JPH0321863Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to an oil seal press-fitting device.

(Prior art) When press-fitting an oil seal into an annular hole formed by a shaft and a housing surrounding it, for example, an oil seal contacting body that supports the oil seal, and a shaft and a housing placed against the said contacting body. For example, a press-fit device as shown in Japanese Unexamined Patent Publication No. 54-83188 is used, which includes a press-fit tool for insertion. Of course, it is also conceivable to support the housing side, push the abutting body, and press-fit the oil seal.

Incidentally, oil seals are often used in pairs with bearings, but if a bearing that blocks airflow on both sides of the bearing is press-fitted first, the annular hole is closed at the back by the bearing, forming a bag-like shape. This means that When press-fitting an oil seal into such a bag-shaped annular hole, the air inside the annular hole is compressed by the oil seal, and after the press-fit is completed, the oil seal protrudes from the annular hole due to the repulsive force of the compressed air. There is.

(Purpose of the invention) The present invention aims to prevent the oil seal from returning after being press-fitted in a device that press-fits an oil seal into a bag-shaped annular hole formed by a shaft and a housing around it. be.

(Structure of the invention) The oil seal press-fitting device of the invention includes an oil seal abutting body that moves relative to the bag-shaped annular hole and press-fits the oil seal into the annular hole, and an oil seal abutting body provided on the oil seal abutting body. It has an arc shape along the circumference of the shaft, and is inserted between the oil seal and the shaft when the oil seal is press-fitted to communicate the inside and outside of the annular hole. The pressure inside and outside the annular hole is kept constant by venting air from the gap.

(Example) Hereinafter, the configuration of the present invention will be explained based on the drawings for an example.

FIG. 1 shows the overall structure of an apparatus for press-fitting an oil seal 1 and a bearing 2 into a housing 4 surrounding a shaft 3. That is, this press-fitting device includes a housing presser 7 attached to the piston rod 5 of the press-fit ram via a connecting member 6, a bearing presser 8 supported by the housing presser 7, and these pressers 7,
The oil seal 1 and the housing 4 have an abutting body 9 facing upward facing the oil seal 1 and the housing 4, and a shaft holder 10 for receiving the lower end of the shaft 3 inserted therethrough.

The housing pressing tool 7 has a housing press-fitting head 11 at its lower end for pressing the upper end surface of the housing 4. Bearing press tool 8
is provided inside the bearing pressing tool 7 so as to be biased downward by a spring 12 so as to be movable up and down.
Further, the lower limit position is regulated by a stopper 13, and a bearing press-fit head 14 for pressing the inner ring of the bearing 2 is provided at the lower end thereof.
In addition, a center shaft 15 for vertically positioning the shaft 3 is provided in the center through hole of the bearing pressing tool 8.
is biased downward by a spring 16 and inserted so as to be movable up and down.

The connecting member 6 is provided with a spacer block 17 which restricts and releases the upward movement of the bearing presser 8 and is movable horizontally from the outside by means of a cylinder device 18. As shown in FIG. 2, this spacer block 17 is formed in a U-shape so that it can enter the inside of the connecting member 6 while avoiding the springs 12 and 16, and when it enters, the bearing pressing tool 8 is pushed upward. The end faces abut against each other, and relative upward movement with respect to the housing presser 7 is restricted.

On the other hand, the contact body 9 of the oil seal 1 and the housing 4 has a substantially U-shaped cross section in order to allow the shaft 3 to move in and out in a vertical position, as shown in FIG. Horizontal guide rail 1
It is elastically supported via a spring 22 by a slide support base 21 which is movably provided at 9 with a cylinder device 20. An oil seal guide 23 that guides the oil seal 1 from the outside during press-fitting is fitted onto this contact body 9, and this oil seal guide 2
A housing receiving jig 24 for receiving the housing 4 is fitted onto the housing 3. The oil seal guide 23 and the housing holder 24 both have a cross section U like the oil seal/housing contact body 9.
It has a letter-shaped shape, is biased upward by springs 25 and 26, and is movable up and down, and a regulating pin 27 restricts the vertical movement distance. In this case, there are guide grooves 28 at three locations on the outer periphery of the abutting body 9 of the oil seal and the housing, and a guide protrusion 29 that is guided by the guide groove 28 is provided on the inner periphery of the oil seal guide 23. Projection 29
guides the oil seal 1 from the outside.

An arcuate projection 30 extending along the circumferential surface of the shaft 3 is fixed to the oil seal/housing abutment body 9 at its inner peripheral edge position so as to protrude upward. As shown in FIG. 4, this protrusion 30 is longer than the vertical length of the abutting surface of the inner lip 1a of the oil seal 1 against the shaft 3, and is thin enough to be inserted between the lip 1a and the shaft 3. The tip is tapered.

Further, the shaft holder 10 below the slide support 21 includes an upper holder 10a and a lower holder 10b of different heights in consideration of application to shafts of different lengths, and a cylinder holder 10 on the support plate 31. device 32
The support plate 31 further includes a shaft holder 10 for the shaft 3.
A cylinder device 33 is connected thereto for receiving (supporting) and releasing the support.

Next, the press-fitting of the bearing 2 and the oil seal 1 by the press-fitting device described above will be explained.

First, as shown in Fig. 1, the oil seal 1 is fitted to the shaft 3, the bearing 2 is assembled to the housing 4, the shaft 3 is fitted into the oil seal and bearing abutting body 9, and the lower end is attached to the shaft. The housing 4 is supported on a pedestal 10, and the housing 4 is supported on a housing holder 24. Also, move the spacer block 17 forward and press the bearing presser 8.
We will regulate the upward movement of

Then, when the press-fit ram is lowered, bearing 2
The inner ring is pressed by the bearing press-fitting head 11 and press-fitted into the shaft 3. At this time, the housing 4 is also lowered at the same time, and the oil seal 1, which has been fitted in advance on the shaft 3, is pushed down by the housing 4, and the oil seal/housing contact body 9
It fits on the outer circumferential side of the protrusion 30. Then, the oil seal 1 comes into contact with the contact body 9 and its downward movement is restricted, and a part of the oil seal 1 fits into the lower end of the housing 4, resulting in the state shown in FIG. 5.

That is, by press-fitting the bearing 2, a bag-shaped annular hole 34 whose upper side is closed by the bearing 2 is formed between the shaft 3 and the housing 4, and a part of the oil seal 1 is inserted into this annular hole 34. It will be in a stuck state.

Next, the press-fitting ram is raised, the spacer block 17 is moved back, and the upper movement restriction of the bearing presser 8 is released, and the shaft holder 10 is moved back to release the support for the lower end of the shaft 3, and the press-fitting ram is moved back. Lower it again. This time, due to the release of the upward motion restriction, there is no pressing action by the bearing press-fitting head 14, and the housing press-fitting head 11 moves toward the housing 4.
is pushed down together with the shaft 3, and the oil seal 1 supported by the oil seal/housing contact body 9 is relatively press-fitted into the annular hole 34.

At this time, the oil seal/housing contact body 9
The projection 30 will be inserted relatively between the shaft 3 and the lip 1a of the oil seal 1 as the shaft 3 descends. 30 is a protrusion 3 between the shaft 3 and the oil seal 1 for air venting that communicates the inside and outside of the annular hole 34.
Formed on both side edges of 0. Therefore, as the oil seal 1 is press-fitted, the air inside the annular hole 34 is discharged from the gap without being compressed. It does not protrude from the hole 34.

The press-fitting of the oil seal 1 is completed when the lower end of the housing 4 comes into contact with the oil seal/housing contact body 9 as shown in FIG. Be on the same page. After the press-fitting is completed, the press-fitting ram is raised and the shaft 3 is removed from the oil seal/housing contact body 9.

Therefore, in the case of the above embodiment, since the inner ring of the bearing 2, which has been assembled in advance in the housing 4, is pressed into the shaft 3, no thrust load is substantially applied between the inner ring and the outer ring of the bearing 2 during press-fitting. Therefore, damage to the bearing 2 is not caused. Moreover, by regulating the upward movement of the bearing presser 8 by the spacer block 17 and releasing it, and by supporting the shaft 3 by the shaft holder 10 and releasing it, the bearing 2 and the oil seal 1 can be press-fitted with one press-fitting device. This can be done without changing the position of the shaft 3. In this way, by removing air when the oil seal 1 is press-fitted, the oil seal 1 can be smoothly press-fitted and the press-fitted state can be maintained.

In the above embodiment, the protrusion 30 that is inserted between the shaft 3 and the oil seal 1 is formed of a single thin piece, but a plurality of protrusions are provided at intervals, and the shaft 3 and the oil seal 1 are inserted between each protrusion. A gap may be formed between them.

Further, in the above embodiment, the protrusion 30 forms an air vent gap that communicates the inside and outside of the annular hole 34 from the time when the oil seal 1 starts being press-fitted.
Even if the above-mentioned gap is created at the time of completion of press-fitting, it is effective in preventing the oil seal from protruding after completion of press-fitting.

In addition, in the case of the above embodiment, the oil seal/housing contact body 9 was basically fixed and the annular hole side was moved, but the annular hole side was fixed and the oil seal contact body moved toward the annular hole. A method may be adopted in which the oil seal is press-fitted by moving the oil seal, and a projection forming the gap may be provided on the oil seal abutting body on the moving side.

(Effects of the invention) According to the invention, when an oil seal is press-fitted into the annular hole formed by the shaft and the housing, the protrusion is inserted between the shaft and the oil seal, and the protrusion is inserted between the shaft and the oil seal, and the protrusion is inserted between the inside and outside of the annular hole. For communicating air bleed
Since the gap is formed, the air inside the annular hole is discharged from the gap, and the oil seal does not protrude from the annular hole after press-fitting is completed.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal cross-sectional view of the press-fitting device, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1. Plan view from arrow view,
Fig. 4 is a longitudinal sectional view showing the relationship between the shaft, oil seal, and gap-forming protrusion, Fig. 5 is a longitudinal sectional view partially omitting the press-fitting device at the time of completion of bearing press-fitting, and Fig. 6 is the oil seal. It is a longitudinal cross-sectional view showing the press-fitting device at the time of completion of press-fitting, with some parts omitted. 1...Oil seal, 2...Bearing, 3...
...Shaft, 4...Housing, 9...Oil seal/housing contact body, 11...Housing press-fit head, 14...Bearing press-fit head, 30
... protrusion, 34 ... annular hole.

Claims (1)

[Scope of utility model registration request] A device for press-fitting an oil seal into a bag-shaped annular hole formed by a shaft and a housing around the shaft, and an oil seal contacting body that press-fits the oil seal into the annular hole by moving relative to the annular hole. Between the shaft and the oil seal, there is an air bleed gap that has an arc shape along the circumference of the shaft and is inserted between the shaft and the lip of the oil seal to communicate the inside and outside of the annular hole when the oil seal is press-fitted. An oil seal press-fitting device characterized by being provided with a protrusion that is formed on the oil seal press-fitting device.