JP2001317638A - Seal structure and compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure and a compressor in which the constitution for preventing leak of gas dissolved in high pressure gas and lubricating oil as much as possible to the outside is positively adopted. SOLUTION: This seal structure has a rotating seal (a shaft side seal member) 7 and a fixed seal (a housing side seal member) 6, an annular groove (a recess) 12 for holding lubricating oil is formed in the rotating seal 7, and both end surfaces are pressed each other to seal a housing, and the annular groove 12 is formed in the vicinity of the outer edge of the rotating seal 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure suitable for a rotary shaft of a compressor or the like used for a car air conditioner, a home air conditioner, etc., and more particularly to a mechanical seal. Further, the present invention relates to a compressor having such a seal structure.

[0002]

2. Description of the Related Art Conventionally, mechanical seals (seal structures) have been widely used for the purpose of sealing (sealing) a rotating shaft. FIG. 14 shows the mechanical seal 5 provided for the rotating shaft of the compressor. In this figure, reference numeral 1 denotes a fixed housing of the compressor, and 2 denotes a rotating shaft. The outside 3 of the housing 1 is atmospheric, and the inside 4 of the housing 1 is a high-pressure chamber filled with a high-pressure gas A. The rotating shaft 2 is provided so as to penetrate the housing 1.
In order to prevent the high pressure gas A from leaking to the outside 3, a mechanical seal 5 is provided. The mechanical seal 5 includes a fixed seal (housing-side sealing member) 6 attached to the housing 1, a rotating seal (rotating-shaft sealing member) 7 attached to a rotating shaft, and a rotating seal 7
And a preload spring 8 for applying a preload so as to always contact the stationary seal 6. Also, the rotating shaft 2
While the is rotating, a lubricating oil supply line 10 for supplying lubricating oil to the sealing surface 9 formed between the fixed seal 6 and the rotating seal 7 is provided.

In the above structure, when the compressor is driven,
The rotating shaft 2 rotates, and the compression medium is compressed by a compression mechanism (not shown) attached to the tip of the rotating shaft 2. While the rotating shaft 2 is rotating, lubricating oil is supplied to the sealing surface 9 from the lubricating oil supply line 10, and in this state, the high-pressure gas A is reliably sealed on the sealing surface 9. It has become. However, when the compressor is not operating, that is, when the rotating shaft 2 is stationary, the pump for supplying the lubricating oil is also stopped, so that the lubricating oil is supplied from the lubricating oil supply line 10 to the seal surface 9. Will be stopped. Therefore, when the rotating shaft 2 is stationary for a long time,
There is a problem that the lubricating oil adhering to the seal surface 9 falls off, thereby leaking the high-pressure gas A to the outside 3. When the rotating shaft 2 is stationary, the lubricating oil falls off,
As means for preventing the high-pressure gas A from leaking to the outside 3, there is a method in which an annular groove (recess) is provided on the sealing surface 9 as disclosed in, for example, Japanese Patent Application Laid-Open No. 57-157865. By this annular groove, even when the rotating shaft 2 is stationary and the supply of the lubricating oil is stopped, the lubricating oil is retained in the annular groove and the high-pressure gas A is prevented from leaking to the outside 3. It is supposed to.

FIGS. 15 and 16 are enlarged views of the vicinity of the seal surface 9 of the conventional mechanical seal 5, and reference numeral 11 denotes an annular groove. In a normal state, the rotary seal 7 is pressed against the fixed seal 6 by the back pressure of the high-pressure gas A (the pressure in the vertical direction in the figure) and the preload of the preload spring 8, regardless of the presence of the annular groove 11. Are sealed (FIG. 15). At this time, the pressure of the lubricating oil held in the annular groove 11 is substantially the same as the pressure of the high-pressure gas A because the pressure of the high-pressure gas A is transmitted to the lubricating oil in the annular groove.

[0005]

However, there are cases where the pressure of the high-pressure gas A decreases due to some cause such as a failure. In this case, the pressure of the high-pressure gas A and the pressure of the lubricating oil held in the annular groove 11 are reduced. The state of equilibrium with is destroyed.
This is because the change in pressure of the high-pressure gas A restricts the followability of the seal due to the viscosity of the lubricating oil on the seal surface, so that the change in pressure on the seal surface is delayed. Therefore,
It takes some time until the pressure of the lubricating oil balances again with the pressure of the high-pressure gas A. Meanwhile, the pressure of the lubricating oil held in the annular groove 11 is higher than the reduced pressure of the high-pressure gas A. The relatively high pressure of the lubricating oil is used as a reaction force against the force for pressing the rotary seal 7 against the fixed seal 6, and is used as the sealing surface 9.
It will work in the direction to widen the gap. In such a state, a force equal to or greater than the force of the high-pressure gas A and the preload spring 8 pressing the rotary seal 7 against the fixed seal 6 is applied.
This is caused by the lubricating oil, the gap between the sealing surfaces 9 is widened (FIG. 16), and there is a problem that the high-pressure gas A and the gas dissolved in the lubricating oil leak to the outside 3. In addition, the pressure on the sealing surface drops rapidly (high-pressure gas A
When the pressure reaches an equilibrium state), the CO ₂ gas dissolved in the lubricating oil foams. As a result, the sealing surface is in a dry state, and the leak increases. On the other hand, high pressure gas A
In some cases, the lubricating oil having a higher pressure may flow into the high-pressure gas A (FIG. 16). Such a case is advantageous in that the high-pressure gas A does not leak. However, there is a problem when it is not desired to introduce gas outside the housing 1 into the inside 4 of the housing 1. Thus, conventionally, it has not been actively performed to determine on which side the gas in the outside 3 or inside 4 of the housing 1 is leaked.

The present invention has been made in view of the above problems, and when the pressure of the high-pressure gas A is reduced and a gap is formed between the sealing surfaces 9, the gas is dissolved in the high-pressure gas A and the lubricating oil. It is an object of the present invention to provide a seal structure 5 and a compressor that positively adopt a configuration in which a gas that leaks to the outside 3 as little as possible. When the gas pressure in the interior 4 of the housing 1 decreases and a gap is formed between the sealing surfaces 9,
It is an object of the present invention to provide a seal structure 5 and a compressor that positively adopt a configuration in which the gas does not leak into the inside 4 of the housing 1.

[0007]

According to a first aspect of the present invention, there is provided a seal structure including a rotary shaft side seal member attached to an outer peripheral side of a rotary shaft and a rotary shaft side seal member. A housing-side sealing member attached to a housing through which the rotating shaft is inserted, and a recess for holding lubricating oil is provided on at least one of an end surface of the rotating shaft-side sealing member and an end surface of the housing-side sealing member. In the formed seal structure for sealing the inside of the housing by pressing the both end surfaces together, the recess is formed near an outer edge of the rotary shaft side seal member or the housing side seal member. Features.

In this sealing structure, the recess is
Since the rotary shaft side seal member or the housing seal member is formed near the outer edge, even when the pressure of the high-pressure gas inside the housing is reduced, the lubricating oil held in the concave portion is rotated by the rotation oil. It flows toward the outer edge of the shaft-side seal member or the housing-side seal member. Hereinafter, this operation will be described in more detail.
In a seal structure in which an annular groove 11 is formed in the middle of a rotary shaft side seal member as in the conventional seal structure shown in FIG. 16, if a gap is formed in the seal surface, the lubrication held in the annular groove 11 The oil flows in both the outer edge direction and the inner edge direction of the rotary shaft side seal member. At this time, along with the flow of the lubricating oil flowing toward the inner edge, a part of the high-pressure gas and the gas dissolved in the lubricating oil leak to the outside. On the other hand, as in the example shown in FIG. 17, in the invention according to the first aspect, the annular groove (recess) 12 is formed on the outer edge of the rotary shaft side seal member. The length to the outer edge is shorter than the length from the annular groove 12 to the inner edge of the rotary seal. When the pressure of the high-pressure gas inside the housing decreases and a gap is generated between the sealing surfaces, the lubricating oil held in the annular groove 12 has a flow resistance higher than that of the rotating shaft side seal member inner edge end direction (leak direction). A small amount (a short flow distance) flows toward the outer edge of the rotary shaft side seal member. Therefore, it is possible to prevent the high-pressure gas inside the housing and the gas dissolved in the lubricating oil from flowing out toward the inner edge end (leak direction) of the rotary shaft side seal member.

The seal structure according to a second aspect of the present invention is arranged such that a rotary shaft side seal member attached to an outer peripheral side of the rotary shaft is opposed to the rotary shaft side seal member, and the rotary shaft is inserted therethrough. A housing-side seal member attached to the housing, wherein a recess for holding lubricating oil is formed on at least one of an end surface of the rotary shaft-side seal member and an end surface of the housing-side seal member.
In the seal structure for sealing the inside of the housing by pressing the both end surfaces together, the recess is formed near an inner edge of the rotary shaft side seal member or the housing side seal member.

When the pressure outside the housing is higher than the pressure inside the housing, the above arrangement operates as follows. In this seal structure, the recess is
Since it is formed near the inner edge of the rotating shaft side seal member or the housing side seal member, the length from the recess to the inner edge of the rotating shaft side seal member or the housing side seal member is the recess. From the length to the outer edge of the rotary shaft side seal member or the housing side seal member, and even if the pressure of the gas inside the housing is reduced, the lubricating oil held in the recess is reduced by the rotary shaft. The flow resistance is smaller (the flow distance is shorter) than the outer edge direction of the side seal member or the housing side seal member, and flows toward the inner edge end of the rotary shaft side seal member or the housing side seal member.

According to a third aspect of the present invention, in the seal structure according to the first aspect, an outer edge side surface from the recess to the outer edge is a predetermined distance from a corresponding end surface of a mating seal member. It is characterized by being separated.

In this seal structure, the recess is formed near the outer edge of the rotary shaft-side seal member or the housing-side seal member, and an end face from the recess to the outer edge is a corresponding end face. In the case where the pressure of the high-pressure gas inside the housing decreases, the gap between the end faces from the recess to the outer edge becomes wider than the gap between the end faces from the recess to the inner edge. However, the lubricating oil held in the recess flows less toward the outer edge (the flow distance is shorter and the width of the flow path is wider) than the inner edge (the leak direction). It will be easier.

According to a fourth aspect of the present invention, in the seal structure according to the second aspect, an inner edge surface from the recess to the inner edge is a predetermined distance from an end surface of a corresponding mating seal member. It is characterized by being separated.

In this seal structure, the recess is formed near the inner edge of the rotating shaft side seal member or the housing side seal member, and an end face from the recess to the inner edge is a corresponding end face. The gap between the end face from the recess to the inner edge becomes wider than the gap between the end face from the recess to the outer edge, and when the pressure of the gas inside the housing decreases. Even so, the lubricating oil held in the recess becomes easier to flow in the inner edge direction where the flow resistance is smaller (the flow distance is shorter and the flow path is wider) than in the outer edge direction.

According to a fifth aspect of the present invention, in the seal structure according to the first aspect, a notch is formed in an outer surface of the rotary shaft side seal member or the housing side seal member in which the recess is formed. It is characterized by being formed.

In this seal structure, the recess is formed in the vicinity of the outer edge of the rotary shaft side seal member or the housing side seal member, and the rotary shaft side seal member or the rotary shaft formed with the recess is formed. Since the notch is formed on the outer side surface of the housing-side seal member, the pressure of the high-pressure gas inside the housing decreases, and the pressure of the lubricating oil held in the recess becomes lower than the pressure of the high-pressure gas inside the housing. If the height is high, the pressure of the lubricating oil held in the recess causes elastic deformation starting from the notch. As a result, a gap is formed between the end surfaces from the recess to the outer edge, and the lubricating oil held in the recess easily flows toward the outer edge.

According to a sixth aspect of the present invention, in the seal structure of the second aspect, a notch is formed in an inner surface of the rotary shaft side seal member or the housing side seal member in which the recess is formed. It is characterized by being formed.

In this seal structure, the recess is formed near the inner edge of the rotary shaft-side seal member or the housing-side seal member, and the rotary shaft-side seal member or the rotary member having the recess formed therein. When the notch is formed in the inner surface of the housing-side seal member, the pressure of the gas inside the housing decreases, and the pressure of the lubricating oil held in the recess is higher than the pressure of the gas inside the housing. Due to the pressure of the lubricating oil held in the recess, elastic deformation starts from the notch. As a result, a gap is formed between the end surfaces from the recess to the inner edge, and the lubricating oil held in the recess easily flows toward the inner edge.

A compressor according to a seventh aspect is characterized in that the seal structure according to the first to ninth aspects is provided for a drive shaft of the compressor.

In this compressor, since the seal structure according to any one of claims 1 to 9 is provided for the drive shaft of the compressor, the high-pressure gas inside the housing of the compressor is controlled by the seal structure. It is sealed and does not leak to the outside. Alternatively, gas outside the housing of the compressor is sealed by the seal structure and does not leak inside.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view showing a scroll compressor (compressor) 20 to which a mechanical seal (seal structure) 5 of the present invention is applied. In FIG. 1, reference numeral 1 denotes a housing, 2 denotes a rotating shaft provided in the housing 1, 21 denotes a motor for driving the rotating shaft, and 22 denotes a orbiting scroll attached to an end of the rotating shaft 2. The housing 1 includes a plurality of bolts 23,
23, the end side (the left side in the figure) is fixed to a casing 24, which is a sealed container for accommodating the rotating shaft 12, the orbiting scroll 16, and the like. In this housing 1, CO _{2 of} about 10 MPa is sealed as high-pressure gas A. This figure 1
A lubricating oil supply line 10 for supplying lubricating oil to a mechanical seal 5 to be described later is formed in an upper part of. The rotating shaft 2 is provided so as to be inserted at one end of the housing 1, and is arranged so as to extend in the horizontal direction. A mechanical seal 5 is provided on the outer peripheral side of the rotating shaft 2 and inside the housing 1. The mechanical seal 5 includes a fixed seal (a housing-side seal member) 6 and a rotary seal (a rotary shaft-side seal member).
7, and a preload spring 8 provided to press the rotary seal 7 against the fixed seal 6.
The fixed seal 6 is fixed to the housing 1 and is stationary with respect to the rotating shaft 2. This fixed seal 6 is formed in a ring shape, and is generally made of silicon carbide (Si).
Hard materials such as C) and tungsten carbide (WC) are used. The right end face of the fixed seal 6 in the figure is a seal face 9 which comes into contact with the corresponding end face of the rotary seal 7. The rotary seal 7 is attached to the outer peripheral side of the rotary shaft 2 and rotates corresponding to the rotary shaft 2. This rotary seal 7 is formed in a ring shape,
Carbon, SiC and the like are often used. An annular groove (recess) for holding lubricating oil is formed on an end face of the rotary seal 7. FIG. 2 is an enlarged view of the vicinity of the seal surface 9. In the figure, the two-dot chain line indicates the vicinity of the seal surface 9 in the normal state, and the solid line indicates the vicinity of the seal surface 9 when the pressure of the high-pressure gas is reduced (described later). In this figure, reference numeral 12 is an annular groove. The annular groove 12 has a wedge shape when viewed in cross section. The maximum width (L ₁ ) at the end face is about 1 mm and the depth (D ₁ ) is about 0.5 mm. In FIG. 2, if the distance from the left edge of the annular groove 12 to the outer edge of the rotary seal 7 is L ₂ , and the distance from the right edge of the annular groove to the inner edge of the rotary seal 7 is L ₃ , L ₂ <L ₃ . This annular groove 12 is formed in the vicinity of the outer edge of the rotary seal 7 so as to form the annular groove 12. As shown in FIG. 1, the orbiting scroll 22 is provided at one end of the rotating shaft 2 so as to be eccentric with respect to the axis of the rotating shaft 2, and is engaged with the corresponding fixed scroll 25. is set up.

The scroll compressor 20 constructed as described above
Works as follows. When the scroll compressor 20 is operated, the rotating shaft 2 rotates, and the gas to be compressed is sucked into a sealed space sandwiched between a plurality of contact lines formed by the fixed scroll 25 and the orbiting scroll 22 meshing with each other ( When the orbiting scroll 22 provided at one end of the rotating shaft 2 makes a revolving motion with respect to the fixed scroll 25 while preventing its rotation, the contact line moves toward the center along the wall of the spiral body. The gas moves and is moved toward the center while the volume is reduced, and the gas is compressed. The compressed gas is discharged from the discharge port 27 to the outside of the scroll compressor 20.

Next, regarding the operation of the sealing surface of the present invention,
This will be described with reference to FIG. During operation of the scroll compressor 20, that is, while the rotating shaft 2 is rotating, lubricating oil is supplied to the seal surface 9 from the lubricating oil supply line 10, and in this state, While the shaft 2 is driven smoothly, the high-pressure gas A is reliably sealed at the sealing surface 9.

When the scroll compressor 20 is not in operation, that is, when the rotating shaft 2 is stationary, the supply of the lubricating oil from the lubricating oil supply line 10 to the sealing surface 9 is stopped. However, lubricating oil is held in the annular groove 12 provided in the rotary seal 7, and the high-pressure gas A is sealed by the lubricating oil held in the seal surface 9 and the annular groove 12.

However, when the pressure of the high-pressure gas A decreases due to some cause such as a failure, the equilibrium normal state between the pressure of the high-pressure gas A and the pressure of the lubricating oil held in the annular groove 12 is broken. This is because the change in pressure of the seal surface is delayed because the followability of the seal due to the change in pressure of the high-pressure gas A is restricted by the viscosity of the lubricating oil on the seal surface.
It takes some time for the pressure of the lubricating oil to balance with the pressure of the high-pressure gas A again. During that time, the pressure of the lubricating oil held in the annular groove 12 becomes higher than the reduced pressure of the high-pressure gas A. The relatively high pressure of the lubricating oil acts as a reaction force against the force pressing the rotary seal 7 against the fixed seal 6 in a direction to widen the gap between the seal surfaces 9. In such a state, a force greater than the force of the high pressure gas A and the preload spring 8 pressing the rotary seal 7 against the fixed seal is generated, and a gap is generated between the seal surfaces 9 as shown by a solid line in FIG. Will be. In this case, the lubricating oil held in the annular groove 12 flows between the rotary seal 7 and the fixed seal 6 in the direction in which the oil easily flows along both end surfaces. In the present embodiment, the annular groove 12
Is formed near the outer edge of the rotary seal 7 (L ₂ <L ₃ ), and the lubricating oil held in the annular groove 12 has a longer flow distance and a longer flow distance than the inner edge. But flows toward the outer edge with short flow resistance.

Therefore, according to the present embodiment, the high-pressure gas A
Even when the pressure is reduced, the high-pressure gas A is sealed by the lubricating oil by flowing the lubricating oil toward the outer edge, so that the high-pressure gas and the gas dissolved in the lubricating oil are externally (in the figure, Leak to the right) can be prevented.

In this embodiment, the annular groove 12 is provided in the rotary seal 7, but the same operation and effect can be obtained by providing the annular groove 12 in the stationary seal 6 as shown in FIG. Can play. Also, the shape of the annular groove 12 is not limited to FIG. For example, as shown in FIG. 4, the shape may be such that it is a right-angled triangle having a right-angled portion on the inner edge side when viewed in cross section. By forming the annular groove 12 in this manner, there is an advantage that the lubricating oil is more difficult to flow toward the inner edge. Because
This is because the right angle part is formed so as to block the outflow path of the lubricating oil. Of course, the right angle portion may be made an acute angle. Further, the annular groove 12 is formed on the outer edge side (L
_{If 2} <L _3, it can be formed at any position. However, as L ₂ becomes smaller, the flow resistance decreases, so that the annular groove 12 is preferably formed at the outer edge position as much as possible. .

Next, a second embodiment of the present invention will be described with reference to FIG. In this figure, the two-dot chain line indicates the vicinity of the sealing surface 9 in a normal state, and the solid line indicates the vicinity of the sealing surface 9 when the pressure of the high-pressure gas is reduced. Note that D ₂
Indicates the width of the gap between the end face of the annular groove 12 on the outer edge side and the corresponding end face of the fixed seal 6 when the pressure of the high-pressure gas A drops, and D ₃ indicates the width of the annular groove 1 when the pressure of the high-pressure gas A drops.
2 shows the width of the gap between the end face on the inner edge side and the corresponding end face of the fixed seal 6. In this embodiment, as compared with the first embodiment, an outer edge side end surface from the annular groove 12 formed in the rotary seal 7 to an outer edge of the rotary seal 7 is a predetermined distance from a corresponding end surface of the fixed seal 6 (for example, The rotating seal 7 is provided with a step 14 (1 μm in height) so as to be spaced apart from the rotating seal 7. In a normal state, there is a small gap between the rotating seal 7 and the fixed seal 6, and a high-pressure gas A
Only when D ₂ > D ₃ . In the above configuration, when the pressure of the high-pressure gas A decreases and a gap occurs in the seal surface 9, the lubricating oil held in the annular groove 12 flows in a direction that is easy to flow (low flow resistance). The flow distance is long (L ₃ ), the flow path width is narrow (D ₃ ), the flow distance is shorter than the inner edge direction (L ₂ ),
In addition, the flow path has a wide width (D ₃ ), so that the flow becomes easier toward the outer edge. Therefore, according to the present embodiment, even when the pressure of the high-pressure gas A decreases, the high-pressure gas A is sealed by the lubricating oil by flowing the lubricating oil toward the outer edge. Can be prevented from leaking to the outside.

In this embodiment, the step 14 is provided with the rotary seal 7, but the same operation and effect can be obtained by providing the step 14 on the stationary seal 6 as shown in FIG. it can. Further, the annular groove 12
Is formed on the stationary seal 6, and the step 14 is
Alternatively, it may be provided on the fixed seal 6.

The height of step 14 is also 1
It is not limited to μm. The height is only required to reduce the flow resistance of the lubricating oil.

Next, a third embodiment of the present invention will be described with reference to FIG. In this figure, the two-dot chain line indicates the vicinity of the sealing surface 9 in a normal state, and the solid line indicates the vicinity of the sealing surface 9 when the pressure of the high-pressure gas is reduced. This embodiment is different from the first embodiment (FIG. 2) only in that a notch 15 is formed on the outer surface of the rotary seal 7. The notch 15 is formed over the entire outer peripheral surface of the rotary seal 7. In the above configuration, when the pressure of the high-pressure gas A decreases and the pressure of the lubricating oil held in the annular groove 12 formed in the rotary seal 7 is higher than that of the high-pressure gas A, the pressure of the lubricating oil held in the annular groove 12 increases. Then, elastic deformation occurs from the notch 15 as a starting point, and a gap is generated between the end faces from the annular groove 12 to the outer edge. Annular groove 12
The lubricating oil held in the nozzle flows in a direction in which the lubricating oil flows easily (has a low flow resistance). In this case, the lubricating oil flows more easily in the outer edge direction in which the end face interval is widened. Therefore, according to the present embodiment, even when the pressure of the high-pressure gas A decreases, the lubricating oil flows toward the outer edge,
Since the high-pressure gas A is sealed by the lubricating oil, it is possible to prevent the high-pressure gas and the gas dissolved in the lubricating oil from leaking to the outside.

Although the rotary seal 7 has the annular groove 12 and the notch 15 in the present embodiment, the same effect can be obtained by forming the annular groove 12 and the notch 15 in the fixed seal 6. , The effect can be achieved.

Next, a fourth embodiment will be described with reference to FIG. In this figure, the two-dot chain line indicates the vicinity of the seal surface 9 in the normal state, and the solid line indicates the vicinity of the seal surface 9 when the pressure of the gas B in the housing is reduced. In addition,
In the figure, L ₄ is the rotation seal 7 from the left edge of the annular groove 13.
Shows the distance to the outer edge, L ₅ represents a distance to the inner end of the rotary seal 7 from the right edge of the annular groove 13. This embodiment is different from the first embodiment only in that the annular groove 13 is formed near the inner edge of the rotary seal 7. In the above configuration, when the pressure of the gas B inside the housing decreases and a gap is generated in the seal surface 9, the lubricating oil held in the annular groove 13 flows in a direction that is easy to flow (less flow resistance). In this case, the flow distance is long (L ₄ ),
The flow distance is shorter (L ₅ ) than in the outer edge direction where the flow resistance is large, and the flow becomes easier in the inner edge direction (right side in the figure) where the flow resistance is small. Therefore, according to the present embodiment, even when the pressure of the gas B decreases, the external gas is sealed by the lubricating oil by flowing the lubricating oil toward the inner edge, so that the external gas leaks into the inside. Never. That is, it is possible to prevent the external gas from being introduced into the housing.

In this embodiment, the annular groove 13 is provided with the rotary seal 7. However, the same operation and effect can be obtained by providing the annular groove 13 in the stationary seal 6 as shown in FIG. be able to. Further, the shape of the annular groove 13 is not limited to FIG. For example, as shown in FIG. 10, when viewed in cross section, the shape may be a right-angled triangle having a right-angled portion on the outer edge side.
By forming the annular groove 13 in this manner, there is an advantage that the lubricating oil is more difficult to flow toward the outer edge. This is because the right angle portion is formed so as to block the outflow path of the lubricating oil. Of course, the right angle portion may be made an acute angle. Further, the annular groove 13 can be formed at an arbitrary position on the inner edge side (L ₄ > L ₅ ) of the rotary seal 7. However, the smaller the L ₅ , the lower the flow resistance. The annular groove 13 is preferably formed at the inner edge position as much as possible.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In this figure, the two-dot chain line
The vicinity of the seal surface 9 in a normal state is shown, and the solid line shows the vicinity of the seal surface 9 when the pressure of the gas B inside the housing is reduced. D ₄ indicates the width of the gap between the outer peripheral end surface of the annular groove 13 and the corresponding end surface of the fixed seal 6 when the pressure of the gas B decreases, and D ₅ indicates the width of the annular groove 13 when the pressure of the gas B decreases. 2 shows the width of the gap between the end face on the inner edge side and the corresponding end face of the fixed seal 6. This embodiment is different from the fourth embodiment in that the inner edge side surface from the annular groove 13 formed in the rotary seal 7 to the inner edge of the rotary seal 7 is a predetermined distance from the corresponding end surface of the fixed seal 6 (for example, Step 16 (1 μm in height) is applied to the rotary seal 7 so as to be separated.
m), and in a normal state, the rotary seal 7
The only difference is that there is a minute gap between the first seal and the fixed seal 6, and when the gas B decreases, D ₄ <D ₅ . In the above configuration, when the pressure of the gas B decreases and a gap is formed in the seal surface 9, the lubricating oil held in the annular groove 13 flows in a direction that is easy to flow (low flow resistance). The flow distance is long (L ₄ ), the flow path width is narrow (D ₄ ), the flow distance is shorter than the outer edge direction (L ₅ ),
In addition, the flow path has a wide width (D ₅ ), so that the flow becomes easier in the inner edge direction. Therefore, according to the present embodiment, even when the pressure of the gas B decreases, the external gas is sealed by the lubricating oil by flowing the lubricating oil toward the inner edge, so that the external gas leaks into the inside. Never. That is, it is possible to prevent the external gas from being introduced into the housing.

In this embodiment, the step 16 is provided with the rotary seal 7. However, the same operation and effect can be obtained even if the step 16 is provided on the fixed seal 6 as shown in FIG. it can. Furthermore, the annular groove 1
3 may be formed on the stationary seal 6, and the step 16 may be provided on the rotary seal 7 or the stationary seal 6.

The height of step 16 is also 1
It is not limited to μm. The height is only required to reduce the flow resistance of the lubricating oil.

Next, a sixth embodiment of the present invention will be described with reference to FIG. In this figure, the two-dot chain line
The sealing surface 9 in a normal state is shown, and the solid line shows the sealing surface 9 when the pressure of the gas B decreases. In the present embodiment, the fourth
This embodiment is different from the embodiment (FIG. 7) only in that a notch 17 is formed in the inner surface of the rotary seal 7. The notch 17 is formed over the entire inner peripheral surface of the rotary seal 7. In the above configuration, when the pressure of the gas B decreases and the pressure of the lubricating oil held in the annular groove 13 formed in the rotary seal 7 is higher than that of the gas B, the pressure of the lubricating oil held in the annular groove 13 causes Elastic deformation occurs from the notch 17 as a starting point, and a gap is generated between the end faces from the annular groove 13 to the inner edge. Since the lubricating oil held in the annular groove 13 flows in a direction in which the lubricating oil flows easily (the flow resistance is small), in this case, the lubricating oil flows more easily in the inner edge direction where the end face interval is widened. Therefore, according to the present embodiment, even when the pressure of the gas B decreases, the gas B is sealed by the lubricating oil by flowing the lubricating oil toward the inner edge, so that the external gas leaks inside. Never. That is, it is possible to prevent the external gas from being introduced into the housing.

In the present embodiment, the annular groove 13 and the notch 17 are formed in the rotary seal 7. However, the same effect can be obtained by forming the annular groove 13 and the notch 17 in the fixed seal 6. , The effect can be achieved.

[0040]

According to the first aspect of the present invention, the pressure of the high-pressure gas in the housing is reduced, and the sealing surface formed between the housing-side seal member and the rotary shaft-side seal member is reduced. When a gap occurs, the recess is
Since it is formed near the outer edge of the rotating shaft side seal member or the housing side seal member, the lubricating oil can flow toward the outer edge of the sealing surface, and the high pressure gas is sealed by the lubricating oil. In addition, the gas dissolved in the lubricating oil can be prevented from leaking to the outside.

According to the second aspect of the present invention, the pressure of the gas in the housing is reduced, and a gap is generated in a seal surface formed between the housing-side seal member and the rotary shaft-side seal member. In this case, the recess is formed near the inner edge of the rotating shaft side seal member or the housing side seal member, so that the lubricating oil can flow toward the inner edge of the sealing surface, and the external gas is lubricating oil. Therefore, it is possible to prevent external gas from being introduced into the housing.

According to the third aspect of the present invention, the pressure of the high-pressure gas in the housing decreases, and a gap is formed in a seal surface formed between the housing-side seal member and the rotary shaft-side seal member. When this occurs, the recess is formed near the outer edge of the rotary shaft-side seal member or the housing-side seal member, and the end surface from the recess to the outer edge is separated from the corresponding end surface. Can flow toward the outer edge of the sealing surface, and the high-pressure gas is sealed with the lubricating oil, so that the high-pressure gas and the gas dissolved in the lubricating oil can be prevented from leaking to the outside.

According to the fourth aspect of the present invention, the pressure of the gas in the housing is reduced, and a gap is generated in a seal surface formed between the housing-side seal member and the rotary shaft-side seal member. In this case, the recess is formed near the inner edge of the rotating shaft side seal member or the housing side seal member, and the end face from the recess to the inner edge is separated from the corresponding end face. Since the gas can be caused to flow toward the inner edge of the sealing surface and the external gas is sealed by the lubricating oil, it is possible to prevent the external gas from being always introduced into the housing.

According to the fifth aspect of the present invention, the pressure of the high-pressure gas in the housing decreases, and a gap is formed in the seal surface formed between the housing-side seal member and the rotary shaft-side seal member. When this occurs, the recess is formed near the outer edge of the rotary shaft-side seal member or the housing-side seal member, and a notch is formed on the outer surface of the rotary shaft-side seal member or the housing-side seal member where the recess is formed. Since the lubricating oil is formed, the lubricating oil can flow toward the outer edge of the sealing surface, and the high-pressure gas is sealed by the lubricating oil. Can be prevented.

According to the invention described in claim 6 of the present invention, the pressure of the gas in the housing is reduced, and a gap is generated in a sealing surface formed between the housing side sealing member and the rotating shaft side sealing member. In this case, the recess is formed near the inner edge of the rotary shaft-side seal member or the housing-side seal member, and a notch is formed in the inner surface of the rotary shaft-side seal member or the housing-side seal member in which the recess is formed. As a result, the lubricating oil can flow toward the inner edge of the sealing surface, and the external gas is sealed by the lubricating oil. Therefore, it is possible to prevent the external gas from being constantly introduced into the housing.

According to the seventh aspect of the present invention, the high-pressure gas inside the housing does not leak to the outside from the seal portion of the drive shaft, or the gas outside the housing leaks to the inside from the seal portion of the drive shaft. The ideal compressor can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a scroll compressor having a seal structure according to the present invention.

FIG. 2 is an enlarged view of the vicinity of a seal surface according to the first embodiment.

FIG. 3 is an enlarged view of the vicinity of a seal surface shown as a modified example of the first embodiment.

FIG. 4 is an enlarged view around a seal surface shown as a modification of the first embodiment.

FIG. 5 is an enlarged view of the vicinity of a seal surface according to a second embodiment.

FIG. 6 is an enlarged view near a seal surface shown as a modification of the second embodiment.

FIG. 7 is an enlarged view near a seal surface according to a third embodiment.

FIG. 8 is an enlarged view near a seal surface according to a fourth embodiment.

FIG. 9 is an enlarged view of the vicinity of a seal surface shown as a modification of the fourth embodiment.

FIG. 10 is an enlarged view of the vicinity of a sealing surface shown as a modification of the fourth embodiment.

FIG. 11 is an enlarged view of the vicinity of a seal surface according to a fifth embodiment.

FIG. 12 is an enlarged view of the vicinity of a seal surface shown as a modification of the fifth embodiment.

FIG. 13 is an enlarged view near a seal surface according to a sixth embodiment.

FIG. 14 is a sectional view showing a conventional mechanical seal.

FIG. 15 is a partial cross-sectional view of FIG.

FIG. 16 is a partial cross-sectional view showing a case where a gap is formed in the seal surface of FIG.

FIG. 17 is a partial sectional view showing the operation of the mechanical seal according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Rotating shaft 5 Mechanical seal 6 Fixed seal (housing-side sealing member) 7 Rotating seal (rotating-shaft side sealing member) 8 Preload spring 10 Lubricating oil supply line 11, 12, 13 Annular groove (recess) 14, 16 Step 15, 17 Notch 20 Scroll type compressor (compressor)

Claims (7)

[Claims] 1. A rotating shaft side seal member attached to an outer peripheral side of a rotating shaft, and a housing side seal attached to a housing which is installed to face the rotating shaft side sealing member and through which the rotating shaft passes. A member for holding lubricating oil is formed on at least one of the end surface of the rotating shaft side seal member and the end surface of the housing side seal member. In the sealing structure for sealing, the recess is formed near an outer edge of the rotating shaft side sealing member or the housing side sealing member. 2. A rotary shaft-side seal member attached to the outer peripheral side of the rotary shaft, and a housing-side seal mounted to the housing through which the rotary shaft is inserted so as to face the rotary shaft-side seal member. A member for holding lubricating oil is formed on at least one of the end surface of the rotating shaft side seal member and the end surface of the housing side seal member. A seal structure for hermetically sealing, wherein the recess is formed near an inner edge of the rotary shaft side seal member or the housing side seal member. 3. The seal structure according to claim 1, wherein an outer edge side surface from the recess to the outer edge is separated from a corresponding end surface of a mating seal member by a predetermined distance. Seal structure. 4. The seal structure according to claim 2, wherein an inner edge side surface from the recess to the inner edge is separated by an arbitrary distance from a corresponding end surface of a mating seal member. Seal structure. 5. The seal structure according to claim 1, wherein a notch is formed in an outer surface of the rotary shaft side seal member or the housing side seal member in which the recess is formed. Seal structure. 6. The seal structure according to claim 2, wherein a notch is formed in the inner surface of the rotating shaft side seal member or the housing side seal member in which the recess is formed. Seal structure. 7. A compressor, wherein the seal structure according to claim 1 is provided for a drive shaft of the compressor.