WO2009081962A1

WO2009081962A1 - Gate rotor and screw compressor

Info

Publication number: WO2009081962A1
Application number: PCT/JP2008/073523
Authority: WO
Inventors: Mohammod Anwar Hossain; Masanori Masuda; Tadashi Okada
Original assignee: Daikin Industries, Ltd.
Priority date: 2007-12-26
Filing date: 2008-12-25
Publication date: 2009-07-02
Also published as: EP2236832A1; US20110165009A1; JP2009174520A; CN101918716A; EP2236832A4

Abstract

A screw compressor which can prevent capacity decrease by a simple arrangement, even when a gate rotor bends during operation due to a temperature difference between a casing and a screw rotor, by preventing the gate rotor from biting into the screw rotor, thereby reducing abrasion of the gate rotor. A gate rotor (3) has a gate rotor main body (30), and a shaft portion (40) for fixing the gate rotor main body (30). A resilient body (5) is arranged in a space (S) between a shaft (41) of the shaft portion (40) and a hole (32) of the gate rotor body (30).

Description

Gate rotor and screw compressor

The present invention relates to a gate rotor and a screw compressor using the gate rotor.

Conventionally, as a screw compressor, as shown in an enlarged cross-sectional view of FIG. 16, a screw rotor 202 is accommodated in a cylinder 210 of a casing 201, and a gate rotor 203 is meshed with the screw rotor 202. In addition, there is one that compresses gas in a compression chamber formed by the mutual engagement of the gate rotor 203 (see Japanese Patent No. 3731399: Patent Document 1).
That is, the groove portion 221 of the screw rotor 202 and the tooth portion 231 of the gate rotor 203 mesh to form the compression chamber. Then, a low pressure gas is sucked into the compression chamber from one end side in the axis 202a direction of the screw rotor 202, the low pressure gas is compressed in the compression chamber, and then the compressed high pressure gas is supplied to the compression chamber. The screw rotor 202 is discharged from the other end side in the direction of the shaft 202a.

The gate rotor 203 has a gate rotor main body 230 having the tooth portion 231 and a shaft portion 240 for fixing the gate rotor main body 230. The shaft portion 240 is supported by the casing 201.
Here, since the gas is compressed in the compression chamber during the operation of the compressor, the screw rotor 202 becomes high temperature, and the thermal expansion of the screw rotor 202 increases. On the other hand, the gate rotor chamber L that houses the gate rotor 203 in the casing 201 has a low pressure, and the gas in the gate rotor chamber L has a relatively low temperature. The thermal expansion of the surrounding part becomes small. The portion of the casing 201 around the gate rotor chamber L is a portion that determines the distance between the shaft 202 a of the screw rotor 202 and the shaft 203 a of the gate rotor 203.
Japanese Patent No. 3731399

However, in the conventional screw compressor, since the gate rotor 203 is supported by the casing 201, the thermal expansion of the screw rotor 202 is increased during the operation of the compressor, while the heat of the casing 201 is increased. There is a problem that the expansion is reduced, and the distance between the shaft 202a of the screw rotor 202 and the shaft 203a of the gate rotor 203 changes. That is, there is a problem that the gate rotor 203 is bent due to a temperature difference between the casing 201 and the screw rotor 202 during operation of the compressor.
At this time, since the gate rotor main body 230 is fixed to the shaft portion 240, the tooth portion 231 of the gate rotor main body 230 bites into the groove portion 221 of the screw rotor 202, and the wear amount of the tooth portion 231 is reduced. It was a lot.
As a result, the gap between the tooth portion 231 of the gate rotor body 230 and the groove portion 221 of the screw rotor 202 is increased, and the performance of the compressor is deteriorated.

In the conventional screw compressor, a high pressure chamber is provided around the cylinder 210 in the casing 201 to reduce the temperature difference between the casing 201 and the screw rotor 202. A high pressure chamber is not provided around the gate rotor chamber L, and the bending of the gate rotor 203 cannot be eliminated.
Therefore, the object of the present invention is to prevent the gate rotor from biting into the screw rotor with a simple configuration even if the gate rotor is bent due to the temperature difference between the casing and the screw rotor during operation of the compressor. An object of the present invention is to provide a screw compressor that reduces the amount of wear of the gate rotor and prevents a reduction in the capacity of the compressor, and a gate rotor used in the compressor.

In order to solve the above problems, a gate rotor according to a first aspect of the present invention includes a gate rotor body and a shaft portion to which the gate rotor body is attached. The gate rotor body includes a plurality of teeth and a central hole. The shaft portion includes a base portion that supports the gate rotor main body on one surface, and a shaft portion that is provided on one surface of the base portion and is inserted into the hole portion, and the shaft portion of the shaft portion. And an elastic body is arranged between the hole of the gate rotor body.
According to the gate rotor of the present invention, since the elastic body is disposed between the shaft portion of the shaft portion and the hole portion of the gate rotor main body, the gate rotor main body is the base of the shaft portion. It becomes possible to slide on the part.
For this reason, when this gate rotor is used for a screw compressor, the tooth portion of the gate rotor body is meshed with the screw rotor and the shaft portion is supported by the casing, the heat of the screw rotor during the operation of the compressor. Even if the expansion of the casing increases, the thermal expansion of the casing decreases, and the distance between the axis of the screw rotor and the axis of the gate rotor (that is, the axis of the shaft portion) changes. The main body slides on the base portion of the shaft portion, and the positional relationship between the screw rotor and the gate rotor main body maintains an appropriate distance.
As a result, the gate rotor body is prevented from biting into the screw rotor, the amount of wear of the gate rotor body is reduced, and the compressor capacity is prevented from being lowered. In addition, useless power due to the gate rotor body and the screw rotor pressing strongly against each other is reduced. Further, the elastic body can maintain the pressure contact force between the gate rotor body and the screw rotor to such an extent that gas does not leak.
Therefore, even if the gate rotor bends due to the temperature difference between the casing and the screw rotor during operation of the compressor, the gate rotor can be prevented from biting into the screw rotor with a simple configuration, and the amount of wear of the gate rotor can be reduced. To reduce the capacity of the compressor.

In the gate rotor of the second invention, the elastic body is a leaf spring.
According to the gate rotor of the second invention, since the elastic body is a leaf spring, the elastic body can be configured simply.

In the gate rotor of the third invention, the leaf spring is an annular wave spring or spiral spring.
According to the gate rotor of the third invention, since the leaf spring is an annular wave spring or spiral spring, the leaf spring can be configured simply.

In the gate rotor of the fourth invention, the elastic body is an annular rubber.
According to the gate rotor of the fourth invention, since the elastic body is an annular rubber, the elastic body can be configured simply.

The screw compressor of the fifth invention includes a casing having a cylinder, a cylindrical screw rotor fitted to the cylinder, and the gate rotor meshing with the screw rotor, and the gate of the gate rotor. A tooth portion of the rotor body meshes with the screw rotor, and the shaft portion of the gate rotor is supported by the casing.
According to the screw compressor of the fifth invention, since the gate rotor is provided, the thermal expansion of the screw rotor is increased during the operation of the compressor, while the thermal expansion of the casing is decreased, Even if the distance between the shaft and the shaft of the gate rotor (that is, the shaft of the shaft portion) changes, the gate rotor body slides on the base portion of the shaft portion, and the screw rotor The positional relationship with the gate rotor body maintains an appropriate distance.
As a result, the gate rotor body is prevented from biting into the screw rotor, the amount of wear of the gate rotor body is reduced, and the compressor capacity is prevented from being lowered. In addition, useless power due to the gate rotor body and the screw rotor pressing strongly against each other is reduced. Further, the elastic body can maintain the pressure contact force between the gate rotor body and the screw rotor to such an extent that gas does not leak.
Therefore, even if the gate rotor bends due to the temperature difference between the casing and the screw rotor during operation of the compressor, the gate rotor can be prevented from biting into the screw rotor with a simple configuration, and the amount of wear of the gate rotor can be reduced. To reduce the capacity of the compressor.

A screw compressor according to a sixth aspect of the present invention includes a screw rotor, a gate rotor, a gate rotor shaft, and an elastic body. The screw rotor has a plurality of spiral grooves on the outer peripheral surface and is rotatable. The gate rotor has an opening at the center thereof. A plurality of teeth meshing with the grooves of the screw rotor are arranged radially around the opening of the gate rotor. The gate rotor shaft is inserted with a gap in the opening of the gate rotor. The elastic body is disposed around at least one of the clearance between the opening of the gate rotor and the gate rotor shaft and / or a plurality of detent pins that stop the rotation of the gate rotor around the gate rotor shaft.
According to the screw compressor of the sixth invention, a gap is formed around the gate rotor shaft, and the elastic body includes a gap around the gate rotor shaft and / or a plurality of detent pins for stopping rotation around the gate rotor shaft. It is possible to absorb the radial extension of the teeth of the gate rotor.

The screw compressor of the seventh invention is the screw compressor of the sixth invention, wherein the elastic body arranged in the gap is directed toward one of the plurality of detent pins with respect to the gate rotor. Gives an elastic force in the radial direction.
According to the screw compressor of the seventh aspect of the invention, the elastic body arranged in the gap gives the gate rotor an elastic force in the radial direction of the gate rotor toward the anti-rotation pin. For teeth whose movement in the direction is constrained, the radial extension can be effectively absorbed by the elastic body.

The screw compressor of the eighth invention is the screw compressor of the sixth invention, and the elastic body arranged in the gap is ring-shaped and fills the entire gap.
According to the screw compressor of the eighth invention, since the elastic body arranged in the gap is ring-shaped and fills the entire gap, it is possible to absorb the radial extension of the teeth of the gate rotor. . Moreover, it is possible to further extend the life of the teeth of the gate rotor by filling a ring-shaped elastic body in the entire gap.

A screw compressor according to a ninth aspect is the screw compressor according to any one of the sixth to eighth aspects, wherein one of the plurality of detent pins is a floating pin. The floating pin connects between the gate rotor shaft and the gate rotor in a state having more play than the other detent pins.
According to the screw compressor of the ninth invention, one of the plurality of detent pins is a floating pin that connects between the gate rotor shaft and the gate rotor in a state having more play than the other detent pins. Therefore, the floating pin can be moved larger than the other non-rotating pins, so that the radial expansion of the teeth of the gate rotor can be absorbed.

A screw compressor according to a tenth aspect of the present invention is the screw compressor according to the ninth aspect of the present invention, wherein the elastic body has a ring shape and is arranged around a rotation prevention pin that is a floating pin.
According to the screw compressor of the tenth aspect of the invention, since the elastic body is ring-shaped and is arranged around the non-rotating pin that is a floating pin, it can absorb the radial extension of the teeth of the gate rotor. Is possible.

According to the gate rotor of the first invention, since the elastic body is disposed between the shaft portion of the shaft portion and the hole portion of the gate rotor body, the gate rotor is used for a screw compressor. In addition, even if the gate rotor bends due to the temperature difference between the casing and the screw rotor during operation of the compressor, the gate rotor can be prevented from biting into the screw rotor with a simple configuration and the amount of wear of the gate rotor can be reduced. To reduce the capacity of the compressor.
According to the second invention, the elastic body can be configured simply.
According to the third invention, the leaf spring can be configured simply.
According to the fourth invention, the elastic body can be configured simply.
According to the screw compressor of the fifth invention, since the gate rotor is provided, even if the gate rotor is bent due to a temperature difference between the casing and the screw rotor during the operation of the compressor, the gate rotor can be configured with a simple configuration. The bite into the screw rotor is prevented, the amount of wear of the gate rotor is reduced, and the compressor capacity is prevented from being lowered.

According to the sixth aspect of the invention, it is possible to absorb the radial extension of the teeth of the gate rotor. As a result, the tooth tips of the gate rotor are not rubbed and worn by the back wall of the groove of the screw rotor, and wear of the gate rotor can be prevented.
According to the seventh aspect of the present invention, the extension in the radial direction can be effectively absorbed by the elastic body with respect to the teeth whose movement in the radial direction is restricted by the detent pin.
According to the eighth aspect of the invention, the radial extension of the teeth of the gate rotor can be absorbed, and the life of the teeth of the gate rotor can be further extended by filling the entire gap with the ring-shaped elastic body. .
According to the ninth aspect of the present invention, the floating pin can be moved larger than the other non-rotating pins so that the radial extension of the teeth of the gate rotor can be absorbed.

According to the tenth invention, it is possible to absorb the radial extension of the teeth of the gate rotor.

1 is a cross-sectional view showing a first embodiment of a gate rotor and a screw compressor of the present invention. It is a top view of the gate rotor main body of FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. It is a top view of the shaft part of FIG. FIG. 5 is a sectional view taken along line BB in FIG. 4. It is a top view of the gate rotor of FIG. FIG. 7 is a cross-sectional view taken along the line CC of FIG. It is a top view which shows 2nd Embodiment of the gate rotor of this invention. The block diagram of the principal part of the single screw compressor concerning the 3rd Embodiment of this invention. The front view of the single screw compressor of FIG. The block diagram which shows arrangement | positioning of the screw rotor of FIG. 9, and a gate rotor. FIG. 10A is a front view and FIG. 9B is a rear view in a portion where the gate rotor and the gate rotor support of FIG. 9 are coupled. The enlarged view of the coil spring periphery part arrange | positioned in the clearance gap around the gate rotor shaft of FIG. The notch front view of the gate rotor of FIG. 9, a gate rotor support, and a gate rotor shaft. FIG. 12 is a partially enlarged cross-sectional view around a rotation restricting hole and an O-ring of the gate rotor of FIG. 11. It is an expanded sectional view of the conventional screw compressor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 10 Cylinder 11 Seal surface 12 Through-hole 13 Discharge port 2 Screw rotor 2a Shaft 21

Groove part

3, 3A Gate rotor 3a Shaft 30 Gate rotor main body 30a Shaft 31 Teeth part 32 Hole part 33 Pin hole 40 Shaft part 40a Shaft 41 1st Shaft part 42 second shaft part 43 base part 43a one surface 44 tooth part 45 pin hole 5 elastic body (leaf spring)
5A Elastic body (rubber)
C compression chamber L gate rotor chamber S gap 101 screw compressor 102 screw rotor 103 casing 104 shaft 105 first gate rotor 106

second gate rotor

108, 109 gate rotor shaft 111 groove 112 tooth 121 opening 122 gap 123 guide pin 124 floating pin 127 Gate rotor support 128 Coil spring (first elastic body)
129 O-ring (second elastic body)

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
(First embodiment)
FIG. 1: has shown the cross-sectional view which is 1st Embodiment of the gate rotor and screw compressor of this invention. This screw compressor is a single screw compressor, and includes a casing 1 having a cylinder 10, a cylindrical screw rotor 2 fitted into the cylinder 10, and a gate rotor 3 meshing with the screw rotor 2. .
The screw rotor 2 has a plurality of spiral grooves 21 on the outer peripheral surface. The gate rotor 3 has a top shape and has a plurality of tooth portions 31 in a gear shape on the outer peripheral surface. The groove portion 21 of the screw rotor 2 and the tooth portion 31 of the gate rotor 3 mesh with each other.

A compression chamber C is formed by the mutual engagement of the screw rotor 2 and the gate rotor 3. That is, the compression chamber C is a space defined by the groove portion 21 of the screw rotor 2, the tooth portion 31 of the gate rotor 3, and the inner surface of the cylinder 10 of the casing 1.
A pair of the gate rotors 3 are arranged on the left and right sides of the screw rotor 2 with the axis 2a of the screw rotor 2 as point symmetry. The casing 1 is provided with a gate rotor chamber L outside the cylinder 10, and the gate rotor 3 is accommodated in the gate rotor chamber L. The gate rotor chamber L and the cylinder 10 communicate with each other through a through hole 12. The gate rotor 3 enters the cylinder 10 through the through hole 12.

The screw rotor 2 rotates about the shaft 2a in the direction of the arrow R, and with the rotation of the screw rotor 2, the gate rotor 3 rotates about the shaft 3a, and the compression chamber Compress the gas in C. The screw rotor 2 is rotated by a motor (not shown) housed in the casing 1.
That is, a low-pressure gas is sucked into the compression chamber C from one end side in the axis 2a direction of the screw rotor 2, the low-pressure gas is compressed in the compression chamber C, and then the compressed high-pressure gas is compressed. Gas is discharged from the discharge port 13 on the other end side of the screw rotor 2 in the axis 2a direction.
The gate rotor 3 includes a gate rotor main body 30 and a shaft portion 40 to which the gate rotor main body 30 is attached. The gate rotor body 30 meshes with the screw rotor 2. The shaft portion 40 is supported by the casing 1. The gate rotor body 30 is made of, for example, resin, and the shaft portion 40 is made of, for example, metal.

As shown in FIGS. 2 and 3, the gate rotor main body 30 has a disc shape and includes a plurality of tooth portions 31 on the outer peripheral surface and a central hole portion 32. FIG. 2 is a plan view of the gate rotor body, and FIG. 3 is a cross-sectional view taken along line AA of FIG.
The tooth portion 31 meshes with the groove portion 21 of the screw rotor 2. The center of the hole 32 coincides with the shaft 30 a of the gate rotor body 30. The gate rotor body 30 is provided with a pin hole 33, and a positioning pin (not shown) is inserted into the pin hole 33.
As shown in FIGS. 4 and 5, the shaft portion 40 includes a base portion 43, a first shaft portion 41 provided on one surface 43 a of the base portion 43, and a first portion provided on the other surface of the base portion 43. 2 shaft portions 42. 4 is a plan view of the shaft portion, and FIG. 5 is a cross-sectional view taken along the line BB of FIG.

The base portion 43 has a plurality of tooth portions 44 on the outer peripheral surface. The tooth portion 44 corresponds to the tooth portion 31 of the gate rotor main body 30. The base portion 43 is provided with a pin hole 45, and a positioning pin (not shown) is inserted into the pin hole 45. The axis of the first shaft portion 41 and the axis of the second shaft portion 42 coincide with the shaft 40 a of the shaft portion 40. The second shaft portion 42 is supported by the casing 1 via a bearing.
As shown in FIGS. 6 and 7, in the gate rotor 3, the gate rotor main body 30 is supported on the one surface 43 a of the base portion 43 of the shaft portion 40. The first shaft portion 41 of the shaft portion 40 is inserted into the hole portion 32 of the gate rotor body 30. 6 is a plan view of the gate rotor, and FIG. 7 is a sectional view taken along the line CC of FIG.
The elastic body 5 is disposed in the gap S between the first shaft portion 41 of the shaft portion 40 and the hole portion 32 of the gate rotor main body 30. In FIG. 6, the elastic body 5 is shown in black for easy understanding.

The elastic body 5 is a leaf spring. This leaf spring is an annular wave spring. The peak portion of the wave spring is located on the outer peripheral surface, and the valley portion of the wave spring is located on the inner peripheral surface. The peak portion of the wave spring is in contact with the inner peripheral surface of the hole portion 32 of the gate rotor body 30, and the valley portion of the wave spring is on the outer peripheral surface of the first shaft portion 41 of the shaft portion 40. Contact. Although not shown, this leaf spring may be a spiral spring.
The elastic body 5 is always biased so that the shaft 30a of the gate rotor main body 30 and the shaft 40a of the shaft portion 40 coincide with each other. When a force is applied to the gate rotor body 30 from the outside, the gate rotor body 30 moves on the base portion 43 of the shaft portion 40 against the elastic force of the elastic body 5.
The pin hole 33 of the gate rotor body 30 and the pin hole 45 of the shaft portion 40 are overlapped so that their axes coincide with each other, and a positioning pin (not shown) is inserted therethrough.

According to the gate rotor 3 having the above configuration, the elastic body 5 is disposed between the shaft portion 41 of the shaft portion 40 and the hole portion 32 of the gate rotor main body 30, and thus the gate rotor main body 30. Is slidable on the base portion 43 of the shaft portion 40.
For this reason, when this gate rotor 3 is used for a screw compressor, when the tooth portion 31 of the gate rotor main body 30 is engaged with the screw rotor 2 and the shaft portion 40 is supported by the casing 1, the compressor is in operation. While the thermal expansion of the screw rotor 2 increases, the thermal expansion of the casing 1 decreases, and the shaft 2a of the screw rotor 2 and the shaft 3a of the gate rotor 3 (that is, the shaft 40a of the shaft portion 40). The gate rotor body 30 slides on the base portion 43 of the shaft portion 40 even if the distance between the screw rotor 2 and the gate rotor body 30 is appropriately determined. Keep a good distance.

As a result, the gate rotor body 30 is prevented from biting into the screw rotor 2, the amount of wear of the gate rotor body 30 is reduced, and the compressor capacity is prevented from being lowered. Further, useless power due to the gate rotor body 30 and the screw rotor 2 being strongly pressed against each other is reduced. Further, the elastic body 5 can maintain the pressure contact force between the gate rotor body 30 and the screw rotor 2 to such an extent that gas does not leak from the compression chamber C.
Therefore, even if the gate rotor 3 is bent due to a temperature difference between the casing 1 and the screw rotor 2 during the operation of the compressor, the gate rotor 3 is prevented from biting into the screw rotor 2 with a simple configuration, and the gate The amount of wear of the rotor 3 is reduced to prevent the compressor from degrading.

Further, since the elastic body 5 is a leaf spring, the elastic body 5 can be configured simply. Further, since the leaf spring is an annular wave spring or spiral spring, the leaf spring can be configured simply.
According to the screw compressor of the above configuration, since the gate rotor 3 is provided, even if the gate rotor 3 is bent due to a temperature difference between the casing 1 and the screw rotor 2 during the operation of the compressor, Biting of the gate rotor 3 into the screw rotor 2 is prevented, the amount of wear of the gate rotor 3 is reduced, and deterioration of the compressor capacity is prevented.
(Second Embodiment)
FIG. 8 shows a second embodiment of the gate rotor of the present invention. The difference from the first embodiment will be described. In the second embodiment, the configuration of the elastic body is different. Note that the same reference numerals as those in the first embodiment have the same configurations as those in the first embodiment, and thus description thereof is omitted.

In the gate rotor 3A of the second embodiment, the elastic body 5A is an annular rubber. The outer peripheral surface of the annular rubber is in contact with the inner peripheral surface of the hole portion 32 of the gate rotor body 30, and the inner peripheral surface of the annular rubber is in contact with the first shaft portion 41 of the shaft portion 40. Contact the outer peripheral surface.
The elastic body 5A is always biased so that the axis of the gate rotor main body 30 and the axis of the shaft portion 40 coincide with each other. When a force is applied to the gate rotor body 30 from the outside, the gate rotor body 30 moves on the shaft portion 40 against the elastic force of the elastic body 5A.
Therefore, in addition to the function and effect of the first embodiment, since the elastic body 5A is an annular rubber, the elastic body 5A can be configured simply.

In addition, this invention is not limited to the above-mentioned embodiment. For example, the shaft portion of the shaft portion of the gate rotor may be one, the gate rotor body may be attached to the one shaft portion, and the one shaft portion may be supported by the casing. Further, the number of gate rotors may be increased or decreased.
(Third embodiment)
Next, a third embodiment of the screw compressor of the present invention will be described with reference to the drawings.
Conventionally, there is a screw compressor including a screw rotor having a spiral groove and a gate rotor having a plurality of teeth meshing with the spiral groove. This gate rotor is often manufactured from a synthetic resin, and reducing the wear of the teeth of the gate rotor is a problem.
Therefore, in order to give a degree of freedom in the rotation direction on the gate rotor support that supports the gate rotor, as in the screw compressor of US Pat. No. 4,890,989, a spring is used around the floating pin, On the other hand, a structure for facilitating movement of the gate rotor in the relative rotational direction has been proposed.

However, the screw compressor has a complicated structure and geometrically has limited parts accuracy and assembly accuracy, and the gap between the gate rotor teeth and the screw rotor groove may not be negligible, and the gap variation is further different. May become violent. Even if such a variation in the gap between the teeth of the gate rotor and the groove of the screw rotor occurs, the structure of the screw compressor disclosed in the above literature cannot absorb the variation in the gap.
In addition, during operation, the teeth of the gate rotor teeth are subjected to thermal expansion and load fluctuations, so that the teeth of the resin gate rotor are worn, causing a decrease in performance. In particular, since the teeth of the gate rotor are generally larger in height than in width, the expansion in the height direction (radial direction) increases when thermally expanded. When the teeth of the gate rotor extend in the radial direction, the tooth tip of the gate rotor is easily rubbed against the back wall of the groove of the screw rotor. Even if the gate rotor teeth are elongated due to such thermal expansion, the structure of the screw compressor disclosed in the above literature cannot absorb the tooth elongation.

Therefore, in a third embodiment described below, a screw compressor is provided that can suppress wear of the gate rotor and performance degradation due to wear.
<Configuration of single screw compressor 101>
A single screw compressor 101 shown in FIGS. 9 to 15 includes one screw rotor 102, a casing 103 that houses the screw rotor 102, a shaft 104 that serves as a rotation shaft of the screw rotor 102, and two gate rotors 105. , 106, a thrust bearing 107 that supports the screw rotor 102 from the axial direction, and

gate rotor shafts

108, 109 for the two

gate rotors

105, 106.
The screw rotor 102 is a cylindrical rotor having a plurality of spiral grooves 111 on the outer peripheral surface. The screw rotor 102 is integrated with the shaft 104 and can rotate inside the casing 103. The screw rotor 102 is supported by a thrust bearing 107 in a direction from the discharge side to the suction side along the axial direction (the direction opposite to the gas suction direction F1). One end of the shaft 104 is coupled to the screw rotor 102, and the other end is connected to a drive motor (not shown) outside the casing 103.

The casing 103 is a cylindrical member and accommodates the screw rotor 102 and the shaft 104 rotatably.
In each of the two gate rotors, that is, the first gate rotor 105 and the second gate rotor 106, an opening 121 is formed at the center, and a plurality of teeth 112 that engage with the groove 111 of the screw rotor 102 are radially formed around the opening 121. It is possible to rotate around the

gate rotor shafts

108 and 109.
The

gate rotors

105 and 106 of the third embodiment are made of synthetic resin. Here, it is preferable to manufacture the

gate rotors

105 and 106 with a synthetic resin having high pressure resistance and wear resistance because of being used for the screw compressor 101.
The

gate rotor shafts

108 and 109 are inserted into the respective openings 121 of the two

gate rotors

105 and 106, and rotatably support the

gate rotors

105 and 106. Specifically, the

gate rotor shafts

108 and 109 have gate rotor supports 127 that support the

gate rotors

105 and 106. The gate rotor support 127 is fixed coaxially to the

gate rotor shafts

108 and 109. The gate rotor support 127 is substantially similar to the

gate rotors

105 and 106 and has a slightly smaller dimension. The

gate rotors

105 and 106 are fixed by pins 124 so that they cannot rotate with respect to the gate rotor support 127. The

gate rotor shafts

108 and 109 are orthogonal to the shaft 104 of the screw rotor 102.

The teeth 112 of the

gate rotors

105 and 106 can mesh with the spiral groove 111 of the screw rotor 102 inside the casing 103 through a slit 114 formed in the casing 103. The two

gate rotors

105 and 106 are arranged symmetrically with respect to the rotation center of the screw rotor 102. In addition, you may arrange | position the

gate rotors

105 and 106 symmetrically up and down.
When the screw rotor 102 rotates, the plurality of teeth 112 of the first gate rotor 105 and the second gate rotor 106 can sequentially mesh with the plurality of grooves 111.
The

gate rotor shafts

108 and 109 are inserted into the openings 121 of the

gate rotors

105 and 106 with a gap 122. The

gate rotor shafts

108 and 109 rotatably support the

gate rotors

105 and 106.

The gap 122 is preferably in the range of about 0.1 to 0.8 mm. That is, if the gap 122 is less than 0.1 mm, the radial extension of the teeth of the

gate rotors

105 and 106 cannot be absorbed, and if it exceeds 0.8 mm, the rotational runout of the

gate rotors

105 and 106 increases, and the teeth 112 Since it becomes difficult to normally engage with the groove 111, the above range is set in consideration of these problems.
A coil spring 128 that is a first elastic body is disposed in a gap 122 between the opening 121 of the

gate rotors

105 and 106 and the

gate rotor shafts

108 and 109.
In addition, the O-ring 129 that is the second elastic body is around the floating pin 124 of at least one of the plurality of detent pins 123 and 124 that stop the rotation of the

gate rotors

105 and 106 around the

gate rotor shafts

108 and 109. Is arranged.

Thus, the gap 122 is formed around the

gate rotor shafts

108 and 109, and the gate rotor 105 is formed by the coil spring 128 and the O-ring 129 around the floating pin 124 disposed in the gap 122 around the

gate rotor shafts

108 and 109. 106, the radial extension of the teeth 112 can be absorbed.
Here, the adjustment of the clearance between the tooth tips of the teeth 112 of the

gate rotors

105 and 106 and the inner wall of the groove 111 of the screw rotor 102, that is, the clearance between the tips, is performed by suction temperature or normal temperature (environmental temperature) during low-load operation. , The tooth tips of the teeth 112 of the

gate rotors

105 and 106 are adjusted so as to contact the inner wall of the groove 111 of the screw rotor 102.
The coil spring 126 disposed in the gap 122 is partly with respect to the

gate rotors

105 and 106, and the radius of the

gate rotors

105 and 106 is directed toward the guide pin 123 that is one of the plurality of detent pins 123 and 124. An elastic force in the direction is given. Accordingly, the coil spring 126 can effectively absorb the radial extension of the teeth 112 whose movement in the radial direction is restricted by the guide pins 123.

The floating pin 124 connects the

gate rotor shafts

108 and 109 and the

gate rotors

105 and 106 in a state having more play than the other detent pins (guide pins 123).
The floating pin 124 is closely fitted to the

gate rotors

105 and 106 without any play. However, the floating pin 124 is free to move (movable) in the rotation direction of the

gate rotors

105 and 106 with respect to the gate rotor support 127. In a state having not only a margin of play but also play in the radial direction (movable margin), the connection is loose.
Therefore, since one floating pin 124 of the two detent pins can be moved more largely than the other guide pin 123, the radial extension of the teeth 112 of the

gate rotors

105 and 106 is absorbed. It is possible.

The play (movable) in the radial direction of the

gate rotors

105 and 106 of the floating pin 124 is 0.1 to 0 .0 so that the amount of elongation due to thermal expansion in the radial direction of the teeth of the

gate rotors

105 and 106 can be absorbed. It is set to about 8 mm. If it is less than 0.1 mm, the extension of the teeth 112 cannot be sufficiently absorbed by the movable margin of the floating pin 124, and if it exceeds 0.8 mm, the smooth rotation of the

gate rotors

105 and 106 is affected.
The O-ring 129 that is the second elastic body has a ring shape and is arranged around the floating pin 124. The O-ring 129 can absorb the radial extension of the teeth 112 of the

gate rotors

105 and 106.
The O-ring 129 is a ring-shaped member made of an elastic material that is more flexible than the gate rotor 105 (lower Young's modulus). For example, the O-ring 129 can be manufactured from synthetic rubber, synthetic resin, or other elastic materials.

A discharge port 110 for discharging the refrigerant gas compressed inside the casing 103 is opened on the outer peripheral surface of the casing 103 one by one corresponding to the first gate rotor 105 and the second gate rotor 106. ing.
These discharge ports 110 are opened at appropriate positions on the outer peripheral surface of the casing 103 so as to be able to communicate with the grooves 111 on the outer peripheral surface of the screw rotor 102 when the screw rotor 102 rotates.
<Description of Operation of Single Screw Compressor 101>
The single screw compressor 101 shown in FIGS. 9 to 15 compresses gas as follows.
First, when the shaft 104 receives a rotational driving force from a motor (not shown) outside the casing 103, the screw rotor 102 rotates in the direction of arrow R1 (see FIG. 9). At this time, the two

gate rotors

105 and 106 meshing with the spiral groove 111 of the screw rotor 102 rotate in the direction of the arrow R <b> 2 when the teeth 112 are pushed against the inner wall of the spiral groove 111. At this time, on the front side of the paper surface of the screw rotor 102 in FIGS. 9 to 10, the compression on the front side of the paper surface formed by being partitioned by the inner surface of the casing 103, the groove 111 of the screw rotor 102, and the teeth 112 of the gate rotor 105. The chamber volume is reduced. At the same time, on the back side of the paper surface of the screw rotor 102, the volume of the compression chamber on the back side of the paper surface formed by the inner surface of the casing 103, the groove 111 of the screw rotor 102, and the teeth 112 of the gate rotor 106 is reduced. To do.

By utilizing the reduction in volume of these two compression chambers, the refrigerant F1 (see FIG. 10) before compression introduced from the suction side opening 115 of the casing 103 is compressed immediately before the groove 111 and the teeth 112 are engaged with each other. The volume of the compression chamber is reduced while the groove 111 and the teeth 112 are engaged with each other and the refrigerant is compressed, and then the compressed refrigerant is immediately after the engagement between the grooves 111 and the teeth 112 is released. F2 (see FIG. 10) is discharged from the discharge port 10 that opens to the front side and the back side of FIG. 10 corresponding to the

gate rotors

105 and 106, respectively.
<Characteristics of Third Embodiment>
(1)
In the screw compressor 101 of the third embodiment, a gap 122 is formed around the

gate rotor shafts

108 and 109, and the coil springs 128 and the floating pins 124 around the

gate rotor shafts

108 and 109 are arranged around the

gate spring shafts

108 and 109. The O-ring 129 can absorb the radial extension of the teeth 112 of the

gate rotors

105 and 106. As a result, the tooth tips of the teeth 112 of the

gate rotors

105 and 106 are not rubbed and worn by the inner wall of the groove 111 of the screw rotor 102, and the wear of the

gate rotors

105 and 106 can be prevented.

(2)
Further, it is possible to manage the gap between the tooth tips of the teeth 112 of the

gate rotors

105 and 106 and the back wall of the groove 111 of the screw rotor 102, that is, the tip gap. For example, the tip clearance is automatically adjusted according to changes in operating conditions. Thereby, it is possible to prevent the performance of the screw compressor 101 from being deteriorated.
(3)
In addition, since the degree of freedom of processing accuracy and assembly accuracy of the screw compressor 101 is widened, it is possible to reduce the manufacturing cost.
(4)
Moreover, even if the refrigerant gas, which is a compression medium, is in a so-called liquid compression state that is introduced into the screw compressor 101 in a liquid state, the load applied to the teeth 112 of the

gate rotors

105 and 106 may fluctuate. Abnormal wear of the teeth 112 of the

rotors

105 and 106 or seizure that occurs between the

gate rotors

105 and 106 and the screw rotor 102 can be prevented. Thereby, the reliability of the screw compressor 101 can be improved.

For example, it includes a gap 122 between the opening 121 of the

gate rotors

105 and 106 and the

gate rotor shafts

108 and 109, a coil spring 128 arranged in the gap 122, and an O-ring 129 arranged around the floating pin 124. The

gate rotors

105 and 106 can move in the radial direction, so that even if abnormal liquid compression occurs, the liquid refrigerant can escape to the outside of the screw compressor 101 from the tip clearance.
(5)
Furthermore, in the screw compressor 101 of the third embodiment, the coil spring 126 disposed in the gap 122 is partially directed toward the guide pin 123 with respect to the

gate rotors

105 and 106 in the radial direction of the

gate rotors

105 and 106. An elastic force is given. Therefore, for the teeth 112 whose movement in the radial direction is restricted by the guide pins 123, the radial extension can be effectively absorbed by the coil spring 126.

(6)
In the screw compressor 101 of the third embodiment, one of the plurality of detent pins 123 and 124 has more play than the other detent pins (guide pins 123), and the

gate rotor shafts

108 and 109. Since the floating pin 124 is connected to the

gate rotors

105 and 106, the floating pin 124 can be moved larger than the guide pin 123, whereby the diameter of the teeth 112 of the

gate rotors

105 and 106 can be increased. It is possible to absorb the elongation in the direction.
(7)
In the screw compressor 101 of the third embodiment, the O-ring 129 that is the second elastic body has a ring shape and is arranged around the floating pin 124, so that the teeth 112 of the

gate rotors

105 and 106 It is possible to absorb radial elongation.

Further, if the dimensions and material of the O-ring 129 are appropriately changed in accordance with the radial extension of the teeth 112 of the

gate rotors

105 and 106, the wear state of the tooth tips, etc., the life of the

gate rotors

105 and 106 is extended. Is also possible.
<Modification of Third Embodiment>
(A)
In the third embodiment, there is provided a configuration including both two types of elastic bodies, that is, a coil spring 128 disposed in the gap 122 around the

gate rotor shafts

108 and 109 and an O-ring 129 around the floating pin 124. However, the present invention is not limited to this.
As a modification of the present invention, either one of the elastic bodies, that is, one of the coil spring 128 disposed in the gap 133 around the

gate rotor shafts

108 and 109 or the O-ring 129 around the floating pin 124 is provided. Even in the configuration, it is possible to absorb the radial extension of the teeth 112 of the

gate rotors

105 and 106.

(B)
In the third embodiment, the coil spring 126 has been described as an example of the elastic body disposed in the gap 122 in the present invention. However, the present invention is not limited to this, and the ring-shaped elasticity is not limited thereto. The body may fill the entire gap 122. In this case, it is possible to absorb the radial extension of the teeth 112 of the

gate rotors

105 and 106 for the entire circumference of the

gate rotors

105 and 106.
Moreover, the life of the teeth 112 of the

gate rotors

105 and 106 can be further extended by filling the entire gap 122 with a ring-shaped elastic body.

The present invention can be widely applied to a screw compressor including a screw rotor and a gate rotor.

Claims

A gate rotor body (30);
A shaft portion (40) for attaching the gate rotor body (30),
The gate rotor body (30) has a plurality of teeth (31) and a central hole (32),
The shaft portion (40) is provided on a base portion (43) for supporting the gate rotor body (30) on one surface (43a), and on one surface (43a) of the base portion (43), and the hole portion (32). And a shaft portion (41) inserted into
An elastic body (5, 5A) is disposed between the shaft portion (41) of the shaft portion (40) and the hole portion (32) of the gate rotor body (30). Rotor.
The gate rotor according to claim 1,
The gate rotor, wherein the elastic body (5) is a leaf spring.
The gate rotor according to claim 2,
The gate rotor, wherein the leaf spring is an annular wave spring or spiral spring.
The gate rotor according to claim 1,
The gate rotor, wherein the elastic body (5A) is an annular rubber.
A casing (1) having a cylinder (10);
A cylindrical screw rotor (2) fitted to the cylinder (10);
The gate rotor (3, 3A) according to any one of claims 1 to 4, which meshes with the screw rotor (2).
The tooth portion (31) of the gate rotor body (30) of the gate rotor (3, 3A) meshes with the screw rotor (2),
The screw compressor, wherein the shaft portion (40) of the gate rotor (3, 3A) is supported by the casing (1).
A rotatable screw rotor (102) having a plurality of spiral grooves (111) on the outer peripheral surface;
An opening (121) is formed in the center, and a plurality of teeth (112) that mesh with the grooves (111) of the screw rotor (102) are radially arranged around the opening (121). When,
A gate rotor shaft (108, 109) inserted in a state having a gap (122) in the opening (121) of the gate rotor (105, 106);
A gap (122) between the opening (121) of the gate rotor (105, 106) and the gate rotor shaft (108, 109) and / or the gate rotor shaft (108, 109) of the gate rotor (105, 106) An elastic body (128, 129) disposed around at least one of the plurality of detent pins for stopping rotation of the rotation;
Screw compressor (101).
The elastic body (128) disposed in the gap (122) is directed toward one of the plurality of detent pins with respect to the gate rotor (105, 106). Gives the elastic force in the radial direction of
The screw compressor (101) according to claim 6.
The elastic body disposed in the gap (122) is ring-shaped and fills the entire gap (122).
The screw compressor (101) according to claim 6.
One of the plurality of detent pins is a floating pin that connects between the gate rotor shaft and the gate rotor in a state having play more than other detent pins.
Screw compressor (101) according to any of claims 6 to 8.
The elastic body (129) has a ring shape, and is disposed around the rotation prevention pin that is the floating pin.
The screw compressor (101) according to claim 9.