JP2007078170A - Mechanical seal for concentric multi shaft rotating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device applied to a concentric multi shaft rotating device. <P>SOLUTION: Double mechanical seals are respectively mounted between a main body and an outer shaft, and between the outer shaft and an inner shaft, a clearance between a spring seat fixed to the main body and the outer shaft is minimized, an outer shaft seal chamber is divided into two, and a liquid supply hole and a liquid discharge hole are formed on the outer shaft to constitute a liquid supply/discharge system of the seal. The flowing direction of cooling liquid is made constant on the basis of inclination angles of the liquid supply and discharge holes, outer diameters of the liquid supply and discharge holes, and formation of a recessed groove on a liquid supply hole portion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

    The present invention relates to a seal device for a concentric multi-axis rotating device.

    The concentric multi-axis rotating mechanism is a special mechanism that has not been used much except for special cases, and mechanical seals for concentric multi-axis are less reported.

Problems to be solved by the invention

    An object of the present invention is to provide a sealing device applicable to a concentric multi-axis rotating device.

Means for Solving the Invention

    The present invention is a concentric biaxial rotating device comprising a hollow outer shaft 2 that can freely rotate in a main body 1 and an inner shaft 3 that is provided in the outer shaft and can be rotated concentrically independently of the rotation of the outer shaft. The seal of the outer shaft 2 is provided between the main body 1 and the outer shaft 2, the seal of the inner shaft 3 is provided between the outer shaft 2 and the inner shaft 3, and the spring seat 4 of the seal of the outer shaft is attached to the main body 1. The spring seat and spring do not rotate with the outer shaft. The spring seat 5 of the inner shaft seal is mounted on the inner shaft 3, and the spring seat and the spring rotate together with the inner shaft. The gap between the outer shaft seal spring seat 4 and the outer shaft 2 attached to the main body 1 is minimized to divide the seal chamber of the outer shaft seal into two parts. Prevents it from flowing out to the mouth 8 immediately. One of the two-divided seal chambers is referred to as a liquid supply chamber 7 and communicates with the coolant supply port 6 of the main body, and the other is referred to as a drainage chamber 9 referred to as a coolant discharge port 8 of the main body. Communicate. In the hollow outer shaft 2, a seal chamber 10 for the inner shaft seal is formed between both seal surfaces of the inner shaft seal. The outer shaft 2 is provided with a liquid supply hole 11 and a drain hole 12 penetrating at a location corresponding to the liquid supply chamber 7 and the inner shaft seal chamber 10, and the drainage chamber 9 and the inner shaft seal chamber 10. The external coolant is supplied through the liquid supply port 6 and enters the liquid supply chamber 7 to cool the seal surface 13, and then enters the inner shaft seal chamber 10 through the liquid supply hole 11 to cool the seal surfaces 14 and 15. Further, the sealing action of the concentric biaxial rotating device is configured by discharging to the drainage chamber 9 through the drainage hole 12 and cooling the seal surface 16 and then discharging to the outside through the drainage port 8 on the main body.

    When the outer shaft rotates, the through-hole provided in the hollow outer shaft becomes like a blade of a centrifugal pump, which applies centrifugal force to the coolant in the through-hole, and the coolant in the liquid supply hole As a result, the liquid may not be supplied and the seal chamber may be in a vacuum state. This can be solved by increasing the supply pressure of the external liquid, but adding excessive pressure to the seal surface leads to faster wear of the seal ring and shorter life. In order not to discharge the coolant in the liquid supply hole, the angle of the liquid supply hole is inclined in the rotation direction, the angle of the drainage hole is inclined in the opposite direction of rotation, and the rotation direction is at the liquid supply hole on the outer shaft. The liquid supply hole is easy to suck in the liquid, and the drainage hole is easy to discharge the liquid.

    In addition, the external diameter of the drain hole provided on the outer shaft is made larger than the outer diameter of the liquid supply hole, and the centrifugal force of the liquid drain hole is made larger than that of the liquid supply hole, thereby supplying liquid from the outside. Even if the pressure is low, the flow direction is constant.

    In addition, since the liquid supply port and the seal surface at the tip of the outer shaft are separated from each other, there is a possibility that the coolant may not reach the seal surface. When rotating, it carries the coolant to the sealing surface like a nut.

    As shown in FIG. 1, the seal of the outer shaft is stationary, the spring seat 4 and the spring are fixed to the main body, and the stationary rings 17 and 18 are pressed against the rotating rings 19 and 20 fixed to the outer shaft by the spring. The seal surface of the outer shaft is configured by attaching.

    The spring seat 5 of the inner shaft seal is attached to the inner shaft 3, the spring seat 5 and the spring rotate together with the inner shaft 3, the inner shaft seal has no stationary ring, and the sealing surface rotates together with the inner shaft 3. The rotary rings 21 and 22 and the rotary rings 23 and 24 that rotate together with the outer shaft 2 are included.

    The outer shaft seal is divided into two parts by the spring seat 4 and the outer shaft 2, and each seal chamber has a liquid supply port 6, a liquid supply chamber 7, a liquid supply hole 11, a seal chamber 10, a liquid discharge hole 12, a liquid discharge chamber 9, a liquid discharge chamber. The liquid inlet 8 constitutes a coolant supply / discharge system.

    In order to take in and discharge the cooling liquid without hindrance, the angle of the liquid supply hole 11 is inclined in the rotational direction as shown in FIG. 2, and the angle of the drainage hole 12 is inclined in the opposite direction of the rotation. As shown in FIGS. 2 and 3, a groove that is recessed in the rotational direction is formed at the liquid supply hole 11.

    Further, as shown in FIG. 1, the outer diameter of the drainage hole 12 provided in the outer shaft 2 is made larger than the outer diameter of the liquid supply hole 11, and the centrifugal force of the liquid drainage hole 12 is changed to the liquid supply hole 11. By increasing the centrifugal force, the liquid flowing in the liquid supply hole is sucked and the flowing direction becomes constant even when the external liquid supply pressure is lowered.

    Even in the case of two or more concentric multi-shafts, the above-described sealing method can be similarly used only by increasing the number of hollow shafts.

The invention's effect

    According to the present invention, a seal device applicable to a concentric multi-axis rotating device is provided.

  1 is an overall structural diagram of the present invention.   It is sectional drawing which shows the direction of a liquid supply hole and a drainage hole.   It is drawing which shows the groove shape dented in the direction of the rotation direction of a liquid supply hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 2 Outer shaft 3 Inner shaft 4 Outer shaft seal spring seat 5 Inner shaft seal spring seat 6 Supply port 7 Supply chamber 8 Drain port 9 Drain chamber 10 Inner shaft seal chamber 11 Supply hole 12 Drain holes 13, 16 Outer shaft seal surface 14, 15 Inner shaft seal surface 17, 18 Outer shaft stationary seal ring 19, 20 Outer shaft rotation seal ring 21, 22, 23, 24 Inner shaft rotation seal ring 25 Spiral 26 like a screw 26 Recessed groove

Claims (5)

    In a concentric biaxial rotating device comprising a hollow outer shaft 2 that can freely rotate in a main body 1 and an inner shaft 3 that is provided in the outer shaft and can be rotated concentrically independently of the rotation of the outer shaft. The seal of 2 is provided between the main body 1 and the outer shaft 2, the seal of the inner shaft 3 is provided between the outer shaft 2 and the inner shaft 3, and the spring seat 4 of the seal of the outer shaft is attached to the main body 1, The spring seat and spring do not rotate with the outer shaft. The spring seat 5 of the inner shaft seal is mounted on the inner shaft 3, and the spring seat and the spring rotate together with the inner shaft. The gap between the outer shaft seal spring seat 4 and the outer shaft 2 attached to the main body 1 is minimized to divide the seal chamber of the outer shaft seal into two parts, whereby the coolant is discharged from the liquid supply port 6. Prevents it from flowing out to the mouth 8 immediately. One of the two-divided seal chambers is referred to as a liquid supply chamber 7 and communicates with the coolant supply port 6 of the main body, and the other is referred to as a drainage chamber 9 referred to as a coolant discharge port 8 of the main body. Communicate. In the hollow outer shaft 2, a seal chamber 10 for the inner shaft seal is formed between both seal surfaces of the inner shaft seal. The outer shaft 2 is provided with a liquid supply hole 11 and a drain hole 12 penetrating at a location corresponding to the liquid supply chamber 7 and the inner shaft seal chamber 10, and the drainage chamber 9 and the inner shaft seal chamber 10. The external coolant is supplied through the liquid supply port 6 and enters the liquid supply chamber 7 to cool the seal surface 13, and then enters the inner shaft seal chamber 10 through the liquid supply hole 11 to cool the seal surfaces 14 and 15. Further, the mechanical seal for the concentric multi-axis rotating device is characterized in that it discharges to the drainage chamber 9 through the drainage hole 12, cools the seal surface 16, and then discharges to the outside through the drainage port 8 on the main body.     A mechanical seal for a concentric multi-axis rotating device, characterized in that the angle of the through-hole liquid supply hole 11 provided in the hollow outer shaft 2 is inclined in the rotation direction, and the angle of the drainage hole 12 is inclined in the opposite direction of rotation.     A mechanical seal for a concentric multi-axis rotating device, characterized in that the liquid supply hole 11 provided in the outer shaft 2 has a groove recessed in the rotational direction.     A mechanical seal for a concentric multi-shaft rotating device, wherein the outer diameter of the drainage hole 12 provided in the outer shaft 2 is larger than the outer diameter of the liquid supply hole 11.     A mechanical seal for a concentric multi-axis rotating device, wherein the tip of the liquid supply hole 11 of the outer shaft 2 has a spiral shape 25 like a screw.

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