JPH0726688B2 - Eccentric shaft seal mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a seal mechanism for an eccentric shaft in a mechanism that drives an eccentric working unit, such as a single-screw pump or an eccentric agitator.

[Conventional technology]

Generally, in a mechanism for driving an eccentric working portion, for example, in a single-screw pump, as shown in FIG. 5, an eccentric shaft 12 (hereinafter, referred to as a driven shaft) for driving an eccentric rotor 10 has a rotating shaft 14 for driving the same. It is configured such that it revolves around (hereinafter referred to as a drive shaft) with a constant inter-axis distance L, and at the same time, it itself rotates in a direction opposite to the revolving direction. Therefore, in such a mechanism, the driven shaft 12 is connected to the drive shaft 14 via the eccentric power transmission mechanism, in this example, the universal joint 16, so that the revolution, that is, the eccentric rotation is allowed. It is configured.

In the uniaxial screw pump, as the rotor 10 is eccentrically rotated as described above, a pumping action is generated between the rotor 10 and the stator 18, whereby the liquid to be handled is sucked into the suction port.
It is discharged from 20 through the discharge port 22 to the outside. The pump is sealed between the drive shaft 14 and the drive shaft 14 by a shaft sealing portion 26 provided in the pump casing 24. Therefore, the universal joint 16 is immersed in the pump handling liquid.
Therefore, the universal joint 16 is coated to prevent direct contact with the handled liquid.

[Problems to be Solved by the Invention]

However, the coating for the universal joint has the following basic drawbacks.

That is, the coating is usually composed of an elastic cover made of rubber or the like, but in general, this type of cover is inferior in corrosion resistance, heat resistance, etc. Therefore, for example, for a solvent or a high temperature handling liquid. There was a difficulty in lacking reliability. Therefore,
It is proposed to use a metal coating excellent in corrosion resistance and heat resistance, for example, a metal bellows instead of the above-mentioned cover. However, in such a metal bellows, the universal joint is generally set to have a large eccentric angle. Therefore, another problem of shortening the service life due to metal fatigue occurs. In this case, if the eccentric angle is set to be small by increasing the distance between the two universal joints, the above problem can be solved, but in this case, the entire pump becomes large and the cost increases. Yet another difficulty arises.

Therefore, an object of the present invention is to connect the eccentric shaft that drives the operating part such as the rotor to the rotating shaft, that is, for the eccentric power transmission mechanism, omit the metal coating required for corrosion resistance and heat resistance, Another object of the present invention is to provide a seal mechanism for an eccentric shaft that can shut off a solution such as a pump handling liquid.

[Means for Solving the Problems]

In order to achieve the above object, the eccentric shaft sealing mechanism according to the present invention includes a rotating shaft and an eccentric shaft that revolves around the rotation of the rotating shaft at a certain distance from the shaft center and at the same time rotates itself. On the eccentric shaft in the vicinity of the connecting portion, a first seal portion arranged around the axis of the rotating shaft and a second seal portion arranged so as to support the eccentric shaft about the axis of the eccentric shaft. A shaft sealing device comprising a seal portion and configured such that the second seal portion is in sliding contact with the first seal portion at a position concentric with the first seal portion.

In this case, the shaft sealing device is arranged so as not to rotate about the shaft center of the rotating shaft, and the eccentric shaft is inserted therethrough.
A hollow fixed ring body having an annular seal surface, a rotary ring body fixed on an eccentric shaft and having a second annular seal surface on one side surface, a hollow portion of the fixed ring body and the eccentric shaft. A driven ring body having first and second annular sliding contact surfaces which are rotatably disposed between and which are in sliding contact with the first and second annular sealing surfaces on both side surfaces, respectively. A first seal portion is constituted by the annular seal surface and the annular slide contact surface, and a second seal portion is formed by the second annular seal surface and the annular slide contact surface.
It is preferable to form the seal part of the above.

[Action]

The connection between the eccentric shaft and the rotary shaft can be shielded from the solution such as the pump handling liquid by the eccentric shaft sealing mechanism. That is, the connection part is not affected by the solution. Therefore, the connection portion is compensated for corrosion resistance and heat resistance. In this case, the liquid contacting parts such as the seal mechanism and the operating part are made of a corrosion resistant and heat resistant material as required.

〔Example〕

Next, regarding the embodiment of the eccentric shaft sealing mechanism according to the present invention,
The following is a detailed description with reference to the accompanying drawings. For convenience of explanation, the same components as those of the conventional example shown in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a sectional view of a main part of a uniaxial screw pump to which an eccentric shaft sealing mechanism according to the present invention is applied. The pump has a driven shaft (eccentric shaft) 12 as a drive shaft, like the pump shown in FIG. (Rotation shaft) 14 is revolved through a universal joint (eccentric power transmission mechanism) 16 while keeping the drive shaft 14 at a fixed distance L from the shaft center, and at the same time, it is opposite to the revolving direction. By rotating in the direction of the axis, a pumping action is generated between the rotor 10 and the stator 18 mounted on the driven shaft 12, whereby the liquid to be handled moves from the suction port 20 to the discharge port (not shown) located in the arrow direction. After that, it is configured to be discharged to the outside.

However, in the single screw pump of the present invention,
An eccentric shaft seal mechanism 30 is provided on the driven shaft 12 in the vicinity of the connecting portion between the driven shaft 12 and the drive shaft 14, that is, the universal joint 16 via a seat 28 mounted on a casing 24 of the pump. . The seat surface of the seat 28 is set around the axis of the drive shaft 14. Further, reference numeral 28a indicates an O-ring.

The eccentric shaft sealing mechanism 30 includes a fixed ring body 32, a driven ring body 34, and a rotating ring body 36. The fixed ring 32 has a seat 28.
Through the insertion bolt 32a and the pressing spring 32b,
That is, the drive shaft 14 is arranged so as not to be rotatable about its axis and biased to the left side in the drawing,
The driven shaft 12 is inserted through the inside thereof, and a first annular seal surface 32c is formed on one side surface. The rotary ring 36 is fixed on the driven shaft 12 and has a second annular seal surface 36a on one side surface.
Has been formed. Reference numeral 36b indicates an O-ring. The driven ring member 34 is rotatably arranged between the hollow portion of the fixed ring member 32 and the driven shaft 12 via roller bearings 34a and 34b, and has the first and second annular sealing surfaces on both side surfaces. First and second annular sliding contact surfaces 34c and 34d which are in sliding contact with 32c and 36a, respectively, are formed. And
As a result, the first annular seal surface 32c and the annular sliding contact surface 3
4c to the first, that is, the seal portion 38 centered on the shaft center of the drive shaft 14, and the second annular seal surface 36a and the annular sliding contact surface 34d to the second center shaft of the driven shaft 12. The seal portions 40 are formed respectively.

In such a configuration, when the driven shaft 12 is eccentrically rotated, the respective seal surfaces and the sliding contact surfaces 32c, 34c and 36a, 34d of the first and second seal portions 38, 40 are always on a constant rotation orbit surface. The shaft seal of the driven shaft 12 is completely achieved by the eccentric shaft seal mechanism 30. As described above, according to the present invention, since the universal joint 16 is completely shut off from the liquid handled by the pump, the liquid contact members such as the rotor 10, the stator 18 and the eccentric shaft seal mechanism 30 may be made of ceramics or metal as necessary. The heat resistance or corrosion resistance of the pump can be completely achieved by using a heat resistant material such as or a corrosion resistant material such as fluororesin or ceramics. Furthermore, since the eccentric shaft sealing mechanism 30 of the present invention can be provided inside the pump casing 24, the pump does not become large.

FIG. 2 shows an embodiment of a uniaxial screw pump to which another eccentric shaft sealing mechanism according to the present invention is applied. The eccentric shaft seal mechanism 50 of the present embodiment is the same as the embodiment shown in FIG. 1 except that the driven ring body is composed of two divided members. That is, the driven ring body 52 is formed of the inner driven ring body 54 and the outer driven ring body 56, and the inner driven ring body 54, the fixed ring body 32, and the driven shaft.
Roller bearing 54a and ball bearing 54b are arranged between 12 and
Roller bearings 56a and 56b are arranged between the outer driven ring body 56 and the inner driven ring body 54 and the driven shaft 12, and between the outer driven ring body 56 and the fixed ring body 32 and the rotating ring body 36. Has first and second seals 38 and 40, respectively. Also in this embodiment, it is clear that basically the same actions and effects as the embodiment shown in FIG. 1 are exerted, and therefore the detailed description will be omitted.

FIG. 3 shows an embodiment of a uniaxial screw pump to which another eccentric shaft sealing mechanism according to the present invention is applied. The eccentric shaft seal mechanism 60 of the present embodiment has the first and second seal portions 38, 40 on the same side surface with respect to the driven ring 70 in the embodiment shown in FIG. That is, the driven ring body 70 composed of two divided members is rotatably disposed in the cylindrical seat 66 between the inner peripheral surface of the seat 66 and the driven shaft 12 via ball bearings 70a and 70b, respectively. The two annular sliding contact surfaces formed on the same side surface of the driven ring body 70 are mounted on the driven shaft 12 and the annular seal surface of the fixed ring body 68 fixed to the projecting end of the seat 66. The rotary shaft 72 is slidably contacted with the ring-shaped sealing surface so that the first and second sealing portions 38, 40 are formed. The sealing portions 38, 40 are given a sealing pressure via the pressing springs 70a, 72a. Also in this embodiment, the first
Since it is clear that the same action and effect as those of the embodiment shown in FIG. 2 or FIG. 2 are exhibited, detailed description thereof will be omitted.

FIG. 4 shows an embodiment of an eccentric agitator to which the eccentric shaft sealing mechanism according to the present invention is applied. In the eccentric stirrer, a driven shaft (eccentric shaft) 12 that drives a stirring blade (actuator) 80 has a drive shaft (rotary shaft) 84 via spur gears (eccentric power transmission mechanism) 82a and 84a.
Is configured to be eccentrically rotated by, and
An eccentric shaft seal mechanism 86 according to the present invention is provided on the driven shaft 82. Reference numerals 82b and 84b denote bearings that support the driven shaft 82 and the drive shaft 84, respectively.

The eccentric shaft seal device 86 is basically the same as the device 30 shown in FIG.
Is a fixed ring body 90 fixed to the seat 88 via a pressing spring 90a in a biased state upward in the figure, and the fixed ring body 90.
90 and a driven ring body 92 rotatably provided to the driven shaft 82 via roller bearings 92a, 92b and a ball bearing 92c,
And a rotary ring body 94 fixed on the driven shaft 82, and a first seal portion 96 is provided between the fixed ring body 90 and the driven ring body 92 and the driven ring body 92 and the rotary ring body. Second seal portions 98 are formed between the body 94 and the body 94, respectively.

According to such a configuration, the drive mechanism including the spur gears 82a, 84a or the drive shaft 84 and the like thereafter is completely shielded from the solution in the stirring blade 80 through the eccentric shaft seal mechanism 86. Even if the solution is, for example, a corrosive solution, it is not affected by corrosion as in a conventional stirring device of this type.

Although the present invention has been described above with reference to the preferred embodiments, the present invention is not limited to these embodiments, and many design changes can be made within the spirit of the present invention. Further, it goes without saying that it can be applied to similar devices other than the pump and the stirrer.

〔The invention's effect〕

As is apparent from the above-described embodiments, the eccentric shaft sealing mechanism of the present invention includes a rotating shaft and an eccentric shaft that revolves around the rotation of the rotating shaft at a constant distance from the shaft center and at the same time rotates itself. On the eccentric shaft in the vicinity of the connecting portion, a first seal portion arranged around the axis of the rotating shaft and a second seal portion arranged so as to support the eccentric shaft about the axis of the eccentric shaft. By providing a shaft sealing device that is composed of a seal portion and is configured such that the second seal portion is in sliding contact with the first seal portion at a position concentric with the first seal portion,
Since the sliding contact surfaces of the first seal portion and the second seal portion are concentric with each other, the contact state thereof is always constant, and the conventional lapping-like contact, swing contact, or the like does not occur. A liquid-tight contact state can be realized without any occurrence.

In particular, when the handling liquid contains solids such as particles, the sliding surface always moves unless it is in the concentric position. If the sliding surface is always in the concentric position and is constant, it is possible to obtain the advantages that particles are hard to be taken in and wear is hard to occur.

Therefore, when the eccentric shaft sealing mechanism of the present invention is applied to, for example, a single-screw pump or an eccentric stirrer having a rotor or stirring blades mounted on the eccentric shaft, a pump handling liquid or stirring solution is conventionally handled in this type of device. It is possible to reliably achieve the cutoff from the handling liquid for the connecting part of each shaft that was immersed in the liquid, and it is possible to omit the metal coating required for corrosion resistance and heat resistance. is there.

Therefore, even when the handled liquid is corrosive or high temperature, unlike the conventional device of this type, it is possible to prevent damage due to corrosion or the like. Further, since the eccentric shaft sealing mechanism of the present invention is formed in a relatively small size, for example, in a pump device, the eccentric shaft sealing mechanism is housed in a normal pump casing and the device is not enlarged.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a uniaxial screw pump to which an eccentric shaft seal mechanism according to the present invention is applied, and FIG. 2 is a sectional view of a main part of a uniaxial screw pump to which another eccentric shaft seal mechanism according to the present invention is applied. FIG. 3 is a sectional view of an essential part of a uniaxial screw pump to which another eccentric shaft sealing mechanism according to the present invention is applied, and FIG. 4 is a sectional view of an essential part of an eccentric agitator to which the eccentric shaft sealing mechanism according to the present invention is applied. Fig. 5 is a cross-sectional view of a conventional single-screw screw pump. 10 ...... Rotor, 12 ...... Driven shaft (eccentric shaft) 14 …… Drive shaft (rotating shaft) 16 …… Universal joint 18 …… Stator, 20 …… Suction port 24 ... Pump casing 28 ... Seat 30 ... Eccentric shaft seal mechanism 32 ... Fixed ring body, 32a ... Insertion bolt 32b ... Press spring 32c ... First annular sealing surface 34 ... Driven ring Body 34a, 34b ...... Roller bearing 34c ...... First annular slide Surface 34d …… Second annular sliding contact surface 36 …… Rotating annular body 36a …… Second annular sealing surface 38 …… First sealing portion 40 …… Second sealing portion 50 …… Eccentric shaft sealing mechanism 52 ...... Driven ring, 54 …… Inner driven ring 54a …… Roller bearing, 54b …… Ball bearing 56 …… Outer driven ring 56a, 56b …… Roller bearing 60 …… Eccentric shaft seal mechanism 62 …… First Seal part 64 …… second seal part 66 …… seat, 68 …… fixed ring body 70 …… driven ring body 70a …… pressing spring 72 …… rotating ring body 72a …… pressing spring 80 …… stirring blade , 82 ...... driven shaft 82a ...... spur gear, 82b …… bearing 84 …… drive shaft, 84a …… spur gear 84b …… bearing 86 …… eccentric shaft seal mechanism 88 …… seat, 90 …… fixed ring body 90a ...... Pressing spring 92 ...... Driven ring 92a, 92b ...... Roller bearing 92c ...... Ball bearing, 94 ...... Rotary ring 96 ...... First seal part 98 ...... Second seal part

Claims (3)

[Claims] 1. An eccentric shaft in the vicinity of a connecting portion between a rotating shaft and an eccentric shaft that revolves around the axis of the rotating shaft at a constant distance from the shaft center and at the same time rotates itself.
A first seal portion arranged around the axis of the rotating shaft,
A second seal portion arranged so as to support the eccentric shaft about the axis of the eccentric shaft, and the second seal portion is in sliding contact with the first seal portion at a concentric position thereof. An eccentric shaft seal mechanism comprising a shaft sealing device configured as described above. 2. A shaft seal device, which is arranged so as not to rotate about the axis of a rotary shaft, inserts an eccentric shaft, and has a hollow fixed ring body having a first annular sealing surface on one side surface. A rotary ring body fixed on the eccentric shaft and having a second annular sealing surface on one side surface, rotatably arranged between the hollow portion of the fixed ring body and the eccentric shaft, and 1 and 2
Driven ring bodies having first and second annular sliding contact surfaces that are respectively in sliding contact with the annular sealing surfaces of the first and second annular sealing surfaces, and the first sealing portion is configured by the first annular sealing surface and the annular sliding contact surface. The eccentric shaft seal mechanism according to claim 1, wherein the second seal portion is constituted by the second annular seal surface and the annular sliding contact surface. 3. The connecting portion between the rotary shaft and the eccentric shaft is composed of an eccentric power transmission mechanism such as a universal joint and a gear train,
The eccentric shaft seal mechanism according to claim 1, wherein the eccentric shaft is configured to drive an operating part such as a rotor or an impeller.