WO2019224943A1

WO2019224943A1 - Screw compressor

Info

Publication number: WO2019224943A1
Application number: PCT/JP2018/019839
Authority: WO
Inventors: 伊藤　雄二; 大嗣堀内
Original assignee: 株式会社日立産機システム
Priority date: 2018-05-23
Filing date: 2018-05-23
Publication date: 2019-11-28
Also published as: JPWO2019224943A1; JP6924902B2

Abstract

Provided is a screw compressor in which machine power for supplying cooling liquid to a cooling flow passage for a screw rotor is reduced. The male rotor 1A of this screw compressor is provided with: a tooth section 6A having a helically shaped outer peripheral surface 20A and a helically shaped inner peripheral surface 21A; a solid section 24A which is disposed inside the tooth section 6A and which has a helically shaped outer peripheral surface 25A; a suction-side shaft section 7A which has a through-hole 28A communicating with a cooling flow passage 27A formed between the tooth section 6A and the solid section 24A; and a discharge-side shaft section 8A which has a through-hole 29A communicating with the cooling flow passage 27A. The screw compressor is configured so that cooling oil is supplied to the cooling flow passage 27A from an oil holder 17 through the through-hole 28A of the suction-side shaft section 7A, and the cooling oil is discharged to the oil holder 27 from the cooling flow passage 27A through the through-hole 29A of the discharge-side shaft section 8A.

Description

Screw compressor

The present invention relates to a screw compressor provided with a screw rotor.

The screw compressor includes, for example, a pair of male and female screw rotors and a casing that houses the screw rotor, and a working chamber is formed between the teeth of the screw rotor and the inner wall of the casing. The working chamber moves in the axial direction of the screw rotor as the screw rotor rotates, and sucks gas through the suction port on one axial side, compressing process for compressing gas, and the other side in the axial direction The discharge process of discharging the compressed gas through the discharge ports is sequentially performed. Since compression heat is generated in the compression process of the working chamber, the screw rotor and the like are heated and thermally expanded. Therefore, in order to suppress thermal expansion of the screw rotor, a technique for cooling the screw rotor has been proposed (see, for example, Patent Document 1).

The screw rotor described in Patent Document 1 includes a tooth portion having a spiral outer peripheral surface and a spiral inner peripheral surface corresponding to the spiral shape of the outer peripheral surface. More specifically, the outer peripheral surface of the tooth portion has a plurality of tooth crests protruding outward in the radial direction (in other words, a portion protruding outward in the radial direction), and these tooth crests spirally extend in the axial direction. It becomes the shape to do. The inner peripheral surface of the tooth portion has a plurality of tooth grooves (in other words, a portion recessed radially outward) formed along a plurality of tooth crests on the outer peripheral surface, and these tooth grooves are in the axial direction. It has a shape that extends spirally.

The screw rotor described in Patent Document 1 is connected to a cooling channel (hollow part) formed inside the tooth part and side plate parts on both outer sides in the axial direction of the tooth part, and has a through hole communicating with the cooling channel. And a cooling liquid (in detail, for example, oil or the like) flows through the cooling passage through the through hole of the shaft part.

JP 2006-097604 A

The conventional technique described in Patent Document 1 requires a pump for supplying a coolant to the cooling flow path of the screw rotor, and there is room for improvement in terms of reducing the mechanical power.

The present invention has been made in view of the above, and an object of the present invention is to reduce mechanical power for supplying the coolant to the cooling flow path of the screw rotor.

In order to solve the above problems, the configuration described in the claims is applied. The present invention includes a plurality of means for solving the above-mentioned problems. For example, the present invention includes a screw rotor and a casing for housing the screw rotor, and the screw rotor has a spiral outer periphery. And a tooth portion having a spiral inner peripheral surface corresponding to the spiral shape of the outer peripheral surface, and a spiral outer periphery disposed inside the tooth portion and corresponding to the spiral shape of the inner peripheral surface of the tooth portion A solid portion having a surface; a plurality of support portions connecting the tooth portion and the solid portion; and a suction side plate that is one side in the axial direction of the tooth portion; Connected to the suction-side shaft portion having a through-hole communicating with the cooling flow path formed between the solid portion and the discharge-side side plate portion on the other axial side of the tooth portion, And a discharge-side shaft that has a through-hole that communicates with it. From the cooling channel, the cooling liquid is supplied to the cooling passage through the through-hole in the suction-side shaft portion, and the cooling liquid is discharged from the cooling passage into the liquid reservoir through the through-hole in the discharge-side shaft portion. Configured to be

According to the present invention, the mechanical power for supplying the coolant to the cooling flow path of the screw rotor can be reduced.

In addition, problems, configurations and effects other than the above will be clarified by the following explanation.

It is a horizontal sectional view showing the structure of the screw compressor in one embodiment of the present invention. FIG. 2 is a vertical sectional view taken along line II-II in FIG. It is a perspective view showing the structure of the screw rotor in one Embodiment of this invention. It is a top view showing the structure of the screw rotor in one Embodiment of this invention. FIG. 5 is a radial cross-sectional view taken along line VV in FIG. 4 and represents the structure of the tooth portion and solid portion of the screw rotor according to an embodiment of the present invention. FIG. 5 is a radial cross-sectional view taken along the line VI-VI in FIG. 4 and represents the structure of the tooth portion and the support portion of the screw rotor in one embodiment of the present invention. FIG. 5 is a radial cross-sectional view taken along arrow VII-VII in FIG. 4 and represents the structure of the tooth portion and the support portion of the screw rotor according to an embodiment of the present invention. It is radial direction sectional drawing equivalent to FIG. 5, and represents the structure of the tooth | gear part, solid part, and support part of the screw rotor in other embodiment of this invention. It is radial direction sectional drawing equivalent to FIG. 6, and represents the structure of the tooth | gear part of the screw rotor in other embodiment of this invention. It is radial direction sectional drawing equivalent to FIG. 7, and represents the structure of the tooth | gear part of the screw rotor in other embodiment of this invention. It is a vertical sectional view showing the structure of the screw compressor in one modification of the present invention. It is a vertical sectional view showing the structure of the screw compressor in other modifications of the present invention.

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a horizontal sectional view showing the structure of the screw compressor in this embodiment, and FIG. 2 is a vertical sectional view taken along the line II-II in FIG. 2 shows an oil reservoir, a supply nozzle, and the like, but FIG. 1 omits them.

The screw compressor of the present embodiment includes a male rotor 1A and a female rotor 1B that are screw rotors, and a casing 2 that houses the male rotor 1A and the female rotor 1B. As shown in FIG. A working chamber 3 is formed between the teeth of the female rotor 1 </ b> B and the inner wall of the casing 2. In addition, the screw compressor of this embodiment is an oil-free type (specifically, oil that does not supply oil to the working chamber 3). Further, the male rotor 1A and the female rotor 1B are arranged such that their axial directions (left and right directions in FIGS. 1 and 2) are horizontal.

The working chamber 3 moves from one axial direction side (left side in FIG. 2) to the other side (right side in FIG. 2) as the male rotor 1A and female rotor 1B rotate, and the suction port on one axial direction side. An intake process for sucking air (gas) through 4 (opening), a compression process for compressing air, and a discharge process for discharging compressed air through the discharge port 5 (opening) on the other side in the axial direction are sequentially performed.

The male rotor 1A includes a tooth portion 6A, a suction side shaft portion 7A connected to one axial side (suction side) of the tooth portion 6A, and a discharge connected to the other axial side (discharge side) of the tooth portion 6A. A side shaft portion 8A. The male rotor 1A is rotatably supported by a suction side bearing 9A disposed on the outer peripheral side of the suction side shaft portion 7A and a plurality of discharge side bearings 10A disposed on the outer peripheral side of the discharge side shaft portion 8A.

The female rotor 1B includes a tooth portion 6B, a suction side shaft portion 7B connected to one axial side (suction side) of the tooth portion 6B, and a discharge connected to the other axial side (discharge side) of the tooth portion 6B. Side shaft portion 8B. The female rotor 1B is rotatably supported by a suction side bearing 9B disposed on the outer peripheral side of the suction side shaft portion 7B and a plurality of discharge side bearings 10B disposed on the outer peripheral side of the discharge side shaft portion 8B.

The tip end portion of the suction side shaft portion 7A of the male rotor 1A protrudes from the casing 2 and is provided with a pinion gear 11. Although not shown, the pinion gear 11 is connected to the rotating shaft of the motor via, for example, a gear mechanism and a belt mechanism. When the rotational force of the motor is transmitted to the male rotor 1A through the pinion gear 11, the gear mechanism, and the belt mechanism, the male rotor 1A rotates.

Timing gears 12A and 12B are provided on the discharge side shaft portion 8A of the male rotor 1A and the discharge side shaft portion 8B of the female rotor 1B, respectively, and the timing gears 12A and 12B are engaged with each other. When the rotational force of the male rotor 1A is transmitted to the female rotor 1B via the timing gears 12A and 12B, the female rotor 1B rotates. Thereby, the male rotor 1A and the female rotor 1B rotate so as to mesh with each other in a non-contact manner.

The casing 2 includes a main casing 13, a suction side casing 14 connected to one axial side (suction side) of the main casing 13, and a discharge side casing connected to the other axial side (discharge side) of the main casing 13. 15. The suction side casing 14 houses the suction side shaft portion 7A of the male rotor 1A, the suction side shaft portion 7B of the female rotor 1B, and the

suction side bearings

9A and 9B. The main casing 13 includes a tooth portion 6A of the male rotor 1A and a proximal end portion of the discharge side shaft portion 8A, a tooth portion 6B of the female rotor 1B and a proximal end portion of the discharge side shaft portion 8B, and discharge

side bearings

10A and 10B. Storing. The gear chamber 16 of the discharge-side casing 15 accommodates the tip end portion of the discharge-side shaft portion 8A of the male rotor 1A, the tip end-side portion of the discharge-side shaft portion 8B of the female rotor 1B, and the timing gears 12A and 12B.

The pinion gear 11 and the above-described gear mechanism are housed in a gear casing, and an oil reservoir 17 (liquid reservoir) is formed in the lower portion of the gear casing. The oil in the oil sump 17 is supplied to the

bearings

9A, 9B, 10A, 10B, the pinion gear 11 and the gear mechanism via an oil supply system (not shown) (specifically, an oil pump, an oil filter, a pipe, etc.). , And timing gears 12A, 12B and the like. The oil that has lubricated the discharge-

side bearings

10A and 10B and the timing gears 12A and 12B is collected in the oil reservoir 17 via the gear chamber 16 and the discharge pipe 18 of the discharge-side casing 15.

Next, the structure of the screw rotor of this embodiment will be described. 3 and 4 are a perspective view and a top view showing the structure of the screw rotor in the present embodiment. 5 is a radial sectional view taken along the arrow VV in FIG. 4, FIG. 6 is a radial sectional view taken along the arrow VI-VI in FIG. 4, and FIG. 7 is a sectional view taken along the arrow VII in FIG. It is radial direction sectional drawing by -VII.

First, the structure of the male rotor 1A will be described. The tooth portion 6A of the male rotor 1A includes a spiral outer peripheral surface 20A, a spiral inner peripheral surface 21A corresponding to the spiral shape of the outer peripheral surface 20A, a suction-side side plate portion 22A that is one side in the axial direction, A discharge-side side plate portion 23A that is the other side in the axial direction. More specifically, the outer peripheral surface 20A of the tooth portion 6A has a plurality of tooth crests (in other words, a portion projecting radially outward) as shown in FIGS. 3 to 7, and these tooth crests extend in the axial direction. It has a shape that extends spirally. As shown in FIG. 5 to FIG. 7, the inner peripheral surface 21A of the tooth portion 6A has a plurality of tooth grooves formed along a plurality of tooth crests of the outer peripheral surface 20A (in other words, a portion recessed radially outward). These tooth spaces are spirally extended in the axial direction.

The male rotor 1A includes a solid portion 24A arranged inside the tooth portion 6A. The solid portion 24A has a helical outer peripheral surface 25A corresponding to the helical shape of the inner peripheral surface 21A of the tooth portion 6A. Have. More specifically, the outer peripheral surface 25A of the solid portion 24A has a plurality of tooth crests (in other words, a radial direction) respectively formed along a plurality of tooth grooves of the inner peripheral surface 21A of the tooth portion 6A as shown in FIG. And the tooth crests are spirally extended in the axial direction.

The male rotor 1A includes a plurality of support portions 26A that connect the tooth portion 6A and the solid portion 24A. The plurality of support portions 26A include a plurality of tooth portions (in other words, portions protruding inward in the radial direction) of the inner peripheral surface 21A of the tooth portion 6A and a plurality of outer peripheral surfaces 25A of the solid portion 24A corresponding thereto. Are connected to the bottom portions of the tooth grooves (in other words, the portions recessed inward in the radial direction) and extend spirally over the entire axial direction of the solid portion 24A (or at a plurality of axial positions). .

A cooling flow path 27A is formed between the tooth portion 6A and the solid portion 24A of the male rotor 1A. The suction side shaft portion 7A of the male rotor 1A is connected to the suction side plate portion 22A of the tooth portion 6A and has a through hole 28A communicating with the cooling flow path 27A. The discharge-side shaft portion 8A of the male rotor 1A is connected to the discharge-side plate portion 23A of the tooth portion 6A and has a through hole 29A communicating with the cooling flow path 27A. As shown in FIG. 2 described above, a supply nozzle 30 for supplying oil from the oil reservoir 17 to the through hole 28A of the suction side shaft portion 7A of the male rotor 1A is provided. Thus, oil (coolant) is supplied from the oil reservoir 17 to the cooling flow path 27A through the supply nozzle 30 and the through hole 28A of the suction side shaft portion 7A. Further, as shown in FIG. 2 described above, oil is discharged from the cooling flow path 27A of the male rotor 1A to the gear chamber 16 of the discharge side casing 15 through the through hole 29A of the discharge side shaft portion 8A. It is collected in the oil sump 17 via the pipe 18.

The supply nozzle 30 is provided independently of the male rotor 1A, and can supply oil from the oil reservoir 17 to the male rotor 1A even when the male rotor 1A rotates. Further, a seal is provided between the supply nozzle 30 and the male rotor 1A so that the supplied oil does not leak.

Next, the structure of the female rotor 1B will be described. The tooth portion 6B of the female rotor 1B includes a helical outer peripheral surface 20B, a helical inner peripheral surface 21B corresponding to the helical shape of the outer peripheral surface 20B, a suction-side side plate portion 22B that is one side in the axial direction, And a discharge-side side plate portion 23B which is the other side in the axial direction. More specifically, the outer peripheral surface 20B of the tooth portion 6B has a plurality of tooth crests (in other words, a portion projecting radially outward) as shown in FIGS. 3 to 7, and these tooth crests extend in the axial direction. It has a shape that extends spirally. As shown in FIGS. 5 to 7, the inner peripheral surface 21B of the tooth portion 6B has a plurality of tooth grooves formed along the plurality of tooth crests of the outer peripheral surface 20B (in other words, a portion recessed outward in the radial direction). These tooth spaces are spirally extended in the axial direction.

The female rotor 1B includes a solid portion 24B disposed inside the tooth portion 6B. The solid portion 24B has a helical outer peripheral surface 25B corresponding to the helical shape of the inner peripheral surface 21B of the tooth portion 6B. Have. More specifically, the outer peripheral surface 25B of the solid portion 24B has a plurality of tooth crests (in other words, a radial direction) formed along a plurality of tooth grooves on the inner peripheral surface 21B of the tooth portion 6B as shown in FIG. And the tooth crests are spirally extended in the axial direction.

The female rotor 1B includes a plurality of support portions 26B that connect the tooth portion 6B and the solid portion 24B. The plurality of support portions 26B include a plurality of tooth crests (in other words, portions protruding inward in the radial direction) of the inner peripheral surface 21B of the tooth portion 6B and a plurality of outer peripheral surfaces 25B of the solid portion 24B corresponding thereto. Are connected to the bottom portions of the tooth grooves (in other words, the portions recessed inward in the radial direction) and over the entire axial direction of the solid portion 24B (or the tooth portion 6B) (or at a plurality of axial positions). Extends in a spiral.

A cooling flow path 27B is formed between the tooth portion 6B and the solid portion 24B of the female rotor 1B, and the suction side shaft portion 7B of the female rotor 1B is connected to the suction side plate portion 22B of the tooth portion 6B. A through hole 28B communicating with the cooling flow path 27B is provided. The discharge-side shaft portion 8B of the female rotor 1B is connected to the discharge-side plate portion 23B of the tooth portion 6B and has a through hole 29B communicating with the cooling flow path 27B. Although not shown, a supply nozzle 30 for supplying oil from the oil reservoir 17 to the through hole 28B of the suction side shaft portion 7B of the female rotor 1B is provided. That is, oil (coolant) is supplied from the oil reservoir 17 to the cooling flow path 27B through the supply nozzle 30 and the through hole 28B of the suction side shaft portion 7B. Further, oil is discharged from the cooling flow path 27B of the female rotor 1B to the gear chamber 16 of the discharge side casing 15 through the through hole 29B of the discharge side shaft portion 8B, and this oil is stored in the oil reservoir 17 via the discharge pipe 18. To be recovered.

The supply nozzle 30 is provided independently of the female rotor 1B, and can supply oil from the oil reservoir 17 to the female rotor 1B even when the female rotor 1B rotates. Further, a seal is provided between the supply nozzle 30 and the female rotor 1B so that the supplied oil does not leak.

As described above, in the male rotor 1A of the present embodiment, the solid portion 24A is provided inside the tooth portion 6A, and the spiral inner periphery 21A of the tooth portion 6A and the spiral outer periphery of the solid portion 24A. A cooling channel 27A is formed between the surfaces 25A. Due to the structure of the cooling flow path 27A, the centrifugal force generated in the oil in the cooling flow path 27A by the rotation of the male rotor 1A is changed to the pushing force from the one axial side (suction side) to the other axial direction (discharge side). Can be converted. Then, compared to the case where the solid portion 24A is not provided or one of the inner peripheral surface 21A of the tooth portion 6A and the outer peripheral surface 25A of the solid portion 24A is not formed in a spiral shape, one side in the axial direction (suction side). To the other side (discharge side) in the axial direction can be increased.

Similarly, in the female rotor 1B of the present embodiment, the solid portion 24B is provided inside the tooth portion 6B, and the helical inner peripheral surface 21B of the tooth portion 6B and the helical outer peripheral surface 25B of the solid portion 24B are provided. The cooling flow path 27B is formed between the two. Due to the structure of the cooling flow path 27B, the centrifugal force generated in the oil in the cooling flow path 27B due to the rotation of the female rotor 1B is changed to the pushing force from one axial side (suction side) to the other axial direction (discharge side). Can be converted. Then, compared to the case where the solid portion 24B is not provided or one of the inner peripheral surface 21B of the tooth portion 6B and the outer peripheral surface 25B of the solid portion 24B is not spiraled, one side in the axial direction (suction side). To the other side (discharge side) in the axial direction can be increased.

Therefore, in this embodiment, a pump for supplying oil (coolant) to the cooling flow path 27A of the male rotor 1A and the cooling flow path 27B of the female rotor 1B is unnecessary, and the mechanical power can be reduced.

Further, in the male rotor 1A of the present embodiment, since the ratio of the area of the inner peripheral surface 21A of the tooth portion 6A to the volume of the cooling flow path 27A can be increased as compared with the case where the solid portion 24A is not provided, the tooth portion The cooling efficiency of 6A can be increased. Similarly, in the female rotor 1B of the present embodiment, the ratio of the area of the inner peripheral surface 21B of the tooth portion 6B to the volume of the cooling flow path 27B can be increased as compared with the case where the solid portion 24B is not provided. The cooling efficiency of the part 6B can be increased. Therefore, the temperature increase of the male rotor 1A and the female rotor 1B can be suppressed, and the thermal expansion of the male rotor 1A and the female rotor 1B can be suppressed. As a result, the gap between the male rotor 1A and the female rotor 1B and the gap between the

rotors

1A, 1B and the casing 2 can be reduced, and the compression performance can be improved.

Another embodiment of the present invention will be described with reference to FIGS. 8 to 10 are radial cross-sectional views corresponding to FIGS. 5 to 7 described above. Note that in this embodiment, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The male rotor 1A of the present embodiment includes a tooth portion 6A, a suction side shaft portion 7A, a discharge side shaft portion 8A, a solid portion 24A, and a cooling flow path 27A, as in the above embodiment. The male rotor 1A of the present embodiment includes a plurality of

support portions

31A and 32A instead of the support portion 26A of the above-described embodiment.

The plurality of support portions 31A connect the suction side plate portion 22A of the tooth portion 6A and one end of the solid portion 24A adjacent thereto, and a plurality of guide flow paths are provided between the plurality of support portions 31A. 33A (first guide channel) is formed. The plurality of guide channels 33A guide the oil flowing in from the through hole 28A of the suction side shaft portion 7A to the cooling channel 27A (that is, radially outward).

The plurality of support portions 32A connect the discharge side plate portion 23A of the tooth portion 6A and the other end portion of the solid portion 24A adjacent thereto, and a plurality of guide flow paths are provided between the plurality of support portions 32A. 34A (second guide channel) is formed. The plurality of guide channels 34A guide the oil flowing in from the cooling channel 27A to the through hole 29A of the discharge side shaft portion 8A (in other words, radially inward).

The female rotor 1B of this embodiment includes a tooth portion 6B, a suction side shaft portion 7B, a discharge side shaft portion 8B, a solid portion 24B, and a cooling flow path 27B, as in the above-described embodiment. The female rotor 1B of this embodiment includes a plurality of

support portions

31B and 32B instead of the support portion 26B of the above-described embodiment.

The plurality of support portions 31B connect the suction-side side plate portion 22B of the tooth portion 6B and one end of the solid portion 24B adjacent to the suction-side side plate portion 22B, and a plurality of guide flow paths are provided between the plurality of support portions 31B. 33B is formed. The plurality of guide channels 33B guide the oil flowing in from the through hole 28B of the suction side shaft portion 7B to the cooling channel 27B (that is, radially outward).

The plurality of support portions 32B connect the discharge-side side plate portion 23B of the tooth portion 6B and the other end portion of the solid portion 24B adjacent thereto, and a plurality of guide flow paths are provided between the plurality of support portions 32B. 34B is formed. The plurality of guide channels 34B guide the oil flowing in from the cooling channel 27B to the through hole 29B of the discharge side shaft portion 8B (in other words, radially inward).

Also in the present embodiment configured as described above, a pump for supplying oil (coolant) to the cooling flow path 27A of the male rotor 1A and the cooling flow path 27B of the female rotor 1B is provided as in the above-described one embodiment. It is unnecessary and the mechanical power can be reduced. Moreover, the cooling efficiency of the tooth | gear part 6A of the male rotor 1A and the tooth | gear part 6B of the female rotor 1B can be improved like the said one Embodiment.

In the above-described embodiment, the male rotor 1A includes the support portion 26A, and the female rotor 1B includes the support portion 26B. For example, in the other embodiment, the male rotor 1A includes the

support portions

31A and 32A. The female rotor 1B has been described with reference to the case where the

support portions

31B and 32B are provided as an example. However, the present invention is not limited to this, and modifications can be made without departing from the spirit and technical idea of the present invention. For example, the male rotor 1A may include

support portions

26A, 31A, and 32A, and the female rotor 1B may include

support portions

26B, 31B, and 32B.

In the above-described embodiment, the supply nozzle 30 has been described as an example in which no pump is interposed. However, the present invention is not limited to this, and the supply nozzle 30 can be modified without departing from the spirit and technical idea of the present invention. For example, as shown in FIG. 11, a pump 36 may be interposed in the supply nozzle 30. In such a modification, the power of the pump 36 can be reduced.

Moreover, in the said embodiment, although bearing 9A, 9B, 10A, 10B demonstrated taking the case where oil was supplied from an oil supply system as an example, it is not restricted to this, The range which does not deviate from the meaning and technical idea of this invention Can be deformed within. For example, as shown in FIG. 11, the suction side shaft portion 7A of the male rotor 1A may have a bearing liquid supply hole 37 for supplying oil from the through hole 28A to the suction side bearing 9A disposed on the outer peripheral side thereof. The discharge side shaft portion 8A may have a bearing liquid supply hole 38 for supplying oil from the through hole 29A to the discharge side bearing 10A disposed on the outer peripheral side thereof. Although not shown, similarly, the suction side shaft portion 7B of the female rotor 1B may have a bearing liquid supply hole 37 for supplying oil from the through hole 28B to the suction side bearing 9B disposed on the outer peripheral side thereof. The discharge-side shaft portion 8B may have a bearing liquid supply hole 38 for supplying oil from the through hole 29B to the discharge-side bearing 10B disposed on the outer peripheral side thereof.

Moreover, in the said embodiment, although the male rotor 1A and the female rotor 1B were arrange | positioned so that those axial directions might turn into a horizontal direction, and demonstrated as an example the case where the supply nozzle 30 was provided, it is not restricted to this. However, modifications can be made without departing from the spirit and technical idea of the present invention. For example, as shown in FIG. 12, the male rotor 1A and the female rotor 1B are such that their axial directions are vertical, and the tip of the suction side shaft portion 7A and the tip of the suction side shaft portion 7B are oil reservoirs 17. It may be arranged so as to be immersed in. By configuring in this way, the configuration such as the supply nozzle 30 and the seal between the supply nozzle 30 and the rotor can be omitted, and the possibility of oil leakage can be reduced.

In the above embodiment, the screw compressor has been described by way of example in which the screw compressor is configured to supply oil as cooling liquid to the cooling flow path 27A of the male rotor 1A and the cooling flow path 27B of the female rotor 1B. The present invention is not limited to this, and modifications can be made without departing from the spirit and technical idea of the present invention. The screw compressor may be configured to supply, for example, water as a cooling liquid to the cooling flow path 27A of the male rotor 1A and the cooling flow path 27B of the female rotor 1B.

In the above description, an oil-free screw compressor has been described as an example of application of the present invention. However, the present invention is not limited to this, and is not limited to this. A liquid-feed type (specifically, a small amount of oil or water in the working chamber) It may be a screw compressor that supplies liquid. If the liquid supplied to the working chamber and the liquid supplied to the cooling channel of the rotor are the same, a through hole is formed in the tooth portion of the rotor, and the cooling channel of the rotor passes through the through hole to the working chamber. A liquid may be supplied. In that case, in order to avoid outflow of compressed gas from the working chamber to the cooling channel of the rotor, it is desirable to form a through hole at a position where the pressure in the working chamber is lower than the pressure in the cooling channel of the rotor.

Moreover, although the screw compressor provided with the male rotor 1A and the female rotor 1B which are two screw rotors was demonstrated to the example as an application object of this invention, it is not restricted to this, For example, one or three or more screws It may be a screw compressor provided with a rotor. Moreover, in the screw compressor provided with the some screw rotor, all the some screw rotors may have the characteristics of this invention, and only one part may have the characteristics of this invention.

DESCRIPTION OF SYMBOLS 1A ... Male rotor, 1B ... Female rotor, 2 ... Casing, 3 ... Working chamber, 4 ... Suction port, 5 ... Discharge port, 6A, 6B ... Tooth part, 7A, 7B ... Suction side axial part, 8A, 8B ... Discharge Side shaft portion, 9A, 9B ... suction side bearing, 10A, 10B ... discharge side bearing, 11 ... pinion gear, 12A, 12B ... timing gear, 13 ... main casing, 14 ... suction side casing, 15 ... discharge side casing, 16 ... Gear chamber, 17 ... Oil sump, 18 ... Drain pipe, 20A, 20B ... Outer peripheral surface of tooth portion, 21A, 21B ... Inner peripheral surface of tooth portion, 22A, 22B ... Suction side plate portion of tooth portion, 23A, 23B ... Discharge side plate part of tooth part, 24A, 24B ... solid part, 25A, 25B ... outer peripheral surface of solid part, 26A, 26B ... support part, 27A, 27B ... cooling flow path, 28A, 28B ... suction side shaft part Through holes, 29A, 29 ... through hole in discharge side shaft part, 30 ... supply nozzle, 31A, 31B ... support part (first support part), 32A, 32B ... support part (second support part), 33A, 33B ... guide flow path (first Guide channel), 34A, 34B ... Guide channel (second guide channel), 36 ... Pump, 37 ... Bearing liquid supply hole in suction side shaft part, 38 ... Bearing liquid supply hole in discharge side shaft part

Claims

A screw rotor and a casing for storing the screw rotor;
The screw rotor is
A tooth portion having a helical outer peripheral surface and a helical inner peripheral surface corresponding to the helical shape of the outer peripheral surface;
A solid portion disposed inside the tooth portion and having a helical outer peripheral surface corresponding to a helical shape of the inner peripheral surface of the tooth portion;
A plurality of support portions connecting the tooth portion and the solid portion;
A suction-side shaft portion connected to a suction-side side plate portion, which is one side in the axial direction of the tooth portion, and having a through hole communicating with a cooling flow path formed between the tooth portion and the solid portion; ,
A discharge-side shaft portion having a through-hole connected to the discharge-side side plate portion, which is the other axial side of the tooth portion, and communicating with the cooling flow path;
Cooling liquid is supplied from the liquid reservoir to the cooling flow path through the through hole in the suction-side shaft portion, and the cooling liquid is supplied from the cooling flow path to the liquid reservoir through the through-hole in the discharge-side shaft portion. A screw compressor configured to be discharged.
The screw compressor according to claim 1,
The plurality of support portions respectively connect the top portions of the plurality of tooth crests on the inner peripheral surface of the tooth portion and the bottom portions of the plurality of tooth gaps on the outer peripheral surface of the solid portion corresponding thereto, and in the axial direction. A screw compressor characterized by extending spirally.
The screw compressor according to claim 1,
The plurality of support portions are:
A plurality of first support portions connecting the side plate portion on the suction side of the tooth portion and one side end portion of the solid portion adjacent thereto; and
It is composed of a side plate portion on the discharge side of the tooth portion and a plurality of second support portions that connect the other end portion of the solid portion adjacent to the side portion,
A screw characterized in that a plurality of first guide channels are formed between the plurality of first support portions, and a plurality of second guide channels are formed between the plurality of second support portions. Compressor.
The screw compressor according to claim 1,
A screw compressor comprising a supply nozzle for supplying a cooling liquid from the liquid reservoir to a through hole of the shaft portion on the suction side.
The screw compressor according to claim 4, wherein
A screw compressor comprising a pump provided in the supply nozzle.
The screw compressor according to claim 1,
The screw compressor, wherein the screw rotor is arranged so that a tip of a shaft portion on the suction side is immersed in the liquid reservoir.
The screw compressor according to claim 1,
At least one of the suction-side shaft portion and the discharge-side shaft portion has a bearing liquid supply hole for supplying a coolant from the through hole to a bearing disposed on the outer peripheral side thereof. Compressor.