JPH0771624A - Seal for rotary unit - Google Patents

Abstract

PURPOSE:To achieve extension of a life while obtaining a sufficient seal effect at a rotational speed in a wide range, in a seal for a rotary unit. CONSTITUTION:At the time of low speed rotation, a contact type seal 7 of a seal member 8 is brought into contact with a disk 6 by springs 13. At the time of high speed rotation, since a movable weight 10 is moved in a radial direction by centrifugal force, a movable collar 11 is moved, and the seal member 8, supported through a bearing 12 to the movable collar 11, is also moved to detach the contact type seal 7 from the disk 6 brought into noncontact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal for hermetically sealing between a rotating shaft and a stator which constitute a rotating body.

[0002]

2. Description of the Related Art When a rotating machine such as a motor is used in a bad environment in which water, oil, etc. are scattered, it is necessary to have a waterproof structure so that water, oil, etc. will not enter the rotating machine. At this time, an oil seal is generally used for sealing between the stator of the rotating machine and the rotating shaft. FIG. 6 is a cross-sectional plan view showing an example of a seal of a rotating body using an oil seal. The rotating shaft 3 is rotatably supported by the stator 2 of the rotating machine 1 via a bearing 4. The oil seal 5 is generally in the shape of a ring made of a rubber material and is fitted in a hole through which the rotary shaft 3 of the stator 2 penetrates. Oil seal 5
Since the outer circumference of the is in pressure contact with the stator 2 and the inner circumference is in contact with the rotating shaft 3, the oil seal 5 is held on the side of the stator 2 when the rotating shaft 3 rotates, and the oil seal 5 and the rotating shaft 3 There is a relative speed difference between. According to this structure, since the rotating shaft 3 and the stator 2 are in close contact with each other by the oil seal 5, sufficient sealing is achieved.

FIG. 7 is a cross-sectional plan view showing an example of a seal of a rotary body using a labyrinth seal, corresponding to FIG. 6, and the same components are designated by the same reference numerals and the description thereof will be omitted. The stator 2 is separated into a case 2a and a cover 2b,
The case 2a has a ring-shaped concavo-convex portion 6 concentric with the rotating shaft 3.
a is formed. A disc 6 having a ring-shaped concavo-convex portion 6b concentric with the rotary shaft 3 is fitted into the rotary shaft 3, and the concavo-convex portion 6a of the case 2a and the concavo-convex portion 6b of the disc 6 are alternately in contact with each other. Engages to form a labyrinth structure. The labyrinth seal portion is covered with the cover 2b. The labyrinth seal has a non-contact structure, and at the time of high-speed rotation, the rotation repels water, oil, etc. slightly entering through the gap and has a sufficient sealing effect.

[0004]

In the seal of the rotating body using the above-mentioned oil seal, when the rotating body rotates at a high speed, the rotating shaft contact portion of the oil seal is rotated by friction,
It wears and heats up, significantly shortening the life of the oil seal. Therefore, the oil seal is used as a seal for a rotating body used at a relatively low speed. Also,
In the case of using a labyrinth to seal a rotating body, the effect is reduced when the rotating body is stopped or at a low speed, and a sufficient effect cannot be exhibited. For this reason, the labyrinth seal is used as a seal for a rotating body that is constantly used at high speed. However, motors used in machine tools, etc. are required to be used in a wide range of rotation speeds from low speed rotation to high speed rotation, and are in an environment where cutting fluid and the like are scattered regardless of whether the motor is stopped or rotating. . Therefore, the oil seal structure has a problem of deterioration of the oil seal at high speed rotation, and the labyrinth seal structure has a problem of insufficient sealing effect at low speed rotation and at stop.

The present invention has been made under the above circumstances, and an object of the present invention is to provide a sufficient seal even when the rotating body is stopped and under a wide range of use conditions from low speed rotation to high speed rotation. Another object of the present invention is to provide a seal for a rotating body that exerts an effect and does not cause wear of the sealing material even at high speed rotation.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a seal for sealing between a rotating shaft and a stator which constitute a rotating body, and the above object of the present invention is to provide a radial direction according to the rotation of the rotating shaft. Has a first collar fitted to the rotary shaft, a ring-shaped concavo-convex portion concentric with the rotary shaft, and a contact-type seal, and moves in the axial direction according to the movement of the movable means. And a second collar fitted to the rotary shaft and having a ring-shaped concavo-convex portion that meshes with the concavo-convex portion in a non-contact manner alternately with the concavo-convex portion and the second collar. And a pressing means for axially pressing the sealing means so that the sealing means is brought into contact with.

[0007]

In the present invention, the contact type seal acts as the sealing of the rotating body at the time of stop and low speed rotation, the contact type seal becomes non-contact at the time of high speed rotation, and the labyrinth seal acts as the sealing of the rotating body. It can be used in a wide range of rotation speeds and can have a long life.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a seal for a rotating body according to the present invention.
7 and FIG. 2 is a partial cross-sectional partial perspective view of FIG. 1, and the same components are designated by the same reference numerals and the description thereof will be omitted. A collar 9 having a radial guide groove as shown in FIG. 3 is fitted on the rotary shaft 3, and a movable weight 10 having a guide protrusion that can be inserted therein is arranged in each guide groove of the collar 9. ing. Movable weight 1
The outer peripheral surface of 0 is tapered, and a ring-shaped movable collar 11 having a tapered inner circumference parallel to the outer peripheral surface as shown in FIG. 4 is arranged on the outer circumference of the movable weight 10.

The disk-shaped seal member 8 is supported by the movable collar 11 via the bearing 12, and is guided by the guide 2 by the cover 2c. Therefore, the seal member 8 is rotated even if the movable collar 11 rotates. Does not rotate. The seal member 8 is provided with a ring-shaped concavo-convex portion 6b which is concentric with the rotating shaft 3 and a contact-type seal 7 made of a ring-shaped rubber or the like.
When the rotary shaft 3 is stopped or rotating at a low speed, the seal member 8 is pushed by the spring 13 via the collar 16 toward the disc 6 as shown in FIG. At this time,
The contact-type seal 7 comes into contact with the disk 6, and the rotating body is sealed.

When the rotary shaft 3 is rotating at high speed,
As shown in FIG. 5, the movable weight 10 is moved in the radial direction by centrifugal force, and the movable collar 11 is moved in the direction of arrow A.
At this time, the seal member 8 supported by the movable collar 11 via the bearing 12 also moves in the direction of arrow A, and the contact-type seal 7 is not in contact with the disk 6. It should be noted that the cover 2d has a drain hole 17, and water, oil and the like blocked by the uneven portions 6a and 6b or the contact type seal 7 flow on the circumference and are drained from the drain hole 17. There is a gap 18 between the cover 2d and the seal member 8, and the diaphragm 14 blocks the entry of water, oil, etc. into the inside of the rotating body from here.

[0011]

As described above, according to the seal for a rotating body of the present invention, the contact type seal acts as a sealing of the rotating body at the time of stop and low speed rotation, and the contact type seal becomes non-contact at the time of high speed rotation. Since the seal acts as a sealing of the rotating body, a long-life rotating body seal that can be used in a wide range of rotation speeds can be obtained, and application to machine tools and the like becomes easy.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing an example of a seal for a rotating body of the present invention.

FIG. 2 is a partial cross-sectional partial perspective view of FIG.

FIG. 3 is a perspective view showing an example of a main part of FIG.

FIG. 4 is a perspective view showing an example of another main part of FIG.

5 is a cross-sectional plan view showing an example of the operation of the seal shown in FIG. 1. FIG.

FIG. 6 is a cross-sectional plan view showing an example of a conventional seal for a rotating body.

FIG. 7 is a cross-sectional plan view showing another example of a conventional seal for a rotating body.

[Explanation of symbols]

 1 Rotating Machine 2 Stator 3 Rotating Shaft 4 Bearing 5 Oil Seal 6 Disc 7 Contact Seal 8 Sealing Member 9 Color 10 Movable Weight 11 Movable Collar 12 Bearing 13 Spring 14 Diaphragm 15 Guide 16 Color 17 Drain Hole 18 Clearance 2a Case 2b Cover 2c case 2d cover 6a uneven part 6b uneven part

Claims (1)

[Claims] 1. A seal for sealing between a rotating shaft and a stator, which constitutes a rotating body, has movable means that moves in a radial direction in accordance with the rotation of the rotating shaft, and is fitted into the rotating shaft. No. 1, a ring-shaped concavo-convex portion concentric with the rotating shaft, and a contact-type seal, and a seal means that moves in the axial direction according to the movement of the movable means, and a ring that meshes with the concavo-convex portion without contact. Has a concave and convex portion,
Rotation comprising: a second collar fitted to the rotating shaft; and pressing means for axially pressing the sealing means so as to bring the contact-type seal into contact with the second collar. Body seal.