JP4482471B2 - Compressor - Google Patents

Description

  The present invention relates to a compressor configured to supply oil for lubrication and shaft sealing to a compressor body, and more particularly to a cooling structure for an electric motor that drives such a compressor.

  Conventionally, an electric motor that drives an impeller and a screw rotor of a compressor rotates at a high speed, and thus generates a large amount of heat. A cooling mechanism for cooling the motor is essential. As such a cooling mechanism, generally, forced cooling by a fan directly connected to a rotor shaft, supply of cooling air by an external cooling device, and the like have been conventionally used.

  However, when the fan is directly connected to the rotor shaft, the rotor shaft length becomes long, so that it becomes difficult to support the rotation of the rotor shaft that rotates at high speed, and when cooling air is supplied from an external cooling device, a separate system is required. The power source and the cooling machine are required, and the apparatus becomes complicated, resulting in a cost increase.

  Therefore, a conventional electric motor proposed for solving the above problems and a cooling method thereof will be described below with reference to FIGS. First, FIG. 3 is an overall configuration diagram of a high-speed motor-driven compressor according to a conventional invention (see Patent Document 1). The high-speed motor-driven compressor 11 shown in FIG. 3 includes an intermediate cooling device 56 that intermediately cools the gas compressed by the first-stage impeller 53 and guides it to the second-stage impeller 54, and the rotor shaft 51 has a two-stage impeller 54. A cooling gas introduction hole 57 for introducing the cooling compressed gas supplied to the motor into the electric motor, and a cooling hole 58 communicating with the cooling gas and communicating with the gap between the rotor and the stator of the electric motor.

  According to the conventional cooling method of the high-speed motor-driven compressor, the gas compressed by the first stage impeller 53 is intermediately cooled by the intercooler built in the intermediate cooling device 56 and led to the second stage impeller 54, where Recompression is performed to obtain a high compression ratio, and the intermediate-cooled compressed gas is injected through the rotor shaft 51 into the gap between the rotor 52a and the stator 52b of the electric motor, so that the rotor shaft 51, the rotor 52a and the fixed gas are fixed. The child 52b is cooled.

  Next, FIG. 4 is an overall configuration diagram of a high-speed rotary electric motor (see Patent Document 2) according to another conventional invention. The high-speed rotary motor 12 shown in FIG. 4 supplies the stator 16 of the motor 12 with an injection port 19 that supplies cooling air provided toward the rotor 15, and supplies water droplets provided in the injection port 19. And a nozzle 10 to be used.

Further, according to the above conventional cooling method of the electric motor, the gas compressed by the first stage impeller 13 is intermediately cooled by the intercooler and led to the second stage impeller 14, where it is recompressed to obtain a high compression ratio, The intermediate-cooled compressed gas is injected into a gap between the rotor 15 and the stator 16 together with fine water droplets to cool the rotor 15 and the stator 16.
JP 2001-254699 A JP 2002-17071 A

  According to the former high-speed motor-driven compressor and its cooling method according to the above conventional example, the air compressed by the compressor itself is used for cooling the electric motor, so that the amount of air that can be discharged by the compressor is reduced. Further, even if compressed air with reduced moisture is used in the intermediate cooler, moisture is condensed in the motor due to a temperature drop during expansion to atmospheric pressure, and rust is generated inside the motor.

  Furthermore, according to the latter electric motor and the cooling method thereof according to the conventional example, the rotor and the stator can be connected by injecting fine water droplets together with the cooling air into the gap between the rotor and the stator. Cooling. However, there is a micro pinhole in the coil in the motor, and when the inside of the motor cools down due to the stop of the motor, if the condensed water droplets adhere, there is a risk that the electrical insulation is lowered and a short circuit occurs. In addition, the stator, rotor, drive shaft, and the like in the electric motor are rusted similarly to the former due to the adhesion of moisture.

  Accordingly, it is an object of the present invention to provide an effective cooling structure for an electric motor that drives a compressor without causing an electrical short circuit or rust in the interior or accompanying a large cost increase.

  In order to achieve the above object, the means employed by the compressor according to claim 1 of the present invention includes a compressor body driven by an electric motor, and one end side connected to the suction port of the compressor body, and the suction port In a compressor provided with a suction flow path provided with a suction adjustment valve for adjusting a flow rate of gas flowing into the motor, a gas supply port and a gas discharge port are provided in the casing of the motor, and suction adjustment of the suction flow path is performed. The upstream side of the valve and the gas supply port are communicated with each other by a gas supply path that supplies a part of the gas flowing toward the suction adjustment valve to the casing, and the gas discharge port and the suction flow path downstream of the suction adjustment valve. The side is communicated with a gas discharge passage through which the gas supplied from the gas supply passage flows into the downstream side of the suction adjustment valve of the suction passage.

  The means employed by the compressor according to claim 2 of the present invention is the compressor according to claim 1, wherein the gas discharge passage allows the gas flow toward the downstream side of the suction adjustment valve of the suction passage. A check valve is interposed in the direction.

  The means employed by the compressor according to claim 3 of the present invention is the compressor according to any one of claims 1 or 2, wherein the connection position of the gas supply path to the suction flow path is: It is the downstream of the suction filter provided in the upstream of the suction adjustment valve interposed by the suction flow path.

The means employed by the compressor according to claim 4 of the present invention is the compressor according to any one of claims 1 to 3 , wherein the position of the gas supply port in the casing is within the casing. The drive shaft is on the opposite side of the insertion portion into the compressor body , and the position of the gas discharge port in the casing is on the same side as the insertion portion .

Means the compressor is adopted according to claim 5 of the present invention is the compressor according to claim 4, below the inserting portion of the compressor body of the drive shaft within the casing, the oil accumulated gas An oil reservoir for discharging is provided at the discharge port.

The means employed by the compressor according to claim 6 of the present invention is the compressor according to claim 5 , wherein the casing is provided with an oil receiver just below the insertion portion of the drive shaft of the casing into the compressor body. An oil recovery path is provided that allows the oil receiver and the oil reservoir to communicate with each other.

The compressor employed in the compressor according to claim 7 of the present invention is the compressor according to any one of claims 1 to 6 , in three directions on the upstream side of the suction adjustment valve of the suction channel. while the interposed a three-way valve air supply passage is connected among, provided with a temperature detector for detecting the temperature T of the stator to the casing of the motor, the specified temperature T _h of the stator set in advance The temperature difference ΔT (= T _h −T) from the stator temperature T detected by the temperature detector was obtained, and the gas supply amount to the gas supply path was increased when the obtained temperature difference ΔT was small. A controller for controlling the opening of the three-way valve is provided so that the gas supply amount to the gas supply path decreases when the temperature difference ΔT is large.

  According to the compressor according to claim 1 of the present invention, the compressor main body driven by the electric motor, and the suction end that is connected to the suction port of the compressor main body and adjusts the flow rate of the gas flowing into the suction port. In the compressor having a suction flow path provided with a regulating valve, a gas supply port and a gas discharge port are provided in the casing of the electric motor, and an upstream side of the suction adjustment valve in the suction flow path and a gas supply port are provided. A part of the gas flowing toward the suction adjusting valve is communicated by a gas supply path for supplying the casing, and a part of the gas flowing into the suction port is introduced into the casing of the electric motor, whereby the stator or the rotor It was set as the structure which cools.

  At the same time, the gas discharge port and the downstream side of the suction adjustment valve of the suction flow path are communicated by a gas discharge path that allows the gas supplied from the gas supply path to flow into the downstream side of the suction adjustment valve of the suction flow path, The cooled gas introduced into the casing is discharged.

  That is, the gas that has been sucked into the suction passage of the compressor is supplied into the casing of the electric motor, and the main part is cooled and then returned to the suction passage again. Therefore, it is possible to cool the electric motor without causing a problem of rusting due to supply of a gas containing moisture and a cost increase due to the need for a separate cooling device.

  In the compressor according to claim 2 of the present invention, in the compressor according to claim 1, the gas discharge path is allowed to allow a gas flow toward the downstream side of the suction adjustment valve of the suction flow path. Since the check valve is interposed, the gas does not flow backward from the suction flow path side to the electric motor side even when the compressor main body is stopped. Furthermore, according to the compressor concerning Claim 2 of this invention, the situation where the lubricating oil in a compressor main body flows backward and enters into an electric motor can be avoided.

  On the other hand, according to the compressor according to claim 3 of the present invention, in the compressor according to any one of claims 1 and 2, the connection position of the gas supply path to the suction flow path is Because it is on the downstream side of the suction filter provided upstream of the suction adjustment valve in the suction flow path, a highly clean cooling gas is sent into the motor to avoid problems such as poor insulation due to contamination of impurities in the motor. can do.

Furthermore, according to the compressor of claim 4 of the present invention, in the compressor according to any one of claims 1 to 3 , the position of the gas supply port in the casing is within the casing. Since the drive shaft is on the opposite side of the insertion portion to the compressor body , and the position of the gas discharge port in the casing is on the same side as the insertion portion, a smooth flow through the casing of the motor can be achieved. Since the flow of the cooling gas is formed, the electric motor can be efficiently cooled.

Furthermore, according to the compressor according to claim 5 of the present invention, in the compressor according to claim 4 , the accumulated oil is placed below the insertion portion of the drive shaft in the casing into the compressor body. Since the oil reservoir for discharging to the gas outlet is provided, it is possible to collect the lubricating oil leaking from the compressor main body side to the electric motor side by dropping to the oil reservoir by transmitting the drive shaft.

Further, according to the compressor according to claim 6 of the present invention, in the compressor according to claim 5 , the oil receiver is provided immediately below the fitting insertion portion of the drive shaft of the casing to the compressor body, and By providing an oil recovery path that allows the oil receiver and the oil reservoir to communicate with each other, the lubricating oil can be recovered more effectively.

Furthermore, according to the compressor according to claim 7 of the present invention, in the compressor according to any one of claims 1 to 6 , on the upstream side of the suction adjustment valve of the suction flow path, interposed a three-way valve air supply passage is connected to one of the three sides, provided with a temperature detector for detecting the temperature T of the stator to the casing of the electric motor, specified temperature of the stator preset T _h And a temperature difference ΔT (= T _h −T) between the temperature detected by the temperature detector and the stator temperature T, and when the obtained temperature difference ΔT is small, the gas supply amount to the gas supply path is increased. By providing a controller that controls the opening of the three-way valve so that the amount of gas supplied to the gas supply path decreases when the temperature difference ΔT is large, the suction flow is only the minimum gas flow required for cooling the motor. Since it is supplied from the road, Reduction of the flow rate can be as much as possible deterrence.

  First, the structure of the compressor which concerns on Embodiment 1 of this invention is demonstrated below using FIG. 1 which is the cooling system figure. The compressor includes a compressor body 20 having a structure in which a pair of male and female screw rotors (not shown) are meshed with each other and are rotatably accommodated inside the rotor casing. A suction flow path 28 is connected to the suction port 20a of the compressor body 20, and a discharge flow path 29 is connected to the discharge port 20b. One (usually a male rotor) of the pair of male and female screw rotors constituting the compressor body 20 is connected to a drive shaft 26 of an electric motor 22.

By rotating the screw rotor by the electric motor 22, the gas supplied from the suction flow path 28 is compressed by the compressor body 20 and discharged to the discharge flow path 29 as a high-pressure fluid.
The electric motor 22 includes a stator 25 fixed to the inner surface of the casing 23 and a rotor 24 that rotates about a drive shaft 26, and the rotational force of the drive shaft 26 is compressed through a fitting portion 37. It is transmitted to the screw rotor of the main body 20.

  The suction flow path 28 is provided with a suction adjustment valve 21 that adjusts the flow rate of the gas passing through the suction flow path 28, and the valve opening degree is controlled by the controller 30. A gas supply port 31 is provided in the casing 23 of the electric motor 22, and the electric motor 22 communicates the upstream side of the suction adjustment valve 21 and the gas supply port 31 of the casing 23 through a gas supply path 34. A part of the gas flowing into the flow path 28 is introduced into the casing 23 of the electric motor 22 and cooled.

  At the same time, the gas discharge port 32 provided in the casing 23 and the downstream side of the suction adjustment valve 21 of the suction flow path 28 are communicated by the gas discharge path 35, and the cooled gas introduced into the casing 23 is supplied. It is discharged to the suction flow path 28.

  A check valve 40 is interposed in the gas discharge passage 35 in a direction that allows a gas flow toward the downstream side of the suction adjustment valve 21 of the suction passage 28. Thereby, even if the compressor main body 20 becomes a stop state, it can prevent that a gas flows backward from the suction flow path 28 side to the housing 23 side of the electric motor 22. Further, it is possible to avoid a situation in which the lubricating oil in the compressor body 20 flows backward and enters the electric motor 22.

  Further, the connection position of the gas supply path 34 to the suction flow path 28 is preferably downstream of the suction filter 36 provided on the upstream side of the suction adjustment valve 21 of the suction flow path 28. As a result, a cooling gas having a high cleanliness can be sent into the electric motor 22. Further, the connection position of the gas discharge path 35 to the suction flow path 28 is preferably disposed in the vicinity of the suction port 20 a of the compressor body 20. If it does so, exhaust gas can be easily discharged | emitted by the negative pressure to the suction flow path 28 so that it may mention later.

  In the suction flow path 28, the upstream flow path A point of the suction filter 36 and the flow path B point between the filter 36 and the suction adjustment valve 21 shown in FIG. Pressure difference is caused by pressure loss due to the road. For example, in a compressor with a rated output of 37 kW, the pressure at the channel B is about 10 kPa lower than the pressure at the channel A (= atmospheric pressure). Further, the pressure at the flow path C point on the suction flow path 28 and between the suction adjustment valve 21 and the suction port 20a further downstream is further reduced by 3.5 kPa from the flow path B point.

  For the above reasons, as shown in FIG. 1, the connection position of the gas supply path 34 to the suction flow path 28 is upstream from the connection position of the gas discharge path 35 to the suction flow path 28, and the suction flow path 28. It is preferable that the suction flow path 28 → the gas supply path 34 → the gas supply port 31 → the electric motor 22 → the gas discharge port 32 → the gas discharge path 35 → the suction flow path 28 are communicated in this order from the high pressure side to the low pressure side.

  The position of the gas supply port 31 in the casing 23 is set on the side opposite to the drive shaft 26, in other words, on the side opposite to the side where the insertion portion 37 is provided with respect to the rotor 24. Further, the position of the gas discharge port 32 in the casing 23 is the same side as the drive shaft 26 side, in other words, the side where the fitting insertion portion 37 is located with respect to the rotor 24. Therefore, a smooth cooling gas flow 44 that flows through the gap between the stator 25 and the rotor 24 inside the casing 23 of the electric motor 22 is formed, and the electric motor 22 can be efficiently cooled.

  Further, the suction flow path 28 is provided with a suction adjustment valve 21 that adjusts the flow rate of the gas passing through the suction flow path 28. The suction adjustment valve 21 is adjusted by a controller 30 based on a detection signal from a pressure gauge, a flow meter, etc. (not shown) provided in the discharge passage 29.

In addition, a three-way valve 46 having an air supply path connected to one of the three sides is interposed on the upstream side of the suction adjustment valve 21 in the suction passage 28. And the temperature detector 45 which detects the temperature T of the stator 25 is provided in the casing 23 of the electric motor 22. The controller 30, based on a signal from the temperature detector 45, the temperature difference [Delta] T (= T _h between the detected stator temperature T at the specified temperature T _h and the temperature detector 45 of the stator 25 which is set in advance -T).

  At the same time, the controller 30 reduces the gas supply amount to the gas supply path 34 when the calculated temperature difference ΔT is large so that the gas supply amount to the gas supply path 34 increases when the calculated temperature difference ΔT is small. Thus, the opening degree of the three-way valve 46 is controlled. Thereby, since only the minimum gas flow rate required for cooling of the electric motor 22 is supplied from the suction flow path 28, the fall of the discharge flow rate of the compressed gas manufactured can be suppressed as much as possible.

  The temperature of the cooling gas supplied from the gas supply path 34 and discharged to the suction flow path 28 by the gas discharge path 35 rises as much as it corresponds to the amount of heat that cools the interior of the motor 22 and removes heat. When the temperature of the gas sucked by the compressor body 20 rises, the weight flow rate decreases, so it is desirable that the amount of cooling gas supplied into the electric motor 22 through the gas supply path 34 is small. By adopting the above control configuration, only the minimum gas flow rate necessary for cooling is supplied from the suction flow path 28, which is preferable from this point.

  Further, an oil reservoir 43 for discharging the accumulated oil to the gas discharge port 32 is provided below the insertion portion 37 of the drive shaft 26 in the casing 23 to the compressor body 20. As a result, the lubricating oil that transmits the drive shaft 26 and leaks from the compressor body 20 side to the electric motor 22 side is dropped onto the oil reservoir 43 and passes through the gas discharge path 35 from the gas discharge port 32. It can be collected in the main body 20. Therefore, main parts inside the motor such as the stator and rotor of the motor are not contaminated with oil.

The opening degree of the three-way valve 46 based on the temperature difference ΔT is controlled as follows, for example. In addition to T _h , a value of T _l (T _h > T _l ) is preset in the controller 30 as a specification temperature. When the flow rate of the gas passing through the three-way valve 46 is 100%, the controller 30 sets the flow rate flowing toward the suction adjusting valve 21 to a%, the gas supply path 34 (that is, toward the electric motor 22). The opening degree of the three-way valve 46 is controlled so that the gas can be branched and flowed such that the flowing flow rate is (100-a)%.

The numerical value a _min is set as a minimum value which is smaller than 100 and larger than 0. That is, when the compressor is not in a stopped state and is in a normal operation state, a changes within a range of 100 or less and a _min or more. In other words, at least a _min % or more of the gas that has passed through the three-way valve 46 is configured to flow toward the suction adjustment valve 21.

When T _h >T> T _l , the controller 30 calculates a based on Equation 1 below.
a = 100 + (a _min −100) × (T−T _l ) / (T _h −T _l ) ( ₁ )
When the above equation 1 is expressed using the temperature difference ΔT, the following equation 2 is obtained.
a = 100 + (a _min −100) × {(T _h −ΔT) −T _l } / (T _h −T _l ) (2)

When the temperature T of the stator 25 of the electric motor 22 is sufficiently low and the temperature T is equal to or lower than T ₁ , that is, ΔT is equal to or higher than (T _h −T ₁ ), a is set to 100. Conversely, the temperature T of the stator 25 of the motor 22 is high, the temperature T is the specified temperature T _h or more, i.e., if ΔT is less than or equal to 0, the a and a _min. Further, the controller 30, the state temperature T of the stator 25 of the motor 22 is equal to or higher than the specified temperature T _h is continues for a predetermined time or more, it is preferably configured to issue a warning by sound signal or the like.

  Next, the compressor which concerns on Embodiment 2 of this invention is demonstrated below using FIG. 2 which is the cooling system figure. Note that the second embodiment of the present invention differs from the first embodiment in that there is a difference in the structure of the lubricating oil recovery, and the rest of the configuration is exactly the same.

  That is, in the first embodiment of the present invention, the oil reservoir 43 that discharges the accumulated oil to the gas discharge port 32 is provided below the insertion portion 37 of the drive shaft 26 in the casing 23 to the compressor body 20. However, in the second embodiment of the present invention, an oil receiver 41 is further provided immediately below the fitting insertion portion 37 of the drive shaft 26 of the casing 23 to the compressor body 20, and the oil receiver 41 and the oil reservoir portion are provided. The oil recovery path 42 that communicates with the engine 43 is provided. With such a configuration, the lubricating oil can be recovered more effectively.

Next, as for the cooling effect of the electric motor according to the compressor of the present invention, the result of a comparative test carried out using a conventional compressor equipped with an electric motor with a rated output of 37 kW and changing the cooling structure will be described below. In the conventional compressor configuration in which an outer fan is provided at the shaft end of the motor and the motor casing is cooled, the motor stator temperature at the rated output is 150 ° C. On the other hand, as a result of supplying 40 L / min of air from the gas supply path into the casing of the motor in the compressor modified to the configuration of FIG. The stator temperature dropped to 130 ° C.

  As described above, according to the compressor of the present invention, one end side is connected to the compressor main body driven by the electric motor and the suction port of the compressor main body, and the flow rate of the gas flowing into the suction port is adjusted. In a compressor provided with a suction flow path provided with a suction adjustment valve, a gas supply port and a gas discharge port are provided in the casing of the electric motor, and an upstream side of the suction adjustment valve of the suction flow path and a gas supply port In this configuration, a part of the gas flowing toward the suction control valve is communicated by a gas supply path that supplies the casing, and a part of the gas flowing into the suction port is introduced into the casing of the electric motor for cooling.

  At the same time, the gas discharge port and the downstream side of the suction adjustment valve of the suction flow path are communicated with each other by a gas discharge path that allows the gas supplied from the gas supply path to flow into the downstream side of the suction adjustment valve of the suction flow path. By adopting a configuration for discharging the introduced cooled gas, the compressor itself uses the gas sucked in without causing rust generation or a large cost increase due to the supply of moisture-containing gas. It becomes possible to cool the electric motor.

  The compressor cooling structure according to the present invention has been described by taking the screw compressor as an example as described above, but needless to say, the gist can be applied to other turbo compressors, reciprocating compressors, and the like. Moreover, although the form which concerns on this invention demonstrated with the figure which the drive coaxial of the electric motor was directly connected with the rotor shaft of the compressor main body, naturally the case where rotation is transmitted via a coupling or a reduction gear between both shafts is also included. It is.

  Furthermore, in the first and second embodiments of the present invention described above, an example is shown in which the three-way valve 46 is interposed on the upstream side of the suction adjustment valve 21 in the suction flow path 28. The present invention is not limited to this, and the three-way valve 46 may be omitted and the gas supply path 34 may be simply branched from the suction flow path 28. However, in that case, in order to make the gas mainly pass through the suction flow path 28 and to effectively adjust the flow rate by the suction adjustment valve 21, the diameter of the gas supply path 34 is larger than that of the suction flow path 28. However, it is desirable that the gas supply path 34 is formed with an orifice.

Alternatively, the three-way valve 46 may be omitted and the gas supply path 34 may be simply branched from the suction flow path 28, and an open / close valve may be interposed in the gas supply path 34. At this time, the on-off valve, opened when the temperature T of the stator 25 of the motor 22 are out of the T _l or more, it is preferable to control so as to close otherwise.

  In the first and second embodiments of the present invention, the suction adjusting valve 21 and the three-way valve 46 are controlled by the controller 30 which is the same control device. Not exclusively. Both may be controlled by different control devices.

It is a cooling system figure of the compressor concerning form 1 of the present invention. It is a cooling system figure of the compressor concerning form 2 of the present invention. It is a whole block diagram of the conventional high-speed motor drive compressor. It is a schematic diagram of the conventional high-speed rotary motor.

A: A flow path upstream of the suction filter, B: A flow path between the suction filter and the suction adjustment valve,
C: Flow path between the suction adjustment valve and the suction port,
20 ... Compressor body, 20a ... Suction port, 20b ... Discharge port, 21 ... Suction adjustment valve,
22 ... Electric motor, 23 ... Casing, 24 ... Stator, 25 ... Rotor,
26 ... Drive shaft, 27 ... Bearing, 28 ... Suction passage, 29 ... Discharge passage,
30 ... Controller, 31 ... Gas supply port, 32 ... Gas discharge port,
34 ... Gas supply path, 35 ... Gas discharge path, 36 ... Intake filter, 37 ... Insertion part,
40 ... Check valve, 41 ... Oil receiver, 42 ... Oil recovery path, 43 ... Oil reservoir,
44 ... Flow of cooling gas, 45 ... Temperature detector, 46 ... Three-way valve

Claims (7)

  A compressor provided with a compressor body driven by an electric motor, and a suction flow path provided with a suction adjustment valve that is connected to one end of the suction port of the compressor body and adjusts the flow rate of gas flowing into the suction port. In the machine, a gas supply port and a gas discharge port are provided in the casing of the electric motor, and a part of the gas flowing toward the suction adjustment valve is provided on the upstream side of the suction adjustment valve and the gas supply port of the suction passage. The gas supply path that supplies the casing communicates with the gas discharge port and the downstream side of the suction adjustment valve of the suction flow path, and the gas supplied from the gas supply path is placed downstream of the suction adjustment valve of the suction flow path. A compressor characterized in that it is communicated by an inflow gas discharge passage.   2. The compressor according to claim 1, wherein a check valve is interposed in the gas discharge path in a direction allowing a gas flow toward a downstream side of the suction adjustment valve of the suction flow path.   3. The connection position of the gas supply path to the suction flow path is the downstream side of a suction filter provided on the upstream side of the suction adjustment valve of the suction flow path. A compressor according to one of the sections. The position of the gas supply port in the casing is the opposite side of the insertion portion of the drive shaft in the casing to the compressor body , and the position of the gas discharge port in the casing is on the same side as the insertion portion. The compressor according to any one of claims 1 to 3 , wherein the compressor is provided. The compressor according to claim 4 , wherein an oil reservoir for discharging the accumulated oil to a gas discharge port is provided below a portion where the drive shaft in the casing is fitted into the compressor body. Provided with a oil pan directly below the inserting portion of the compressor body of the drive shaft of the casing, according to claim 5, characterized in that a oil recovery passage for communicating the the oil receiving and oil reservoir Compressor. A temperature detector for detecting the temperature T of the stator is provided in the casing of the motor, with a three-way valve connected to one of the three sides upstream of the suction adjustment valve of the suction flow path. together, determine the temperature difference ΔT between the stator temperature T detected at the specified temperature T _h and a temperature detector of the stator set in advance (= T h _-T), when the temperature difference ΔT obtained is small gas supply A controller for controlling the opening of the three-way valve is provided so that the gas supply amount to the gas supply passage decreases when the obtained temperature difference ΔT is large so that the gas supply amount to the passage increases. The compressor according to any one of claims 1 to 6 .

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