JP2000161373A - Seal structure of pneumatic rotating device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide excellent dustproof and waterproof effects even when a pneumatic rotating device is used or stopped. SOLUTION: A seal ring 15 having a V-shaped cross section is fixed to an outer peripheral surface of a casing 2, and a lip piece 15a thereof is provided.
Is pressed against the outer peripheral corner of the dustproof cover 12 fixed to the rotating shaft 3 such that a rabbi ring gap 13 is formed with respect to the casing 2. Thereby, when the rotary dresser rotation drive device 1 is stopped, the coolland or the like is prevented from entering the labyrinth gap 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure of a pneumatic rotary device powered by compressed air, for example, a pneumatic rotary dresser rotary drive device for correcting a grinding wheel.

[0002]

2. Description of the Related Art A grinding wheel used for a grinding machine or the like, when a predetermined number of workpieces are ground, the ground surface becomes clogged,
Since uneven grinding causes the grinding efficiency to decrease and the processing accuracy to deteriorate, it is necessary to make regular adjustments (sharpening).

FIG. 4 shows a conventional pneumatic rotary dresser rotation driving device 1 used for modifying a grinding wheel G, with a main portion cut away. The rotating shaft 3 is a pair of left and right ball bearings 4
(The right one is not shown) and is rotatably supported.

[0004] At the left end of the rotating shaft 3 protruding from the casing 2, a rotary dresser 5 having abrasive grains such as diamond fixed to the outer peripheral surface of the tip is attached.

[0005] An air turbine (not shown) is fixed to the rotating shaft 3 in the casing 2, and the compressed air supplied from the air supply pipe 6 is vigorously blown to the air turbine, so that the rotating shaft 3 rotates at high speed. Let me do. Reference numeral 7 denotes an exhaust pipe for air in the casing 2.

At a position near the ball bearing 4 around the left end of the rotating shaft 3, a rotating cover 8 rotating integrally with the rotating shaft 3 and a fixed cover 9 attached to the inner surface of the casing 2 are provided. A dustproof cover 10 is provided, and a labyrinth gap 11 is formed between the covers 8 and 9, the right end of which is open to the ball bearing 4, and the left end of which is open to the rotary dresser 5.

A part of the compressed air supplied to the casing 2 flows into the labyrinth clearance 11 through the clearance of the ball bearing 4 and is discharged from the left end opening. As a result, the sealing performance of the dustproof cover 10 is maintained, and foreign matter is prevented from entering the ball bearing 4 side.

[0008]

The sealing structure of the conventional rotary dresser rotary driving device described above does not cause any problem in the sealing performance during the repair work of the grinding wheel G.

However, in a rotary dresser rotary driving device incorporated and used in a grinding machine or the like, when the rotary dresser is stopped, the discharge of air from the labyrinth gap 11 also stops. Splashes, abrasive grains of the grinding wheel G, chips, and the like may enter the labyrinth gap 11 toward the bearing 4 side, which may accelerate the wear of the bearing 4 or cause variations in the number of revolutions.

In order to prevent such a problem from occurring, it is necessary to continue operating the rotary dresser rotary drive after the correction, or to stop the supply of coolant before stopping the rotary dresser rotary drive. Alternatively, after covering the entire dresser with a cover, it must be stopped and the like, which complicates the operation.

On the other hand, it is conceivable to provide an oil seal or the like in contact with the outer peripheral surface of the rotating shaft 3 on the left side of the bearing 4 instead of the above-described seal structure using the labyrinth gap. Although the sealing effect such as waterproofing is high, there is a problem that the power loss due to frictional resistance is large, the rotation speed is reduced, and frictional heat is generated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a seal structure of a pneumatic rotating device capable of obtaining excellent dustproof and waterproof effects even when the device is stopped as well as when the device is used. It is intended to provide.

[0013]

In order to achieve the above object, a seal structure of a pneumatic rotating device according to the present invention has a rotating shaft portion rotated by compressed air introduced into a casing, and has a rotating shaft. In a pneumatic rotating device provided with a gap through which compressed air can pass between the shaft portion and the casing, in the vicinity of the opening where the compressed air flows out in the gap between the casing and the rotating shaft portion, It is characterized in that an elastic seal member that normally presses and closes the opening and closes the opening when the compressed air is supplied is elastically deformed by the outflow pressure to open the opening. According to the seal structure having the above configuration, when the pneumatic rotation device to which compressed air is not supplied is stopped, the opening of the gap is closed by the elastic seal member, so that there is no possibility that foreign matter enters the gap. In addition, since the rotating shaft does not operate unless compressed air flows in, the elastic seal is less likely to receive frictional force due to relative rotation at the time of starting.

[0014] In the above-mentioned sealing structure, it is preferable that the rotating shaft portion includes a rotating shaft and a dustproof cover, and the elastic seal member is provided in an opening of a gap between the casing and the dustproof cover. According to the seal structure having the above structure, the dustproof cover has a large diameter, so that the elastic seal can be mounted with higher accuracy.

In the above-mentioned sealing structure, one end of the gap is opened on the outer peripheral surface side of the casing and the dustproof cover, and an annular sealing member having a V-shaped cross section is fixed to the outer peripheral surface of the casing. The elastically deformable lip piece is preferably pressed against the outer peripheral corner of the dustproof cover so as to always close the opening of the gap.
By doing so, the surface pressure of the contact surface between the outer peripheral corner of the dust-proof cover and the lip piece is increased, so that the sealing performance when the pneumatic rotation device is stopped is improved, and the pressure due to the compressed air during operation is improved. The lip piece is easily elastically deformed, so that air can flow out of the opening.

In the above seal structure, one end of the gap is
An annular seal member having a V-shaped cross-section is fixed to the outer peripheral surface of the dust-proof cover, and a lip piece that can be elastically deformed inside and outside the casing has an outer peripheral angle of the casing. It is preferable that the portion is always in pressure contact with the opening so as to close the opening of the gap. In this case, in addition to the above-described operation, the centrifugal force of the dust-proof cover is applied at the time of starting, so that the lip is easily elastically deformed. With this structure, the press-contact force to the casing can be initially set large, and the sealing performance when the apparatus is stopped can be further improved.

In the above-mentioned sealing structure, the sealing member having the elastically deformable lip piece is housed in the annular groove formed in the casing or the dustproof cover so that the lip piece always closes the gap. preferable. This prevents the seal member from directly contacting a solution such as a coolant, so that the material is prevented from being deteriorated and the sealing property is impaired.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. The same members as those in the related art are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 shows an example in which the first embodiment of the present invention is applied to a rotary dresser rotary driving device 1 similar to a conventional one. A left end portion of a rotary shaft 3 protruding from a casing 2 is provided with dustproof. The cover 12 is fixed so as to rotate integrally with the rotating shaft 3.

A labyrinth gap 13 is formed between the opposing surfaces of the dust cover 12 and the casing 2, with one end opening on the ball bearing 4 side and the other end opening on the outer peripheral surface of the casing 2 and the dust cover 12. Have been. 14
Is a bearing retainer attached in the cylindrical portion at the left end of the casing 2.

A V-shaped seal ring 15 made of elastic rubber or synthetic resin is fixed to a small-diameter stepped portion 2a formed on the outer peripheral surface at the left end of the casing 2, and its lip piece 15a is dustproof. The right end of the cover 12 is pressed against the outer peripheral corner with an appropriate contact pressure.
Is closed at the open end of the outer periphery. 16 is a fastening wire.

In the first embodiment, when the rotary dresser rotary drive unit 1 is operated by compressed air to repair the grinding wheel, the rotating shaft 3 rotates and at the same time the air passing through the bearing 4 flows into the labyrinth gap 13. I do.
Then, the lip piece 15a of the seal ring 15 is elastically deformed outward by the pressure of air as shown by the imaginary line, and is separated from the dust-proof cover 12 that rotates together with the rotating shaft 3. Thereby, the air that has flowed into the labyrinth gap 13 is discharged to the outside. Therefore, during operation of the rotary dresser rotation drive device 1, foreign substances such as coolant and chips do not enter the labyrinth gap 13.

When the rotary dresser rotation driving device 1 is stopped and the flow of air from the labyrinth gap 13 stops, the lip piece 15a elastically restores inward and again comes into pressure contact with the outer corner of the dustproof cover 12. Since the opening of the labyrinth gap 13 is closed, there is no danger of coolant or the like entering.

Therefore, as in the prior art, the rotary dresser rotation driving device 1 continues to be operated even after the correction work is completed,
There is no need for troublesome work such as stopping the supply of the coolant or covering the rotary dresser rotation drive device 1 with a cover.

FIG. 2 shows a main part of a second embodiment of the present invention. In this embodiment, a seal ring 15 similar to that described above is fixed to the outer peripheral surface on the dustproof cover 12 side, and the lip piece 15a is pressed against the outer peripheral corner at the left end of the casing 2. Let me do it. In the second embodiment, the same operation and effect as those of the first embodiment can be obtained.

The lip 15a tends to be elastically deformed outward due to the centrifugal force when the dust-proof cover 12 rotates. Can be large. As a result, the sealing performance when the rotary dresser rotation driving device 1 is stopped can be improved.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, the inner peripheral surface of the dustproof cover 12 fitted to the cylindrical portion of the casing 2 communicates with the labyrinth gap 13. An annular groove 17 is formed, and an elastic seal ring 18 is provided in the annular groove 17 with a lip piece 18a connected to the inner surface thereof and inclined inward in the air flow direction. 13 is fitted so as to close.

Also in this embodiment, when the rotary dresser rotation driving device 1 is operated, the compressed air flows into the labyrinth gap 1.
When the air flows into the labyrinth 3, the lip 18 a elastically changes outward due to the pressure and discharges air to the outside, so that there is no possibility that foreign substances such as coolant enter the labyrinth gap 13.

When the rotary dresser rotary drive 1 is stopped, the lip 18a is elastically restored inward,
Since the labyrinth gap 13 is closed, the coolant and the like do not enter the seal ring 18 inward.

Further, since the seal ring 18 is accommodated in the dustproof cover 12, the seal ring 18 does not come into direct contact with the coolant or the like, thereby preventing deterioration of the material or the like and deterioration of the sealing performance. be able to.

The present invention is not limited to the above embodiment, but can take various embodiments. For example, in each of the embodiments, the mounting position of the seal rings 15 and 18 is appropriate depending on the shape of the labyrinth gap 13, the casing 2, the dust cover 12, and the like, or the position of the opening end. Also,
In the third embodiment, the seal ring 18 is
It may be provided on the side. The present invention can, of course, be applied to pneumatic rotary devices other than the rotary dresser rotary drive device.

[0032]

According to the present invention, the following effects can be obtained.

(A) According to the first aspect of the present invention, when the pneumatic rotation device in which the sealing property is a problem is stopped, the opening of the gap is closed by the elastic sealing member.
Excellent dustproof and waterproof effects are obtained, and there is almost no possibility that foreign matter enters the gap. In addition, since the rotating shaft does not operate unless compressed air flows in, the elastic seal is less likely to receive frictional force due to relative rotation at the time of starting.

(B) According to the second aspect of the invention, since the dust-proof cover has a large diameter, the work of attaching the elastic seal can be performed with higher accuracy.

(C) According to the third aspect of the present invention, the contact pressure between the dust-proof cover and the lip piece can be increased, so that the sealing property at the time of stoppage is improved and the lip piece at the time of operation is improved. Can be easily elastically deformed to allow air to flow out.

(D) According to the fourth aspect of the present invention, in addition to the effect of (c), the centrifugal force of the dustproof cover is applied at the time of starting, so that the lip piece is easily elastically deformed. With this structure, the pressing force to the casing can be initially set to be large, and the sealing performance when the apparatus is stopped can be further improved.

(E) According to the fifth aspect of the present invention, since the seal member does not directly come into contact with a solution such as a coolant, the material is deteriorated and the sealability is impaired.
It is possible to prevent the durability from being reduced.

[0038]

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a rotary dresser rotation driving device to which a first embodiment of the present invention is applied.

FIG. 2 is a longitudinal sectional front view of a main part of a rotary dresser rotation driving device to which a second embodiment is applied.

FIG. 3 is a vertical sectional front view of a main part of a rotary dresser rotation drive device to which a third embodiment is applied.

FIG. 4 is a partially cutaway front view of a rotary dresser rotation drive device having a conventional seal structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Rotary dresser rotation drive device (pneumatic rotation device) 2 Casing 3 Rotating shaft 4 Ball bearing 5 Rotary dresser 6 Air supply pipe 7 Exhaust pipe 12 Dustproof cover 13 Labyrinth gap 14 Bearing press 15 Seal ring (seal member) 15a Lip piece 16 Tightening Wire with attachment 17 Annular groove 18 Seal ring (seal member) 18a Lip piece

Claims (5)

[Claims] 1. A pneumatic device having a rotating shaft portion rotated by compressed air introduced into a casing, and having a gap between the rotating shaft portion and the casing for allowing compressed air to pass therethrough. In the rotating device, in the vicinity of the opening where the compressed air flows out in the gap between the casing and the rotating shaft portion, the opening is normally in pressure contact with the opening to close the opening, and when the compressed air is supplied, the pressure is caused by the outflow pressure. A seal structure for a pneumatic rotating device, comprising an elastic seal member elastically deforming and opening an opening. 2. The empty space according to claim 1, wherein the rotating shaft portion includes a rotating shaft and a dustproof cover, and the elastic seal member is provided in an opening of a gap between the casing and the dustproof cover. Seal structure of pressure rotating device. 3. An annular seal member having a V-shaped cross section is fixed to the outer peripheral surface of the casing, and one end of the gap is opened on the outer peripheral surface side of the casing and the dustproof cover. 3. The seal structure for a pneumatic rotating device according to claim 2, wherein a possible lip piece is pressed against an outer peripheral corner of the dustproof cover so as to always close the opening of the gap. 4. An apparatus in which one end of the gap is opened on the outer peripheral surface side of the casing and the dust-proof cover, wherein a ring-shaped sealing member having a V-shaped cross section is fixed to the outer peripheral surface of the dust-proof cover and has elasticity inside and outside thereof. The seal structure for a pneumatic rotating device according to claim 2, wherein the deformable lip piece is pressed against the outer peripheral corner of the casing so as to always close the opening of the gap. 5. A sealing member having an elastically deformable lip piece is housed in an annular concave groove formed inside a casing or a dustproof cover such that the lip piece always closes a gap. A seal structure for a pneumatic rotation device according to claim 2.