JPH10339294A - Centrifugal fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal fluid machine which prevent oil leakage when a rotation is stopped, and which is provided with an oil seal which does not give a sliding resistance in a rotating state. SOLUTION: The centrifugal fluid machine comprises an impeller 65, a casing which supports an impeller shaft 35 rotatably via a bearing 71, piston ring 115 provided between a casing side collar 113 and the impeller shaft 35 side, and a lip type seal 117. The rip type seal 117 has a contact part 123 which is in contact with the collar 113 by its resiliency. When the impeller shaft stops, the contact part 123 prevents oil leakage, and when the impeller shaft 35 rotates, the contact part 123 is separated from the collar 113 by the centrifugal force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal fluid machine used as a compressor or an expander.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 4-44123 discloses a bearing device 201 as shown in FIG. This bearing device 2
Numeral 01 is used for the centrifugal compressor 203 and includes a sliding bearing 205, a fin-shaped seal 207, a labyrinth seal 209, and the like.

[0003] A thread is provided on the outer periphery of the impeller shaft 211.
213, 215 and 217 are fixed. The slide bearing 205 includes sleeves 213 and 215 and a housing 219.
And supports the impeller shaft 211 and the impeller 221, and is lubricated by oil from the conduit 223.

The fin-shaped seal 207 comprises a disk 225 formed on a sleeve 215 and a first chamber 226 which contains the disk 225 in a non-contact manner.
Reference numeral 9 denotes a number of annular projections 227 formed on the sleeve 217.
And the compressor housing 229.

[0005] The housing 219 has a fin-shaped seal.
A second chamber 231 communicating with the labyrinth seal 209 and the labyrinth seal 209 and an annular gap 233 are provided.

The oil of the sliding bearing 205 enters the first chamber 226 by the rotation of the disk 225 by the fin-shaped seal 207, and is discharged from the first port 235. At this time, the labyrinth seal 209 has impeller 2
Air flows from the side 21 toward the fin-shaped seal 207 to prevent oil from leaking to the impeller 221 side.

[0007]

A centrifugal fluid machine such as the compressor 203 has a high rotational speed. Therefore, if a seal such as a lip seal is used, the seal life is short and the rotational resistance is reduced. Becomes larger. Therefore, the compressor 203
A labyrinth seal 209 which is a non-contact type seal is used.

However, the labyrinth seal 209 prevents oil leakage if the impeller 221 rotates as described above. However, since the labyrinth seal 209 is a non-contact type, the labyrinth seal 209 starts rotating when the impeller 221 is not rotating or starts rotating. When you do,
Oil flows through the gap of labyrinth seal 209 to impeller 2
The oil leaks to the side of the compressor 21 and oil is mixed into the fluid discharged from the compressor 203, and the reliability is reduced due to the oil leak.

A centrifugal compressor may be used in, for example, a CFC-less air-conditioning system. If oil is mixed into a discharged fluid, the system cannot be opened and the cool air cannot be directly blown into a freezer or a living room. .

[0010] Injecting cold air directly requires an oil removal device to remove the oil from the cold air, making the system more complex and expensive.

Further, even if the system is closed cycle, a heat exchanger is required, and the system becomes complicated and expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a centrifugal fluid machine having an oil seal that prevents oil leakage when rotation is stopped and does not provide sliding resistance when rotating.

[0013]

According to the first aspect of the present invention, a fluid inlet and a fluid outlet are provided at both ends of a spiral fluid flow path whose cross-sectional area perpendicular to the moving direction of the fluid changes toward one side. A housing provided with a shaft, an impeller rotatably disposed inside the housing, a casing rotatably supporting a shaft of the impeller via a bearing, and a casing on the impeller shaft side and the casing side. A first oil seal, which is provided between the casing and the casing and has a non-contact portion at least partially on the periphery thereof, and a seal disposed between the impeller shaft and the casing. ,
Pressing means for pressing the seal portion to prevent oil leakage, and the seal against the pressing means when the impeller rotates.
A second oil seal having pressure releasing means for forming a gap in the screw portion.

As described above, the seal portion disposed between the impeller shaft side and the casing side, the pressing means for pressing the seal portion to prevent oil leakage, and operating when the impeller rotates. A second oil seal having pressure releasing means for forming a gap in the seal portion against the pressure means is disposed.

In the stationary state of the centrifugal fluid machine, the seal portion is pressed by the pressing means in the second oil seal to prevent oil leakage. When the centrifugal fluid machine rotates, oil leakage is prevented by the first oil seal having at least partially a non-contact portion on the periphery with respect to the casing side, and the second oil seal is prevented. In this case, since a gap is formed in the seal portion by the pressing release means, rotation resistance due to sliding of the seal portion is prevented, and heat generation and reduction in efficiency are prevented.

Further, the reliability of the centrifugal fluid machine is improved by preventing oil leakage.

As described above, oil is not mixed into the fluid in both the stationary state and the rotating state. Therefore, when the system is used for a compressor or a turbine of a CFC-free air conditioner system, the system is set to an open cycle to cool the air. It can be blown directly into a freezer or living room.

Accordingly, since an oil removing device for removing oil from cold air and a heat exchanger for forming a closed cycle are not required, the structure of the system is simplified and the cost is reduced.

According to a second aspect of the present invention, there is provided the centrifugal fluid machine according to the first aspect, wherein the second oil seal comprises:
An elastic seal having a base fixed to the impeller shaft side and a contact portion provided at the tip end side of the base and bent toward the casing side and pressed. A contact portion that is bent and pressed toward the casing side, wherein the pressing means is an elastic force of a seal that presses the contact portion toward the casing side when the impeller shaft is not rotating; The release means is a centrifugal force that separates the contact portion from the casing side when the impeller shaft rotates.

In the stationary state of the centrifugal fluid machine, the contact portion of the seal portion of the second oil seal bent to the casing side presses the casing side by elasticity to prevent oil leakage, When the centrifugal fluid machine rotates, the contact portion receives centrifugal force and separates from the casing side, so that a gap is formed in the seal portion.

In this way, the same effect as that of the first aspect is obtained.

In addition, this structure for opening and closing the seal by centrifugal force has a very simple structure and is low in cost.

According to a third aspect of the present invention, there is provided the centrifugal fluid machine according to the first aspect, wherein the second oil seal comprises:
An actuator comprising a cylinder member and a piston member, a contact portion provided between the piston member and the impeller shaft side, and a device for pressing the seal portion through the piston member to prevent oil leakage. A biasing member, and a pressure passage for guiding pressure from the housing side to the actuator,
The seal portion is the contact portion, the pressing means is an urging member, and the pressing release means receives the pressure and retreats the piston member against the urging member so that the seal member is pressed against the urging member. It is characterized in that it is an actuator that creates a gap.

In the stationary state of the centrifugal fluid machine, the seal portion is pressed via the piston member by the urging member of the second oil seal to prevent oil leakage. or,
When the centrifugal fluid machine rotates, the piston member is retracted by the pressure guided to the actuator via the pressure passage, and a gap is formed in the seal portion.

Thus, the same effect as that of the first aspect is obtained.

In addition, the structure in which the second oil seal is operated by using the fluid pressure generated on the housing side provides a large operation force, so that the operation is reliable.

[0027]

1 to 3 show a first embodiment of the present invention.
An embodiment will be described. This embodiment has the features of the first and second aspects. Hereinafter, the left and right directions are the left and right directions in each drawing, and members without reference numerals and the like are not shown.

FIG. 1 shows a mechanical supercharger 1. The mechanical supercharger 1 includes an input pulley 3, a planetary gear type speed increasing mechanism 5, and a centrifugal air compressor 7 (first type). (Centrifugal fluid machine of the embodiment).

The air compressor 7 may be used as, for example, a compressor for a refrigerator that compresses a refrigerant in a refrigeration cycle and driven by an engine or a motor.

The input pulley 3 comprises a pulley body 9 and a hub 11.
The hub 11 is fixed to the input shaft 15 of the speed increasing mechanism 5 with a key 17 and a nut 19. The input pulley 3 is connected to a pulley on the crankshaft side via a belt, and is driven to rotate by the driving force of the engine.

The input shaft 15 is caged by a bearing 21.
It is supported by a boss 25 of the thing 23. Further, a seal 27 is arranged between the input shaft 15 and the casing 23.

The speed-increasing mechanism 5 includes a flange 2 of the input shaft 15.
The air compressor 7 includes an internal gear 31, a plurality of pinion gears 33 arranged at regular intervals in the circumferential direction, and a sun gear 37 formed on an impeller shaft 35 of the air compressor 7. Each gear is composed of a helical gear.

The pinion gear 33 is supported on a pinion shaft 41 via a bearing 39. The pinion shaft 41 is supported through a flange member 43 fixed to the casing 23, and includes a ball 45 and the ball 45.
Screw 45 is pressed against the flange member 43 by a bolt 47.

The speed increasing mechanism 5 increases the driving force of the engine input from the input pulley 3 to the internal gear 31 from the pinion gear 33 via the sun gear 37.

The flange member 43 includes a bearing holder 4
9 is press-fitted. The bearing holder 49 is a cylindrical part 5
1 and a conical convex portion 53, and the convex portion 53 is the input shaft 1
It penetrates through a slight gap into a conical concave portion 55 formed on the fifth side.

A sun gear 37 is provided on the impeller shaft 35.
Ring 57, ring 59, spacer 61,
The bush 63 and the impeller 65 are mounted and fixed with the nut 67.

On the left side of the sun gear 37, a sliding bearing 69 (bearing) is arranged between the impeller shaft 35 and the bearing holder 49. Also, Spacer 6
Between the bearing 1 and the bearing holder 49
(Bearing) is arranged.

Between each of the sliding bearings 69, 71 and the bearing holder 49, an oil plug 73 attached to the casing 23, a nozzle 75 and a bearing holder 49 are provided.
Pressurized oil is supplied from an external oil pump through an oil passage 77 formed through the flange member 43 and an oil film damper.

Each of the sliding bearings 69 and 71 is floating supported by the oil film damper, and supports the impeller shaft 35 while absorbing vibration.

A thrust washer 79 is mounted on the bearing holder 49.
The leading end of 9 engages a groove 81 formed between the rings 57 and 59 and receives a thrust force generated in the impeller 65 and a meshing thrust force of each helical gear generated in the speed increasing mechanism 5.

The above-described pressurized oil is supplied from the oil passage 83 to the groove 8.
1 to lubricate the sliding portion with the thrust washer 79, and further to the seal 27 via the oil passage 85,
Lubricate this.

An O-ring 87 is arranged between the casing 23 and the flange member 43 to prevent oil leakage.

The casing 23, the flange member 43, and the compressor housing 89 of the air compressor 7 are formed of a casing.
The connecting member 93 engaged with the circumferential groove 91 of the thing 23 and a bolt 95 for fixing the connecting member 93 to the compressor housing 89 are fixed.

The impeller shaft 3 of the air compressor 7
The 5 (impeller 65) is driven to rotate at a high speed by the driving force of the engine increased in speed by the speed increasing device 5. The air compressor 7 sucks engine intake air from an intake port 97 (inflow port), and the intake air is compressed by a centrifugal force of the impeller 65 in a swirling chamber 99 of a compressor housing 89 and is discharged from a discharge port (outflow port). To supercharge the engine.

The speed increasing mechanism 5 and the air compressor 7 are separated by a partition wall 101 of the flange member 43. A labyrinth ring 103 having a sawtooth-shaped groove is fixed to the partition wall portion 101 by bolts 105, and forms a labyrinth seal 107 with the impeller 65. The labyrinth seal 107 reduces air leakage from the air compressor 7 by the pressure reducing action.

The mechanical supercharger 1 is arranged downstream of the throttle valve, and a space 109 is formed between the bearing holder 49, the flange member 43 and the impeller 65. This space 109 is located downstream of the throttle valve.
Communicates with the bypass passage 110 via a control valve. When the throttle valve is closed and a negative pressure is generated on the right side of the impeller 65, the space 109 is opened to the atmosphere side by the control valve and is always maintained at the positive pressure.

Further, a hollow-113 is press-fitted into a hollow portion 111 provided on the right end side of the bearing holder 49, and is positioned at the left end portion with respect to the hollow portion 111.

Between the bush 63 and the collar-113,
A piston ring (first oil seal) 115 having a partially cut-out portion on the periphery and engaging at least this portion as a non-contact portion and engaging with a groove formed in the bush 63 is arranged. Oil leakage and air leakage from the air compressor 7 are prevented.

As described above, the space 109 is always maintained at a positive pressure and does not become a negative pressure.
The burden is light, and the leak prevention function works effectively.

A rubber (elastic) lip seal 117 (second oil seal) is disposed in the hollow portion 111.

As shown in FIGS. 2 and 3 in an enlarged manner, the lip seal 117 has a base 119 fixed to the flange 121 of the spacer 61, and a tip of the base 119 on the collar-113 side. Is provided with a bent contact portion 123.

When the impeller shaft 35 is not rotating, as shown in FIG. 2, the contact portion 123 has elasticity (pressing means).
When the impeller shaft 35 is rotated by pressing the collar 113, the contact portion 123 is separated from the collar 113 by receiving a centrifugal force (press release means) as shown in FIG.

Thus, the mechanical supercharger 1 is configured.

As described above, when the air compressor 7 is stationary, oil leakage is prevented by the lip seal 117. When the air compressor 7 rotates, the labyrinth is added to the piston ring 115. The addition of the seal 107 prevents oil leakage,
Since a gap is formed between the contact portion 123 and the collar-113 in the lip seal 117, rotation resistance due to sliding thereof is prevented, and heat generation and a decrease in efficiency are prevented.

Further, the reliability of the air compressor 7 is improved by preventing oil leakage.

Further, a lip seal 117 is formed using centrifugal force.
The structure for opening and closing the contact portion 123 is extremely simple in structure and low in cost.

Since oil is not mixed into the discharged air as described above, for example, when the air compressor 7 is used in a Freon-less air conditioner system, the system is set to an open cycle and cool air is directly blown into a freezer or a room. It is possible.

Accordingly, since an oil removing device for removing oil from cold air and a heat exchanger for forming a closed cycle are not required, the structure of the system is simplified and the cost is reduced.

The same effect can be obtained by using a labyrinth seal that is not in contact with the entire circumference in addition to the piston ring 115.

Next, the second embodiment of the present invention will be described with reference to FIGS.
An embodiment will be described. This embodiment has the features of claims 1 and 3. The left and right directions are the left and right directions in each drawing, and members without reference numerals and the like are not shown.

In the description of FIGS. 4 to 6 and the second embodiment, members having the same functions as those of the first embodiment are given the same reference numerals and are quoted, and redundant description of these same members is omitted.

FIG. 4 shows a mechanical supercharger 125,
This mechanical supercharger 125 has an input pulley 3 and a planetary
Gear type speed increasing mechanism 5 and centrifugal air compressor 127
(The centrifugal fluid machine of the second embodiment).

The air compressor 127 is driven to rotate at a high speed by the driving force of the engine increased in speed by the speed increasing device 5, and supercharges the engine with pressurized intake air.

In the air compressor 127, an oil seal (second oil seal) 129 is disposed in the cavity 111 of the bearing holder 49.

As shown in an enlarged manner in FIG. 5, the oil seal 129 has a cover 131 (cylinder member) press-fitted into the hollow portion 111 and positioned at the left end, and a cover-1.
A piston member 133 movably disposed on 31;
An actuator 135 (pressing release means) comprising a cover 131 and a piston member 133;
137 (contact portion) provided between the cover 131 and the spacer 61 on the side of the impeller shaft 35, and disc springs 139, 139 (located on the cover 131 to move the piston member 133 to the left). (A biasing member: pressing means), the partition wall 101 of the flange member 43 and the bearing holder 49, and are provided through the spiral chamber 9 of the compressor housing 89.
9 and a pressure chamber 143 that communicates with the pressure chamber 141.

The piston member 133 is a ring having an outer convex portion 145 and an inner convex portion 147.
37 is formed between the flange portion 121 of the spacer 61 by coating a resin 149 such as Teflon on the inner convex portion 147.

A ring 151 is press-fitted into the inner periphery of the cover 131, and the outer convex portion 145 of the piston member 133 is provided.
An O-ring 153 is disposed between the ring 151 and the ring 151. Further, as shown in an enlarged manner in FIG. 6, the O-ring 1 is provided between the outer periphery of the piston member 133 and the cover 131.
55 are arranged.

The pressure chamber 141 is formed between the piston member 133, the ring 151, and the cover 131.

The piston ring (first oil seal) 115 is disposed between the cover 131 and the bush 63.

The oil seal 129 thus constructed
When the impeller shaft 35 is not rotating, the piston member 133 is pressed to the left by the urging force of the disc springs 139 and 139, so that the resin 149 and the flange portion 121 come into contact with each other in the seal portion 137, and Prevent leaks.

When the impeller shaft 35 rotates,
The positive pressure generated in the spiral chamber 99 is guided to the pressure chamber 141 via the pressure flow path 143, and as shown in FIG.
3 is pushed back to the right to form a gap 155 in the seal portion 137.

Thus, the mechanical supercharger 125 is constituted.

As described above, when the air compressor 127 is stationary, the mechanical seal 125 is
When the air compressor 127 rotates, the labyrinth seal 107 is added to the piston ring 115 to prevent oil leakage, and the oil seal 129 prevents the oil leak from occurring.
Since 55 occurs, rotational resistance due to sliding of the seal portion 137 is prevented, and heat generation and efficiency reduction are prevented.

Thus, the same effect as that of the first embodiment is obtained.

Further, the configuration in which the oil seal 129 is operated using the discharge pressure of the air compressor 127 provides a large operation force, so that the operation is reliable.

Since oil is not mixed into the discharged air, similarly to the first embodiment, when the air compressor 127 is used for a Freon-less air conditioner system, the system is set to an open cycle, and the cool air is supplied to a freezer or a living room. Since it is possible to inject directly, there is no need for an oil removal device for removing oil from cold air or a heat exchanger for making a closed cycle, so the system structure becomes simpler and costs are reduced. Can be configured.

The centrifugal fluid machine of the present invention can be used not only as a compressor for compressing a fluid by applying a rotational force to an impeller as in each embodiment, but also for expanding a pressurized fluid. You may use as an expander which takes out a rotational force.

[0078]

According to the centrifugal fluid machine of the first aspect, in a stationary state, the seal portion is pressed by the pressing means of the second oil seal to prevent oil leakage. -Oil leakage is prevented by the
In the second oil seal, a gap is formed in the seal portion by the pressing release means, rotation resistance due to sliding of the seal portion is prevented, and heat generation and efficiency reduction are prevented.

Further, by preventing oil leakage, the reliability of the centrifugal fluid machine is improved.

As described above, since oil is not mixed into the fluid, if it is used for a Freon-less air conditioner system, for example,
By making the system an open cycle, it is possible to blow cold air directly into the freezer or living room, eliminating the need for an oil removal device for removing oil from the cold air or a heat exchanger for making a closed cycle. Yes, the structure of the system becomes simpler and lower cost.

According to a second aspect of the present invention, when the centrifugal fluid machine is at rest, the contact portion of the seal portion bent toward the casing side of the second oil seal presses the casing side by elasticity. Wherein when the centrifugal fluid machine rotates, the contact portion receives centrifugal force and separates from the casing side to form a gap in the seal portion. The same effect as that of the configuration is obtained.

This structure in which the seal is opened and closed using centrifugal force has a very simple structure and is low in cost.

According to a third aspect of the present invention, when the centrifugal fluid machine is at a standstill, the sealing is performed by the urging member of the second oil seal.
The oil is prevented from leaking by pressing the
The piston member is retracted by the pressure guided to the actuator via the pressure flow path, and a gap is formed in the seal portion. The same effect as that of the first aspect is obtained.

In addition to this, the structure in which the second oil seal is operated by using the fluid pressure generated on the housing side provides a large operation force, so that the operation is reliable.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1 showing a state where an oil seal is operating.

FIG. 3 is an enlarged view of a main part of FIG. 1, showing a state where an oil seal is opened.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is an enlarged view of a main part of the second embodiment.

FIG. 6 is an enlarged view of a main part of FIG. 5;

FIG. 7 is a sectional view of a conventional example.

[Explanation of symbols]

7, 127 centrifugal air compressor (centrifugal fluid machine) 23 casing 35 impeller shaft 65 impeller 69, 71 sliding bearing (bearing) 89 compressor housing 97 suction port (inlet port) 115 piston ring (first oil seal) ) 117 Lip seal (second oil seal) 119 Base of lip seal 123 Contact part of lip seal (seal part) 129 Oil seal (second oil seal) 131 Cover (cylinder member) ) 133 Piston member 135 Actuator (press release means) 137 Seal part (contact part) 139 Disc spring (biasing member: press means) 143 Pressure flow path

Claims (3)

[Claims] 1. A housing in which a fluid inlet and an outlet are provided at both ends of a spiral fluid flow path whose cross-sectional area perpendicular to the direction of movement of the fluid changes toward one side; An impeller rotatably disposed; a casing rotatably supporting a shaft of the impeller via a bearing; and a perimeter provided between the impeller shaft side and the casing side and peripheral to the casing side. A first oil seal at least partially having a non-contact portion, a seal portion disposed between the impeller shaft side and the casing side, and pressing the seal portion to prevent oil leakage. A centrifugal fluid machine, comprising: a second oil seal having a pressing means for performing a pressing operation, and a pressing release means for forming a gap in the seal portion against the pressing means when the impeller rotates. 2. The invention according to claim 1, wherein said second oil seal is provided on a base portion fixed to an impeller shaft side and provided at a tip end side of said base portion, and is bent and pressed toward a casing side. An elastic body seal having a contact portion to be bent, wherein the seal portion is a contact portion which is bent and pressed toward the casing side, and wherein the pressing means rotates the impeller shaft. When not in contact, the elasticity of a seal pressing the contact portion toward the casing side, and the pressing release means is a centrifugal force separating the contact portion from the casing side when the impeller shaft rotates. And a centrifugal fluid machine. 3. The invention according to claim 1, wherein the second oil seal is provided between an actuator composed of a cylinder member and a piston member, and between the piston member and the impeller shaft side. A contact portion, a biasing member that presses the seal portion through the piston member to prevent oil leakage, and a pressure flow path that guides pressure from the housing side to the actuator. Is a contact portion, wherein the pressing means is a biasing member, and wherein the pressing release means receives a pressure to retract the piston member against the biasing member to form a gap in the seal portion. Centrifugal fluid machine characterized by the fact that: