JPH0525312Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of a sealing device for a sliding portion of a propeller shaft of an automobile.

(Prior Art) An automobile propeller shaft includes a sliding part in which a spline shaft is slidably engaged within a sliding yoke. A grease nipple is provided for injecting grease into the sliding portion, and a sealing member is provided between the end of the sliding yoke and the spline shaft to prevent foreign matter from entering the sliding portion. However, the grease in the sliding part accumulates inside the sealing member due to the sliding movement of the spline shaft, and the compressive force of this accumulated grease pushes out the sealing member, reducing the sealing performance. This has the disadvantage that the spline shaft may wear out or become unbalanced, making the movement of the spline shaft unsmooth.

(Objective of the invention) An object of the invention is to provide a sealing device for a propeller shaft sliding portion that can prevent grease from accumulating on the sealing member and thereby prevent deterioration in sealing performance.

(Structure of the invention) A sealing device for a sliding part of a propeller shaft to which the invention is applied has a grease nipple for injecting grease into the sliding part of a propeller shaft, and seals between an end of a sliding yoke and a spline shaft. The member is provided with a breather which is provided close to the seal member and penetrates the wall of the sliding yoke and opens into the spline portion of the spline shaft, and a grease passageway which returns grease escaping to the breather to the grease nipple. It is characterized by

In this way, when the grease accumulated on the sealing member is compressed and its pressure increases, this pressure is released by the breather and some of the grease is returned to the grease nipple, so the sealing member will not be destroyed. , therefore, there is no reduction in sealing performance.

(Embodiment) An embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 shows a sealing device 10 for a propeller shaft sliding portion according to the present invention, and a propeller shaft sliding portion 12 is a sealing device 10 for a propeller shaft sliding portion according to the present invention. It consists of a sliding yoke 14 and a spline shaft 16 that is slidably engaged within the sliding yoke 14. This propeller shaft sliding section 12 has a grease nipple 18 that injects grease 13 into this sliding section 10. have The sealing device 10 connects the end of the sliding yoke 14 and the spline shaft 1.
It consists of a sealing member 20 provided between 6 and 6. In FIG. 1, reference numeral 22 is a universal joint provided at the end of the sliding yoke 14, and reference numeral 24 is a plug provided at the end of the sliding yoke 14 on the side of the universal joint 20.

The seal device 10 of the present invention includes a breather 26 which is provided close to the seal member 20 and penetrates the wall of the sliding yoke 14 and opens into the spline portion 16a of the spline shaft 16. 18. Breather 2
6, as shown in FIG. 2, comprises a ball valve 30 that closes the through hole 14a passing through the wall of the sliding yoke 14, and a spring 32 that normally biases the ball valve 30 to close. In FIG. 2, reference numeral 34 is a nut connecting the breather 26 to the grease passage 28.

Since the breather 26 is located close to the seal member 20 in this way, when the grease 13 is accumulated on the seal member 20 side due to sliding of the spline shaft 16 and its compressive force becomes large, the ball valve 30 of the breather 26 springs. 32 and releases the grease 13 into the grease passage 28, the sealing member 20 is not pushed out by the compressive force of the grease 13.
Therefore, there is no reduction in sealing performance. It should be noted that both the breather 26 and the grease passage 28 are necessary, and if only the breather 26 is used, the grease 13 easily escapes from the breather 26, reducing the ability to retain the grease, and if only the grease passage 28 is used, When the spline contracts, the grease tends to flow back, making it difficult for the same grease to spread throughout the sliding parts.

(Effects of the invention) According to the invention, as described above, when the grease accumulated in the sealing member is compressed and its pressure increases, this pressure is released by the breather and a part of the grease is pushed into the grease nipple. Since the sealing member is returned, the sealing member is not destroyed, so there is no deterioration in sealing performance, and there is a practical advantage that the grease can be retained effectively and sealing can be performed effectively without causing backflow.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a sealing device for a propeller shaft sliding portion according to the present invention, and FIG. 2 is an enlarged sectional view of a breather used in the present invention. 10... Seal device, 12... Propeller shaft sliding part, 13... Grease, 14... Sliding yoke, 16... Spline shaft, 18
... Grease nipple, 20 ... Seal member, 26
... Breather, 28 ... Grease passage, 30 ... Ball valve, 32 ... Spring.

Claims (1)

[Claims for Utility Model Registration] (1) A spline shaft is slidably engaged in the sliding yoke of the propeller shaft, and the sliding yoke has a grease nipple for injecting grease into the sliding part of the propeller shaft. In a sealing device for a propeller shaft sliding part, in which a sealing member is provided between an end portion and the spline shaft, the spline of the spline shaft is provided near the sealing member and passing through a wall of the sliding yoke. 1. A sealing device for a sliding part of a propeller shaft, comprising: a breather opening in the sliding part of the propeller shaft; and a grease passage for returning grease escaped into the breather to the grease nipple. (2) The breather comprises a ball valve that closes a through hole penetrating the wall of the sliding yoke, and a spring that normally biases the ball valve to close. The sealing device for the sliding part of the propeller shaft described above.