JP3447918B2 - Sealing device for relative rotating part - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for sealing a relative rotating part of a spindle or the like of a machine tool.

[0002]

2. Description of the Related Art In this type of sealing device,
O-rings and X-rings are used when the peripheral speed of the relative rotating part is low. However, if the peripheral speed of the rotating portion becomes high, these rings may be seized, so a mechanical seal is used in which carbon and silicon carbide are brought into contact with each other for sealing. However, the mechanical seal has a drawback that it is easily worn and easily generates heat, and is therefore unsuitable for a spindle of a machine tool that rotates at a higher peripheral speed.

Therefore, conventionally, a technique has been proposed in which a relative rotating portion such as a main shaft is sealed in a non-contact manner. For example, in Japanese Examined Patent Publication No. 5-85792, as shown in FIG. 3, the liquid flowing out from the gap G between the inner fixed circular pipe 51 and the outer rotary circular pipe 52 is sucked together with the external compressed air 53 by the suction pump 54. There is disclosed a device that prevents liquid leakage by sealing and seals a relative rotating part. Since this sealing device is non-contact, it has an advantage that it can prevent wear and heat generation during high-speed rotation, unlike a mechanical seal.

[0004]

However, according to the above sealing device, the gap G between the fixed circular pipe 51 and the rotating circular pipe 52 is formed.
Has a simple shape and is formed relatively wide (20 to 100 μm), the amount of liquid drained by the suction pump 54 increases, and the liquid supply efficiency of the cooling liquid supply mechanism such as the main shaft decreases. .

Therefore, an object of the present invention is to provide a device capable of efficiently and reliably sealing the relative rotating portion while minimizing the amount of drained liquid in the sealing portion.

[0006]

[0007]

Meanwhile SUMMARY OF THE INVENTION, when the rotating member is relatively rotated portion provided on the inner side, it may become much leakage amount from the sealing portion by the centrifugal force during high-speed rotation. Therefore, in order to avoid the influence of the centrifugal force in the liquid supply mechanism, the sealing device of the present invention has a fixed member assembled to the outside of the rotary member, and a relative rotation for supplying the liquid from the outside of the fixed member to the inside of the rotary member. In the portion, forming a convex portion on the inner circumference of the fixing member, providing a supply passage in the fixing member so as to penetrate the convex portion, forming a labyrinth-shaped fixed seal portion on the side surface of the convex portion, the rotating member, A labyrinth-shaped rotary seal portion that meshes with the fixed seal portion and an inlet communicating with the supply passage are formed, and a discharge passage communicating with the gap between the fixed seal portion and the rotary seal portion is provided in the fixed member, and the discharge passage serves as a suction means. It is configured by connecting (claim 1 ).

Further, in the liquid recovery mechanism, in order to efficiently recover the liquid by utilizing the centrifugal force, in the sealing device of the present invention, the fixing member is assembled on the outer side of the rotating member,
In the relative rotating part that collects liquid from the inside of the rotating member to the outside of the fixed member, a convex portion is formed on the outer periphery of the rotating member, a recovery passage is provided in the rotating member so as to penetrate the convex portion, and a side surface of the convex portion is formed. A labyrinth-shaped rotary seal portion is formed, and the fixed member has a labyrinth-shaped fixed seal portion that meshes with the rotary seal portion, an outlet that communicates with the recovery passage, and a discharge passage that communicates with the gap between the fixed seal portion and the rotary seal portion. And
The discharge passage is connected to the suction means.
2 ).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a spindle of a machine tool will be described below with reference to the drawings. Figure 1 shows the spindle 1
3 shows a sealing device for a relative rotating part in the cooling liquid supply mechanism 2 of FIG. In this relative rotating portion, the fixed member 3 is assembled on the outer side of the main shaft 1 as a rotating member, and the cooling liquid C is supplied from the outer side of the fixed member 3 to the inner side of the main shaft 1.

A seal ring 4 forming a convex portion is inserted into the inner periphery of the fixing member 3, and is retained integrally with the fixing member 3 by a retainer 5. Fixed member 3 and seal ring 4
The cooling liquid C supply passages 6 and 7 are pierced therethrough so as to communicate with each other. Further, labyrinth-shaped fixed seal portions 8 are formed on both side surfaces of the seal ring 4 so that the width becomes narrower toward the inner diameter side.

A sleeve 9 is inserted around the outer periphery of the main shaft 1,
It is integrally connected to the main shaft 1. On the end surface of the sleeve 9 and the stepped surface of the main shaft 1 facing the end surface, labyrinth-shaped rotary seal portions 10 and 11 that mesh with the fixed seal portion 8 of the seal ring 4 are formed. Rotating seal part 10,1
A predetermined gap g is provided between the fixed seal portion 8 and the fixed seal portion 1 in the axial direction of the main shaft 1. Further, the main shaft 1 is formed with an inlet 12 communicating with the supply passage 7 of the seal ring 4.

On the other hand, the fixed member 3 and the seal ring 4 are provided with discharge passages 13 and 14 which are in communication with each other, and seal portions 8, 10, and 1.
It is formed so as to communicate with the first gap g. And
The discharge passage 13 of the fixed member 3 is connected to a suction pump 16 via a pipe 15.

In the sealing device constructed as described above, the cooling liquid C leaking from the relative rotating portion of the cooling liquid supply mechanism 2 is absorbed by the suction pump 16 and the sealing portion 8,
It is discharged to the outside through the discharge passages 13 and 14 through the gap g of 10 and 11. In this case, since the fixed seal portion 8 and the rotary seal portions 10 and 11 mesh with each other in a complicated labyrinth shape, it is possible to minimize the amount of liquid drained by the suction pump 16 and efficiently seal the relative rotary portion. it can.

In the supply mechanism 2, the seal ring 4 is integrally assembled with the fixed member 3 to
Relative rotation part, that is, the supply passage 7 of the seal ring 4 and the spindle 1.
The connection portion with the inlet 12 is set near the axis of the main shaft 1. Therefore, it is possible to reduce the discharge pressure due to the centrifugal force at the time of high speed rotation, and to minimize the amount of liquid leakage from the relative rotating portion.

FIG. 2 shows a seal device for the relative rotating portion of the cooling liquid recovery mechanism 22 of the main shaft 1. In this relative rotating part, the fixed member 23 is assembled on the outer side of the main shaft 1 as a rotating member, and the cooling liquid C is collected from the inner side of the main shaft 1 to the outer side of the fixed member 23.

A seal ring 24 forming a convex portion is inserted around the outer periphery of the main shaft 1 and is retained integrally with the main shaft 1 by a retainer 25. Recovery passages 26 and 27 for the cooling liquid C are provided through the main shaft 1 and the seal ring 24 so as to communicate with each other. Further, on both side surfaces of the seal ring 24, a labyrinth-shaped rotary seal portion 28 having a width narrower on the outer diameter side is formed.

The fixed member 23 is provided with a pair of divided pieces 23a and 23b sandwiching the seal ring 24, and labyrinth-shaped fixed seal portions 30 and 31 which mesh with the rotary seal portion 28 are formed on their relative surfaces. Fixed seal part 30,
A predetermined gap g is provided between the shaft 31 and the rotary seal portion 28 in the axial direction of the main shaft 1. One divided piece 23a
The outlet 3 communicating with the recovery passage 27 of the seal ring 24
2 is formed, and a discharge passage 33 communicating with the gap g between the seal portions 28, 30, 31 is formed in both of the divided pieces 23a, 23b. Then, these discharge passages 33
Is connected to a suction pump 36 via a pipe 35.

In the sealing device constructed as described above, the cooling liquid C leaking from the relative rotating part of the cooling liquid recovery mechanism 22 is attracted by the suction pump 36 and the sealing part 2
It is discharged to the outside through the discharge passage 33 through the gap g of 8, 30, 31. In this case, since the rotary seal portion 28 and the fixed seal portions 30 and 31 mesh with each other in a complicated labyrinth shape, it is possible to minimize the amount of liquid drained by the suction pump 36 and efficiently seal the relative rotary portion. it can.

In the recovery mechanism 22, the seal ring 24 is integrally assembled with the main shaft 1 to
The relative rotating portion, that is, the connecting portion between the recovery passage 27 of the seal ring 24 and the outlet 32 of the fixed member 23 is set at a position far away from the axis of the main shaft 1. Therefore, there is an advantage that the discharge pressure of the cooling liquid C can be increased by utilizing the centrifugal force at the time of high speed rotation, and the recovery efficiency thereof can be improved.

In the above embodiment, the labyrinth-shaped seal portion is provided on the seal ring which is separate from the fixed member or the rotating member, but the seal portion is provided on the convex portion integrally formed with the fixed member or the rotating member. May be . As a further, the present invention such as to apply to the cooling mechanism or lubricating mechanism of various machines,
It is also possible to appropriately change the shape and configuration of each part without departing from the spirit of the present invention.

[0021]

As described in detail above, according to the sealing device of the present invention, since the labyrinth-shaped seal portion is provided on the fixed member and the rotating member, the amount of liquid discharged from the seal portion by the suction means is minimized. This has an excellent effect that the relative rotating portion can be efficiently and surely sealed while being restrained to the limit.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a main shaft showing an embodiment in which a sealing device of the present invention is applied to a relative rotating portion of a cooling liquid supply mechanism.

FIG. 2 is a partial cross-sectional view of a main shaft showing an embodiment in which the sealing device of the present invention is applied to a relative rotating portion of a cooling liquid recovery mechanism.

FIG. 3 is a cross-sectional view showing a conventional sealing device.

[Explanation of symbols]

1 ... Main spindle 2, Coolant supply mechanism 3, Fixing member,
4 ... Seal ring, 6, 7 ... Supply passage, 8 ... Fixed seal part, 10, 11 ... Rotating seal part, 12 ... Inlet, 13, 14 ... Discharge passage, 16 ... Suction pump, 2
2 ... Cooling liquid recovery mechanism, 23 ... Fixing member, 24 ... Seal ring, 26, 27 ... Recovery passage, 28 ... Rotating seal part, 30, 31 ... Fixed seal part, 32 ... Outlet,
33 ... Discharge passage, 36 ... Suction pump, g ...
C ... Coolant.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-266101 (JP, A) JP-A-4-60281 (JP, A) JP-A-2-224945 (JP, A) JP-A-6- 337073 (JP, A) Actually open 53-165146 (JP, U) Actually open 61-91625 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16J 15/40-15 / 447

Claims (2)

(57) [Claims] 1. A fixed member is attached to the outside of a rotary member,
In the relative rotation part that supplies the liquid from the outside of the fixed member to the inside of the rotary member, a convex portion is formed on the inner circumference of the fixed member, and a supply passage is provided in the fixed member so as to penetrate the convex portion, and the side surface of the convex portion. A labyrinth-shaped fixed seal portion is formed on the rotary member, and a labyrinth-shaped rotary seal portion that meshes with the fixed seal portion and an inlet communicating with the supply passage are formed on the rotary member, and the fixed member and the rotary seal portion are formed on the fixed member. A sealing device in which a discharge passage communicating with the gap is provided and the discharge passage is connected to suction means. 2. A fixed member is attached to the outside of the rotary member,
In the relative rotating part that collects liquid from the inside of the rotating member to the outside of the fixed member, a convex portion is formed on the outer periphery of the rotating member, a recovery passage is provided in the rotating member so as to penetrate the convex portion, and a side surface of the convex portion is formed. A labyrinth-shaped rotary seal portion is formed, and the fixed member has a labyrinth-shaped fixed seal portion that meshes with the rotary seal portion, an outlet that communicates with the recovery passage, and a discharge passage that communicates with the gap between the fixed seal portion and the rotary seal portion. And
A sealing device in which the discharge passage is connected to suction means.