WO2012146153A1

WO2012146153A1 - Coupling device

Info

Publication number: WO2012146153A1
Application number: PCT/CN2012/074470
Authority: WO
Inventors: Jinjian QIU; Jian Li; Yuming LU
Original assignee: Shenzhen Byd Auto R&D Company Limited; Byd Company Limited
Priority date: 2011-04-29
Filing date: 2012-04-20
Publication date: 2012-11-01
Also published as: CN202100619U

Abstract

A coupling device comprises: a first half-coupling (101); a second half-coupling (102); and an elastic connection mechanism (10) disposed between the first half-coupling (101) and the second half-coupling (102). The elastic connection mechanism comprises: a first torque transmitting member (501) having a first ring base (141), at least one pair of first protrusions (301) disposed on an inner circumferential surface of the first ring base (141); a second torque transmitting member (502) having a third ring base (142), at least one pair of third protrusions (302) disposed on an inner circumferential surface of the third ring base (142); an intermediate elastic member (6) having a second ring base (15), at least one pair of second protrusions (4) disposed on an inner circumferential surface of the second ring base (15); and a connection means disposed on the first torque transmitting member (501) and the second torque transmitting member (502) respectively.

Description

COUPLING DEVICE

CROSS-REFERENCE TO RELATED APPLICATION

The present disclosure claims priority to and the benefits of Chinese Patent Application No. 201120133599.8 filed with the State Intellectual Property Office of P. R. China on April 29, 2011, which is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to a coupling device, which is mainly used in a coupling structure between a motor shaft and a worm shaft in an electric power steering apparatus for a vehicle.

BACKGROUND

Conventionally, the coupling between a motor shaft and a worm shaft in an electric power steering apparatus is mostly a rigid coupling between a metal spline shaft and a spline sleeve. Due to the mesh clearance between the spline shaft and the spline sleeve, the impact between inner and outer spline teeth may produce abnormal noise when the motor is subject to steering rotation with a small angle frequently. Moreover, the vibration caused by the impact may be transferred to a steering wheel, thus causing hearing and hand feeling discomfort of drivers and passengers. If the mesh clearance between the spline shaft and the spline sleeve is strictly required, the requirement for the assembly coaxiality may be improved, thereby improving the manufacturing cost and the assembly difficulty.

SUMMARY

In viewing thereof, embodiments of the present disclosure seek to solve at least one of the problems existing in the prior art to at least some extent, particularly a problem that a motor shaft and a worm shaft in an electric power steering apparatus easily produces an impact to cause abnormal noise and vibration because rigid coupling is adopted, or to provide a consumer with a useful commercial choice. Accordingly, a coupling device is provided, which may reduce abnormal noise and vibration caused by the impact.

According to an embodiment of the present disclosure, a coupling device is provided. The coupling device comprises: a first half-coupling; a second half-coupling; and an elastic connection mechanism disposed between the first half-coupling and the second half-coupling. The elastic connection mechanism comprises: a first torque transmitting member having a first ring base, at least one pair of first protrusions being disposed on an inner circumferential surface of the first ring base at intervals around an axial direction of the first ring base and extended inward along a radial direction of the first ring base, two first protrusions in each pair being symmetrical to each other; a second torque transmitting member having a third ring base, at least one pair of third protrusions being disposed on an inner circumferential surface of the third ring base at intervals around an axial direction of the third ring base and extended inward along a radial direction of the third ring base, two third protrusions in each pair being symmetrical to each other, and the third protrusions being corresponded to the first protrusions; an intermediate elastic member disposed between the first torque transmitting member and the second torque transmitting member and having a second ring base, at least one pair of second protrusions being disposed on an inner circumferential surface of the second ring base at intervals around an axial direction of the second ring base and extended inward along a radial direction of the second ring base, two second protrusions in each pair being symmetrical to each other, the second protrusions being corresponded to the first protrusions and the third protrusions respectively, and a width of the second protrusions along the axial direction of the second ring base being larger than each of a width of the first protrusions along the axial direction of the first ring base and a width of the third protrusions along the axial direction of the third ring base; and a connection means disposed on the first torque transmitting member and the second torque transmitting member respectively and configured to tightly connect the first torque transmitting member, the intermediate elastic member and the second torque transmitting member successively.

Further, the connection means comprises: a first fitting part integrally disposed at an outer periphery of the first ring base and extended toward the third ring base; a first boss part disposed at an outer periphery of the third ring base and fitted with the first fitting part; a second fitting part integrally disposed at the outer periphery of the third ring base and extended toward the first ring base; a second boss part disposed at the outer periphery of the first ring base and fitted with the second fitting part.

Further, a first groove is formed in an outer circumferential surface of the first ring base at a position corresponding to that of the first protrusion, and the second boss part is disposed within the first groove; a second groove is formed in an outer circumferential surface of the third ring base at a position corresponding to that of the third protrusion, and the first boss part is disposed within the second groove; and a third groove is formed in an outer circumferential surface of the second ring base at a position corresponding to that of the second protrusion, and a number of the third groove is equal to that of the second protrusion.

Further, a plurality of first fitting parts are disposed at the outer periphery of the first ring base and corresponding to the first protrusions respectively; a plurality of second fitting parts are disposed at the outer periphery of the third ring base and corresponding to the third protrusions respectively; the first fitting parts and the second boss parts are alternately disposed at intervals along a circumferential direction of the first ring base, and the second fitting parts and the first boss parts are alternately disposed at intervals along a circumferential direction of the third ring base; and the first fitting parts are fitted with the first boss parts by passing through corresponding third grooves respectively, and the second fitting parts are fitted with the second boss parts by passing through the other corresponding third grooves respectively.

Further, each of the first fitting part and the second fitting part has a rectangular hole, and each of the first boss part and the second boss part is caught within the rectangular hole and is slidable along a length direction of the rectangular hole.

Further, a length of each of the first fitting part and the second fitting part in the length direction of the rectangular hole is smaller than a sum of a thickness of the second ring base and a thickness of one of the first ring base and the third ring base.

Further, the first protrusion, the third protrusion and the second protrusion are stacked together, and the second protrusion is disposed between the first protrusion of the first ring base and the third protrusion of the third ring base in the axial direction of the first and third ring bases; and each of the first protrusion, the third protrusion and the second protrusion has a rectangular structure, and a chamber is formed between two adjacent rectangular structures.

Further, the circumferential surfaces of the first ring base, the third ring base and the second ring base are smooth and are located at the same circle.

Further, the first half-coupling has a first cylindrical base part and first boss structures disposed on a side of the first cylindrical base part and extended along an axial direction of the first cylindrical base part; the second half-coupling has a second cylindrical base part and second boss structures disposed on a side of the second cylindrical base part and extended along an axial direction of the second cylindrical base part; each of a number of the first boss structures of the first half-coupling and a number of the second boss structures of the second half-coupling is half of that of the chambers; and the first boss structures and the second boss structures are alternately fitted within the chambers.

Further, end surfaces of the first protrusion, the second protrusion and the third protrusion away from the inner circumferential surfaces of the first, second and third ring bases define a cylindrical chamber; and an elastic body is disposed in the cylindrical chamber and has a cylindrical base and protuberances integrally formed on an outer circumferential surface of the cylindrical base, and the protuberances are symmetrically arranged on the outer circumferential surface of the cylindrical base.

The beneficial effects of the present disclosure are as follows. The first protrusion, the second protrusion and the third protrusion are disposed in the first, second and third ring bases respectively, and the width of the second protrusion is larger than each of the widths of the first and third protrusions, so that the first half-coupling is not connected with the second half-coupling by rigid coupling directly, but is connected with the second half-coupling by spacing the aforementioned protrusions. Moreover, the second protrusion may provide a buffering force. When a steering shaft is rotated repeatedly, the impact caused by the rigid coupling may be avoided, thus reducing the abnormal noise caused by the impact, and the fact that the vibration caused by the impact is transferred to a steering wheel to cause discomfort of a driver may be reduced. Furthermore, the transmission environment of the whole coupling device is closed, thus effectively avoiding the harmful effect resulted from entrance of impurities such as iron scraps into the coupling device.

Additional aspects and advantages of embodiments of present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of the disclosure will become apparent and more readily appreciated from the following descriptions taken in conjunction with the drawings in which:

Fig. 1 is an exploded perspective view of a coupling device according to an embodiment of the present disclosure;

Fig. 2 is a sectional view of a coupling device according to an embodiment of the present disclosure; and

Fig. 3 is an exploded perspective view of a connection mechanism of a coupling device according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the present disclosure. The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions.

As shown in Figs. 1-3, a coupling device according to an embodiment of the present disclosure comprises a first half-coupling 101, a second half-coupling 102 and an elastic connection mechanism 10 disposed between the first half-coupling 101 and the second half-coupling 102. The rotation torque of the first half-coupling 101 is transmitted to the second half-coupling 102 via the elastic connection mechanism 10.

The elastic connection mechanism 10 comprises a first torque transmitting member 501, a second torque transmitting member 502, an intermediate elastic member 6 disposed between the first torque transmitting member 501 and the second torque transmitting member 502, a connection means disposed on the first torque transmitting member 501 and the second torque transmitting member 502 respectively for tightly connecting the first torque transmitting member

501, the intermediate elastic member 6 and the second torque transmitting member 502 successively.

The first torque transmitting member 501 has a first ring base 141. The second torque transmitting member 502 has a third ring base 142. At least one pair of first protrusions 301 is disposed on an inner circumferential surface of the first ring base 141 at intervals around an axial direction of the first ring base 141, that is, along a circumferential direction of the first ring base 141, and extended inward along a radial direction of the first ring base 141, and two first protrusions 301 in each pair are symmetrical to each other for dividing an interior of the first ring base 141 into two chambers with the same shape and the same size. At least one pair of third protrusions 302 is disposed on an inner circumferential surface of the third ring base 142 at intervals around an axial direction of the third ring base 142, that is, along a circumferential direction of the third ring base 142, and extended inward along a radial direction of the third ring base 142, two third protrusions 302 in each pair are symmetrical to each other for dividing an interior of the third ring base 142 into two chambers with the same shape and the same size, and the first protrusions 301 are corresponded to the third protrusions 302 with respect to the axial direction of the third ring base 142. The intermediate elastic member 6 has a second ring base 15.

At least one pair of second protrusions 4 is disposed on an inner circumferential surface of the second ring base 15 at intervals around an axial direction of the second ring base 15, that is, along a circumferential direction of the second ring base 15, and extended inward along a radial direction of the second ring base 15, two second protrusions 4 in each pair are symmetrical to each other for dividing an interior of the second ring base 15 into two chambers with the same shape and the same size, the second protrusions 4 are corresponded to the first protrusions 301 and the third protrusions 302 with respect to the axial direction of the second ring base 15 respectively, and a width of the second protrusions 4 along the axial direction of the second ring base 15 is larger than each of a width of the first protrusions 301 along the axial direction of the first ring base 141 and a width of the third protrusions 302 along the axial direction of the third ring base 142.

As shown in Fig. 1 and Fig. 3, the connection means comprises: a first fitting part 701 integrally disposed at an outer periphery of the first ring base 141 and extended toward the third ring base 142; a first boss part 112 disposed at an outer periphery of the third ring base 142 and fitted with the first fitting part 701; a second fitting part 702 integrally disposed at the outer periphery of the third ring base 142 and extended toward the first ring base 141 ; and a second boss part 111 disposed at the outer periphery of the first ring base 141 and fitted with the second fitting part 702. The connection means tightly connects the first torque transmitting member 501, the intermediate elastic member 6 and the second torque transmitting member 502 successively by fitting the first fitting part 701 and the first boss part 112 and fitting the second fitting part 702 and the second boss part 111.

A first groove 161 is formed in an outer circumferential surface of the first ring base 141 at a position corresponding to that of the first protrusion 301, and the second boss part 111 is disposed within the first groove 161. A second groove 162 is formed in an outer circumferential surface of the third ring base 142 at a position corresponding to that of the third protrusion 302, and the first boss part 112 is disposed within the second groove 162. A third groove 17 is formed in an outer circumferential surface of the second ring base 15 at a position corresponding to that of the second protrusion 4, and a number of the third groove 17 is equal to that of the second protrusion 4.

A plurality of first fitting parts 701 are disposed at the outer periphery of the first ring base

141 and corresponding to the first protrusions 301 respectively. A plurality of second fitting parts 702 are disposed at the outer periphery of the third ring base 142 and corresponding to the third protrusions 302 respectively. The first fitting parts 701 and the second boss parts 111 are alternately disposed at intervals along a circumferential direction of the first ring base 141, and the second fitting parts 702 and the first boss parts 112 are alternately disposed at intervals along a circumferential direction of the third ring base 142.

The first fitting parts 701 are fitted with the first boss parts 112 by passing through corresponding third grooves 17 respectively, and the second fitting parts 702 are fitted with the second boss parts 111 by passing through the other corresponding third grooves 17 respectively. Each of the first fitting part 701 and the second fitting part 702 has a rectangular hole 9, and each of the first boss part 112 and the second boss part 111 can be caught within the rectangular hole 9 and is slidable along a length direction of the rectangular hole 9. A length of each of the first fitting part 701 and the second fitting part 702 in the length direction of the rectangular hole 9 is smaller than a sum of a thickness of the second ring base 15 and a thickness of one of the first ring base 141 and the third ring base 142. Therefore, it is not easy to break off the first fitting part 701 and the second fitting part 702 when the intermediate elastic member 6 is compressed.

As shown in Fig. 1 and Fig. 3, the first protrusion 301, the third protrusion 302 and the second protrusion 4 are stacked together, and the second protrusion 4 is disposed between the first protrusion 301 of the first ring base 141 and the third protrusion 302 of the third ring base 142 in the axial direction of the first and third ring bases 141, 142. Each of the first protrusion 301, the third protrusion 302 and the second protrusion 4 has a rectangular structure, and a chamber 18 is formed between two adjacent rectangular structures. The circumferential surfaces of the first ring base 141, the third ring base 142 and the second ring base 15 are smooth and are located at the same circle, so that the first ring base 141, the third ring base 142 and the second ring base 15 may be rotated in a steering column easily.

As shown in Fig. 1, the first half-coupling 101 has a first cylindrical base part 802 and first boss structures 201 disposed on a side of the first cylindrical base part 802 and extended along an axial direction of the first cylindrical base part 802. The second half-coupling 102 has a second cylindrical base part 801 and second boss structures 202 disposed on a side of the second cylindrical base part 801 and extended along an axial direction of the second cylindrical base part 801. Each of a number of the first boss structures 201 of the first half-coupling 101 and a number of the second boss structures 202 of the second half-coupling 102 is half of that of the chambers 18. The first boss structures 201 and the second boss structures 202 are alternately fitted within the chambers 18.

After the boss structures 201, 202 are fitted into the chamber 18, because the width of the second protrusions 4 along the axial direction of the second ring base 15 is larger than each of the width of the first protrusions 301 along the axial direction of the first ring base 141 and the width of the third protrusions 302 along the axial direction of the third ring base 142, the second protrusion 4 is compressed slightly, thus providing a buffering force.

As shown in Fig. 1 and Fig. 2, end surfaces of the first protrusion 301, the second protrusion 4 and the third protrusion 302 away from the inner circumferential surfaces of the first, second and third ring bases 141, 15, 142 define a cylindrical chamber. An elastic body 3 is disposed in the cylindrical chamber and has a cylindrical base 13 and protuberances 12 integrally formed on an outer circumferential surface of the cylindrical base 13, and the protuberances 12 are symmetrically arranged on the outer circumferential surface of the cylindrical base 13. The elastic body 3 is in a compressed state during the assembling. The elastic body 3 may provide a predetermined axial force when compressed to prevent the displacement of a transmission shaft caused by the axial clearance of a bearing. By disposing the protuberances 12, the elastic body 3 may be located at a center of the elastic connection mechanism 10. Because the whole coupling device is closed, the transmission environment of the whole coupling device is closed, thus effectively avoiding the harmful effect resulted from entrance of impurities such as iron scraps into the coupling device.

In summary and with reference to the drawings, when an electric steering shaft is rotated, a motor shaft drives the first half-coupling 101 to rotate, and the first boss structure 201 of the first half-coupling 101 drives the first protrusion 301 of the first torque transmitting member 501 and the third protrusion 302 of the second torque transmitting member 502 of the elastic connection mechanism 10 to rotate together, and then the first protrusions 301 of the first torque transmitting member 501 and the third protrusions 302 of the second torque transmitting member 502 may drive the second boss structure 202 of the second half-coupling 102 to rotate, so as to drive a worm shaft to rotate and achieve the aim of transferring rotation.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that changes, alternatives, and modifications can be made in the embodiments without departing from spirit and principles of the disclosure. Such changes, alternatives, and modifications all fall into the scope of the claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. A coupling device, comprising:

a first half-coupling (101);

a second half-coupling (102); and

an elastic connection mechanism (10) disposed between the first half-coupling (101) and the second half-coupling (102) and comprising:

a first torque transmitting member (501) having a first ring base (141), at least one pair of first protrusions (301) being disposed on an inner circumferential surface of the first ring base (141) at intervals around an axial direction of the first ring base (141) and extended inward along a radial direction of the first ring base (141), two first protrusions (301) in each pair being symmetrical to each other;

a second torque transmitting member (502) having a third ring base (142), at least one pair of third protrusions (302) being disposed on an inner circumferential surface of the third ring base (142) at intervals around an axial direction of the third ring base (142) and extended inward along a radial direction of the third ring base (142), two third protrusions (302) in each pair being symmetrical to each other, and the third protrusions (302) being corresponded to the first protrusions (301);

an intermediate elastic member (6) disposed between the first torque transmitting member (501) and the second torque transmitting member (502) and having a second ring base (15), at least one pair of second protrusions (4) being disposed on an inner circumferential surface of the second ring base (15) at intervals around an axial direction of the second ring base (15) and extended inward along a radial direction of the second ring base (15), two second protrusions (4) in each pair being symmetrical to each other, the second protrusions (4) being corresponded to the first protrusions (301) and the third protrusions (302) respectively, and a width of the second protrusions (4) along the axial direction of the second ring base (15) being larger than each of a width of the first protrusions

(301) along the axial direction of the first ring base (141) and a width of the third protrusions

(302) along the axial direction of the third ring base (142); and

a connection means disposed on the first torque transmitting member (501) and the second torque transmitting member (502) respectively and configured to tightly connect the first torque transmitting member (501), the intermediate elastic member (6) and the second torque transmitting member (502) successively.

2. The coupling device of claim 1, wherein the connection means comprises:

a first fitting part (701) integrally disposed at an outer periphery of the first ring base (141) and extended toward the third ring base (142);

a first boss part (112) disposed at an outer periphery of the third ring base (142) and fitted with the first fitting part (701);

a second fitting part (702) integrally disposed at the outer periphery of the third ring base (142) and extended toward the first ring base (141);

a second boss part (111) disposed at the outer periphery of the first ring base (141) and fitted with the second fitting part (702).

3. The coupling device of claim 2, wherein a first groove (161) is formed in an outer circumferential surface of the first ring base (141) at a position corresponding to that of the first protrusion (301), and the second boss part (111) is disposed within the first groove (161);

wherein a second groove (162) is formed in an outer circumferential surface of the third ring base (142) at a position corresponding to that of the third protrusion (302), and the first boss part (112) is disposed within the second groove (162); and

wherein a third groove (17) is formed in an outer circumferential surface of the second ring base (15) at a position corresponding to that of the second protrusion (4), and a number of the third groove (17) is equal to that of the second protrusion (4).

4. The coupling device of claim 3, wherein a plurality of first fitting parts (701) are disposed at the outer periphery of the first ring base (141) and corresponding to the first protrusions (301) respectively;

wherein a plurality of second fitting parts (702) are disposed at the outer periphery of the third ring base (142) and corresponding to the third protrusions (302) respectively;

wherein the first fitting parts (701) and the second boss parts (111) are alternately disposed at intervals along a circumferential direction of the first ring base (141), and the second fitting parts (702) and the first boss parts (112) are alternately disposed at intervals along a circumferential direction of the third ring base (142); and

wherein the first fitting parts (701) are fitted with the first boss parts (112) by passing through corresponding third grooves (17) respectively, and the second fitting parts (702) are fitted with the second boss parts (111) by passing through the other corresponding third grooves (17) respectively.

5. The coupling device of claim 4, wherein each of the first fitting part (701) and the second fitting part (702) has a rectangular hole (9), and each of the first boss part (112) and the second boss part (111) is caught within the rectangular hole (9) and is slidable along a length direction of the rectangular hole (9).

6. The coupling device of claim 5, wherein a length of each of the first fitting part (701) and the second fitting part (702) in the length direction of the rectangular hole (9) is smaller than a sum of a thickness of the second ring base (15) and a thickness of one of the first ring base (141) and the third ring base (142).

7. The coupling device of claim 1, wherein the first protrusion (301), the third protrusion (302) and the second protrusion (4) are stacked together, and the second protrusion (4) is disposed between the first protrusion (301) of the first ring base (141) and the third protrusion (302) of the third ring base (142) in the axial direction of the first and third ring bases (141, 142); and each of the first protrusion (301), the third protrusion (302) and the second protrusion (4) has a rectangular structure, and a chamber (18) is formed between two adjacent rectangular structures.

8. The coupling device of claim 1, wherein the circumferential surfaces of the first ring base (141), the third ring base (142) and the second ring base (15) are smooth and are located at the same circle.

9. The coupling device of claim 7, wherein the first half-coupling (101) has a first cylindrical base part (802) and first boss structures (201) disposed on a side of the first cylindrical base part (802) and extended along an axial direction of the first cylindrical base part (802);

wherein the second half-coupling (102) has a second cylindrical base part (801) and second boss structures (202) disposed on a side of the second cylindrical base part (801) and extended along an axial direction of the second cylindrical base part (801);

wherein each of a number of the first boss structures (201) of the first half-coupling (101) and a number of the second boss structures (202) of the second half-coupling (102) is half of that of the chambers (18); and

wherein the first boss structures (201) and the second boss structures (202) are alternately fitted within the chambers (18).

10. The coupling device of claim 1, wherein end surfaces of the first protrusion (301), the second protrusion (4) and the third protrusion (302) away from the inner circumferential surfaces of the first, second and third ring bases (141, 15, 142) define a cylindrical chamber; and

wherein an elastic body (3) is disposed in the cylindrical chamber and has a cylindrical base (13) and protuberances (12) integrally formed on an outer circumferential surface of the cylindrical base (13), and the protuberances (12) are symmetrically arranged on the outer circumferential surface of the cylindrical base (13).