CN110679064A

CN110679064A - Rotating electric machine and semi-hermetic screw compressor provided with same

Info

Publication number: CN110679064A
Application number: CN201880037933.4A
Authority: CN
Inventors: 壶井昇; 垣内哲也; 铃木胜之; 神吉英次; 大仓正词
Original assignee: Kobe Steel Workshop
Current assignee: Kobe Steel Workshop; Kobe Steel Ltd
Priority date: 2017-06-09
Filing date: 2018-05-24
Publication date: 2020-01-10
Also published as: JP2018207761A; WO2018225523A1; JP6971644B2

Abstract

The motor (3) is provided with a stator (33) and a rotor (32) which are arranged in a corrosive gas atmosphere. The stator (33) is provided with a stator core (41) and a plurality of windings (42). The annular member (54) has corrosion resistance against corrosive gas and is disposed outside the winding end (42 b). The binding belt (45) has corrosion resistance against corrosive gas, and binds and fixes the winding end (42 b) to the annular member (44).

Description

Rotating electric machine and semi-hermetic screw compressor provided with same

Technical Field

The present invention relates to a rotating electric machine and a semi-hermetic screw compressor including the same.

Background

The stator of the rotating electric machine disclosed in patent document 1 has a winding end supporting device that allows thermal expansion of the winding and suppresses deformation of the winding end caused by electromagnetic force.

Patent document 1: japanese patent laid-open No. S48-57101.

The winding end supporting device of patent document 1 includes a support ring that fixes the winding end to suppress deformation due to electromagnetic force, and a support arm that is fixed to a fixing member, and has a complicated structure in which the support ring and the support arm are coupled to each other so as to allow displacement due to thermal expansion of the winding.

The winding end support device of patent document 1 does not consider the use of a corrosive gas atmosphere such as an ammonia gas atmosphere. In general, varnish, epoxy resin, or the like is applied to the winding end to reinforce the winding end, thereby suppressing deformation of the winding end due to electromagnetic force. However, for example, varnish, epoxy resin, and the like corrode in an ammonia gas atmosphere, and this method cannot be employed.

Disclosure of Invention

The purpose of the present invention is to allow thermal expansion of the winding of a stator and suppress deformation caused by electromagnetic force of the winding end by a simple configuration in a corrosive gas atmosphere.

A first aspect of the present invention is a rotating electrical machine including a stator and a rotor arranged in a corrosive gas atmosphere, wherein the stator includes a stator core, a plurality of windings, a 1 st support member, and a 1 st bundling member, the plurality of windings are formed of a plurality of wires wound around the stator core, and each of the plurality of windings includes a winding side accommodated in the stator core and a winding end arranged outside an end portion of the stator core, the 1 st support member is corrosion resistant with respect to the corrosive gas and arranged outside the winding end, the 1 st bundling member is corrosion resistant with respect to the corrosive gas, the winding end is bundled and fixed with respect to the 1 st support member, and the 1 st support member is not fixed to an element other than the winding end.

The winding end is fixed by the 1 st bundling member with respect to the 1 st supporting member, whereby deformation of the winding end due to the electromagnetic force is suppressed or prevented. The 1 st support member is not connected to an element other than the winding end, and therefore allows thermal expansion of the winding. With such a simple structure that the winding end is bound and fixed to the 1 st supporting member by the 1 st binding member, thermal expansion of the winding of the stator is allowed, and deformation of the winding end due to electromagnetic force can be suppressed. Since both the 1 st supporting member and the 2 nd bundling member have corrosion resistance against corrosive gas, the suppression of deformation of the winding end due to electromagnetic force is not affected by corrosion of the 1 st supporting member or the 2 nd bundling member.

The corrosive gas is, for example, ammonia gas. The lead may include a core wire made of aluminum or an aluminum alloy, and a teflon outer covering the core wire.

The 1 st supporting member is, for example, an annular member or an arc-shaped member.

The first binding member 1 may be a flexible elongated member. In this case, the winding end is bound to the 1 st supporting member by the 1 st binding member.

The winding device further includes a bundling element for bundling the plurality of wires at a portion of the winding end adjacent to the winding side.

With this configuration, deformation of the winding end due to electromagnetic force can be more reliably suppressed without affecting the allowable thermal expansion of the winding.

Specifically, the bundling element may include a collar member that surrounds the outside of the plurality of lead wires, and a fastening member that fastens the collar member and the plurality of windings together.

The rotating electric machine may further include a 2 nd support member disposed outside the winding end and having corrosion resistance to the corrosive gas, and a 2 nd binding member having corrosion resistance to the corrosive gas and binding and fixing the winding end to the 2 nd support member. In this case, the 2 nd support member is not fixed to the element other than the winding end.

The rotating electric machine may further include a 3 rd supporting member disposed inside an end portion of the winding end and having corrosion resistance to the corrosive gas, and a 3 rd binding member having corrosion resistance to the corrosive gas and binding and fixing the winding end to the 3 rd supporting member. In this case, the 3 rd supporting member is not fixed to the element other than the winding end.

A second aspect of the present invention provides a semi-hermetic screw compressor comprising the rotary electric machine according to the first aspect of the present invention and a screw compressor main body for compressing the corrosive gas, wherein the rotary electric machine is an electric motor for driving the screw compressor main body, and a casing of the electric motor for housing the fixed member and the rotary member and a casing of the screw compressor main body are connected in a state where inner spaces thereof communicate with each other.

Effects of the invention

According to the rotary electric machine and the semi-hermetic screw compressor including the rotary electric machine of the present invention, it is possible to suppress deformation of the winding end due to electromagnetic force while allowing thermal expansion of the winding of the stator with a simple structure in a corrosive gas atmosphere.

Drawings

Fig. 1 is a sectional view of a compressor including a motor according to embodiment 1 of the present invention.

Fig. 2 is a view of the fixture as viewed from the direction of arrow a in fig. 1.

Figure 3 is a side view of the fixture.

Fig. 4 is an enlarged partial cross-sectional view showing the coil ends and the annular member.

Fig. 5 is a cross-sectional view of a lead.

Fig. 6 is a sectional view of the ring member.

Fig. 7 is a sectional view of a portion where the winding edge protrudes from the end of the fixing member.

FIG. 8 is an enlarged partial cross-sectional view showing an alternative to the ring member.

Fig. 9 is a side view of a stator of a motor according to embodiment 2 of the present invention.

Fig. 10 is a view similar to fig. 2 of a stator of a motor according to embodiment 3 of the present invention.

Detailed Description

(embodiment 1)

The compressor 1 shown in fig. 1 is a semi-hermetic screw compressor, and includes a compressor main body 2 (screw compressor main body) and a motor 3 according to embodiment 1 of the present invention. The compressor body 2 includes a 1 st-stage compressor body 4 and a 2 nd-stage compressor body 5. The compressor body 2 of the present embodiment compresses ammonia gas, which is one of corrosive gases.

In fig. 1 of the casing 6 of the compressor main body 2, a casing 7 of the motor 3 is connected to the right side, and a connection space 8 sealed from the outside is defined between end portions of these

casings

6, 7.

The casing 6 of the compressor main body 2 includes a rotor chamber 12 in which the screw rotor pair 11 of the 1 st stage compressor main body 4 is rotatably accommodated, and a rotor chamber 14 in which the screw rotor pair 13 of the 2 nd stage compressor main body 5 disposed below the rotor chamber 12 is accommodated.

Rotor shafts

16 and 17 constituting the screw rotors of the respective

screw rotor pairs

11 and 13 are rotatably supported in a posture extending in the horizontal direction by

bearings

18A, 18B, 19A and 19B held by the housing 6.

Driven gears

21 and 22 are fixed to ends of the connection space 8 located between the

rotor shafts

16 and 17.

In fig. 1 of the casing 6, a suction port 23 of the 1 st-stage compressor body 4 is provided at the upper left portion. The discharge port 24 of the 1 st stage compressor body 4 opens to the connecting space 8. The suction port 25 of the 2 nd stage compressor body 5 also opens to the connecting space 8. That is, the discharge port 24 of the 1 st stage compressor body 4 and the suction port 25 of the 2 nd stage compressor 1 are fluidly communicated via the connecting space 8. In fig. 1 of the casing 6, a discharge port 26 of the 2 nd stage compressor body 5 is provided at a lower left portion.

The motor 3 includes an output shaft 31, a rotor 32 fixed to the output shaft 31, and a stator 33 fixed to the case 7. The stator 33 is substantially cylindrical and is disposed at a distance from the outer peripheral surface of the rotor 32. The fixed member 33 and the rotating member 32 are accommodated in the inner space 34 of the housing 7. The output shaft 31 is rotatably supported in a posture extending in the horizontal direction by

bearings

35A and 35B held by the case 7. The output shaft 31 is mostly accommodated in the internal space 34 of the housing 7, but the end portion on the left side in the drawing protrudes into the connection space 8. A drive gear 36 is fixed to an end portion of the output shaft 31 projecting into the connection space 8. The drive gear 36 is engaged with the driven gear 21 of the 1 st compressor body 2 and the driven gear 22 of the 2 nd compressor body 2.

The rotation of the output shaft 31 of the motor 3 is transmitted to the pair of

screw rotors

11 and 12 of the 1 st and 2 nd stage compressor bodies 4 and 5 via the drive gear 36 and the driven gears 21 and 22. The rotation of the

screw rotor pair

11, 12 compresses the ammonia gas sucked from the suction port 23 of the 1 st-stage compressor body 4, and discharges the ammonia gas from the discharge port 26 of the 2 nd-stage compressor body 5. Specifically, the ammonia gas sucked from the suction port 23 of the 1 st-stage compressor body 4 is compressed by the screw rotor pair 11, and is discharged from the discharge port 24 of the 1 st-stage compressor body 4 to the connecting space 8. The ammonia gas discharged into the connecting space 8 is sucked from the suction port 25 of the 2 nd compressor body 2, compressed by the screw rotor pair 13, and discharged from the discharge port 26. The connection space 8 and the internal space 34 of the housing 7 of the motor 3 are in fluid communication via a communication hole 7a provided at the end of the housing 7 on the right side in fig. 1. Therefore, not only the

rotor chambers

12 and 14 and the connecting space 8 but also the internal space 34 is filled with ammonia gas during the operation of the compressor body 2. That is, as described above, the fixed member 33 and the rotating member 32 accommodated in the internal space 34 are in an ammonia gas atmosphere (corrosive gas atmosphere). In other words, the casing 7 of the motor 3 and the casing 6 of the compressor main body 2 are connected, whereby the inner space 34 of the casing 7 and the

rotor chambers

12, 14 as the inner space of the casing 6 communicate with each other. Further, a corrosive gas atmosphere in a semi-closed state is formed by the inner space 34 and the

rotor chambers

12 and 14 communicating with each other.

Referring to fig. 2 to 4 in addition to fig. 1, the stator 33 includes a stator core 41 formed of stacked electromagnetic steel plates, and a plurality of windings (coils) 42. A plurality of slots 41a are formed inside the stator core 41. Each winding 42 is formed by winding a lead wire 43 around a slot 41a of the stator core 41. That is, each winding 42 is constituted by a plurality of wires 43. Each winding 42 includes a winding side (coil side) 42a accommodated in the slot 41a, and a winding end (coil end) 42b arranged outside the end portion of the stator core 41. The winding ends 42b are bent in the circumferential direction of the output shaft 31, and the adjacent winding ends 42b are adjacent to each other so as to overlap each other in the circumferential direction.

Referring to fig. 5, the lead 43 of the present embodiment includes a core wire 43a made of aluminum or an aluminum alloy, and an outer covering 43b made of teflon (PTFE) covering the core wire 43 a. As described above, since the internal space 34 in which the fixing member 33 is disposed is in an ammonia atmosphere, the core wire 43a is protected from corrosion by being covered with the teflon outer cover 43 b.

The electromagnetic force acting on the winding end 42B in the operation of the motor 3 intends to deform the winding end 42B in the direction indicated by the arrow B in fig. 1 (radial direction of the output shaft 31). As a result of the deformation of the electromagnetic force, the winding end 42b comes into contact with the case 7 or the rotor 32, which may cause the lead wires 43 to burn out. On the other hand, during operation of the motor 3, the winding 42, in particular, the lead wire 43 of the winding side 42a thermally expands, and the winding end 42b is displaced in the direction indicated by the arrow C in fig. 1 (the longitudinal direction of the output shaft 31) due to the thermal expansion. In the present embodiment, in order to suppress or prevent deformation of the winding ends 42b due to electromagnetic force while allowing thermal expansion of the windings 42, the respective winding ends 42b are fixed to the annular member 44 (the 1 st support member) disposed outside the plurality of winding ends 42 b.

Referring to fig. 6, the annular member 44 of the present embodiment includes a main body 44a, which is a rigid body having an integral structure, and an insulating tape 44b wound around the main body 44a to cover the outer peripheral surface of the main body 44 a. The main body 44a is made of a material that is a non-magnetic body, and needs to have a strength enough to restrain deformation of the winding end 42b due to electromagnetic force. Further, the main body 44a needs to have corrosion resistance against ammonia gas. In the present embodiment, the main body 44a of the annular member 44 is formed by covering a ring made of a metal material entirely covered with a nonmagnetic plastic, a nonmagnetic stainless steel, or a nonmagnetic plastic tape with an insulating tape 44 covered with teflon (PTFE) in order to obtain corrosion resistance. The non-magnetic plastic tape may be replaced with the insulating tape 44 made of teflon (PTFE). The insulating tape 44b has not only insulation but also corrosion resistance to ammonia gas.

As best shown in fig. 4, in the present embodiment, the winding ends 42b are fixed to the annular member 44 by binding the winding ends 42b to the annular member 44 with a binding band 45 (1 st binding member) which is a flexible elongated member. The binding band 45 is made of a fluororesin (e.g., PTFE), has strength that can be maintained in a state in which the coil ends 42b are fixed to the annular member 44 against electromagnetic force, and has corrosion resistance against ammonia gas.

The ring member 44 is fixed to the winding end 42b by the binding band 45, and is not fixed to any element (e.g., the stator core 41) constituting the motor 3. The method of fixing the winding end 42b of the binding band 45 and the ring-shaped member 44 (i.e., the manner of winding the binding band 45) is not limited to the manner shown in fig. 4.

As shown most clearly in fig. 4, in each winding 42, at a portion of the winding end 42b adjacent to the winding side 42a, the wires 43 constituting the winding 42 are fastened from the outside by a binding member (binding element) 47. This can improve the rigidity of the winding 42 at the winding end 42b adjacent to the winding edge 42 a. The bundling tool 47 of the present embodiment includes a short cylindrical collar member 48 covering the outer sides of the plurality of lead wires 43, and a band 49 (fastening member) for fastening the plurality of lead wires 43 from the outside via the collar member 48. The collar member 48 is provided with a slit 48a for fitting outside the bundle of the wires 43. The collar member 48 and the band 49 are each made of fluororesin (e.g., PTFE) and have corrosion resistance against ammonia gas.

The winding end 42B is fixed to the annular member 44 by the binding band 45, whereby deformation of the winding end 42B (see arrow B in fig. 1) due to electromagnetic force is suppressed or prevented. Since the annular member 44 is not coupled to an element other than the winding end 42b, thermal expansion of the winding 42 is allowed (see arrow C in fig. 1). That is, with such a simple structure that the winding end 42b is bound and fixed with respect to the annular member by the binding band 45, thermal expansion of the winding 42 of the fixing member 33 is allowed, and deformation caused by electromagnetic force of the winding end 42b can be suppressed.

Further, the portion of the winding end 42b adjacent to the winding edge 42a is fastened from the outside by the binder 47, so deformation of the winding end 42b caused by electromagnetic force can be more effectively suppressed or prevented without affecting the allowance of thermal expansion of the winding 42.

Further, the ring member 44, the bundling band 45, the collar member 48, and the bundling band 49 are all corrosion resistant with respect to ammonia gas, and therefore, the electromagnetic force deformation suppression of the winding end 42b is not affected by any corrosion thereof.

The ring-shaped member 44 of the alternative shown in fig. 8 is made of resin having corrosion resistance against ammonia gas, and includes two semicircular parts, i.e., half-

cut portions

50A and 50B. Both ends of the half-

cut portions

50A and 50B are coupled to each other by engaging, for example, an arrow-shaped engaging portion 50A provided on one side with an engaging hole 50B provided on the other side. The ring-shaped member may be one element divided at one place and may be an element connected at one divided place. The annular member may be a member that connects three or more elements.

The winding end 42b may be fixed to the annular member 44 by using a flexible rope having corrosion resistance against ammonia gas instead of the binding band 45.

(embodiment 2)

In the motor 3 according to embodiment 2 of the present invention shown in fig. 9, the ring member 44 is disposed outside the plurality of winding ends 42b, and the winding ends 42b are bound and fixed to the ring member 44 by the binding band 45, as in embodiment 1. Further, a separate annular member 52 (the 2 nd support member) is disposed outside the plurality of winding ends 42b at a position closer to the stator core 41 than the annular member 44. Each winding end 42b is also fixed with respect to the ring member 52 by a binding band 53 (2 nd binding member). The annular member 45 is not connected to elements other than the winding end 42 b. The material and structure of the annular member 52 and the binding band 53 are the same as those of the annular member 44 and the binding band 45, respectively. The structure shown in fig. 8 can also be applied to the annular member 52.

Since the respective winding ends 42b are fixed to the two

annular members

44 and 52 arranged outside the plurality of winding ends 42b, thermal expansion of the winding 42 is allowed, and deformation of the winding ends 42b due to electromagnetic force can be more effectively suppressed.

More than 3 annular members may be disposed outside the plurality of winding ends 42b, and the winding ends 42b may be fixed to the annular members with a binding band.

(embodiment 3)

In the motor 3 according to embodiment 2 of the present invention shown in fig. 10, the ring member 44 is disposed outside the plurality of winding ends 42b, and the winding ends 42b are bound and fixed to the ring member 44 by the binding band 45, as in embodiment 1. Further, another annular member 54 (the 3 rd support member) is disposed inside the plurality of winding ends 42 b. Each winding end 42b is also fixed to the ring member 54 by a binding band 55 (3 rd binding member). The annular member 54 is not connected to elements other than the winding end 42 b. The material and structure of the annular member 54 and the binding band 55 are the same as those of the annular member 44 and the binding band 45, respectively. The structure shown in fig. 8 can also be applied to the annular member 54.

The respective winding ends 42b are fixed to the two

annular members

44, 54 respectively disposed outside and inside the plurality of winding ends 42b, so that thermal expansion of the winding 42 is allowed, and deformation of the winding ends 42b caused by electromagnetic force is more effectively suppressed.

Two or more annular members may be disposed outside the plurality of winding ends 42b, and each winding end 42b may be fixed to each annular member with a binding band. Further, one or more ring members other than the ring member 44 may be disposed outside the plurality of winding ends 42b, and the winding ends 42b may be fixed by a binding band.

The present invention is not limited to the motor of the 2-stage screw compressor disposed vertically as in embodiment 1, and can be applied to motors for driving tandem type 2-stage screw compressors and other types of compressors including single-stage screw compressors. The present invention can also be applied to a rotating electric machine other than the electric motor of the compressor. For example, the present invention can also be applied to a generator driven by an expander such as a screw expander.

Further, as the support member of the present invention, when the deformation of a specific part of the winding ends connected in the circumferential direction is suppressed, an arc-shaped member having a length including not only the annular member but also the specific part may be used. Further, in the above-described embodiments of the present invention, the support member, the binding element, the collar member, and the fastening member are made of a fluororesin (e.g., PTFE), but the material is not limited thereto, and at least the surface may be made of a material having corrosion resistance to ammonia gas.

Description of the reference numerals

1 compressor

2 compressor body

3 electric motor

41 st stage compressor body

52 nd stage compressor body

6. 7 case

7a communication hole

8 connecting space

11 screw rotor pair

12 rotor chamber

13 screw rotor pair

14 rotor chamber

16. 17 rotor shaft

18A, 18B, 19A, 19B bearing

21. 22 driven gear

23. 25 suction inlet

24. 26 discharge port

31 output shaft

32 rotating member

33 fixing member

34 inner space

35A, 35B bearing

36 drive gear

41 fixed part iron core

41a slot

42 winding

42a winding edge

42b winding end

43 conducting wire

43a core wire

43b outer package

44 Ring component (No. 1 supporting component)

44a main body

44b insulating tape

45 bundling belt (1 st bundling part)

47 bundling piece (bundling element)

48 Collar parts

48a slit

49 belting (fastening component)

50A, 50B half-cut part

52 annular member (No. 2 support member)

53 binding belt (No. 2 binding component)

54 Ring component (No. 3 supporting component)

55 binding band (3 rd binding member).

Claims

1. A rotating electrical machine is characterized in that,

comprises a fixed member and a rotating member arranged in a corrosive gas atmosphere,

the stator includes a stator core, a plurality of windings, a 1 st support member, a 1 st binding member,

the plurality of windings are formed by a plurality of wires wound around the stator core, and each have a winding edge accommodated in the stator core and a winding end arranged outside an end portion of the stator core,

the 1 st support member is corrosion resistant to the corrosive gas and is disposed outside the winding end,

the 1 st bundling member has corrosion resistance against the corrosive gas, the winding end is bundled and fixed with respect to the 1 st supporting member,

the 1 st support member is not fixed to an element other than the winding end.

2. The rotating electric machine according to claim 1,

the 1 st support member is an annular member or an arc-shaped member.

3. The rotating electric machine according to claim 2,

the 1 st binding member is a flexible elongated member, and the winding end is bound to the 1 st supporting member via the 1 st binding member.

4. The rotating electric machine according to claim 1,

the winding device is provided with a bundling element for bundling the plurality of wires at a portion of the winding end adjacent to the winding side.

5. The rotating electric machine according to claim 4,

the bundling element includes a collar member surrounding the outside of the plurality of lead wires, and a fastening member fastening the collar member and the plurality of windings together.

6. A rotating electric machine according to claim 3,

further comprising a 2 nd supporting member disposed outside the winding end and having corrosion resistance to the corrosive gas, and a 2 nd binding member having corrosion resistance to the corrosive gas and binding and fixing the winding end to the 2 nd supporting member,

the 2 nd support member is not fixed to an element other than the winding end.

7. The rotating electric machine according to claim 4,

the 2 nd support member is not fixed to an element other than the winding end.

8. The rotating electric machine according to claim 5,

the 2 nd support member is not fixed to an element other than the winding end.

9. A rotating electric machine according to claim 3,

further comprising a 3 rd supporting member disposed inside the winding end and having corrosion resistance to the corrosive gas, a 3 rd binding member having corrosion resistance to the corrosive gas and binding and fixing the winding end to the 3 rd supporting member,

the 3 rd supporting member is not fixed to an element other than the winding end.

10. The rotating electric machine according to claim 4,

11. The rotating electric machine according to claim 5,

12. The rotating electric machine according to any one of claims 3 to 11,

the corrosive gas is ammonia gas.

13. The rotating electric machine according to claim 12,

the lead wire includes a core wire made of aluminum or an aluminum alloy, and a Teflon outer covering the core wire.

14. A semi-hermetic screw compressor is characterized in that,

a screw compressor body for compressing the corrosive gas, comprising the rotating electric machine according to claim 13,

the rotary electric machine is an electric motor for driving the screw compressor main body,

the housing of the motor and the housing of the screw compressor main body, which house the fixed member and the rotating member, are connected in a state where the inner spaces communicate with each other.