JPH0441151A - Built-in motor cooling system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cooling device for a built-in motor used mainly in a machine tool such as a lathe.

(Prior art) Conventionally, as a cooling device for lathes, etc., JP-A-56-134
The one described in Japanese Patent No. 153 is known, and the one described in this publication has a bush (T
), the main shaft (S) is supported within the bush (T) via bearings (B, B), and a cooling part (E) formed with a spiral groove is provided on the outer peripheral surface of the bush (T). The cooling section (E) is used as an evaporator of a refrigeration system (R) equipped with an expansion mechanism (V) consisting of a compressor (C), a condenser (D), and a capillary tube. Due to the evaporation action of the refrigerant in E), the bearings (B, B) and the main shaft (S)
is cooled to reduce thermal expansion caused by heat generation and improve machining accuracy.

(Problems to be Solved by the Invention) In the above cooling device, when the cooling unit (E) is cooled by the refrigeration device (R), a predetermined set temperature is set for cooling. When the humidity of the outside air is high, there have been problems such as dew condensation on the outer surface of the housing (A) and rust, and also when there is a temperature difference between the set temperature and the outside air temperature. is the main axis (S
), distortion occurred due to the difference in thermal expansion, which adversely affected machining accuracy.

The present invention was made in view of the above-mentioned problems, and its purpose is to cool the motor and the main shaft without causing dew condensation on the outer surface of the housing, and to reduce the temperature of the main shaft. It is an object of the present invention to provide a cooling device for a built-in motor that can improve processing accuracy by reducing the temperature difference between the inside temperature and the outside air (indoor) temperature.

(Means for Solving the Problems) In order to achieve the above object, the first invention includes a motor (2) and a main shaft (3) driven by the motor (2) in the housing (1). Interior and said housing (1)
An outer wall temperature detector for detecting the outer wall temperature of the housing (1) in a cooling device for a built-in motor in which a cooling section (15) is provided in the housing (1), and the cooling section (15) is interposed in a refrigerant circuit as an evaporator of a refrigerator. (5) and a cooling adjustment means (6) for adjusting the cooling temperature in the cooling section (15).
and a controller (7) that controls the cooling adjustment means (6) to a temperature at which the temperature of the outer wall cooled by the cooling unit (15) is not lowered below the dew point temperature. This is what it means.

Further, in the second invention, the motor (
2) and a main shaft (3) driven by the motor (2), a cooling section (15) is provided in the housing (1), and the cooling section (15) is used as an evaporator of the refrigerator to cool the refrigerant. In the built-in motor cooling device installed in the circuit, an outer wall temperature detector (5) for detecting the outer wall temperature of the housing (1) is provided, and a cooling adjustment means for adjusting the cooling temperature in the cooling section (15). (8), and a controller (7) for controlling the cooling adjustment means (6) to a temperature at which the temperature of the outer wall cooled by the cooling unit (15) is not lowered below the outside air temperature. It is characterized by this.

(Function) In the first invention, the outer wall temperature of the housing (1) is detected by the outer wall temperature detector (5), and the cooling adjustment means uses an output from the controller (7) based on the detection result. (6) is controlled so that the cooling temperature in the cooling section (15) is adjusted to a temperature that does not cool the outer wall temperature of the housing (1) below the dew point temperature,
Therefore, while condensation on the housing (1) can be reliably prevented, the motor (2), the main shaft (3), etc. can be cooled, and the temperature of the main shaft (3) can be brought close to the outside temperature. be.

Further, in the second invention, the outer wall temperature of the housing (1) is determined by the outer wall temperature detector (5) as in the case described above.
) and the controller (7) based on this detection result.
The cooling adjustment means (6) is controlled by the output from the cooling unit (15) so that the cooling temperature in the cooling unit (15) is set to a temperature that does not cause the outer wall temperature of the housing (1) to fall below the outside air (indoor) temperature. Therefore, the motor (2), the main shaft (3), etc. are cooled without causing dew condensation on the housing (1), and the main shaft (3) is cooled. The temperature can be brought closer to the outside (indoor) temperature.

(Example) Fig. 4 shows a cooling device for a built-in motor used in a machine tool such as a lathe. A motor (2) comprising an outer shell (12) and a stator (21) and a rotor (22) inside the inner shell (11).
At the same time, the main shaft (3) protruding outward from the housing (1) is coupled to the rotor (22) of the motor (2), and both sides of the main shaft (3) in the axial direction are connected to the rotor (22) of the motor (2). The inner shell (11) is rotatably supported via a plurality of bearings (13°13), while the inner shell (11) and the outer shell (12)
), and the end plates (14, 14) are attached to both sides of the inner shell (11) and the outer shell (
A cooling section (16) is formed in a space defined by the cooling section (12) and the cooling section (16). In the figure, (IE3) (17) is the cooling part (1).
5) are the refrigerant inlet and outlet provided at the upper and lower parts.

Further, the cooling section (15) is installed in the refrigerant circuit as an evaporator of the refrigerator, that is, as shown in FIG. 1, a compressor (41) and a fan (42a) are attached. A refrigerant circuit of a refrigerator (4) including a condenser (42) and a temperature-sensitive expansion valve (43), with a liquid pipe on the outlet side of the expansion valve (43) and a liquid pipe on the inlet side of the compressor (41). Between the gas pipe, the inlet (16) and outlet (17)
The cooling section (15) is connected to the cooling section (
By circulating the refrigerant in the refrigerant circuit in 15), the cooling section (15) acts as an evaporator to cool the motor (2), main shaft (3), etc. In the figure, (44) is a temperature-sensitive cylinder of the temperature-sensitive expansion valve (43), and (45) is a pipe connected between the temperature-sensitive expansion valve (43) and the suction side of the compressor (41). It is a pressure equalizing pipe.

Therefore, in the first invention, in the above configuration, as shown in FIG. 1, the outer wall temperature of the outer shell (12) of the housing (1) is detected near the outer shell (12). An outer wall temperature sensor (5) is provided, and the cooling part (
15) cooling adjustment means (6) for adjusting the cooling temperature;
The cooling adjustment means (6) is equipped with a controller (7) that controls the temperature of the outer wall cooled by the cooling section (15) to a temperature that does not fall below the dew point temperature.

The cooling adjustment means (e) shown in FIG. 1 uses an electric on-off valve, and the on-off valve (8) is connected to the outlet (
17) side and the suction side of the compressor (41), and adjusts the opening degree of the on-off valve (6) to
The cooling temperature in step 5) can be controlled.

That is, for example, by adjusting the opening degree of the on-off valve (6), the differential pressure between the evaporation pressure (PE) on the cooling part (15) side and the suction pressure CPS' on the compressor (41) side can be increased. When the suction pressure (PS) is adjusted to be small, the suction pressure (PS) becomes high and the capacity of the compressor (41) is improved, and the flow rate of refrigerant to the cooling section (15) is increased to increase the suction pressure (PS). ), and the cooling temperature in the cooling section (15) can be lowered. Also, contrary to the above case, by adjusting the opening degree of the on-off valve (6), the evaporation pressure can be lowered. When the pressure difference between the suction pressure (PE) and the suction pressure (PS) is adjusted to be large, the suction pressure (PS) becomes low, the compression function decreases, and the pressure to the cooling part (15) side decreases. Reduce the refrigerant flow rate.
The evaporation temperature in the cooling section (15) can be increased, and the cooling temperature in the cooling section (15) can be increased.

Then, to the input side of the controller (7), the outside air (indoor) temperature detected by the outside wall temperature detector (5) and the outside air temperature detector (81) is output after being corrected based on a predetermined humidity. A refrigerant circuit connected to the corrector (82) that is connected to the on-off valve ( Evaporation pressure (PE) detectors (91) are installed on the inlet and outlet sides of 6).
and a suction pressure (PS) detector (92), and these detectors (91) and (92) are connected to the input side of the controller (7). The output side of the valve is connected to the on-off valve (6). The corrector (82)
Generally, the outside air temperature detected by the outside air temperature detection base (81) is set to a humidity of 80, which is approximately the maximum humidity in the outside air.
The dew point temperature of the outside air is detected by correcting the temperature difference ((4°C)) which is the dew point temperature based on %.
This correction value is compared with the outer wall temperature of the outer shell (12) detected by the outer wall temperature detector (5), and
1) Evaporation pressure (PE) and suction pressure (PS) according to (92)
) By controlling the opening and closing of the on-off valve (6) using the output signal from the controller (7) based on the detected value of To ensure that the temperature does not fall below the correction value (4℃), in other words,
This controls the outer wall temperature so that it does not fall below the dew point temperature. Further, in the present invention, the outside air temperature detector (81)
Instead of using the above-mentioned corrector (82) to control the outer wall temperature so that it does not fall below the dew point temperature, a dew point thermometer (83) is used to control the dew point temperature, as shown by the two-dot chain line in the figure. A meter (83) is connected to the input side of the controller (7), and the dew point thermometer (83) and the outer wall temperature detector (5)
In comparison, it is also possible to control the cooling temperature in the cooling section (15) so that it does not fall below the dew point temperature.

Therefore, when working on a lathe or the like, the outer wall temperature of the outer shell (12) detected by the outer wall temperature detector (5) and the outside air temperature detector (81) are input to the input side of the controller (7).
) and corrected by the corrector (82), that is, the dew point temperature of the outside air, or by comparison with the dew point temperature of the outside air detected by the dew point thermometer (83). Evaporation pressure measured by each detector (91) (92) (
The on-off valve (6) is controlled by an output signal from the controller (7) which also outputs detected values of PE) and suction pressure (PS).
) to control the cooling temperature in the cooling section (15),
Since the temperature of the outer wall of the outer shell (12) in the housing (1) is adjusted to a temperature that will not allow the humidity to drop below the dew point humidity, the cooling can be performed while reliably preventing dew condensation from occurring on the outer shell (12). The main shaft (3) is connected to the main shaft (3) by the part (15).
This allows it to be cooled to a temperature close to the outside temperature.

Further, in the above embodiment, the cooling adjustment means (6
), and the cooling temperature in the cooling section (work 5) is adjusted by controlling the opening and closing of the on-off valve (6). In place of the valve (6), for example, an orifice with a constant opening degree is used, and an outer wall temperature detector (5), an outside air temperature detector (81), and a corrector (82) are provided on the input side of the controller (7).
and controlling the start/stop of the compressor (41) based on the output signal output from the controller (7) in response to the detection results from each of the detectors (5) and (81), Through this start/stop control, it is also possible to adjust the cooling temperature in the cooling section (15). That is, as shown in FIG. This switch (6) is connected to the output side of the controller (7), and when the outer wall temperature is higher than the dew point temperature of the outside air, the switch (6) is connected to the output side of the controller (7). The compressor (41) may be operated by turning on the switch (6) in accordance with the output signal of the compressor (41), and may be controlled to stop the compressor (41) when the dew point temperature of the outside air is reached. It is possible to adjust the cooling temperature in the cooling section (step 5).

Further, as the cooling adjustment means (6), although not shown, for example, a frequency converter that converts the frequency of the compressor (41) is used, and this converter converts the frequency of the compressor (41). Accordingly, the cooling temperature in the cooling unit (15) may be adjusted, and a rotation controller that controls the rotation speed of the fan (42a) attached to the condenser (42) may be used to adjust the cooling temperature in the cooling unit (15). The rotation controller rotates the fan (4
It is also possible to adjust the cooling temperature in the cooling section (15) by controlling the rotation speed of the cooling section (15).

Moreover, as shown in FIG.
An outer wall temperature detector (5) is installed to detect the outer wall temperature of the cooling regulator (6), and the cooling regulator (6) is composed of the above-mentioned electric on-off valve, compressor start/stop switch, etc. , the outer shell (cooled by the cooling section (15))
12) and a controller (7) that controls the temperature of the outer wall so that it is not cooled below the outside (indoor) temperature. That is, in the first invention, the cooling unit (15) is controlled so that the outer wall temperature of the outer shell (12) does not fall below the dew point temperature, whereas in the second invention, the cooling unit (15) The outer wall temperature of the outer shell (12) is outside air (indoor).
It is designed to be cooled so that the temperature does not drop below that level.

Specifically, on the input side of the controller (7), the outer wall temperature detector (5) and an outside air temperature detector (84) that detects the outside air temperature and directly inputs it to the controller (7) are provided. In addition, as in the case described above, each detector (91) (92) for detecting the evaporation pressure (PE) and suction pressure (PS) in the refrigerant circuit of the refrigerator (4) is connected. The controller (7) outputs an output signal to the cooling adjustment means (6) based on these input signals, and the cooling adjustment means (6) outputs an output signal to the cooling adjustment means (6).
) to adjust the cooling temperature of the cooling section (15) to the outer shell (12).
) so that the outside wall temperature does not fall below the outside (indoor) temperature.

In this case as well, the cooling temperature of the cooling unit (15) is set so that the outer wall temperature of the outer shell (12) does not fall below the outside air (indoor) temperature, so even if the outside air has poor humidity conditions, In general, since the humidity does not exceed 80%, dew condensation can be prevented from occurring on the outer shell (12), and the temperature of the main shaft (3) can be brought close to the outside (indoor) temperature. , machining accuracy can be improved.

In the embodiment shown in FIG. 3, as shown in FIG. 2, an orifice with a constant opening, for example, is used instead of the electric on-off valve (8) whose opening can be adjusted, and the controller ( 7), an external wall temperature sensor (5), an outside air temperature sensor (81), and a corrector (82) are connected to the input side of the sensor, and the sensor corresponds to the detection results from each of the above-mentioned detectors (5) and (81). the compressor (4) based on the output signal output from the controller (7).
1), or by converting the frequency of the compressor (41) or controlling the rotation speed of the fan (42a) attached to the condenser (42). It is also possible to adjust the cooling temperature at ).

Further, in the embodiment described above, the cooling part (15) is formed between the inner shell (11) and the outer shell (12), but the cooling part (15) is formed between the inner shell (11) and the outer shell (12).
2), the inner shell (11), that is, the motor (2)
) and the main shaft (3) may be formed inside the housing (1).

(Effects of the Invention) As described above, the built-in motor cooling device according to the first invention includes an outer wall temperature detector (5) for detecting the outer wall temperature of the housing (1), and also includes an outer wall temperature detector (5) for detecting the outer wall temperature of the housing (1). a cooling adjustment means (6) for adjusting the cooling temperature in the cooling section (15) provided in the cooling section (15);
and a controller (7) that controls the temperature of the outer wall cooled by the cooling unit (15) to a temperature that does not fall below the dew point temperature, thereby ensuring fog formation in the housing (1). In addition, since the temperature of the main shaft (3) supported by the housing (1) can be brought closer to the outside temperature, when setting the desired temperature, The accuracy can be improved by comparison.

Further, in the cooling device according to the second invention, the housing (1
) is provided, as well as a cooling adjustment means (6) for adjusting the cooling temperature in the cooling section (15); Since it is equipped with a controller (7) that controls the temperature of the outer wall to be cooled by the part (15) to a temperature such that it is not cooled below the outside air temperature, it is similar to the first invention described above without detecting the dew point temperature of the outside air. This can eliminate the problem of dew condensation occurring in the housing (1), and has the effect of bringing the temperature of the main shaft (3) closer to the outside (indoor) temperature.

[Brief explanation of the drawing]

Fig. 1 is a piping system diagram showing a cooling device for a built-in motor according to the first invention, Fig. 2 is a control system diagram of main parts showing another embodiment, and Fig. 3 is a piping system diagram showing a cooling device of the second invention. A system diagram, FIG. 4 is a sectional view of the cooling device, and FIG. 5 is a sectional view showing a conventional example. (1)...Housing (15)...Cooling part (2)...Motor (3)...Main shaft (5)...ΦOuter wall temperature detector (6 )...Cooling adjustment means (7)...Controller Fig. 1 Fig. 3

Claims (1)

[Claims] 1) A motor (2) within a housing (1);
2), a cooling part (15) is provided in the housing (1), and the cooling part (15)
) is installed in a refrigerant circuit as an evaporator of a refrigerator, the built-in motor cooling device is provided with an outer wall temperature detector (5) for detecting the outer wall temperature of the housing (1), and the cooling part (15 ), and the cooling adjustment means (6) is controlled to a temperature at which the outer wall temperature cooled by the cooling section (15) is not cooled below the dew point temperature. A built-in motor cooling device, characterized in that it is equipped with a controller (7). 2) A motor (2) in the housing (1), and a motor (2) in the housing (1).
2), a cooling part (15) is provided in the housing (1), and the cooling part (15)
) is installed in a refrigerant circuit as an evaporator of a refrigerator, the built-in motor cooling device is provided with an outer wall temperature detector (5) for detecting the outer wall temperature of the housing (1), and the cooling part (15 ), and the cooling adjustment means (6) is controlled to a temperature at which the outer wall temperature cooled by the cooling unit (15) is not cooled below the outside air temperature. A built-in motor cooling device, characterized in that it is equipped with a controller (7).