KR101865049B1 - A boot unit for a contant velocity joint - Google Patents

Abstract

The present invention relates to a boot unit for a constant velocity joint, and more particularly, to a boot unit for a constant velocity joint capable of ensuring smooth air discharge performance while minimizing or preventing the possibility of leakage of grease in a joint housing.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a motorcycle comprising: a flange portion provided in a cylindrical shape and into which a driven shaft is inserted; A bent portion connected to an end of the flange portion; An extension part connected to the bending part and spaced apart from the flange part in a radial direction and being in contact with a joint cover provided outside; And an air flow path formed on the inner surface of the flange portion and formed along the longitudinal direction of the flange portion in a negative angle shape, wherein the width of the air flow path is formed to be different at the inner end portion and the outer end portion. .
According to the present invention, since the width of the inner end portion of the air flow path is formed to be narrower than the width of the outer end portion, leakage of grease can be prevented while discharging the high temperature air smoothly.

Description

[0001] The present invention relates to a boot unit for a constant velocity joint,

TECHNICAL FIELD The present invention relates to a boot unit for a constant velocity joint, and more particularly, to a boot unit for a constant velocity joint capable of ensuring smooth air discharge performance while minimizing or preventing leakage of grease in a joint housing.

Generally, two kinds of TPE (Thermo Plastic Elastomer) material and rubber material can be applied to the boot which is used to maintain the airtightness of the grease applied to the constant velocity joint used for the propeller shaft.

In the case of PE material, when the material itself is rigid and the boot is used for a cross groove joint in which the boot moves in the longitudinal direction, it is used to absorb the change in the longitudinal direction by applying a wrinkled shape. It can be applied in a state where the inner part is strongly sealed to the left.

In case of rubber material, it is not hard and hard like TPE material. When it is used for high-speed rotation like propeller shaft, the shape of the cross section of the cover to cover the boot is molded into "ㄷ" do.

However, the above conventional rubber material boot is hermetically sealed between the joint housing and the driven shaft to prevent leakage of the grease. However, when the internal heat is generated by the drive shaft and the driven shaft rotating at a high speed in the constant velocity joint, Which is made of a rubber material, hardly absorbs the boot having a low hardness, so that deformation and breakage may occur.

In addition, when the boot is deformed and broken, the grease filled in the constant velocity joint leaks to the outside, resulting in a quality problem, resulting in deterioration of the merchantability. To prevent this, a vent hole is formed in the cover portion of the constant velocity joint Structure, but it requires a separate process to process the vent hole, which makes it difficult to apply to a boot having a relatively low manufacturing cost.

In order to overcome such a problem, Korean Patent Laid-Open Publication No. 10-2011-0060563 discloses a pair of protrusions protruding from the inner surface of a flange of a boot, and the slave shaft and the inner surface of the flange are separated from each other by the protrusion, .

By this air bridging hole, the space inside the joint housing communicates with the outside, and heat of high temperature and high pressure can be discharged to the outside.

However, in such a case, the spacing space is wide, so that the grease inside the joint housing can leak to the outside through the air bridging hole, and external moisture can be introduced into the joint housing.

It is an object of the present invention to provide a joint boot unit capable of minimizing or preventing leakage of grease by minimizing a space between the flange portion and the driven shaft.

The present invention also provides a joint boot which is capable of smoothly discharging high-temperature air inside the joint housing by maintaining the air communication performance between the inside and the outside of the joint housing and preventing external moisture from flowing into the joint housing. There is another purpose in providing the unit.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a motorcycle comprising: a flange portion provided in a cylindrical shape and into which a driven shaft is inserted; A bent portion connected to an end of the flange portion; An extension part connected to the bending part and spaced apart from the flange part in a radial direction and being in contact with a joint cover provided outside; And an air flow path formed on the inner surface of the flange portion and formed along the longitudinal direction of the flange portion in an obtuse-angled shape, wherein a width of the air flow path is formed to be different at an inner end portion and an outer end portion. .

And the width of the inner end of the air passage is narrower than the width of the outer end.

Wherein the air flow path includes a first region having a width wider from an inner end portion toward an outer direction and a second region having a width formed to be constant from the end point of the first region toward the outer end portion .

And a band fastening portion for fastening a slave shaft and a band for fixing the flange portion is provided on the outer circumferential surface of the flange portion. And the imaginary line at the best end of the band fastening portion and the position of the inside end portion are the same or the inside end portion is disposed outwardly of the best end portion of the band fastening portion.

The air flow path includes: A plurality of inner air flow paths formed on an inner surface of the flange portion inner region and spaced apart from each other, an outer air flow path formed on the outer surface of the flange portion outer region, And a connecting flow path for connecting the plurality of inner air flow paths and the outer air flow path at the same time.

And is inclined with respect to the center line of the flange portion.

And the sum of the widths of all the inner air flow paths connected to the outer air flow path is smaller than the width of the outer air flow path.

And a band fastening portion for fastening a slave shaft and a band for fixing the flange portion is provided on the outer circumferential surface of the flange portion. And the inner end or the best end of the inner air flow passage is arranged so as to be further inserted in the inner direction than the imaginary line at the best end of the band fastening portion.

According to the present invention, since the width of the inner end portion of the air flow path is formed to be narrower than the width of the outer end portion, leakage of grease can be prevented while discharging the high temperature air smoothly.

Particularly, since the air flow path is formed in an obtuse angle, the remaining portion of the inner surface of the flange except the air flow path is interposed between the driven shaft and the driven shaft, thereby improving the sealing performance and maintaining the internal pressure of the joint.

Since high temperature air can be easily discharged, it is possible to prevent the quality of the grease from being adversely affected and minimize the thermal load applied to the internal components of the joint.

Therefore, the durability of the parts can be improved and the grease life can be increased.

On the other hand, in the prior art, since the protrusion processing step is omitted, the cost can be reduced and the internal shape of the boot can be simplified to improve the assemblability.

1 is a side cross-sectional view of a joint to which a boot unit according to the present invention is applied.
2 is a perspective view and a side sectional view of the boot unit of the first embodiment of the present invention.
3 is a perspective view and a side sectional view of a boot unit according to a second embodiment of the present invention.
Figure 4 is a perspective view of a prior art boot unit.
5 (a) and 5 (b) are cross-sectional views showing a state of engagement between the boot unit and the driven shaft of the prior art.
Figs. 5 (c) and 5 (d) are cross-sectional views showing a state of engagement between the boot unit and the driven shaft according to the first embodiment of the present invention.
5 (e) and 5 (f) are cross-sectional views showing a state of engagement between the boot unit and the driven shaft according to the second embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings.

However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises "and / or" comprising "used in the specification do not exclude the presence or addition of components other than the components mentioned.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The constant velocity joint 1 to which the boot unit 100 according to the present invention is applied includes an outer ring 10 connected to a drive shaft 2 such as a drive shaft or a propeller shaft as shown in Fig.

An inner ring 20 in which a track is formed on the outer circumferential surface of the outer ring 10, a ball 30 disposed in the track of the inner ring 20, and a cage 40 do.

A track is also formed on the inner surface of the outer ring 10 and the ball 30 can move between a track on the inner surface of the outer ring 10 and a track formed on the outer surface of the inner ring 20.

The driven shaft 50 is coupled to the inner ring 20, and serrations are formed on the inner peripheral surface of the inner ring 20 and the outer peripheral surface of the coupled portion of the driven shaft 50, and the power can be transmitted.

When the drive shaft 2 and the driven shaft 50 are folded together, the ball 30 moves in the forward and backward direction on the track and transmits the power of the drive shaft 2 to the driven shaft 50.

The inner space 11 of the outer ring 10 is filled with grease for smooth operation of its internal components (inner ring, ball, and cage).

On the other hand, a cover 60 is mounted on the side of the opening 12 of the outer ring 10.

The cover 60 is constituted by a first cover portion 61 which is in contact with the end portion of the outer ring 10 and is bent and a second cover portion 62 which extends from the first cover portion 61, The inner diameter of the cover portion 61 is formed larger than the inner diameter of the second cover portion 62.

A driven shaft 50 passes through the second cover portion 62 and a boot unit 100 is provided between the driven shaft 50 and the inner surface of the second cover portion 62.

The boot unit 100 includes a flange portion 110 to be brought into contact with the surface of the driven shaft 50, a bent portion 120 bent in a curved shape from an end portion of the flange portion 110, And an extension portion 130 extending to be engaged with the second cover portion 62.

The end portion of the second cover portion 62 is bent into a U-shape and is coupled with the extension portion 130 in the form of wrapping the end portion of the extension portion 130 or by a separate band member (not shown) .

A mounting groove 140 is formed on the outer circumferential surface of the flange portion 110. When the driven shaft 50 is inserted and arranged in the flange portion 110, the band can be mounted so that the mounting state can be maintained.

The inner space of the flange portion 110 is divided into a first space region 111 and a second space region 112. The inner diameter of the first space region 111 is formed larger than the driven shaft 50, The inner peripheral surface of the space area 111 is spaced apart from the outer peripheral surface of the driven shaft 50. [

The inner diameter of the second spatial area 112 is substantially equal to the outer diameter of the driven shaft 50 and the inner circumferential surface of the second spatial area 112 is in contact with the driven shaft 50.

2 and 3) 150 and 160 are formed on the inner surface of the flange 110 to guide the high temperature air generated during the heating of the constant velocity joint 1 to the outside.

When the constant velocity joint 1 is rotated at several thousand RPM, the internal temperature of the constant velocity joint 1 is increased due to self heating, which may adversely affect the quality of the grease and may also cause deformation of internal components .

Therefore, it is necessary to form the air flow paths 150 and 160 on the inner surface of the flange portion 110 so that the high temperature air can escape to the outside, while preventing leakage of the grease and preventing the inflow of external moisture.

Fig. 2 shows a first embodiment of the boot unit 100 according to the present invention.

As shown in Fig. 2 (a), an air flow path 150 formed in an engraved (grooved) shape is provided on the inner surface of the flange portion 110. [

The air flow path 150 is preferably formed in a straight shape along the longitudinal direction of the flange portion 110 on the inner peripheral surface of the flange portion 110.

2 (b) and 2 (c) are side cross-sectional views showing a state in which the air flow path 150 is disposed on the inner surface of the flange portion 110. FIG.

The air flow path 150 has an inner end 151 and an outer end 152 and the width of the inner end 151 is narrower than the outer end 152.

The air flow path 150 includes a first flow path region 153 tapered so as to gradually increase in width from the inner end portion 151 toward the outer end portion 152, And a second flow path region 154 extending from the end point toward the outer end portion 152 and having a constant width.

The reason why the width of the inner end 151 of the air flow path 150 is narrow is that the high temperature air generated during the rotation of the joint smoothly escapes but is prevented from leaking out of the grease, Is prevented from flowing into the outer ring through the inner end portion (151).

2 (b), the position of the inside end 151 of the air flow path 150 can be arranged in the outward direction as compared with the position of the best end 140a of the band mounting groove 140 have.

The distance A from the end of the flange portion 110 to the inside end of the air flow path 150 is smaller than the distance D from the end of the flange portion 110 to the best end portion 140a of the band mounting groove 140, Or it is preferable that the two distances are the same as shown in Fig. 2 (c).

The ratio of the width of the inner end portion 151 to the width of the outer end portion 152 is suitably in the range of about 0.3 to 0.5: 1. In this ratio, when the volume of the air in the boot unit 100 expands, It is important not to get out of grease.

To this end, the position of the inner end 151 of the air flow passage 150 is arranged in the outward direction as compared with the position of the best end 140a of the band mounting groove 140.

This is to prevent the leakage of the grease contained in the inner space while keeping the air pressure in the inner space formed by the inner ring (see FIG. 1) 10 and the cover (see FIG.

FIG. 3 shows a second embodiment of the boot unit 100 according to the present invention.

As shown in Figs. 3 (a) and 3 (b), it is preferable that the air flow path 160 according to the second embodiment is provided in the Y shape, but it is not limited to the Y shape, ) Is branched.

The air passage 160 includes a plurality of inner air passages 161 and 162 disposed in an area inside the flange 110 and spaced from each other, an outer air passage 164, a plurality of inner air passages 161 and 162, And a connection passage 163 for connecting the flow paths 164 at one time.

The connecting flow passage 163 is disposed obliquely relative to the central axis of the flange portion 110.

Here, it is preferable that the width of the inner air passage 164 is formed to be constant.

The inner air flow paths 161 and 162 are spaced apart from each other and the connection flow path 163 extending from the inner air flow paths 161 and 162 is converged at the starting point of the outer air flow path 164.

Accordingly, the plurality of inner air flow paths 161 and 162 and the one outer air flow path 164 can be connected.

On the other hand, the sum of the widths of the plurality of inner air flow paths 161, 162 is preferably narrower than the width of the outer air flow path 164.

The reason why the sum of the widths of the inner air flow paths 161 and 162 is formed to be narrower than the width of the outer air flow path 164 is to prevent the high temperature air from escaping smoothly and to prevent leakage of the grease, And moisture is prevented from flowing into the outer ring 10 through the inner ends 161a and 162a. A portion of the end portion of the connecting flow path 163 connected to the inner air flow paths 161 and 162 is equal to the width of the inner air flow paths 161 and 162. The outer air flow path 164, The portion to be connected is formed to be equal to the width of the outside air passage (164).

It is preferable that the inner ends 161a and 162a of the inner air flow paths 161 and 162 are disposed to be inward of the best end 140a of the band mounting groove 140.

The distance C from the end of the flange portion 110 to the inner end portions 161a and 162a of the inner air flow paths 161 and 162 is smaller than the distance C from the end portion of the flange portion 110 to the tip end portion of the band mounting groove 140 Is longer than the distance (D) to the first electrode (140a).

This is to maintain the pressure of the inner space formed by the inside of the outer ring 10 and the cover 60.

The ratio of the sum of the widths of the inner end portions 161a and 162a of the inner air flow paths 161 and 162 to the width of the outer end portion 164a of the outer air flow path 164 is preferably 0.3 to 0.5:

In this embodiment, the ratio between the widths of one inner end 161a or 162a and the outer end 164a is preferably about 0.15 to 0.25: 1. However, when the number of the inner air flow paths 161 and 162 increases, The ratio will vary to that quantity (eg 0.1: 1).

In this case, since the width of the single inside end portions 161a and 162a is significantly narrower than the width of the outside end portion 164, the grease does not easily pass even when air passes through. Therefore, it is preferable that the inner end portions 161a and 162a are disposed so as to be inwardly inward of the best end portion 140a of the band mounting groove 140 to achieve two technical effects of smooth air discharge and prevention of leakage of grease You can help.

4 shows a boot unit 1000 according to the prior art.

4, protrusions 1400 are formed on the inner surface of the flange portion 1100, and two protrusions 1400 are formed to be spaced apart from each other, and a spacing space S3 is formed therebetween. The protrusion 1400 is disposed in the longitudinal direction of the flange portion 1100.

5 (a) and 5 (b) show a state in which the driven shaft 50 is coupled to the boot unit 1000 according to the prior art shown in FIG. 4, and FIGS. 5 (c) 5E and 5F show a state in which the driven shaft 50 is engaged with the boot unit 100 according to the second embodiment. FIG.

5B is a sectional view of the protruding portion 1400 taken along the line AA of the protruding portion 1400. The protruding portion 1400 is cut at a position corresponding to the inner end of the protruding portion 1400, Shape and the interval between the protruding portions 1400 are the same as the inner end or the outer end.

In this state, when the driven shaft 50 is inserted into the flange portion 1100, a part of the inner surface of the flange portion 1000 and the outer peripheral surface of the driven shaft 50 are separated by the protruding portion 1400.

That is, the space S3 between the protrusions 1400 and the upper space S1 of the protrusions and the lower space S2 of the protrusions are formed, through which the grease can be leaked, .

This is because the cross-sectional area of the upper space is relatively large.

5 (c) is a cross-sectional view taken along the line A-A in Fig. 5 (C). In Fig. 5 (C), the position corresponding to the inner end 151 of the air flow path is cut in the first embodiment. The corresponding position is cut off.

As described above, the width of the inner end 151 of the first embodiment is formed to be significantly narrower than that of the outer end 152.

Therefore, it is possible to prevent foreign matter or moisture from entering the inner space of the outer ring 10 and the cover 60 while riding in the air passage.

Since the width of the inner end 151 of the air flow path is very narrow, the air can escape, but the viscous grease can be prevented from escaping to the outside.

Since the air flow path is formed in an obtuse angle, the inner surface of the flange portion 110 can be brought into contact with the outer surface of the driven shaft 50 except for the portion where the air flow path is formed, so that the sealing performance is improved as compared with the prior art .

5 (e) is a cross-sectional view taken along the line A-A in FIG. 5, and FIG. 5 (F) is a cross-sectional view taken along the line A- ) Is cut off at a position corresponding to the position.

As described above, since the internal air flow path (see FIG. 4, 161 and 162) is branched from the external air flow path (see FIG. 4, 164), when the region corresponding to the inside end portions 161a and 162a is cut, A plurality of end portions 161a and 162a (two in this drawing) are formed, and the inner end portions 161a and 162a are spaced apart from each other.

In the second embodiment as well, since the air flow path is formed in a negative angle shape, all the inner surfaces of the flange portion 110 except the air flow path portion can be placed on the outer surface of the driven shaft 50, It can be improved compared to the first embodiment.

The width of the outer end portion 164a of the air flow path is formed to be significantly larger than the sum of the widths of the inner end portions 161a and 162a.

Accordingly, external foreign matter and moisture inflow are prevented, and leakage of grease is prevented, so that air can be smoothly discharged.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be appreciated that one embodiment is possible.

Accordingly, the true scope of the present invention should be determined by the technical idea of the claims.

100: boot unit 110: flange portion
150, 160: air passage 151, 161a, 162a: inner end
152, 164a: outer end

Claims (6)

A flange portion provided in a cylindrical shape and into which a driven shaft is inserted;
A bent portion connected to an end of the flange portion;
An extension part connected to the bending part and spaced apart from the flange part in a radial direction and being in contact with a joint cover provided outside;
An air flow path formed on the inner surface of the flange portion and formed along the longitudinal direction of the flange portion in a negative-
And a band fastening portion for fastening a slave shaft and a band for fixing the flange portion to the outer circumferential surface of the flange portion,
The width of the flow path of the inner region in the air flow path is formed narrower than the width of the outer region,
Wherein a bottom surface of the air flow path is formed in a continuous shape from an inner end portion to an outer end portion,
The point where the width of the air flow passage changes is located in the flange portion inner surface region corresponding to the region where the band fastening portion is located,
Wherein the width of the inner end of the air flow path is narrower than the width of the outer end,
The inner end of the band fastening portion is located at the same position as the imaginary line of the best end of the band fastening portion or the inner end is positioned inward of the best end of the band fastening portion,
The air flow path includes a first region formed in an outward direction at an inner end portion and a second region extending from an end point of the first region to the outer end portion,
The width of the first region increases from the inner end toward the outer direction, the state is continuously maintained toward the outer direction,
And the width of the second region is formed wider than the width of the first region, and the state is maintained in the outer end direction. The method according to claim 1,
Wherein the width of the first region is increased from the inner end toward the outer end and the width of the second region is constantly increased from the end of the first region to the outer end. 3. The method of claim 2,
Wherein the first region is provided in a tapered shape and the width thereof is changed in order. A flange portion provided in a cylindrical shape and into which a driven shaft is inserted;
A bent portion connected to an end of the flange portion;
An extension part connected to the bending part and spaced apart from the flange part in a radial direction and being in contact with a joint cover provided outside;
An air flow path formed on the inner surface of the flange portion and formed along the longitudinal direction of the flange portion in a negative-
And a band fastening portion for fastening a slave shaft and a band for fixing the flange portion to the outer circumferential surface of the flange portion,
The width of the flow path of the inner region in the air flow path is formed narrower than the width of the outer region,
Wherein a bottom surface of the air flow path is formed in a continuous shape from an inner end portion to an outer end portion,
The point where the width of the air flow passage changes is located in the flange portion inner surface region corresponding to the region where the band fastening portion is located,
Wherein the width of the inner end of the air flow path is narrower than the width of the outer end,
The inner end of the band fastening portion is located at the same position as the imaginary line of the best end of the band fastening portion or the inner end is positioned inward of the best end of the band fastening portion,
The air flow path includes:
A plurality of inner air flow paths formed on an inner surface of the flange portion inner region and spaced apart from each other,
An outer air flow path formed on an outer surface of the flange portion outside region;
And a connecting flow path for connecting the plurality of inner air flow paths and the outer air flow path at a time,
The connection channel is disposed in the band fastening region,
The width of the outer air flow path is made wider than the width of the inner air flow path, the state is maintained in the outer end direction,
Wherein a portion of the end portion of the connection passage which is connected to the inner air passage is equal to a width of the inner air passage and a portion of the end portion of the connection passage which is connected to the outer air passage is equal to a width of the outer air passage, . 5. The method of claim 4,
Wherein the connecting flow path is disposed to be inclined with respect to a center line of the flange portion. 5. The method of claim 4,
Wherein the sum of the widths of all the inner air flow paths connected to the outer air flow path is smaller than the width of the outer air flow path.

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