JP2019127966A - Seal member and steering device - Google Patents

Abstract

To provide a seal member capable of being easily attached to an odd-shaped tube.SOLUTION: A seal member comprises: a housing overlapped with a tube fitted to a shaft; an annular first seal lip supported to the housing and contacting with an outer peripheral surface of the shaft; and an annular second seal lip supported to the housing and contacting with an outer peripheral surface of the tube. The housing comprises a cylindrical body part. An inner peripheral surface of the body part faces to the outer peripheral surface of the tube at an interval. The second seal lip is attached to the body part.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a seal member and a steering device.

  A vehicle is provided with a steering device as a device for transmitting an operation of an operator (driver) to a steering wheel to the wheel. A structure including a tube and a shaft that fits inside the tube may be used for the steering device. The tube and shaft can transmit torque to one another and can move axially relative to one another as required. In order to suppress the entry of foreign matter into the gap between the tube and the shaft, the gap is preferably closed. For example, Patent Document 1 describes a seal member that prevents foreign matter from entering the gap between the spline shaft and the spline sleeve. For example, Patent Document 2 describes that a retaining member is fixed to the opening-side end portion of the female steering shaft, and a foreign material is prevented from entering by a seal member fixed to the retaining member.

JP 2003-161331 A JP 2013-60092 A

  By the way, the connection method which fits an elliptical tube and a round shaft may be used. When the seal member of Patent Document 1 and Patent Document 2 is used, if the tube is oval, the outer peripheral surface of the tube is processed to match the shape of the outer peripheral surface of the tube and the shape of the inner peripheral surface of the seal member. Necessary. For this reason, a sealing member cannot be easily attached to an elliptical tube.

  This indication is made in view of the above-mentioned subject, and aims at providing a sealing member which can be easily attached to a tube of irregular shape.

  In order to achieve the above object, a seal member according to an aspect of the present disclosure includes a housing that overlaps a tube that is fitted to a shaft, an annular first seal lip that is supported by the housing and that is in contact with the outer peripheral surface of the shaft. And an annular second seal lip supported by the housing and in contact with the outer peripheral surface of the tube, the housing including a cylindrical main body, the inner peripheral surface of the main body being the outer periphery of the tube The second seal lip is attached to the main body portion.

  The gap between the inner peripheral surface of the main body and the outer peripheral surface of the tube allows the second seal lip to be easily deformed in the gap. Since the second seal lip is deformed so as to follow the outer shape of the tube, the second seal lip can block the gap over the entire circumference of the tube even when the outer shape of the tube is not circular. For this reason, according to a sealing member, the process with respect to the tube for raising the adhesiveness of a 2nd seal lip becomes unnecessary. Thus, the sealing member can be easily attached to the irregularly shaped tube.

  As a desirable mode of the seal member, the second seal lip is attached to the inner peripheral surface of the main body.

  Thereby, the center of the 2nd seal lip when it sees from an axial direction becomes difficult to shift | deviate with respect to the center of a main-body part. Therefore, when the seal member is inserted into the tube, the second seal lip can be used as a guide. Therefore, the assembly of the seal member and the tube is facilitated.

  As a preferred aspect of the seal member, an annular sub seal lip supported by the housing and in contact with the outer peripheral surface of the tube is provided, and the sub seal lip is opposite to the first seal lip with respect to the second seal lip. It is arrange | positioned at the edge part of the said main-body part.

  The sub seal lip prevents foreign matter from entering the space from the end of the main body to the second seal lip. For this reason, even when the second seal lip is disposed above the first seal lip, the accumulation of foreign matter around the second seal lip is suppressed. In addition, since friction occurs between the tube and the second seal lip and between the tube and the sub seal lip, the seal member is less likely to come off the tube.

  As a desirable mode of the seal member, before the second seal lip and the sub seal lip contact the outer peripheral surface of the tube, the minimum inner diameter of the sub seal lip is larger than the minimum inner diameter of the second seal lip.

  Thereby, when the seal member is viewed in the axial direction and from the sub seal lip side, the second seal lip is visible. For this reason, the seal member can suppress the entry of foreign matter by the sub-seal lip and can use the second seal lip as a guide.

  As a desirable mode of the seal member, the second seal lip extends toward the first seal lip side.

  Thereby, even if the force which goes to the direction of a shaft is added to a seal member, the front-end | tip of a 2nd seal lip is hooked on a tube. That is, the second seal lip functions as a so-called return. For this reason, the seal member is less likely to come off the tube. Further, when assembling the seal member and the tube, the second seal lip is not easily caught on the tube, so that the assembly is easy.

  A steering device according to an aspect of the present disclosure includes the above-described seal member. Thereby, the durability of the steering device is improved.

  According to the present disclosure, a seal member that can be easily attached to a profiled tube can be provided.

FIG. 1 is a schematic view of a steering apparatus of the present embodiment. FIG. 2 is a perspective view of the steering device of the present embodiment. FIG. 3 is a side view of the intermediate shaft of the present embodiment. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 5 is a cross-sectional view taken along the line BB in FIG. 6 is a cross-sectional view taken along the line CC in FIG. FIG. 7 is a cross-sectional view of the seal member of the present embodiment. FIG. 8 is a cross-sectional view of a modified seal member.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following embodiments (hereinafter referred to as embodiments). Further, constituent elements in the following embodiments include those which can be easily conceived by those skilled in the art, substantially the same ones, and so-called equivalent ranges. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.

(Embodiment)
FIG. 1 is a schematic diagram of a steering apparatus according to the present embodiment. FIG. 2 is a perspective view of the steering apparatus of the present embodiment. As shown in FIG. 1, the steering device 80 includes a steering wheel 81, a steering shaft 82, a steering force assist mechanism 83, a first universal joint 84, and an intermediate shaft 85 in the order in which the force given by the operator is transmitted. And a second universal joint 86, which are joined to the pinion shaft 87. In the following description, the front of the vehicle on which the steering device 80 is mounted is described simply as the front, and the rear of the vehicle is described as the rear.

  As shown in FIG. 1, the steering shaft 82 includes an input shaft 82a and an output shaft 82b. One end of the input shaft 82a is connected to the steering wheel 81, and the other end of the input shaft 82a is connected to the output shaft 82b. Further, one end of the output shaft 82b is connected to the input shaft 82a, and the other end of the output shaft 82b is connected to the first universal joint 84.

  As shown in FIG. 1, the intermediate shaft 85 connects the first universal joint 84 and the second universal joint 86. One end of the intermediate shaft 85 is connected to the first universal joint 84. The other end of the intermediate shaft 85 is connected to the second universal joint 86. One end of the pinion shaft 87 is connected to the second universal joint 86. The other end of the pinion shaft 87 is connected to the steering gear 88. The first universal joint 84 and the second universal joint 86 are, for example, cardan joints. The rotation of the steering shaft 82 is transmitted to the pinion shaft 87 via the intermediate shaft 85. That is, the intermediate shaft 85 rotates with the steering shaft 82.

  As shown in FIG. 1, the steering gear 88 includes a pinion 88 a and a rack 88 b. The pinion 88 a is coupled to the pinion shaft 87. The rack 88 b meshes with the pinion 88 a. The steering gear 88 converts the rotational motion transmitted to the pinion 88a into a linear motion by the rack 88b. The rack 88 b is connected to the tie rod 89. The movement of the rack 88b changes the angle of the wheel.

  As shown in FIG. 1, the steering force assist mechanism 83 includes a speed reducer 92 and an electric motor 93. The speed reducer 92 is, for example, a worm speed reducer. The torque generated by the electric motor 93 is transmitted to the worm wheel via the worm in the reduction gear 92 to rotate the worm wheel. The reduction gear 92 increases the torque generated by the electric motor 93 by the worm and the worm wheel. Then, the reduction gear 92 applies an auxiliary steering torque to the output shaft 82b. That is, the steering device 80 is a column assist system.

  As shown in FIG. 1, the steering device 80 includes an ECU (Electronic Control Unit) 90, a torque sensor 94, and a vehicle speed sensor 95. The electric motor 93, the torque sensor 94, and the vehicle speed sensor 95 are electrically connected to the ECU 90. The torque sensor 94 outputs the steering torque transmitted to the input shaft 82 a to the ECU 90 by CAN (Controller Area Network) communication. The vehicle speed sensor 95 detects the traveling speed (vehicle speed) of the vehicle body on which the steering device 80 is mounted. The vehicle speed sensor 95 is provided on the vehicle body and outputs the vehicle speed to the ECU 90 by CAN communication.

  The ECU 90 controls the operation of the electric motor 93. The ECU 90 obtains signals from the torque sensor 94 and the vehicle speed sensor 95, respectively. Electric power is supplied to the ECU 90 from the power supply device 99 (for example, an on-board battery) while the ignition switch 98 is on. The ECU 90 calculates an auxiliary steering command value based on the steering torque and the vehicle speed. The ECU 90 adjusts the power value supplied to the electric motor 93 based on the assist steering command value. The ECU 90 acquires information on the induced voltage from the electric motor 93 or information output from a resolver or the like provided in the electric motor 93. The control of the electric motor 93 by the ECU 90 reduces the force required to operate the steering wheel 81.

  FIG. 3 is a side view of the intermediate shaft of the present embodiment. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 5 is a cross-sectional view taken along the line BB in FIG. 6 is a cross-sectional view taken along the line CC in FIG. FIG. 7 is a cross-sectional view of the seal member of the present embodiment.

  As shown in FIG. 3, the intermediate shaft 85 includes a shaft 1, a tube 2 and a seal member 5.

  The shaft 1 is a substantially cylindrical member. The shaft 1 is a solid member. For example, the shaft 1 is formed of carbon steel for machine structure (SC material (Carbon Steel for Machine Structural Use)) or the like. As shown in FIG. 4, the shaft 1 includes a base 11 and a first fitting portion 15.

  The base 11 is fixed to the second universal joint 86. The base 11 has a cylindrical shape with a substantially constant diameter. The first fitting portion 15 is located at the rear end of the shaft 1 (the end on the tube 2 side). As shown in FIG. 4, the first fitting portion 15 includes a serration 15 a on the outer peripheral surface and a recess 150 on the end surface on the rear side.

  In the following description, the axial direction of the shaft 1 is simply referred to as the axial direction. The direction orthogonal to the axial direction is described as the radial direction. A direction along a circle around the rotation axis of the shaft 1 is described as a circumferential direction. FIG. 4 is a cross section of the intermediate shaft 85 cut along a plane orthogonal to the radial direction.

  The tube 2 is a substantially cylindrical member. For example, the tube 2 is formed of a carbon steel tube for mechanical structure (STKM material (Carbon Steel Tubes for Machine Structural Purposes)) or the like. As shown in FIG. 4, the tube 2 includes a base 21 and a second fitting portion 25.

  The base 21 is fixed to the first universal joint 84. The second fitting portion 25 is arranged at the front end portion (end portion on the shaft 1 side) of the tube 2. The first fitting portion 15 is inserted into the second fitting portion 25. The 2nd fitting part 25 equips the inner skin with serration 25a. The serration 25a meshes with the serration 15a. Thus, the shaft 1 and the tube 2 can transmit torque to each other.

  As shown in FIG. 5, the outer shape of the first fitting portion 15 draws a circle in a cross section orthogonal to the axial direction. In the cross section shown in FIG. 5, the outer shape of the second fitting portion 25 draws an ellipse. As shown in FIG. 6, the outer shape of the first fitting portion 15 draws an ellipse in the cross section including the recess 150 among the cross sections orthogonal to the axial direction. In the cross section shown in FIG. 6, the external shape of the 2nd fitting part 25 draws a circle. Note that the shapes of the second fitting portion 25 of FIG. 5 and the first fitting portion 15 of FIG. 6 are exaggerated for the sake of description, and are different from the actual shape. In practice, all teeth of serration 25a are each located between two teeth of serration 15a. That is, the teeth of the serration 25a located on the left and right sides of FIG. 5 are not in contact with the teeth of the serration 15a, but are located between the two teeth of the serration 15a. The teeth of the serrations 25a located on the upper and lower sides of FIG. 6 are not in contact with the teeth of the serrations 15a, but are located between the two teeth of the serrations 15a. Further, the difference between the major axis (length of the major axis) and the minor axis (length of the minor axis) of the elliptical shape shown in FIGS. 5 and 6 may be different from the actual one.

  When assembling the intermediate shaft 85, a part of the first fitting portion 15 is inserted into the second fitting portion 25. Then, the first fitting portion 15 and the second fitting portion 25 are pressed from two directions at the position corresponding to the recess 150. Thereafter, the first fitting portion 15 is further pushed into the second fitting portion 25. Thereby, the cross-sectional shape shown in FIG. 5 and FIG. 6 is formed. In addition, such a connection method of the 1st fitting part 15 and the 2nd fitting part 25 may be called ellipse fitting.

  The movement of the second fitting portion 25 with respect to the first fitting portion 15 is restricted by the friction generated in the contact portion of the first fitting portion 15 with the second fitting portion 25. That is, the second fitting portion 25 does not move relative to the first fitting portion 15 during normal use (when no collision occurs).

  When the vehicle collides, a load is applied to the steering gear 88. The load applied to the steering gear 88 is transmitted to the shaft 1 via the second universal joint 86. When a predetermined axial load is applied to the shaft 1 at the time of the collision, the first fitting portion 15 moves with respect to the second fitting portion 25. That is, the shaft 1 is connected to the tube 2 so that it can move relative to the tube 2 at the time of a collision. When the shaft 1 and the tube 2 move relative to each other, the friction between the first fitting portion 15 and the second fitting portion 25 absorbs an impact.

  In the intermediate shaft 85, the shaft 1 does not necessarily have to be positioned in front (downward) of the tube 2. That is, the tube 2 may be disposed in front (downward) of the shaft 1. In this case, when the vehicle collides, it is transmitted to the tube 2 via the second universal joint 86. Then, the tube 2 moves relative to the shaft 1, and the impact is absorbed by the friction between the first fitting portion 15 and the second fitting portion 25.

  As in the intermediate shaft 85 described above, in a portion including two members that can move relative to each other, a gap is generated between the two members. In order to maintain appropriate performance, it is desirable that foreign matter do not enter the gap between the two members as much as possible. The foreign material is, for example, water or dust.

  The seal member 5 of the present embodiment is a member for closing a gap between the shaft 1 and the tube 2. As shown in FIG. 7, the seal member 5 includes a housing 50, a first seal lip 51, and a second seal lip 52. FIG. 7 shows the seal member 5 before being attached to the intermediate shaft 85.

  As shown in FIG. 7, the housing 50 is cylindrical and overlaps the tube 2. The housing 50 is formed of, for example, a metal subjected to an anticorrosion treatment. The housing 50 may be formed of polyamide (PA) or polyacetal (POM) or the like. The housing 50 is preferably made of a material that can withstand the environment outside the passenger compartment. As shown in FIG. 7, the housing 50 includes a main body portion 501 and a bottom surface portion 502.

  The main body 501 is a cylindrical member. The inner peripheral surface 501a of the main body portion 501 faces the outer peripheral surface of the second fitting portion 25 with a gap. The main body portion 501 overlaps a portion of the second fitting portion 25 which is deformed into an elliptical shape. As shown in FIG. 6, the inner diameter D501 of the main body portion 501 is larger than the outermost diameter D251 (long diameter) of the second fitting portion 25. The width S of the gap between the main body portion 501 and the second fitting portion 25 shown in FIG. 6 differs depending on the position in the circumferential direction. The width S is, for example, about 0.5 mm or more and 3 mm or less. The bottom portion 502 is a disk-like member having a hole in the center. It extends radially inward from the front end of the main body 501 (the end on the shaft 1 side). The bottom surface portion 502 is in contact with the end surface of the second fitting portion 25.

  When assembling the seal member 5 and the tube 2, for example, the seal member 5 is pressed into the tube 2. At this time, the tube 2 is inserted into the opening on the opposite side of the bottom portion 502 of the housing 50. The bottom surface portion 502 is in contact with the end surface of the second fitting portion 25, so that the seal member 5 is positioned. After assembly, even if a force is applied to the seal member 5 in the direction opposite to the shaft 1, the bottom portion 502 is hooked on the tube 2. Therefore, the seal member 5 is less likely to come off the tube 2. For example, when the tube 2 is disposed below the shaft 1, the bottom portion 502 is pressed against the tube 2 by gravity, so that the movement of the seal member 5 is restricted.

  As shown in FIG. 7, the first seal lip 51 is an annular member and is supported by the housing 50. The first seal lip 51 is attached to the inner peripheral surface of the hole in the bottom surface portion 502. The first seal lip 51 is formed of, for example, a synthetic rubber. As shown in FIG. 4, the first seal lip 51 is in contact with the outer peripheral surface of the base 11 of the shaft 1 over the entire periphery.

  The minimum inner diameter D51 of the first seal lip 51 shown in FIG. 7 is smaller than the outer diameter D11 of the base 11 shown in FIG. When the shaft 1, the tube 2 and the seal member 5 are assembled, the first seal lip 51 is deformed. The elasticity of the first seal lip 51 presses the first seal lip 51 against the shaft 1. The first seal lip 51 closes the gap between the housing 50 and the shaft 1 and suppresses entry of foreign matter into the gap.

  As shown in FIG. 7, the second seal lip 52 is an annular member and is supported by the housing 50. The second seal lip 52 is attached to the inner peripheral surface 501 a of the main body 501. The second seal lip 52 is formed of, for example, a synthetic rubber. As shown in FIG. 4, the second seal lip 52 contacts the outer peripheral surface of the second fitting portion 25 over the entire circumference. The second seal lip 52 is disposed at a predetermined distance from the end face of the main body 501 as shown in FIG. That is, the second seal lip 52 is disposed at a position recessed with respect to the end face of the main body portion 501.

  The second seal lip 52 extends toward the first seal lip 51 side. For example, when the tube 2 is arranged on the upper side with respect to the shaft 1, there is a possibility that the seal member 5 moves downward (on the shaft 1 side) due to vibration or the like. On the other hand, since the second seal lip 52 extends toward the first seal lip 51 side, the tip of the second seal lip 52 is hooked on the tube 2. Thereby, the seal member 5 is suppressed from moving downward.

  The minimum inner diameter D52 of the second seal lip 52 shown in FIG. 7 is smaller than the minimum outer diameter D252 (short diameter) of the second fitting portion 25 shown in FIG. When the shaft 1, the tube 2 and the seal member 5 are assembled, the second seal lip 52 is deformed. The magnitude of deformation of the second seal lip 52 varies depending on the circumferential position. Due to the elasticity of the second seal lip 52, the second seal lip 52 is pressed against the tube 2 over the entire circumference. The second seal lip 52 closes the gap between the housing 50 and the tube 2 and suppresses the entry of foreign matter into the gap.

  Note that the seal member 5 is not necessarily used for the intermediate shaft 85. The seal member 5 can be widely applied to structures including a member corresponding to the shaft 1 and a member corresponding to the tube 2. For example, the seal member 5 may be used for the steering shaft 82 (input shaft 82a and output shaft 82b) shown in FIG. Further, the seal member 5 may be used in a device other than the steering device 80.

  The second seal lip 52 may not necessarily be attached to the inner peripheral surface of the main body portion 501. For example, the second seal lip 52 may be attached to the end face of the main body portion 501. Further, the shape of the second seal lip 52 is not limited to the one described above. For example, the second seal lip 52 may extend on the opposite side of the first seal lip 51.

  The seal member 5 may include a plurality of first seal lips 51. The seal member 5 may include a plurality of second seal lips 52.

  As described above, the seal member 5 includes the housing 50 that overlaps the tube 2 that is fitted to the shaft 1, the annular first seal lip 51 that is supported by the housing 50 and contacts the outer peripheral surface of the shaft 1, and the housing 50. And an annular second seal lip 52 supported on the outer circumferential surface of the tube 2. The housing 50 includes a cylindrical main body 501. The inner peripheral surface 501 a of the main body 501 faces the outer peripheral surface of the tube 2 with a gap. The second seal lip 52 is attached to the main body portion 501.

  By forming a gap between the inner circumferential surface 501 a of the main body 501 and the outer circumferential surface of the tube 2, the second seal lip 52 can be easily deformed in the gap. Since the second seal lip 52 is deformed so as to follow the outer shape of the tube 2, the second seal lip 52 can block the gap over the entire circumference of the tube 2 even when the outer shape of the tube 2 is not circular. For this reason, according to the sealing member 5, the processing on the tube 2 for increasing the adhesion of the second sealing lip 52 is not necessary. Therefore, the seal member 5 can be easily attached to the deformed tube 2.

  In the seal member 5, the second seal lip 52 is attached to the inner peripheral surface 501 a of the main body 501.

  As a result, the center of the second seal lip 52 when viewed from the axial direction does not easily shift with respect to the center of the main body portion 501. For this reason, when the seal member 5 is inserted into the tube 2, the second seal lip 52 can be used as a guide. Therefore, the assembly of the seal member 5 and the tube 2 is facilitated.

  In the seal member 5, the second seal lip 52 extends toward the first seal lip 51 side.

  Thereby, even if a force directed in the direction of the shaft 1 is applied to the seal member 5, the tip of the second seal lip 52 is caught on the tube 2. That is, the second seal lip 52 functions as a so-called return. Therefore, the seal member 5 is less likely to come off the tube 2. Further, when assembling the seal member 5 and the tube 2, the second seal lip 52 is hard to be caught on the tube 2, so that the assembly is easy.

  The steering device 80 includes the seal member 5. Thereby, the durability of the steering device 80 is improved.

(Modification)
FIG. 8 is a cross-sectional view of a modified seal member. Note that the same components as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 8, the seal member 5 </ b> A of the modification includes a sub seal lip 53. FIG. 8 shows the seal member 5A before being attached to the intermediate shaft 85.

  As shown in FIG. 8, the sub seal lip 53 is an annular member and is supported by the housing 50. The sub seal lip 53 is made of, for example, synthetic rubber. The sub seal lip 53 is in contact with the outer peripheral surface of the second fitting portion 25 over the entire circumference. The sub seal lip 53 is disposed at the end of the main body 501 opposite to the bottom surface 502. As shown in FIG. 8, the sub seal lip 53 is attached to an annular recess provided on the end surface of the main body 501. For example, the length of the sub seal lip 53 in the axial direction is equal to the depth of the recess.

  As shown in FIG. 8, the minimum inner diameter D53 of the sub seal lip 53 is larger than the minimum inner diameter D52 of the second seal lip 52. The minimum inner diameter D53 of the sub seal lip 53 is smaller than the minimum outer diameter D252 (short diameter) of the second fitting portion 25 shown in FIG. That is, the interference of the sub seal lip 53 with respect to the second fitting portion 25 is smaller than the interference of the second seal lip 52 with respect to the second fitting portion 25. The rigidity of the sub seal lip 53 is smaller than the rigidity of the second seal lip 52. For example, the sub seal lip 53 is formed of the same material as the second seal lip 52, and the axial thickness of the root portion of the sub seal lip 53 is greater than the axial thickness of the root portion of the second seal lip 52. Is also small.

  As described above, the seal member 5 </ b> A includes the annular sub seal lip 53 that is supported by the housing 50 and is in contact with the outer peripheral surface of the tube 2. The sub seal lip 53 is disposed at the end of the main body 501 opposite to the first seal lip 51 with respect to the second seal lip 52.

  The sub seal lip 53 suppresses foreign matter from entering the space from the end of the main body 501 to the second seal lip 52. For this reason, even when the second seal lip 52 is disposed above the first seal lip 51, accumulation of foreign matter around the second seal lip 52 is suppressed. In addition, since friction occurs between the tube 2 and the second seal lip 52 and between the tube 2 and the sub seal lip 53, the seal member 5 is less likely to come off the tube 2.

  In the seal member 5 </ b> A, the minimum inner diameter D <b> 53 of the sub seal lip 53 is larger than the minimum inner diameter D <b> 52 of the second seal lip 52 before the second seal lip 52 and the sub seal lip 53 contact the outer peripheral surface of the tube 2.

  Thus, when the seal member 5A is viewed in the axial direction and from the sub seal lip 53 side, the second seal lip 52 is visible. Therefore, the seal member 5A can suppress the entry of foreign matter by the sub seal lip 53, and can use the second seal lip 52 as a guide.

DESCRIPTION OF SYMBOLS 1 Shaft 11 Base 15 1st fitting part 150 Recess 15a Serration 2 Tube 21 Base 25 Second fitting part 25a Serration 5, 5A Seal member 50 Housing 501 Main body part 501a Inner peripheral surface 502 Bottom face part 51 First seal lip 52 First 2 seal lip 53 sub seal lip 80 steering device 81 steering wheel 82 steering shaft 82a input shaft 82b output shaft 83 steering force assist mechanism 84 first universal joint 85 intermediate shaft 86 second universal joint 87 pinion shaft 88 steering gear 88a pinion 88b rack 89 tie rod 90 ECU
92 Speed reducer 93 Electric motor 94 Torque sensor 95 Vehicle speed sensor 98 Ignition switch 99 Power supply

Claims (6)

A housing overlying a tube that fits into the shaft;
An annular first seal lip supported by the housing and in contact with the outer peripheral surface of the shaft;
An annular second seal lip supported by the housing and in contact with the outer peripheral surface of the tube;
With
The housing comprises a cylindrical body portion,
The inner peripheral surface of the main body portion faces the outer peripheral surface of the tube with a gap therebetween,
The second seal lip is a seal member attached to the main body. The seal member according to claim 1, wherein the second seal lip is attached to an inner peripheral surface of the main body portion. An annular sub-seal lip supported by the housing and in contact with the outer peripheral surface of the tube;
The seal member according to claim 2, wherein the sub seal lip is disposed at an end of the main body opposite to the first seal lip with respect to the second seal lip. The seal member according to claim 3, wherein the minimum inner diameter of the sub seal lip is larger than the minimum inner diameter of the second seal lip before the second seal lip and the sub seal lip contact the outer peripheral surface of the tube. The seal member according to any one of claims 1 to 4, wherein the second seal lip extends toward the first seal lip side.   A steering device comprising the seal member according to any one of claims 1 to 5.

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