JP6080645B2 - Electric motor for compressor of turbo refrigerator - Google Patents

Description

  The present invention relates to an electric motor for a compressor in a turbo chiller, and more particularly to an electric motor for a compressor that cools the electric motor by introducing a part of refrigerant from a refrigeration cycle to an electric motor that drives the turbo compressor in the turbo chiller. It is.

  Conventionally, a turbo refrigerator used in a refrigeration air conditioner or the like is configured by a closed system in which a refrigerant is enclosed, an evaporator that takes heat from cold water (fluid to be cooled) and evaporates the refrigerant to exert a refrigeration effect; A compressor that compresses the refrigerant gas evaporated in the evaporator to form a high-pressure refrigerant gas; a condenser that cools and condenses the high-pressure refrigerant gas with cooling water (cooling fluid); and depressurizes the condensed refrigerant. An expansion valve (expansion mechanism) that is expanded by being connected by a refrigerant pipe.

  FIG. 1 is a schematic view showing an example of a conventional turbo refrigerator. As shown in FIG. 1, a turbo refrigerator includes a turbo compressor 1 that compresses refrigerant, a condenser 2 that cools and compresses the compressed refrigerant gas with cooling water (cooling fluid), and cold water (cooled fluid). ), An evaporator 3 that evaporates the refrigerant and exerts a refrigeration effect, and an economizer 4 that is an intermediate cooler disposed between the condenser 2 and the evaporator 3. Are connected by a refrigerant pipe 5 that circulates.

  In the turbo refrigerator shown in FIG. 1, the turbo compressor 1 is composed of a multistage turbo compressor and is driven by an electric motor 11. The turbo compressor 1 is connected to the economizer 4 by a refrigerant pipe 8, and the refrigerant gas separated by the economizer 4 is an intermediate portion (in this example, two stages) of the multistage compression stage of the turbo compressor 1 (in this example). It is introduced in the part between the first stage and the second stage).

  Many of the electric motors of the turbo compressor are semi-hermetic motors housed in a sealed state in a split casing. The motor 11 shown in FIG. 1 is also exemplified by a semi-hermetic motor. As shown in FIG. 1, the rotating shaft 12 of the electric motor 11 is rotatably supported by a bearing, and a speed increaser 14 is provided at the shaft end of the rotating shaft 12, and an impeller shaft 16 that supports an impeller 15 of the compressor. Is rotated at an increased speed to ensure a predetermined pressure head and air volume of the compressor.

  As shown in FIG. 1, a refrigerant supply pipe 5BP that branches from a refrigerant pipe 5 that connects the condenser 2 and the economizer 4 and guides the refrigerant from the condenser side to the electric motor 11 is installed. The refrigerant supply pipe 5BP is connected to the motor casing 17 of the electric motor 11, and the refrigerant condensed by the condenser 2 is introduced into the casing 17 of the electric motor 11. That is, for cooling the heat generated by the electric motor, the liquid refrigerant of the refrigeration cycle is sprayed onto the stator, the rotating shaft, the coil, and the like in the motor casing 17 of the electric motor 11 and the latent heat of evaporation of the liquid refrigerant is used.

  On the other hand, an oil tank 19 is provided in the lower part of the gear casing 18 that accommodates the speed increaser 14, and oil that is compatible with the refrigerant is supplied from the oil tank 19 to the bearings and the speed increaser 14 by the pump P. Thus, the bearing and the speed-up gear 14 are lubricated and cooled. Since the gear casing 18 with the oil tank 19 and the motor casing 17 communicate with each other through a through-hole through which the rotary shaft 12 penetrates, the oil leaks into the refrigerant system, and the oil level of the oil tank 19 is lowered to supply the oil. Refrigerator by bypassing refrigerant gas that does not contribute to refrigeration cycle from high-pressure part to low-pressure part of the refrigeration cycle There is a problem of causing a decrease in efficiency. Therefore, a labyrinth seal LS having a toothed shape is provided on the inner surface of the communication hole between the gear casing 18 having the oil tank 19 and the motor casing 17 to ensure a shaft seal function. A similar labyrinth seal LS is also provided on the other end side of the rotating shaft 12.

  FIG. 2 is an enlarged view of a main part showing a labyrinth seal LS provided at a portion where the rotating shaft 12 passes through the motor casing 17 and the gear casing 18 of the electric motor 11 shown in FIG. As shown in FIG. 2, the rotating shaft 12 of the electric motor passes through the labyrinth seal member 20 provided at the end of the motor casing 17, and the labyrinth seal LS is provided on the inner peripheral surface of the labyrinth seal member 20. Yes.

  The labyrinth seal member 20 includes a substantially cylindrical main body 21 and a flange 22 that extends from the main body 21 toward the outer peripheral side. The substantially cylindrical main body 21 has a space 21s in the middle part, and has a labyrinth seal LS composed of two groups of tooth rows on the inner peripheral surface of both sides with the space 21s interposed therebetween. The flange portion 22 has a plurality of bolt holes 22h on the outer peripheral portion, and is fixed to the motor casing 17 by bolts.

Japanese Patent Application Laid-Open No. 2000-291587

  In the labyrinth seal member 20 having the labyrinth seal LS that is a shaft seal mechanism as shown in FIG. 2, when the labyrinth seal member 20 is attached to and detached from the rotary shaft 12, the tooth row that is the seal mechanism rotates. Contact with the shaft 12 may damage or break a part of the dentition. In order to sufficiently secure the sealing function of the labyrinth seal LS, the clearance between the labyrinth seal LS and the rotary shaft 12 has a very narrow structure of about 0.1 mm in the diameter direction. Therefore, partial breakage or breakage of the dentition can cause not only a decrease in the sealing function, but also a failure of the apparatus due to the rotator involving the damaged piece.

  The present invention has been made in view of the above circumstances, and prevents the labyrinth seal from being damaged or broken when the labyrinth seal is attached to and detached from the rotating shaft of the electric motor that drives the turbo compressor. An object of the present invention is to provide an electric motor for a compressor of a turbo chiller that can ensure the soundness of the labyrinth, simplify the assembly work of the labyrinth seal portion, and reduce the assembly time.

In order to achieve the above-mentioned object, a first aspect of the present invention includes an evaporator that takes heat from cold water and evaporates the refrigerant to exert a refrigeration effect, a turbo compressor that compresses the refrigerant with an impeller, and a compressor. A motor that drives the turbo compressor in a turbo chiller having a condenser that cools and condenses the refrigerant gas with cooling water, and performs shaft sealing opposite to the outer peripheral surface of the rotating shaft of the motor A labyrinth seal member having a labyrinth seal composed of a row of teeth is provided, and the labyrinth seal member is provided with a plurality of guide portions having the same diameter as the inner diameter of the labyrinth seal and spaced apart from each other. located in the axial direction of the central portion toward the rotation axis from the seal, the the rotary shaft forms a plurality of circumferential grooves in a position facing the plurality of guide portions, the labyrinth Sea When attaching and detaching the member to the rotating shaft, wherein the plurality of guide members, characterized in that it is configured so as to guide said labyrinth seal member in contact with the outer peripheral surface of the rotary shaft.

  According to the present invention, when the labyrinth seal member is attached to the rotating shaft, the guide portion having the same diameter as the inner diameter of the labyrinth seal contacts the outer peripheral surface of the rotating shaft to guide the labyrinth seal member. Since the clearance between the guide portion and the rotation shaft is a very narrow structure of about 0.1 mm, the labyrinth seal member can maintain concentricity with respect to the axis of the rotation shaft. That is, the blur of the labyrinth seal member can be suppressed. Therefore, the labyrinth seal tooth row does not contact the outer peripheral surface of the rotating shaft and receive a force while the labyrinth seal member is mounted, and a part of the labyrinth seal tooth row is not damaged or broken. . Further, when the labyrinth seal member is removed from the rotating shaft, the labyrinth seal member is similarly guided with respect to the rotating shaft.

According to a preferred aspect of the present invention, the plurality of guide portions are provided 30 mm to 50 mm apart from each other.
According to the present invention, since the plurality of guide portions are separated from each other by 30 mm to 50 mm, the labyrinth seal member can be prevented from blurring when the labyrinth seal member is attached to or detached from the rotating shaft.

According to a preferred aspect of the present invention, the labyrinth seal is composed of two groups of dentitions, and a space is formed between the two groups of dentitions.
According to a preferred aspect of the present invention, the labyrinth seal includes a group of teeth.
According to a preferred aspect of the present invention, the thickness of each guide portion in the axial direction of the rotation shaft is 5 mm to 10 mm.
According to the present invention, since the axial thickness of each guide portion is 5 mm to 10 mm, the inner peripheral surface of each guide portion has a predetermined area, and when the labyrinth seal member is attached to or detached from the rotary shaft, The blur of the labyrinth seal member can be suppressed.

The second aspect of the present invention includes an evaporator that takes heat from cold water and evaporates the refrigerant to exert a refrigeration effect, a turbo compressor that compresses the refrigerant with an impeller, and cools the compressed refrigerant gas with cooling water And a condenser for condensation, wherein the electric motor that drives the turbo compressor is the electric motor for a compressor according to any one of claims 1 to 5 .
According to the present invention, since the labyrinth seal performs a sufficient shaft sealing function without being broken or broken, the amount of refrigerant gas bypassed from the high pressure portion to the low pressure portion of the refrigeration cycle can be minimized. Therefore, it is possible to prevent the efficiency of the refrigerator from decreasing.

The present invention has the following effects.
(1) When the labyrinth seal is attached to and removed from the rotating shaft of the electric motor, the teeth of the labyrinth seal can be prevented from being damaged or broken to ensure the soundness of the seal mechanism.
(2) When attaching the labyrinth seal member to the rotary shaft, it is not necessary to fear the breakage or breakage of the labyrinth seal, so that the assembly work of the labyrinth seal portion can be simplified and the assembly time can be shortened.
(3) When removing the labyrinth seal member from the rotating shaft, there is no need to fear damage or breakage of the labyrinth seal, so that the maintenance work of the labyrinth seal portion can be simplified and the maintenance time can be shortened.
(4) Since the labyrinth seal performs a sufficient shaft sealing function without being broken or broken, the amount of refrigerant gas bypassed from the high pressure portion to the low pressure portion of the refrigeration cycle can be minimized. Therefore, it is possible to prevent the efficiency of the refrigerator from decreasing.

FIG. 1 is a schematic view showing an example of a conventional turbo refrigerator. FIG. 2 is an enlarged view of a main part showing a labyrinth seal provided at a portion where the rotating shaft passes through the motor casing and the gear casing of the electric motor in the turbo refrigerator shown in FIG. 1. FIG. 3 is a cross-sectional view showing a configuration of a labyrinth seal member and a rotary shaft in the compressor motor of the turbo refrigerator of the present invention. FIGS. 4A, 4B, and 4C are schematic cross-sectional views showing a procedure for attaching the labyrinth seal member to the rotating shaft.

Hereinafter, an embodiment of a compressor motor for a turbo refrigerator according to the present invention will be described with reference to FIGS. 3 and 4.
The electric motor for the compressor of the turbo chiller according to the present invention has the same basic configuration as the electric motor 11 provided in the turbo compressor 1 shown in FIG. 1, and only the labyrinth seal member 20 and the rotating shaft 12 are different. Yes. Therefore, in the following description, the configuration of the labyrinth seal member 20 and the rotating shaft 12 in the electric motor of the present invention will be described.

  FIG. 3 is a cross-sectional view showing the configuration of the labyrinth seal member 20 and the rotary shaft 12 in the compressor motor of the turbo refrigerator of the present invention. As shown in FIG. 3, the rotating shaft 12 of the electric motor passes through the labyrinth seal member 20 provided at the end of the motor casing 17 (see FIG. 1), and the labyrinth seal is formed on the inner peripheral surface of the labyrinth seal member 20. LS is provided. In order to sufficiently secure the function of the labyrinth seal LS, the clearance between the labyrinth seal LS and the rotary shaft 12 has a very narrow structure of about 0.1 mm in the diameter direction. The labyrinth seal member 20 includes a substantially cylindrical main body 21 and a flange 22 that extends from the main body 21 toward the outer peripheral side. The flange portion 22 has a plurality of bolt holes 22h on the outer peripheral portion, and is fixed to the motor casing 17 by bolts.

  The substantially cylindrical main body 21 in the labyrinth seal member 20 of the present invention is longer than the main body 21 in the labyrinth seal member 20 shown in FIG. 2, and further from the end of the labyrinth seal LS to the center of the rotary shaft 12. It extends toward the part side. That is, the substantially cylindrical main body 21 in the labyrinth seal member 20 of the present invention has a labyrinth seal LS composed of two groups of teeth on the inner peripheral surface of both sides across the space 21s. An extension portion 21e extending further toward the center of the rotating shaft 12 from the inner dentition portion of the two groups of LS LS. And two guide parts G1, G2 having the same diameter as the inner diameter d of the labyrinth seal LS are formed on the inner peripheral surface of the extension part 21e. Each guide part G1, G2 has an axial thickness t set to 5 mm to 10 mm. Of the two guide parts G1, G2, one guide part G1 is provided adjacent to the labyrinth seal LS, and the other guide part G2 is provided apart from the guide part G1 in the axial direction of the rotary shaft 12 by a distance L. It has been. When the labyrinth seal member 20 is attached to and detached from the rotary shaft 12, the two guide portions G <b> 1 and G <b> 2 come into contact with the outer peripheral surface of the rotary shaft 12, so that the labyrinth seal member 20 is the same as the axis of the rotary shaft 12. The core can be maintained. In the illustrated example, two guide portions G1 and G2 are provided, but three or more guide portions may be provided.

  On the other hand, two circumferential grooves g1 and g2 are formed in the rotary shaft 12 at positions facing the guide portions G1 and G2 of the labyrinth seal member 20. The axial widths of the circumferential grooves g1 and g2 are set to 10 mm to 15 mm, and are wider than the thickness t of the guide portions G1 and G2. Further, the depths of the circumferential grooves g1 and g2 are set to dimensions such that a clearance of 0.3 mm to 0.6 mm is formed between the guide portions G1 and G2 and the circumferential grooves g1 and g2. By setting the dimensional relationship between the guide portions G1 and G2 and the circumferential grooves g1 and g2 as described above, the fluid flow to the labyrinth seal LS is not hindered.

4A, 4 </ b> B, and 4 </ b> C are schematic cross-sectional views illustrating a procedure for attaching the labyrinth seal member 20 to the rotating shaft 12.
FIG. 4A shows a state before the labyrinth seal member 20 is mounted on the rotary shaft 12. As shown in FIG. 4A, the shaft center of the rotating shaft 12 and the shaft center of the labyrinth seal member 20 are roughly aligned, and the extension portion 21 e of the labyrinth seal member 20 is attached to the shaft end side of the rotating shaft 12. To go.
FIG. 4B shows a state in which the labyrinth seal member 20 is being attached to the rotary shaft 12. As shown in FIG. 4B, when the labyrinth seal member 20 is pushed toward the central portion of the rotating shaft 12, the guide portions G 1 and G 2 having the same diameter as the inner diameter d of the labyrinth seal LS are The labyrinth seal member 20 is guided in contact with the outer peripheral surface. Since the clearance between the guide portions G1 and G2 and the rotating shaft 12 has a very narrow structure of about 0.1 mm, the labyrinth seal member 20 can maintain concentricity with respect to the axis of the rotating shaft 12. That is, blurring of the labyrinth seal member 20 can be suppressed. Therefore, the tooth row of the labyrinth seal LS does not come into contact with the outer peripheral surface of the rotary shaft 12 and receives a force during the mounting of the labyrinth seal member 20, and the tooth row of the labyrinth seal LS is partially damaged or broken. Never happen.

  FIG. 4C shows a state after the labyrinth seal member 20 is mounted on the rotary shaft 12. As shown in FIG. 4C, the guide portions G1 and G2 of the labyrinth seal member 20 and the circumferential grooves g1 and g2 of the rotating shaft 12 face each other, and the guide portion G1, the circumferential groove g1 and the guide portion G2 are opposed to each other. And a circumferential groove g2, a predetermined clearance is formed so as not to hinder the flow of fluid to the labyrinth seal LS.

  As shown in FIGS. 4A to 4C, when attaching the labyrinth seal member 20 to the rotating shaft 12, it is not necessary to fear damage or breakage of the labyrinth seal LS, so that the assembly work of the labyrinth seal portion is simplified. As a result, assembly time can be shortened. Further, when removing the labyrinth seal member 20 from the rotary shaft 12, the reverse procedure of FIGS. 4 (a) to 4 (c) may be performed. And when removing the labyrinth seal member 20 from the rotating shaft 12, since it is not necessary to fear damage or breakage of the labyrinth seal LS, the maintenance work of the labyrinth seal portion can be simplified, and the maintenance time can be shortened.

3 and 4 exemplify the labyrinth seal LS composed of two groups of teeth, the space 21s between the two groups of teeth may be eliminated to form one group of teeth.
3 and 4 exemplify the labyrinth seal LS on the gear casing 18 side, the labyrinth seal LS (see FIG. 1) on the opposite side of the gear casing 18 and at the shaft end of the rotary shaft 12 is also illustrated. It is the same composition.

  Although the embodiment of the present invention has been described so far, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention may be implemented in various different forms within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Turbo compressor 2 Condenser 3 Evaporator 4 Economizer 5 Refrigerant piping 5BP Refrigerant supply piping 8 Refrigerant piping 11 Electric motor 12 Rotating shaft 14 Speed increaser 15 Impeller 16 Impeller axle 17 Motor casing 18 Gear casing 19 Oil tank 20 Labyrinth seal member 21 body portion 21e extension portion 21s space 22 flange portion 22h bolt hole G1, G2 guide g1, g2 circumferential groove LS labyrinth seal

Claims (6)

An evaporator that takes heat from cold water and evaporates the refrigerant to exert a refrigeration effect, a turbo compressor that compresses the refrigerant with an impeller, and a condenser that cools and compresses the compressed refrigerant gas with cooling water An electric motor for driving the turbo compressor in the turbo refrigerator,
Providing a labyrinth seal member having a labyrinth seal composed of a tooth row for carrying out a shaft seal facing the outer peripheral surface of the rotating shaft of the electric motor;
The labyrinth seal member is provided with a plurality of guide portions having the same diameter as the inner diameter of the labyrinth seal so as to be spaced apart from each other, and the plurality of guide portions are located closer to the center portion in the axial direction of the rotating shaft than the labyrinth seal,
The rotating shaft is formed with a plurality of circumferential grooves at positions facing the plurality of guide portions ,
When attaching and detaching the labyrinth seal member to and from the rotating shaft, the plurality of guide members are configured to contact the outer peripheral surface of the rotating shaft and guide the labyrinth seal member. Electric motor for compressor of turbo refrigerator.   2. The electric motor for a compressor of a turbo chiller according to claim 1, wherein the plurality of guide portions are provided 30 mm to 50 mm apart from each other.   The electric motor for a compressor of a turbo chiller according to claim 1 or 2, wherein the labyrinth seal is composed of two groups of tooth rows, and a space is formed between the two groups of tooth rows.   The electric motor for a compressor of a turbo refrigerator according to claim 1 or 2, wherein the labyrinth seal includes a group of teeth.   The electric motor for a compressor of a turbo refrigerator according to any one of claims 1 to 4, wherein the thickness of each guide portion in the axial direction of the rotation shaft is 5 mm to 10 mm. An evaporator that takes heat from cold water and evaporates the refrigerant to exert a refrigeration effect, a turbo compressor that compresses the refrigerant with an impeller, and a condenser that cools and compresses the compressed refrigerant gas with cooling water In the turbo refrigerator
The turbo chiller according to any one of claims 1 to 5 , wherein the electric motor that drives the turbo compressor is the electric motor for a compressor according to any one of claims 1 to 5 .

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