JP2912698B2 - Rotary body seal structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary body seal structure provided with a seal member for preventing foreign matter from entering.

(Prior art) Conventionally, in such a rotating body sealing structure, although it varies depending on the rotating speed and application of the rotating shaft, a labyrinth packing or grease is used, or a bearing hole and a rotating shaft are used. In general, there are many seal structures in which a bearing hole 2 is provided in a support member 1 and a seal member 3 is fixed in the bearing hole 2 as shown in FIG. Can be seen.

The sealing member 3 used in such a sealing structure
The base end 3a is fixed to the peripheral wall 2a of the bearing hole 2 and the tip 3b is oriented in a direction to close the bearing hole 2.

When the rotating shaft 4 is inserted, the tip 3b of the seal member 3 is forcibly pushed open and bent by the rotating shaft 4, and the tip 3b slides on the outer peripheral surface of the rotating shaft 4 so that foreign matter enters from the bearing hole 2. I try to prevent it.

(Problems to be Solved by the Invention) By the way, in the rotating body sealing structure configured as described above, for example, the one using the labyrinth packing, no sealing action is performed when the rotating shaft is stopped. In the case of using grease, dust adheres and accumulates to cause a rotation failure of the rotating shaft, which is troublesome for maintenance.

Further, in the case where the gap is provided, a sufficient sealing action is not performed. In the case where the seal member 3 is provided, the rotating shaft is in a state where the tip 3b of the seal member 3 is forcibly pushed open. 4 is in sliding contact with the outer peripheral surface,
The friction torque with respect to the rotating shaft 4 was large.

In addition, if there is an error in the diameter of the rotating shaft 4, for example, if the diameter of the rotating shaft 4 is large in the direction in which the seal member 3 is pushed open, the friction torque becomes extremely large, and the diameter of the rotating shaft 4 in the opposite direction is large. Therefore, the dimensional control of the rotating shaft 4 is very troublesome because the sealing effect is reduced.

Further, as shown in FIG. 7, in the case of a structure in which the insertion direction of the rotating shaft 4 can be inserted from the inner side IS of the support member 1 to the outer side OS, the tip 3b of the seal member 3 is 8 is bent toward the external side OS, so that invasion of foreign matter can be satisfactorily prevented. However, as shown in FIG.
FIG. 9 shows a structure in which a small-diameter bearing hole 7 is formed behind a large-diameter bearing hole 6 provided so that the rotary shaft 8 can be inserted only from the outside OS of the support member 5. As shown, the tip 9a of the sealing member 9 is
And the problem that the intrusion of the foreign matter becomes easy is caused.

In view of the above circumstances, the present invention suppresses a change in the contact pressure of the seal member due to an error in the diameter of the rotary shaft, reduces the friction torque between the rotary shaft and the seal member, and further reduces the wear of the seal member. It is an object of the present invention to provide a seal structure of a rotating body that can prevent the rotation.

(Means for Solving the Problems) In order to achieve the object, the invention described in claim 1 is
A rotating shaft is inserted through a bearing hole provided in the support member, a seal member having an annular groove near the tip that can be filled with a lubricant is supported around the bearing hole, and a tapered surface is formed on the periphery of the rotating shaft. When the pressure on the outer side of the support member is higher than the pressure on the inner side of the support member, the tip of the seal member slides on the tapered surface so as to urge against the tapered surface. Is what is being done.

Further, in the invention according to claim 2, at least one of the fixed side member and the rotating side member is formed in a hollow shape, and a seal member for preventing intrusion of foreign matter is provided on one of the opposed end portions facing each other. Provided, the other is formed with a tapered surface,
The seal member is configured such that when the external pressure becomes higher than the internal pressure, the distal end of the seal member is pressed against the tapered surface.

(Operation) In such a configuration, according to the first and second aspects of the present invention, the rotating body can be supported in a state where the bending of the tip of the seal member is minimized.

(Embodiment) An embodiment in which the rotating body seal structure of the present invention is applied to a surveying instrument will be described with reference to the drawings.

In FIG. 1, reference numeral 11 denotes a location where a surveying instrument is mounted, 12 denotes a surveying stand, and 13 denotes an optical distance meter as a surveying instrument. Lightwave rangefinder
13 has a fixing portion 14. The fixed part 14 is provided with a horizontal rotating part 15. The horizontal rotation unit 15 has a pair of support members 16,16.

As shown in FIG. 2, the support member 16 has inner wall surfaces 16a and 16a.
a are provided with bearing holes 17, 17 respectively, and the rotating shafts 18, 18 are inserted through the two bearing holes 17, 17 from the inner side IS of the support member 16 to the outer side OS, and the inner side of the support member 16 is IS, supported via bearings 19, 19 fixed to IS.

The rotating shaft 18 is located at the tip end of the support member 16 that projects to the outside OS.
The diameter of the shaft 18a is set smaller than the diameter of the base 18b located on the inner side IS, and the angle θ (30 ° to 60 °) with respect to the rotation axis P between the front 18a and the base 18b. (Approximately ゜).

In addition, a screw hole 21 is formed in the front end surface of the front end side 18a,
Through this screw hole 21, the telescope 22 is rotated by the left and right rotating shafts 18, 18.
And screwed connection.

On the other hand, in the bearing holes 17, 17, a seal member 23 formed of a ring-shaped elastic body such as rubber, which is thick at the base end 23a side and thin at the front end 23b side, is disposed.

As shown in FIG.
The base end 23a is embedded and fixed in the peripheral wall 17a of the bearing hole 17, and is disposed orthogonal to the axis P of the rotating shaft 18 so that the distal end 23b of the seal member 23 contacts the tapered surface 20. .

Further, when the pressure on the outer side OS of the support member 16 becomes higher than the pressure on the inner side IS of the support member 16, the seal member 23 presses the distal end 23b of the seal member 23 in the direction of the tapered surface 20. In addition, when the rotating shaft 18 is inserted into the support member 16, the direction of the distal end 23b of the seal member 23 is directed to the direction of being pushed out to the external side OS of the support member 16 via the tapered surface 20. ing.

In the above configuration, first, the distal end side 18a of the rotating shaft 18 is inserted from the inner side IS of the support member 16 to the outer side OS.

Then, the rotating shaft 18 is supported by the bearing 19 of the support member 16,
At the same time, the tip 23b of the seal member 23 comes into sliding contact with the tapered surface 20.

At this time, the tip 23b of the seal member 23 is urged toward the outer side OS of the support member 16 by the tapered surface 20.

In addition, the tapered surface 20 may be
, The friction torque that hinders the rotation of the rotating shaft 18 can be reduced.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention, in which a sectional view of a main part is shown.

The seal structure of the rotating body shown in this example shows a seal structure in the case where the rotating shaft 31 is inserted from the outer side OS of the support member 30 to the inner side IS.

That is, while the bearing member 32 is provided with the bearing hole 32, the sealing member 33 formed of an elastic cylinder made of rubber or the like located at the bearing hole 32 and having a thicker base end 33a and a thinner end 33b is provided. Is provided.

The rotating shaft 31 is located on the distal end side of the support member 30 protruding to the outside OS
The shaft diameter of 31a is set larger than the shaft diameter of the proximal end 31b located on the inner side IS, and the tapered surface 34 between the distal end 31a and the proximal end 31b.
have.

The sealing member 33 has a base end portion 33a embedded and fixed in a peripheral wall 32a of the bearing hole 32, and a tip end 33b is connected to the outside OS
So that it is in contact with the tapered surface 34
The axis P of the shaft 31 and the extending direction of the seal member 33 are arranged in parallel.

In such a configuration, the rotating shaft 31 is inserted into the bearing hole 32 from the outer side OS of the support member 30 to the inner side IS.

Then, the sealing member 33 is slidably contacted by the tapered surface 34 without being drawn into the internal side IS from the external side OS of the support member 30.

By the way, the material and the like of the seal members 23 and 33 used in the present invention are not limited to rubber and the like as in the above-described embodiment, and a proper seal material may be used depending on the rotation speed of the rotating shaft and the like. Can be. FIG. 5 (A),
As shown in (B), the tips 23b, 33b
The annular grooves 23c and 33c are formed in the groove (the sealing member may have a double structure), and the annular grooves 23c and 33c are filled with a lubricant G such as grease. Wear and friction torque of the members 23 and 33 can be reduced.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention, and is an enlarged sectional view of a main part.

The seal structure of the rotating body shown in this example is a seal structure at a connection portion between the fixed portion 14 (fixed side member) and the horizontal rotating portion 15 (rotary side member) of the first embodiment. I have.

The fixing portion 14 has a bearing mounting portion 14a at a central portion, and an outer peripheral wall 14b is formed so as to surround the bearing mounting portion 14a.

A cylindrical bearing member 51 that rotatably supports the shaft 50 is screwed to the bearing mounting portion 14a.

In addition, a sealing member 52 made of rubber or the like is provided on the outer peripheral wall 14b of the fixing portion 14 so as to be thick at the base end 52a side and thin at the front end 52b side.

 This seal member 52 is formed in a ring shape.

On the other hand, the upper end of the shaft 50 is fixed to the lower end 16b of the inner wall surfaces 16a, 16a by bolts 53. In the figure, reference numeral 54 denotes a ring for retaining the shaft 50 screwed to the lower end of the shaft 50.

Further, a tapered surface 55 is formed on the lower peripheral wall of the outer walls 16c, 16c of the support member 16.

The seal member 52 has a base end portion 52a embedded and fixed to an end surface 14c of the outer peripheral wall 14b, and abuts against the tapered surface 55 with the distal end 52b protruding toward the support member 16 side.

The taper surface 55 is inclined in a direction in which the seal member 52 faces the external side OS when the support member 16 is mounted and arranged rotatably about the shaft 50 with respect to the fixed portion 14.

Therefore, the seal member 52 is slidably contacted by the tapered surface 55 without being drawn into the inner side (hollow shape) IS from the outer side OS of the support member 16 by the tapered surface 55.

By the way, in the third embodiment, the sealing member 52 is embedded in the fixing portion 14 and fixed, and the tapered surface 55 is formed in the horizontal rotating portion 15. It may be provided.

(Effects of the Invention) As described above, according to the first and second aspects of the present invention, when the external pressure becomes higher than the internal pressure, the distal end of the seal member is urged toward the tapered surface. The sliding contact with the tapered surface so as to suppress a change in the contact pressure of the seal member due to an error in the diameter of the rotating shaft,
The friction torque between the rotating shaft and the seal member can be reduced, and the wear of the seal member can be prevented.

[Brief description of the drawings]

The drawings show an embodiment of the seal structure of the rotating body according to the present invention, FIG. 1 is a front view showing the appearance of a surveying instrument, FIG. 2 is a sectional view of an optical distance meter, and FIG. FIG. 4 is an enlarged sectional view of a main part showing a second embodiment of the present invention, FIG. 5 (A) is an enlarged sectional view of a seal member of the embodiment, and FIG. 5 (B) is a second embodiment. FIG. 6 is an enlarged cross-sectional view of a main part showing a third embodiment of the present invention, and FIGS. 7 to 9 show a conventional rotary body sealing structure. FIG. 8 is a cross-sectional view of a main part in a state where the rotary shaft is inserted, FIG. 8 is a cross-sectional view of a main part before the rotary shaft is inserted, and FIG. 14 ... fixed part (fixed side member) 15 ... horizontal rotating part (rotary side member) 16 ... support member 17 ... bearing hole 17a ... peripheral wall 18 ... rotating shaft 20, 55 ... tapered surface 23, 52: Seal member 23a: Seal member base end 23b: Seal member distal end IS: Inside support member OS: Outside support member

Claims (2)

(57) [Claims] 1. A rotary shaft is inserted into a bearing hole provided in a support member, and a seal member having an annular groove at a tip end thereof capable of being filled with a lubricant is supported around the bearing hole, and a peripheral portion of the rotary shaft is provided. A taper surface is formed on the support member, and when the pressure on the outer side of the support member becomes higher than the pressure on the inner side of the support member, the taper is applied so that the tip of the seal member urges against the taper surface. A seal structure for a rotating body, which is in sliding contact with a surface. 2. A method according to claim 1, wherein at least one of the fixed side member and the rotating side member has a hollow shape, and a seal member for preventing intrusion of foreign matter is provided at one of the opposing ends, and the other is provided at the other end. A tapered surface is formed, and the sealing member
A seal structure for a rotating body, wherein when the external pressure becomes higher than the internal pressure, the tip of the seal member is urged toward the tapered surface.