JP2000320462A - Enclosed type motor-driven compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the temperature of an electric motor even at time of deficient refregerant by providing a discharge port making fluid discharged from a pump mechanism flow into a motor chamber at the inside of a housing housing the motor, and providing a temperature sensor at the housing in the vicinity of the port. SOLUTION: An electric compressor 100 has a pumping mechanism 110 for sucking and compressing a refregerant, and the mechanism 110 is accommodated in a housing 120 together with an electric motor 130. At the longitudinal end of the housing 120, a suction inlet 141 to be connected to a refregerant outlet side of an evaporator is formed, while a discharge outlet 142 to be connected to a refregerator inlet side of a radiator is formed at the other end thereof. A temperature sensor Sp is arranged at an outer wall of a housing 120 in the vicinity of a discharge port 143 for leading the refregerant discharged from the mechanism 110 to a motor chamber 133. When the detection temperature of the sensor Sp reaches a prescribed temperature, the motor 130 is stopped for the protection thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hermetic electric compressor in which a pump mechanism and an electric motor are integrated, and is effective when applied to a compressor for a refrigeration cycle.

[0002]

2. Description of the Related Art As a hermetic electric compressor for a refrigeration cycle, for example, in the invention described in Japanese Patent Application Laid-Open No. 7-35080, a temperature sensor is provided at a portion corresponding to a stator core in a housing (sealed container) accommodating an electric motor. To detect the temperature of the electric motor, and stop the electric motor when the temperature detected by the temperature sensor reaches a predetermined temperature (a temperature corresponding to the heat-resistant temperature of the electric motor). Is protected.

[0003]

By the way, the inventors of the present invention have made various examinations on which part of the temperature sensor for detecting the temperature of the electric motor should be appropriately disposed in the housing. , The following results were obtained. That is, each of the three temperature sensors Sp, Sm, and Spr is disposed at a different portion of the housing (regions Ap, Am, and Apr) as shown in FIG. 5, and the detected temperature Tp of each of the temperature sensors Sp, Sm, and Spr. , Tm and Tpr were measured.

The detected temperature Tp is the detected temperature of the temperature sensor Sp, the detected temperature Tm is the detected temperature of the temperature sensor Sm, and the detected temperature Tpr is the detected temperature of the temperature sensor Spr. FIG. 6 shows each of the temperature sensors Sp, Sm, and Sm in a case where a sufficient amount of refrigerant is secured for the heat load in the evaporator.
FIG. 7 is a graph showing detected temperatures of the respective temperature sensors Sp, Sm, and Spr when the refrigerant is insufficient for the heat load on the evaporator.

As is apparent from FIGS. 6 and 7, when a sufficient amount of refrigerant for the heat load is secured, the detected temperature Tp of each of the temperature sensors Sp, Sm and Spr is determined.
While there is no large temperature difference between Tm and Tpr (about 5 deg in this example), when the refrigerant is insufficient for the heat load, the detected temperature of each temperature sensor Sp, Sm, Spr A large temperature difference (about 10 to 30 deg in this example) occurs between Tp, Tm, and Tpr.

In other words, when a sufficient amount of refrigerant for the heat load is secured, the temperature distribution of the electric motor becomes approximately uniform, whereas when the refrigerant is insufficient, the electric motor The temperature distribution of the motor is such that the temperature increases toward the pump mechanism. For this reason, if the temperature sensor is provided only at the portion where the temperature sensor Spr is provided, for example, it is difficult to accurately detect the temperature of the electric motor when the refrigerant is insufficient, so that the electric motor burns (heat). Damage).

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to prevent a thermal damage to an electric motor by arranging a temperature sensor at an appropriate position.

[0008]

According to the present invention, in order to achieve the above object, according to the first and fourth aspects of the present invention, the temperature sensor (Sp) includes a housing (Sp) corresponding to the vicinity of the discharge port (143). 120). Thus, even when the fluid is insufficient, the temperature of the electric motor (130) can be accurately detected, so that the electric motor (130) can be reliably prevented from being thermally damaged.

According to the second and fourth aspects of the invention, in the hermetic electric compressor in which the fluid flows in the axial direction of the rotor (132), the temperature sensor (Sp) includes the discharge port (14).
3) It is provided in the housing (120) corresponding to the vicinity. Thus, even when the fluid is insufficient, the temperature of the electric motor (130) can be accurately detected, so that the electric motor (130) can be reliably prevented from being thermally damaged.

According to the third and fourth aspects of the present invention, the temperature sensor (Sp) is connected to the rotor (1) of the housing (120).
32), is disposed at a position corresponding to the discharge port (143) side from the discharge port (143). Thus, the temperature sensor (Sp) is disposed near the discharge port (143), so that the electric motor (130) can be operated even when the fluid is insufficient, similarly to the first aspect of the invention. Electric motor (130) that can accurately detect temperature
Can be reliably prevented from being thermally damaged.

Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
FIG. 1 is a schematic diagram of a refrigeration cycle, in which a hermetic electric compressor (hereinafter, abbreviated as an electric compressor) according to the present invention is applied to a compressor for a refrigeration cycle.

In FIG. 1, reference numeral 100 denotes an electric compressor for sucking and compressing a refrigerant (fluid), and reference numeral 200 denotes a radiator (condenser) for cooling the refrigerant discharged from the electric compressor 100. 30
Reference numeral 0 denotes a receiver (gas-liquid separation unit) that separates the refrigerant flowing out of the radiator 200 into a gaseous refrigerant and a liquid-phase refrigerant, stores excess refrigerant in the refrigeration cycle, and discharges the liquid-phase refrigerant. This is a decompressor that reduces the pressure of the refrigerant flowing out of the receiver 300.

The decompressor 400 is connected to the electric compressor 100
This is a temperature-type expansion valve that adjusts the opening degree (degree of pressure reduction) so that the degree of heating of the refrigerant sucked into the refrigerant reaches a predetermined value. 500
Is an evaporator that evaporates the refrigerant that has been decompressed by the decompressor 400 to be in a gas-liquid two-phase state and exhibits a refrigerating ability. Next, the electric compressor 100 will be described.

Reference numeral 110 denotes a pump mechanism for sucking and compressing the refrigerant. The pump mechanism 110 includes a fixed scroll 111 fixed (not movable) with respect to the housing 120 and an orbiting scroll 112 orbited with respect to the fixed scroll 111. This is a well-known scroll type pump mechanism. Reference numeral 130 denotes an electric motor (hereinafter abbreviated as a motor) for driving the pump mechanism 110.
Is composed of a stator 131 fixed in a substantially cylindrical housing 120, and a magnet rotor (hereinafter abbreviated as rotor) 132 rotating in the stator 131.

Here, the stator 131 is connected to the housing 1.
A stator core 131a made of a magnetic material and firmly fixed to the housing 120 by press-fitting means such as shrink fit (fitting fit) in the stator 20, and the stator core 131a
(Bound) 131b. On the other hand, the rotor 132 has a permanent magnet (magnet) 1
Rotor core 132 made of a magnetic material having embedded therein 32a
and a shaft 132c that rotates integrally with the rotor core 132b and supports the rotor core 132b.

The energization of the coil 131b is controlled by an inverter. By this energization control, a rotating magnetic field is generated in the stator 131 to rotate the rotor 132, thereby being fixed to the shaft 132c (rotor 132). The orbiting scroll 112 (pump mechanism 110) is operated. Incidentally, the rotor 132 (the shaft 132
c) is rotatably supported in the housing 120 by a bearing 132d fixed to the housing 120.

A suction port 141 connected to the refrigerant outlet side of the evaporator 500 is formed at one longitudinal end of the housing 120, and a refrigerant inlet of the radiator 200 is formed at the other longitudinal end of the housing 120. A discharge port 142 connected to the side is formed. The refrigerant drawn into the pump mechanism 110 from the suction port 141 is supplied to the housing 120.
Of the rotor 133 (hereinafter, this space is referred to as a motor chamber) 133 flows in the axial direction of the rotor 132 (a direction parallel to the shaft 132c), and flows from the discharge port 142 to the outside of the housing 120 ( The heat is discharged toward the radiator 200).

Reference numeral 143 denotes a discharge port for guiding the refrigerant discharged from the pump mechanism 110 to the motor chamber 133, and the outer wall of the housing 120 near the discharge port 143, that is, the rotor 13 of the outer wall of the housing 120.
A temperature sensor Sp that detects the temperature of the motor 130 is provided at a position corresponding to the discharge port 143 side from the position 2.

As described in the section of "Prior Art", the temperature sensor Sp is activated when the temperature detected by the temperature sensor Sp reaches a predetermined temperature (a temperature corresponding to the heat-resistant temperature of the motor 130). This is for protecting the motor 130 by stopping the motor 130 or the like. Next, features of the present embodiment will be described.

By the way, when the electric compressor 100 is started from a state where the temperature of each part of the electric compressor 100 is equal to the room temperature, in the initial stage, the temperature of the refrigerant discharged from the pump mechanism 110 is lower than the temperature of the motor 130. Since the temperature is high, as shown in FIG. 6, the temperature is higher near the discharge port 143 of the motor 130. And the motor 130
Continue to operate, the motor temperature due to the heat generated by the motor 130 exceeds the temperature of the discharged refrigerant, and the discharged refrigerant
Since the temperature of the motor 30 is cooled, the temperature of the motor 130 becomes lower near the discharge port 143.

When a sufficient amount of refrigerant is secured for the heat load, the temperature distribution of the motor 130 is such that the temperature of the motor 130 decreases as it goes closer to the discharge port 143. However, as mentioned above,
The temperature difference is small, and there is no practical problem in arranging the temperature sensor Sp at any position. On the other hand, when the refrigerant is insufficient,
The degree of heating of the refrigerant by the compression work of the evaporator 500 and the pump mechanism 110 is large, and the temperature of the refrigerant increases more than when a sufficient amount of refrigerant is secured.
Also increases in temperature. Therefore, as shown in FIG. 7, before the detected temperature Tp and the detected temperature Tpr reverse, the detected temperature Tp reaches a temperature (allowable temperature) corresponding to the heat-resistant temperature of the motor 130.

Therefore, if the temperature sensor Sp is provided in the vicinity of the discharge port 143 where the temperature becomes the highest (the region of Ap in FIG. 2) when the refrigerant is insufficient, the evaporator can be clearly understood from FIGS. It is possible to accurately detect the temperature of the motor 130 even when a sufficient amount of refrigerant is secured with respect to the heat load of the motor 500 and also when the refrigerant is insufficient, thereby reliably preventing thermal damage to the motor 130. can do.

FIG. 3 is a table summarizing the test results shown in FIGS. 5 to 7. As is clear from this table, it can be seen that the temperature sensor Sp should be disposed near the discharge port 143. Here, ◎ indicates a difference between the temperature of the motor 130 and the temperature detected by the temperature sensor (hereinafter, this difference is referred to as a temperature error).
Means less than 1-5 deg, ○ indicates a temperature error of 10 deg
x means that the temperature error is 10 deg or more.

(Second Embodiment) As described in the first embodiment, if the temperature sensor Sp is disposed near the discharge port 143, the temperature of the motor 130 can be accurately detected. In FIG. 4, the temperature sensor Sp is disposed in a portion Ape of the housing 120 corresponding to the discharge port 143 side from the coil end 131d of the coil 131b in the housing 120.

In the above embodiment, the suction port 141 is provided at one end of the housing 120 in the longitudinal direction, and the discharge port 142 is provided at the other end, so that the discharged refrigerant flows in the axial direction of the rotor 132. The discharge port 142 may be provided in the region Ap or Ape so that the discharged refrigerant does not flow in the axial direction of the rotor 132.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a refrigeration cycle.

FIG. 2 is a schematic diagram of the electric compressor according to the first embodiment of the present invention.

FIG. 3 is a table summarizing a position of a temperature sensor and a detection mode.

FIG. 4 is a schematic diagram of an electric compressor according to a second embodiment of the present invention.

FIG. 5 is a schematic view of a test electric compressor.

FIG. 6 shows a case where a sufficient amount of refrigerant is secured.
5 is a graph showing a relationship between time and a temperature detected by a temperature sensor.

FIG. 7 is a graph showing a relationship between time and a temperature detected by a temperature sensor when the refrigerant is insufficient.

[Explanation of symbols]

110 pump mechanism, 120 housing, 130 electric motor, 131 stator, 132 rotor, 133
... Motor chamber, 141 ... Suction port, 142 ... Discharge port, 143
... Discharge port.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H003 AA00 AB03 AC03 AD01 CD01 CE03 CF01 3H029 AA02 AA15 AB03 BB32 BB47 BB54 CC07 CC09 CC25 CC27 CC56 CC62 CC65

Claims (4)

[Claims] A pump mechanism (11) for sucking and compressing a fluid.
0) and an electric motor (130) having a stator (131) and a rotor (132) to drive the pump mechanism (110).
And a temperature sensor (Sp) for detecting the temperature of the electric motor (130), and a housing (120) forming a motor chamber (133) for housing the electric motor (130). ) Flows through the motor chamber (133) to allow the housing (12)
0) In the hermetic electric compressor that discharges outside, the pump mechanism (1) is provided in the housing (120).
And a discharge port (143) for allowing a fluid discharged from 10) to flow into the motor chamber (133). The temperature sensor (Sp) is connected to the discharge port (143).
A hermetic electric compressor, which is disposed in the housing (120) corresponding to the vicinity. 2. A pump mechanism (11) for sucking and compressing a fluid.
0) and an electric motor (130) having a stator (131) and a rotor (132) to drive the pump mechanism (110).
And a temperature sensor (Sp) for detecting the temperature of the electric motor (130), and a housing (120) forming a motor chamber (133) for housing the electric motor (130). ), The fluid discharged from the motor chamber (133) flows in the axial direction of the rotor (132) and is discharged outside the housing (120). In the housing (120), the pump mechanism (1) is provided.
And a discharge port (143) for allowing a fluid discharged from 10) to flow into the motor chamber (133). The temperature sensor (Sp) is connected to the discharge port (143).
A hermetic electric compressor, which is disposed in the housing (120) corresponding to the vicinity. 3. A pump mechanism (11) for sucking and compressing a fluid.
0) and an electric motor (130) having a stator (131) and a rotor (132) to drive the pump mechanism (110).
And a temperature sensor (Sp) for detecting the temperature of the electric motor (130), and a housing (120) forming a motor chamber (133) for housing the electric motor (130). ) Flows through the motor chamber (133) to allow the housing (12)
0) In the hermetic electric compressor that discharges outside, the pump mechanism (1) is provided in the housing (120).
And a discharge port (143) through which a fluid discharged from 10) flows into the motor chamber (133). The temperature sensor (Sp) is connected to the housing (120).
Out of the discharge port (1) than the rotor (132).
43) A hermetic electric compressor, which is disposed at a portion corresponding to the side. 4. The stator (131) includes a stator core (131a) made of a magnetic material and the stator core (1).
31a) and a coil (131b) wound around the housing (120).
Of the coil (131b)
The hermetic electric compressor according to any one of claims 1 to 3, wherein the hermetic electric compressor is disposed at a position corresponding to the discharge port (143) side with respect to d).