refer to Figure 6 and Figure 7 The sensor assembly 12 is provided with a buckle 123 , and the buckle 123 is fixed in the slot 204 .

[0047] In this embodiment, the inner diameter of the sensor assembly 12 is sleeved on the input-output shaft combination 4, and a buckle 123 is provided on the circumferential side of the sensor assembly 12 corresponding to the opening position of the slot 204. The buckle 123 cooperates with the slot 204, thereby achieving the purpose of circumferential positioning of the sensor assembly 12 by using the slot 204 on the middle shell 2.

[0048] Further, refer to Figure 3 , Figure 6 and Figure 7The sensor assembly 12 includes a sensor body 121 and a sensor rotor 122; wherein the buckle 123 is provided on the circumferential side of the sensor body 121, and the inner diameter of the sensor body 121 is fixed on the lower part 402 of the input shaft; the inner diameter of the sensor rotor 122 is fixed on the output shaft 401.

[0049] That is, the sensor assembly 12 of this embodiment has a snap 123 arranged on the circumferential side of the sensor body 121, and the inner diameters of the sensor body 121 and the sensor rotor 122 are respectively fixed on different components in the input-output shaft combination 4. This arrangement can improve the installation stability between the sensor assembly 12 and the input-output shaft combination 4.

[0050] Furthermore, the middle housing 2 includes a bottom 201 and an outer side 202 connected to the bottom 201 , and the outer side 202 is provided with an opening 205 adapted to the cable connector 11 .

[0051] That is, an opening 205 is provided on the outer side 202 of the middle shell 2 and diagonally opposite to the slot 204, and the opening 205 is used to install the cable connector 11. At this time, the sensor assembly 12 can be connected to an external controller through the cable connector 11, thereby realizing real-time transmission of sensor signals.

[0052] Furthermore, an annular flange 207 is provided on the circumference of the outer side 202, and the annular flange 207 is provided with bolt mounting ears for mounting bolts 9. One side of the annular flange 207 is fixedly connected to the lower shell 1, and the other side of the annular flange 207 is fixedly connected to the upper shell 3. The annular flange 207 can provide accurate positioning support for the installation of the left and right shells.

[0053] It can be understood that the annular flange 207 can divide the middle shell 2 into a first part that is connected to the lower shell 1 and a second part that is connected to the upper shell 3. This arrangement can improve the stability of the entire shell.

[0054] Furthermore, a bearing mounting hole 203 is provided in the middle of the bottom 201 , and a plurality of reinforcing ribs 206 are provided on the back side of the bottom 201 along the circumference of the bearing mounting hole 203 .

[0055] That is, a bearing mounting hole 203 protruding outward is provided in the middle of the bottom 201 of the middle shell 2, and the bearing mounting hole 203 is used to install the second bearing 8. A plurality of triangular reinforcing ribs 206 are evenly provided on the back of the bottom 201 along the circumference of the bearing mounting hole 203. At this time, the long side of the triangular reinforcing rib 206 is fixedly connected to the bottom 201, and the short side of the triangular reinforcing rib 206 is fixedly connected to the bearing mounting hole 203 protruding outward. It can be understood that the middle shell 2 of this embodiment is provided with a bearing mounting hole 203 for installing the second bearing 8, and the reinforcing rib 206 is provided to improve the radial support force of the second bearing 8, so as to ensure the normal operation of the second bearing 8, and at the same time, it can increase the structural strength of the middle shell 2 and avoid deformation and cracking of the middle shell 2.

[0056] As a preferred embodiment, refer to Figure 2 and Figure 3 The lower housing 1 is provided with a worm mounting cavity, and the worm 6 is mounted in the worm mounting cavity.

[0057] In this embodiment, the lower shell 1 includes an integrally designed main shell and a worm mounting cavity, and the worm mounting cavity is communicated with the main shell. At this time, the worm 6 is arranged in the worm mounting cavity, and the worm wheel 5 meshing with the worm 6 is arranged in the main shell.

[0058] As a preferred embodiment, refer to Figure 2 and Figure 3 The input-output shaft combination 4 includes an output shaft 401, an input shaft lower portion 402, an input shaft upper portion 404 and a torsion bar 403; the output shaft 401 is connected to the input shaft lower portion 402 through the torsion bar 403, and the input shaft lower portion 402 is connected to the input shaft upper portion 404; the inner hole of the first bearing 7 and the inner hole of the second bearing 8 are both clearance-matched with the output shaft 401.

[0059] It can be understood that the electric steering column for automobiles with a middle housing in this embodiment has an input-output shaft assembly 4 including a torsion bar 403, one end of which is fixed to the output shaft 401, and the other end of which is fixed to the input shaft lower portion 402, the input shaft lower portion 402 and the input shaft upper portion 404 are welded as one body, and when the input shaft lower portion 402 rotates, the output shaft 401 is driven to rotate through the torsion bar 403. Furthermore, a sliding bearing is provided at the connection between the output shaft 401 and the input shaft lower portion 402 to support and position the input shaft lower portion 402.

[0060] Secondly, the first bearing 7 installed on the lower shell 1 has an inner hole that matches the input-output shaft combination 4 with a small clearance, and the second bearing 8 installed on the middle shell 2 has an inner hole that matches the input-output shaft combination 4 with a small clearance. At this time, the input-output shaft combination 4 is supported by the first bearing 7 and the second bearing 8, and then axially fixed by the double nut 10 with the entire shell formed by the lower shell 1, the middle shell 2 and the upper shell 3. Through this arrangement, the input-output shaft combination 4 can maintain a stable rotation state during rotation, effectively reducing shaking and deviation.

[0061] As a preferred embodiment, refer to Figure 1 and Figure 2 A combined pipe sleeve 13 is installed at the front end of the upper shell 3, and an input shaft upper part 404 is arranged inside the combined pipe sleeve 13.

[0062] It is understandable that the electric power steering column with a middle housing in this embodiment further includes a combined sleeve 13 , through which the input and output shaft assembly 4 passes, and one end of the combined sleeve 13 is press-fitted onto the upper housing 3 .

[0063] Furthermore, the combined sleeve 13 includes a first sleeve 131 and a second sleeve 132 ; the second sleeve 132 is sleeved on the outside of the first sleeve 131 , and one end of the first sleeve 131 away from the second sleeve 132 is fixedly mounted on the upper shell 3 .

[0064] In this embodiment, the combined sleeve 13 includes a first sleeve 131 fixedly mounted on the upper housing 3, and a second sleeve 132 sleeved on the first sleeve 131. During use, if the position of the steering column assembly needs to be adjusted, the length of the combined sleeve 13 can be quickly adjusted by stretching the second sleeve 132. In addition, by providing the combined sleeve 13 consisting of the first sleeve 131 and the second sleeve 132, the installation flexibility can be improved.

[0065] As a preferred embodiment, refer to Figure 1 , Figure 2 and Figure 3 A motor and controller combination 14 is installed on the lower housing 1 , and the motor and controller combination 14 is connected to the worm 6 .

[0066] It can be understood that the electric power steering column with a middle shell in this embodiment also includes a motor and controller combination 14, which is fixedly installed in the position of the lower shell 1 corresponding to the worm mounting cavity. The motor and controller combination 14 mainly includes an electronic controller (ECU) and a power-assisted motor. The electronic controller (ECU) can be integrated on the power-assisted motor, and the output end of the power-assisted motor is connected to the worm 6 in the worm mounting cavity. At this time, when the electronic controller (ECU) receives the vehicle steering signal, it sends the instruction to the power-assisted motor after processing, and the power-assisted motor transmits the torque to the input and output shaft combination 4 through the worm 6 and the worm wheel 5, thereby assisting the vehicle steering operation.

[0067] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An electric power steering column with a middle housing, characterized in that: It comprises an input and output shaft assembly (4), a worm wheel (5), a worm (6), a lower housing (1), a middle housing (2), an upper housing (3), a first bearing (7), a second bearing (8) and a sensor assembly (12); The lower shell (1), the middle shell (2) and the upper shell (3) are connected in sequence with clearance fit and fixed by bolts (9); The outer diameter of the worm wheel (5) is meshedly connected with the worm (6), and the worm wheel (5) and the worm (6) are arranged in a first space formed by the combination of the lower housing (1) and the middle housing (2); The sensor assembly (12) is arranged in a second space formed by the combination of the middle shell (2) and the upper shell (3); The input-output shaft assembly (4) is sleeved with the first bearing (7), the worm gear (5) and the second bearing (8) in sequence along the axial direction, and the input-output shaft assembly (4) is axially fixed by a double nut (10); The outer diameter of the first bearing (7) is connected to the lower housing (1); The outer diameter of the second bearing (8) is connected to the middle housing (2).

2. The electric power steering column with a middle housing as claimed in claim 1, characterized in that: The middle housing (2) is provided with a clamping groove (204) for clamping the sensor assembly (12).

3. The electric power steering column with a middle housing as claimed in claim 2, characterized in that: The sensor assembly (12) is provided with a buckle (123), and the buckle (123) is fixed in the buckle slot (204).

4. The electric power steering column with a middle housing as claimed in claim 2, characterized in that: The middle shell (2) comprises a bottom (201) and an outer side (202) connected to the bottom (201), and the outer side (202) is provided with an opening (205) adapted to the cable connector (11).

5. The electric power steering column with a middle housing as claimed in claim 4, characterized in that: An annular flange (207) is provided on the circumferential side of the outer edge (202), and the annular flange (207) is provided with a bolt mounting ear hole for mounting a bolt (9).

6. The electric power steering column with a middle housing as claimed in claim 4, characterized in that: A bearing mounting hole (203) is provided in the middle of the bottom (201), and a plurality of reinforcing ribs (206) are provided on the back side of the bottom (201) along the circumference of the bearing mounting hole (203).

7. The electric power steering column with a middle housing as claimed in claim 1, characterized in that: The lower housing (1) is provided with a worm mounting cavity, and the worm (6) is mounted in the worm mounting cavity.

8. The electric power steering column with a middle housing as claimed in claim 1, characterized in that: The input-output shaft assembly (4) comprises an output shaft (401), an input shaft lower portion (402), an input shaft upper portion (404) and a torsion bar (403); the output shaft (401) is connected to the input shaft lower portion (402) via the torsion bar (403), and the input shaft lower portion (402) is connected to the input shaft upper portion (404); the inner hole of the first bearing (7) and the inner hole of the second bearing (8) are both clearance-matched with the output shaft (401).

9. The electric power steering column with a middle housing as claimed in claim 1, characterized in that: A combined pipe sleeve (13) is installed at the front end of the upper shell (3), and an upper portion (404) of the input shaft is arranged inside the combined pipe sleeve (13).

10. The electric power steering column with a middle housing as claimed in claim 1, characterized in that: A motor and controller combination (14) is mounted on the lower housing (1), and the motor and controller combination (14) is connected to the worm (6).

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