JPH0743493Y2 - Seal structure of spline joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a seal structure of a spline coupling portion, which is applied to a universal joint between an output shaft and a propulsion shaft of a transmission of a vehicle, for example.

[Prior Art] In a universal joint that rotationally connects an output shaft of a transmission and a propulsion shaft, a sleeve of one joint element and the propulsion shaft are connected by a spline so as to be slidable in the axial direction. In order to prevent dust adhering to the outer peripheral surface of the shaft from being caught in the spline fitting part due to relative axial sliding of the sleeve and shaft,
In the spline coupling section disclosed in 59-144225,
The seal member attached to the sleeve end is in sliding contact with the smooth outer peripheral surface of the shaft without splines. Therefore, in the above-mentioned seal structure of the spline joint, it is necessary to provide a smooth shaft portion without a spline of a length corresponding to the sliding length, and the shaft becomes longer by that amount, and the existing spline joint portion Not applicable to. Further, since the seal member slides in contact with the shaft portion and works to remove the dust adhering to the shaft portion to the outside, it is easily worn and its durability becomes a problem.

The seal structure of the spline joint portion disclosed in Japanese Utility Model Laid-Open No. 60-101225 also has a smooth shaft portion without splines so that the inner peripheral edge portion of the bellows-shaped boot mounted between the sleeve and the shaft makes sliding contact. It is not applicable to existing spline joints that are required and do not have a smooth shaft.

[Problems to be Solved by the Invention] In view of the above-mentioned problems, the object of the present invention is to be applied to an existing seal structure of a spline joint portion having no smooth shaft portion,
It is an object of the present invention to provide a seal structure for a spline joint, in which dust and the like are removed by the flow of air, and thus wear of the seal member is reduced.

[Means for Solving the Problem] In order to achieve the above object, the structure of the present invention covers the outer peripheral surface of the end portion of the sleeve and the spline fitting portion of the sleeve and the shaft with a seal ring having an L-shaped cross section. A plurality of blades that are mounted and engage with the outer peripheral surface of the seal ring are arranged side by side in the circumferential direction on the inner peripheral surface of the duct having an L-shaped cross section, and between the end plate of the duct and the end plate of the seal ring, and between the end plate of the duct. A gap is provided between the inner edge and the shaft.

[Operation] When the duct rotates together with the shaft, the blades provided on the inner peripheral surface of the duct serve as a blower, and the air sucked from the end of the duct causes the end plate of the seal ring and the end of the duct. After passing through the gap between the plate and the plate, it is blown out from the gap between the inner edge of the end plate of the duct and the shaft. Therefore, even if dust adheres to the outside of the seal ring, it is removed to the outside by the air flow,
The sliding portion between the seal ring and the spline shaft is kept clean, and the wear life of the seal ring is extended.

[Embodiment of the Invention] FIG. 1 is a side sectional view of a seal structure of a spline joint according to the present invention. The spline shaft 8a of the shaft 8 is fitted into the spline hole 2a of the sleeve 2, and thus the sleeve 2
Is transmitted to the shaft 8 and the shaft 8 is slidable in the axial direction. For example, in a connecting portion between an output shaft of a transmission and a propulsion shaft in a vehicle, the sleeve 2 is a joint element of a universal joint, and the shaft 8 corresponds to the propulsion shaft.

The end surface L is attached to the end portion of the sleeve 2 so that dust does not enter from the outside to the axial sliding portion of the spline hole 2a and the spline shaft 8a.
A letter-shaped seal ring 7 is mounted. That is, in the elastic seal ring 7 made of rubber or synthetic resin, the cylindrical portion 7a is externally fitted to the outer peripheral surface of the end portion of the sleeve 2, the end plate 7b covers the end surface of the sleeve 2, and the inner edge 7c of the end plate 7b is formed. The spline hole is fitted on the spline shaft 8a. The seal ring 7 is connected to the sleeve 2 by any suitable means so as not to move axially with respect to the sleeve 2. When the shaft 8 moves inward (leftward) of the sleeve 2 while dust and the like are attached to the spline shaft 8a, the dust and the like attached to the spline shaft 8a is scraped back by the end plate 7b of the seal ring 7. However, in this situation, the load of the seal ring 7 is large, and the inner edge that engages with the spline shaft 8a is
The sealing function is likely to deteriorate due to wear of 7c.

According to the present invention, the duct 3 having an L-shaped cross section is mounted outside the seal ring 7. A large number of twisted blades 6 circumferentially spaced on the inner peripheral surface of the cylindrical portion 4 of the duct 3 (see FIG. 2).
Are integrally formed, and the tip edge of the blade 6 is externally fitted to the cylindrical portion 7a of the seal ring 7. A gap a is provided between the end plate 7b of the seal ring 7 and the end plate 5 of the duct 3. Further, a gap b is provided between the inner edge of the end plate 5 and the outer peripheral surface of the spline shaft 8a.

According to the present invention, when the duct 4 is rotated together with the sleeve 2, air is sucked into the duct 3 from the end of the cylindrical portion 4 by the blades 6 as shown by an arrow in FIG. It passes between the plate 7b and the end plate 5, and is discharged from a gap b between the inner edge of the end plate 5 and the outer peripheral surface of the spline shaft 8a. Therefore, adhesion of dust or the like to the spline shaft 8a outside the seal ring 7 is prevented, and even if dust or the like is attached, it is blown away by the flow of air. In this way, since the spline shaft 8a is always kept clean, the load on the end plate 7b of the seal ring 7 is reduced and the wear life of the seal ring 7 is extended.

[Effects of the Invention] As described above, the present invention mounts the seal ring having an L-shaped cross section so as to cover the outer peripheral surface of the end portion of the sleeve and the spline fitting portion of the sleeve and the shaft, and A plurality of blades that engage with the outer peripheral surface of the seal ring are arranged side by side in the circumferential direction on the inner peripheral surface, and there are gaps between the end plate of the duct and the end plate of the seal ring and between the inner edge of the end plate of the duct and the shaft. Therefore, as the sleeve rotates, air is sucked in from the end of the duct by the blades of the duct and blown out from the gap between the end plate of the duct and the spline shaft. Dust attached to the spline shaft is eliminated. Therefore, the amount of dust trapped between the seal ring and the spline shaft is reduced, and the wear life of the seal ring is extended. Naturally, the spline fitting portion between the sleeve and the shaft is kept clean, and smooth sliding is maintained.

Since the present invention does not require a smooth shaft portion, it can be applied to the existing spline joint seal structure.

[Brief description of drawings]

FIG. 1 is a side sectional view of a seal structure of a spline joint portion according to the present invention, and FIG. 2 is a perspective view showing the seal structure with a part of a duct removed. 2: Sleeve, 3: Duct, 5: End plate: 6: Blade, 7: Seal ring, 7
b: End plate, 8: Shaft

Claims (1)

[Scope of utility model registration request] 1. A seal ring having an L-shaped section is mounted so as to cover an outer peripheral surface of an end portion of a sleeve and a spline fitting portion of a sleeve and a shaft, and an outer peripheral surface of the seal ring is attached to an inner peripheral surface of a duct having an L-shaped section. A plurality of blades that engage with the surface are arranged side by side in the circumferential direction, and a gap is provided between the end plate of the duct and the end plate of the seal ring, and between the inner edge of the end plate of the duct and the shaft, respectively. Seal structure.