JPH0659629U - Drive shaft - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a drive shaft which can sufficiently extend the lubricant to the spline fitting portion to prolong the life and reduce the number of times of lubrication. In a drive shaft in which an inner shaft and an outer shaft sleeve are spline-fitted to be slidable in a certain range in the axial direction, a recessed portion 15 that opens to the outside is formed in the inner shaft 1, and the recessed portion 15 is deep inside. A small hole is formed so as to communicate with the spline fitting portion space 4 on the outer surface, and a seal 7 having spline teeth 71 formed on the outer periphery is attached to the outer peripheral portion of the inner shaft end. A grease cap 8 having an air hole communicating from the outer peripheral groove to the outside is attached to the shaft, and a small hole 19 communicating with the spline fitting space 4 is formed in the radial direction at the end of the inner shaft 1. And drive shaft.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention aims at extending the service life of a lubricant such as a drive shaft such as a propeller shaft of a vehicle, more specifically, a drive side shaft and a driven side shaft by spline fitting, and lubricating the fitting portion. Regarding the drive shaft that can do.

[0002]

[Prior art]

 As shown in FIG. 4, the drive shaft of the vehicle has a spline 311 formed on the outer surface of the inner shaft 31 on the drive shaft side and a spline formed on the inner peripheral surface of the outer shaft sleeve 32 on the yoke side. 321 is spline-fitted and is connected to the axial direction to some extent so that the rotational torque can be transmitted. The spline fitting portion between the inner shaft 31 and the outer shaft sleeve 32 is designed to seal the lubricant (grease) with a felt seal 33, a dust cap 34 which also serves as a lubricant. However, since the lubricant easily leaks from the air holes 34a of the dust cap 34 and the sealing performance is not so high, frequent lubrication is required. For this reason, it has been proposed to circulate the lubricant in the spline fitting part so that the structure does not require much lubrication. For example, as disclosed in Japanese Utility Model Laid-Open No. 63-34723, a spline shaft (inner shaft side) provided near the seal member and penetrating the wall of the spline yoke (outer shaft side). A seal device for a sliding portion of a propeller shaft having a breather that opens to a spline portion of the propeller shaft and a passage that returns grease (lubricant) escaped to the breather to the grease nipple is known. Has been. Alternatively, as disclosed in Japanese Utility Model Laid-Open No. 60-79094, a closing member is provided at the sliding fitting portion of the spline fitted propulsion shaft and the yoke so as to close the shaft hole. , A bottomed hole is formed in the propulsion shaft, and a piston is fitted in this hole so as to be slidable in the axial direction to form an air chamber on the bottom side of this hole, which is formed between these closing member and piston. A seal structure in a sliding fitting portion of a propulsion shaft and a yoke, which is characterized in that a grease is enclosed in a space, is known.

[0003]

[Problems to be Solved by the Invention] It is preferable that the drive shaft that is spline-fitted reduces the number of times of lubrication to facilitate maintenance as much as possible. For that purpose, it is important to improve the hermeticity. Also, in order to extend the life of the lubricant, the structure must be such that the encapsulated lubricant can be effectively used. The present invention has been made in view of the above problems, and the purpose thereof is that the lubricant is sufficiently spread to the spline fitting portion, so that the encapsulated lubricant can be effectively used and the life is extended. It is to provide a drive shaft that can reduce the number of refueling times.

[0004]

[Means for Solving the Problems]

 That is, in order to solve the above-mentioned problems, the present invention employs a spline fit between an inner shaft and an outer shaft sleeve, and a dust in which an air hole is formed at one spline end of the outer shaft sleeve. In a drive shaft in which a cap is fitted, a sealing seal is fitted at the other end of the spline, and which is slidable in a certain range in the axial direction, a concave portion that opens to the outside is formed in the inner shaft and the outer portion is formed inside the concave portion. A small hole is formed so as to reach the spline fitting part of the inner shaft, and a seal having spline teeth with the same pitch as the outer spline shape of the inner shaft is formed on the outer circumference of the inner shaft end. An outer peripheral groove is formed at the concave end of the shaft, and a grease cap having an air hole communicating from the outer peripheral groove to the outside is attached, and further, the spline teeth of the seal are provided in the radial direction of the concave part at the inner shaft end. And spline mating Characterized in that bored a small hole leading to the space.

[0005]

[Action]

 The operation when the drive shaft of the present invention is used as the above means will be described with reference to the reference symbols in the accompanying drawings (FIGS. 1 to 3). First, the inner shaft 1 and the outer shaft sleeve 2 slide in the axial direction by a certain distance, and the inner shaft 1 and the outer shaft sleeve 2 relatively contract (i.e., the inner shaft 1 moves in the direction of the white arrow). The pressure in the space 10 is high and the pressure in the recess 15 and the space 4 is low when the slide is moved (movement), but the high-pressure air has air holes 6a and the air holes 82 formed in the grease cap 8. The pressure is adjusted by the groove 81 and the small hole 19. That is, the high-pressure air escapes to the outside by the air hole 6a, passes through the air hole 82, the groove 81, and the small hole 19 and passes through the spline fitting space 4 and the small hole 16 into the concave portion 15 and the space 10 and this space. The pressure difference between the spline fitting space 4 and the recess 15 becomes small. Next, when the inner shaft 1 and the outer shaft sleeve 2 slide in a direction in which they relatively extend (that is, the inner shaft 1 moves in the direction of the black arrow), the pressure in the space 10 becomes low, and The air pressure in the space becomes high. In this case, air enters from the outside through the air hole 6a, but the air in the recess 15 escapes from the small hole 16 to the space 10 through the spline fitting space 4, the small hole 19 and the air hole 82. In this case, the lubricant falls into the groove 81 or the groove 81 to the spline fitting space 4 on the lower side and does not flow out. Therefore, the lubricant is sufficiently spread over the splines 11 and 21 of the inner shaft 1 and the outer shaft 2, and the lubricant hardly flows out from the sealed space 4, so that the lubricant lasts a long time.

[0006]

【Example】

 Hereinafter, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an axial sectional view of a drive shaft of the present invention, FIG. 2 is an enlarged view of a portion P of FIG. 1, and FIG. 3 is a view taken in the direction of an arrow Q of FIG. In this drive shaft, a spline 11 is engraved on the outer surface of the inner shaft 1 on the driving side, and a spline 21 is engraved on the inner peripheral surface of the outer shaft sleeve 2 of the driven side yoke. Rotating torque is transmitted so that it can slide in a certain direction in a certain direction. A step portion 12 is formed at the end of the inner shaft 1 and a key groove 13 is provided.

Next, one of the spline fitting portion spaces 4 between the inner shaft 1 and the sleeve 2 is sealed with a felt seal 3.

A hole 14 opening to the outside and a recess 15 having a diameter smaller than the diameter of the hole 14 are formed in the central portion of the inner shaft 1 on the driving side, and a small hole 16 is provided in the back of the recess 15. Are provided so as to communicate with the external spline fitting space 4. A lubricant (grease) G is filled in the recess 15 and the small hole 16. The outer shaft sleeve 2 is provided with a plug hole 22 in which the plug 5 is fitted. When the lubricant is filled, the plug 5 is removed and filled. Further, a dust cap 6 having an air hole 6a is fitted at the end of the outer shaft sleeve 2 to prevent foreign matter from entering and to move the inner shaft 1 and the outer shaft sleeve 2 relative to each other. It acts to adjust the pressure of the internal space 10.

Next, 7 is a seal attached to the end of the inner shaft 1 and made of, for example, an iron rubber or the like, but as shown in FIG. 3, it has the same shape as the outer peripheral spline 11 of the inner shaft 1. Pitch spline teeth 71 are formed on the outer circumference. A convex portion 72 is formed on the seal 7, and the convex portion 72 is fitted in a key groove 13 provided in a step portion 12 formed at the end portion of the inner shaft 1 and attached by a retaining ring 17. Thus, the seal 7 is fixed immovably in both the circumferential direction and the axial direction. The stepped portion 12 of the inner shaft 1 may be provided with a screw so that the seal 7 is "screwed", but in this case, it is necessary to fix the splines at a fixed pitch.

Reference numeral 8 is a grease cap 8 made of, for example, an iron rubber, which is attached so as to close a recess 15 formed in the central portion of the inner shaft 1. A groove 81 is formed on the outer circumference of the grease cap 8, and an air hole 82 communicating from the outer circumference groove 81 to the outside is formed. The grease cap 8 is fixed by a pressing ring 9. The pressing ring 9 is fitted and fixed in an inner peripheral groove 18 formed near the end of the hole 14 provided at the end of the inner shaft 1. Further, a small hole 19 communicating with the outer peripheral groove 81 of the grease cap 8 and the fitting portion between the seal 7 and the splines 11 and 21 is formed near the end of the inner shaft 1. Has been done.

This drive shaft is configured as described above, and when the inner shaft 1 and the outer shaft sleeve 2 are spline-fitted, a space 10 is formed by the dust cap 6 and the inner shaft 1 and the outer shaft sleeve 2. , A space in which a pressure difference between the inner shaft 1 and the recess 15 for filling the lubricant, which communicates with the spline fitting space 4, is generated. In this way, the inner shaft 1 and the outer shaft sleeve 2 slide in the axial direction by a predetermined distance, and the inner shaft 1 and the outer shaft sleeve 2 relatively contract (i.e., the inner shaft 1 is in the direction of the white arrow). The pressure in the space 10 is high and the pressure in the recess 15 and the space 4 is low when the slide hole is moved to the air hole 6a and the air hole formed in the grease cap 8. The pressure is adjusted by 82, the groove 81, and the small hole 19. That is, the high-pressure air escapes to the outside through the air hole 6a, passes through the air hole 82, the groove 81, and the hole 19 and passes through the spline fitting space 4 and the small hole 16 to enter the recess 15 and the space 10. The pressure difference between the spline fitting space 4 and the recess 15 becomes small.

Next, when the inner shaft 1 and the outer shaft sleeve 2 slide in the direction in which they relatively extend (that is, the inner shaft 1 moves in the black arrow direction), the pressure in the space 10 becomes low, The air pressure in the space inside the recess 15 increases. In this case, air enters from the outside through the air hole 6a, but the air in the recess 15 escapes from the small hole 16 to the space 10 through the spline fitting space 4, the small hole 19 and the air hole 82. In this case, the lubricant falls into the groove 81 or the groove 81 to the spline fitting space 4 on the lower side and does not flow out. Therefore, the lubricant is sufficiently spread over the splines 11 and 21 of the inner shaft 1 and the outer shaft 2, and the lubricant hardly flows out from the sealed space 4, so that the lubricant lasts a long time.

[0013]

[Effect of device]

 Since the drive shaft of this invention has the structure described in detail above, not only can the sealability of the splice fitting portion and the lubricant holding space be improved, but also the spline fitting portion can be sufficiently lubricated. You can Then, it will be possible to extend the life of the lubricant while constantly lubricating the spline joint of the drive shaft. Further, the amount of lubricant used can be reduced and the maintenance interval can be lengthened and facilitated.

[Brief description of drawings]

FIG. 1 is an axial sectional view of a drive shaft according to the present invention.

FIG. 2 is an enlarged view of a P part in FIG.

FIG. 3 is a view on arrow Q in FIG.

FIG. 4 is an axial sectional view of a conventional drive shaft.

[Explanation of symbols]

1 Inner shaft 11 Spline 12 Step 13 Key groove 15 Recess 16 Small hole 2 Outer shaft sleeve 21 Spline 3 Sealing seal 4 Spline fitting space 6 Dust cap 6a Air hole 7 Seal 71 Spline tooth 8 Grease -Scap 81 Outer peripheral groove 82 Air hole 10 Dust cap internal space 9 Holding ring 19 Small hole

Claims (1)

[Scope of utility model registration request] 1. An inner shaft and an outer shaft sleeve are spline-fitted, a dust cap having an air hole is fitted into one spline end portion of the outer shaft sleeve, and the other spline end portion is fitted into the dust cap. In a drive shaft in which a sealing seal is fitted and which is slidable in a certain range in the axial direction, a recess opening to the outside is formed in the inner shaft, and a small hole is formed in the recess so as to communicate with the external spline fitting portion. The outer peripheral portion of the inner shaft is provided with a seal having spline teeth with the same pitch as the outer peripheral spline shape of the inner shaft formed on the outer periphery, and an outer peripheral groove is formed at the concave end of the inner shaft. At the same time, a grease cap having an air hole communicating from the outer peripheral groove to the outside is attached, and further communicates with the space between the spline teeth of the seal and the spline fitting in the radial direction of the recess of the inner shaft end. Characterized by drilling small holes And drive shaft.