JP2521695Y2 - Propeller shaft - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION The present invention comprises a female spline shaft portion and a male spline shaft portion which is relatively non-rotatable with respect to the female spline shaft portion and which is fitted into the spline so as to be slidable in the axial direction. It relates to a propeller shaft.

[0002]

2. Description of the Related Art In such a conventional propeller shaft, as shown in FIG. 4, the male spline shaft portion 1 does not receive back pressure and the outer female spline shaft portion 8 has a spline shaft hole 9 The end portion of the spline shaft hole 9 opposite to the tip end side of the female spline shaft portion 8 in the axial direction is communicated with the atmosphere through the small vent hole 15 so that the spline shaft hole 9 can enter the inside. Further, a nipple 16 for injecting lubricating grease is provided outside the female spline shaft portion 8, and lubricating grease is supplied from this nipple 16 to a spline engagement surface with a male spline through an oil supply hole 17 provided in the female spline. Was.

[0003]

However, in such a conventional propeller shaft, the end of the female spline shaft portion in the axial direction of the spline shaft hole on the side opposite to the tip side is provided with a small vent hole. Since it is in communication with the atmosphere, the lubricating grease gradually leaks from the small vents, runs out of oil after long-term use, and grease refilling work is required. Further, since the spline meshing surface communicates directly with the outside air through the spline shaft hole and the small ventilation hole, water or dust may enter and cause rust or dirt.

Therefore, an object of the present invention is to obtain a propeller shaft that does not require re-lubrication work on the spline meshing surface and prevents rust and dirt from occurring on the spline meshing surface.

[0005]

In order to achieve this object, the propeller shaft of the present invention has a male spline shaft portion provided with an internal hole coaxial with the male spline shaft portion. The piston element is slidably arranged,
It is characterized in that the end of the internal hole opposite to the tip side of the male spline shaft in the axial direction is communicated with the atmosphere through a small vent hole.

[0006]

According to this structure of the present invention, the piston element is
Since the end of the internal hole in the axial direction opposite to the tip side of the male spline shaft communicates with the atmosphere through the small ventilation hole, the internal pressure change during sliding sliding between the spline shafts Absorbs due to movement within the internal pores. Therefore, the spline shaft portions can slide and slide without resistance.

Further, according to the present invention, the piston element arranged in the inner hole of the male spline has the spline shaft hole of the female spline shaft portion without directly communicating with the atmosphere.
Shut off from the atmosphere.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described with reference to the drawings.

FIG. 1 shows a schematic longitudinal section of a first embodiment of a propeller shaft of the present invention, in which the male spline shaft portion 1 extends from the tip portion 1a to the inner bottom surface of the forked yoke 2. An internal hole 3 that penetrates is provided. A closing cap 4 is provided on the inner bottom surface of the bifurcated yoke 2, and a small vent hole 5 is provided in the closing cap 4. An elongated cup-shaped piston element 6 is arranged in the internal hole 3, and a flange 6a is provided at the end portion of the male spline shaft portion on the side close to the tip. An oil seal 7 is provided on the inner surface of the tip portion 1a of the male spline shaft portion of the inner hole 3.

Spline shaft hole 9 of female spline shaft portion 8
No vent hole is provided in the rear end portion 9a of the spline shaft, and grease is applied to the inner surface of the spline shaft hole 9 or the inside of the spline shaft hole 9 is filled with lubricating oil. Thereafter, the male spline shaft portion 1 having the piston element 6 mounted therein is inserted and fitted into the spline shaft hole 9, and the spline shaft hole 9 is sealed by the oil seal 10 at the tip of the female spline shaft portion 8.

The male spline shaft portion 1 has a spline shaft hole 9
When advancing toward the rear end portion 9a of the male spline shaft portion 1, the air existing in the closed space 11 between the front end portion 1a of the male spline shaft portion 1 and the rear end portion 9a of the spline shaft hole 9 is compressed and the pressure becomes high. However, the air in the atmosphere communicating space 12 in the inner hole 3 of the male spline shaft portion 1 is exhausted through the small vent hole 5, and the piston element 6 retracts into the inner hole 3 of the male spline shaft portion 1. As a result, the pressure in the closed space 11 is maintained constant, and the male spline shaft portion 1 can advance toward the rear end portion 9a of the spline shaft hole 9 without resistance.

When the male spline shaft portion 1 retracts in the direction away from the inner end 9a of the spline shaft hole 9, a small vent hole 5 is formed in the atmosphere communication space 11 of the inner hole 3 of the male spline shaft portion 1. Air is sucked in through the piston element 6 and the piston element 6 projects from the internal hole 3 of the male spline shaft portion 1,
The pressure in the closed space 12 is maintained constant, and the male spline shaft portion 1 can be retracted in a direction away from the inner end portion 9a of the spline shaft hole 9 without resistance.

Since the closed space 11 between the tip portion 1a of the male spline shaft portion 1 and the rear end portion 9a of the spline shaft hole 9 is cut off from the atmosphere communication space 12 by the piston element 6,
Lubricating grease or lubricating oil on the spline meshing surface does not leak from the small air holes 5, and unlike conventional propeller shafts, there is no need to refill the lubricating oil, maintenance is free, and rust and dirt on the spline meshing surface are eliminated. Outbreak disappears.

FIG. 2 shows a schematic longitudinal section of a second embodiment of the propeller shaft according to the present invention. In this embodiment,
Instead of providing the cup-shaped piston element 6 and the oil seal 7, a drum-shaped oil seal piston 60 is provided, and stop rings 13 for preventing the oil seal piston 60 from coming out of the inner hole 3 are provided near both ends of the inner hole 3. The third embodiment is the same as the first embodiment except that the second embodiment is different.

FIG. 3 shows a schematic longitudinal section of a third embodiment of the propeller shaft according to the present invention. In this embodiment,
The inner hole 3 provided in the male spline shaft portion 1 is not a through hole, but a blind hole formed up to the vicinity of the spline portion where the teeth of the spline are formed toward the tip. 2 is different from that shown in FIG. 2 only in that a plurality of radial holes 14 penetrating radially from the vicinity to the male spline shaft portion 1 in the valley portion of the spline are provided at equal intervals in the circumferential direction. This is the same as the second embodiment.

In the case of the third embodiment shown in FIG. 3, a slight clearance between the male spline shaft portion 1 and the female spline shaft portion 8 at the spline meshing surface forms a lubricating oil passage, and the spline shaft portions are mutually inserted and removed. Lubricating oil flows through the spline meshing surface and is lubricated by dynamic suction and extrusion, so that lubrication is efficiently performed.

[0017]

[Effects of the Invention] As described above, by absorbing the internal pressure change during the spline sliding and keeping the internal pressure constant, the sliding resistance is reduced, the seal is stabilized, and the lubricating oil retention characteristic is improved. There is no need for re-lubrication work on the spline meshing surface, and there is an effect that a maintenance-free structure that does not cause rust or dirt on the spline meshing surface can be obtained.

Furthermore, in the case of the embodiment in which the lubricating oil path is the spline meshing surface, the lubricating efficiency is extremely good, and it is possible to obtain the effect that oil running out on the tooth surface can be eliminated and seizure can be completely prevented.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a first embodiment of a propeller shaft according to the present invention.

FIG. 2 is a partially cutaway side view of a second embodiment of a propeller shaft according to the present invention.

FIG. 3 is a side view showing a partially cutaway cross section of a third embodiment of a propeller shaft according to the present invention.

FIG. 4 is a diagrammatic explanatory view of a conventional propeller shaft.

[Explanation of symbols]

 1 Male Spline Shaft 2 Bifurcated Yoke 3 Inner Hole 4 Closing Cap 5 Small Vent 6,60 Piston Element 6a Flange 7,10 Oil Seal 8 Female Spline Shaft 9 Spline Shaft 9a Back End 11 Closed Space 12 Atmosphere Communication space 13 Stop ring 14 Radial hole

Claims (1)

(57) [Scope of utility model registration request] 1. A propeller shaft comprising a female spline shaft portion and a male spline shaft portion which is non-rotatable relative to the female spline shaft portion and is spline-inserted into the female spline shaft portion so as to be slidable in the axial direction. The male spline shaft portion is provided with an internal hole coaxial with the male spline shaft portion, and the piston element is slidably arranged in the internal hole, and the male spline shaft portion in the axial direction of the internal hole is provided. The propeller shaft is characterized in that the end portion on the side opposite to the tip side of the is communicated with the atmosphere through a small ventilation hole.