JPH06147553A - Cooling unit - Google Patents

Abstract

PURPOSE:To suppress a temperature rise of a blower for supplying the air to a condenser with a simple structure and to improve its life. CONSTITUTION:The cooling unit comprises a condenser 8 for condensing refrigerant discharged from a compressor for constituting a refrigerating cycle, and a blower 10 having a fan 20 and a fan motor 21 for rotating the fan 20 to supply the air to the condenser 8. The motor 21 is operated during operating of the compressor, and the motor 21 is stopped by delaying a predetermined time after the compressor 2 is stopped. A thermally conductive fan boss 26 for mounting a shaft 24 of the motor 21 is provided in the fan 20. The boss 26 protrudes oppositely to the motor 21 from the fan 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling unit which is provided with a compressor and a condenser forming a refrigeration cycle, and a blower for air-cooling the condenser and which is used as an outdoor unit such as an air conditioner.

[0002]

2. Description of the Related Art Heretofore, this type of cooling unit has a function of causing a high-temperature and high-pressure gas refrigerant discharged from a compressor to flow into a condenser and air-cooling the condenser with outside air to condense the refrigerant. However, in order to circulate the outside air through such a condenser, for example, in Japanese Utility Model Publication No. Sho 39-1258.
No. 2 (126M201) or Japanese Patent Publication No. 59-220
A blower as shown in Japanese Patent Publication No. 80 (F04D29 / 38) is used.

That is, this type of blower is composed of a fan having many blades and a fan motor for rotating the fan, and has a structure in which wind flows from the fan motor direction to the fan direction. The motor includes a motor case forming a motor main body, a shaft attached to the inside of the motor case, a fan is attached to the motor case, a winding wound around the shaft, and the shaft. And a bearing for supporting the bearing, and these parts are mainly made of metal. When the blower is used for the outdoor unit or the like, it is usually operated and stopped in synchronization with the compressor.

[0004]

Here, the bearing temperature and the winding temperature during the operation of the fan motor are the outside air temperature,
It changes when the load applied to the fan motor changes due to the pressure loss of the condenser and the load of the fan.Generally, when the outside air temperature is high and the condenser has a high static pressure, the winding temperature Rises. Such an increase in temperature causes the shaft and the bearing to expand or deteriorate the grease between them, causing their wear and damage to the windings. Therefore, it is desirable to keep the temperature of the fan motor during operation as low as possible, but it takes a great deal of cost to solve the basic internal structure of the fan motor by changing the design.

Further, when the compressor is operating,
The temperature of the air flowing around the blower becomes higher than the outside air temperature due to the heat radiation from the condenser, but the heat generated from the fan motor windings of the blower is also transferred to the bearing, shaft and motor case by this circulating air. Therefore, the bearing temperature of the fan motor during operation of the blower (that is, during operation of the compressor) is maintained at a constant temperature of, for example, about + 78 ° C.

However, when the fan motor is stopped in synchronization with the stop of the compressor as described above, the flow of air is also stopped, and the heat generated from the fan motor loses its place of escape.
It will be stored in bearings and windings. Therefore, the temperature of the bearings and windings rises rapidly immediately after the blower is stopped,
The temperature rises to an abnormally high temperature of about ℃. At such a high temperature, as described above, most of the components of the fan motor are made of metal, so the windings are overheated and burned, and the shaft and bearing expand due to heat. Worn out,
In the worst case, seizure may occur, which shortens the life of the fan motor.

The present invention has been made in order to solve the above-mentioned conventional technical problems, and suppresses the temperature rise of the blower for circulating the air to the condenser with a simple structure and improves the life of the cooling device. The purpose is to provide a unit.

[0008]

A cooling unit 1 of the present invention
Is a compressor 2 that constitutes a refrigeration cycle, and this compressor 2
A condenser 8 for condensing the refrigerant discharged from the fan, and a fan 20.
And a fan motor 21 for rotating the fan 20, and a blower 10 for circulating air to the condenser 8. The fan motor 21 is operated during operation of the compressor 2 and after the compressor 2 is stopped. In addition to providing the controller 22 for stopping the fan motor 21 after a predetermined period of delay, the fan 2
0 is provided with a fan boss 26 having good heat conductivity for attaching the shaft 24 of the fan motor 21, and the fan boss 26 is projected from the fan 20 in the direction opposite to the fan motor 21.

[0009]

When the compressor 2 is operated, the high temperature and high pressure gas refrigerant discharged from the compressor 2 is supplied to the condenser 8. Along with the operation of the compressor 2, the fan motor 21 of the blower 10 is also operated by the control device 22, and the air is circulated to the condenser 8 by the blower 10 so that the refrigerant is air-cooled and condensed and liquefied. Then, even if the compressor 2 is stopped, the fan motor 21 is continuously operated by the control device 22. On the other hand, when the compressor 2 is stopped, the supply of the high-temperature refrigerant to the condenser 8 is also stopped. Therefore, after the compressor 2 is stopped, the temperature of the air passed through the condenser 8 by the blower 10 moves toward the outside air temperature. Going down. Therefore, after the compressor 2 is stopped, the air whose temperature has been lowered to substantially the outside air temperature by the operation of the fan motor 21 passes around the blower 10, so that the fan motor 21 is cooled by the circulating air. Become.

At this time, the shaft 24 of the fan motor 21 is attached to the fan boss 26 of the fan 20, and the fan boss 26 has good heat conductivity and projects from the fan 20 in the opposite direction to the fan motor 21. The heat conducted from the windings to the shaft 24 through the bearings 28 and 23 is transmitted to the fan boss 26, and is dissipated into the air flowing through the portion protruding from the fan 20.
As a result, the heat from the fan motor 21 can be smoothly dissipated, and the bearing 28 during operation of the fan motor 21,
It becomes possible to suppress the temperature rise of 23 and suppress the deterioration of the grease in that portion and their wear.

The fan motor 21 is connected to the control device 22.
After the compressor 2 is stopped, the compressor 2 is stopped with a delay for a predetermined period. As described above, the fan motor 21 is cooled by air having a low temperature and the fan boss 2 is stopped during the delay period.
Since the heat is smoothly dissipated by 6, it is possible to suppress a rapid temperature rise at the time of stop and eliminate the occurrence of damage as described above. Further, due to the operation of the fan motor 21 after the compressor 2 is stopped, the refrigerant (superheated steam,
Since it is possible to completely condense and liquefy the saturated vapor state), it is possible to suppress the pressure increase at the time of restarting the compressor 2 and reduce the starting load.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. 1 is a vertical sectional side view of a cooling unit 1 as an outdoor unit such as an air conditioner, FIG. 2 is a partially cutaway side view of a blower 10, and FIG. 3 is an electric circuit diagram of a controller 22 of the cooling unit 1. . A machine room 5 is located in the lower part of the cooling unit 1.
And a cooling chamber 9 is formed above the machine chamber 5. A compressor 2, a liquid receiver 4, and a blower 3 for cooling the compressor are arranged in the machine room 5. Also,
The cooling chamber 9 is provided with a condenser 8 composed of a wire fin type heat exchanger, and the compressor 2, the condenser 8 and the liquid receiver 4 together with an evaporator of an indoor unit (not shown) form a well-known refrigeration cycle. Constitute.

Further, a suction port 6 is formed on the side plate defining the cooling chamber 9 so as to face the condenser 8, and the suction port 6 is formed so that the lower portion of the condenser 8 is separated from the suction port 6. It is installed at an angle to. Further, a discharge port 7 is formed above the condenser 8 and above the cooling chamber 9.
A blower 10 for air-cooling the condenser 8 is installed inside the discharge port 7 and above the condenser 8.

This blower 10 is operated to suck the outside air from the suction port 6 as shown by the arrow in FIG. 1, and after passing it to the condenser 8, it passes around itself and is blown out from the upper discharge port 7. is there. The blower 10 is a so-called propeller fan, and includes the fan 20 and the fan 20.
And a fan motor 21 for rotating the fan.

The fan motor 21 is made of aluminum die casting as shown in FIG. 2 and has a plurality of fins.
The motor case 27 is composed of a motor 27 and a shaft 24 that is rotatably provided in the motor case 27 by an upper bearing 28 and a lower bearing 23 and has windings.
It is attached to the cooling unit 1 so as to project upward from the cooling unit 1. The fan motor 21 has a structure in which a magnetic field is formed in the motor case 27 by applying a power source to rotate the shaft 24 having a winding, and an upper bearing 28
The lower bearing 23 is usually made of metal, and the friction with the shaft 24 is reduced by grease.

The fan 20 is molded of hard synthetic resin, and is composed of a circular base portion 29 located at the center and a plurality of blades 31 provided around the base portion 29 at an angle. . A through hole 32 penetrating vertically is formed in the center of the base portion 29 of the fan 20, and a fan boss 26 for mounting the shaft 24 is integrally embedded in the inner surface of the through hole 32.

The fan boss 26 is a hollow cylindrical body made of a material having good heat conductivity such as aluminum, and its inner diameter is slightly larger than the outer diameter of the shaft 24. A narrowed portion 33 having a small diameter is formed in the middle of the fan boss 26, and the tip of the fan boss 26 projects upward from the upper surface of the base portion 29 by a predetermined dimension.
The fan motor 2 is inserted into the fan boss 26 having the above structure from below.
The shaft 24 of No. 1 is inserted, and when the tip reaches the constricted portion 33, the fan boss 26 and the shaft 24 are screwed with a screw (not shown).
The fan 20 is attached to the upper end of the shaft 24 by fixing. At this time, the upper end of the fan boss 26 is the fan motor 2
The shape is such that it projects from the base 29 in the direction opposite to 1.

Next, in the control device 22 shown in FIG. 3, the low-voltage switch 12 is connected in series to the compressor electromagnetic contactor 11, and the normally closed contact 15 of the compressor electromagnetic contactor 11 is connected to the delay timer 13. It is connected in series. The blower electromagnetic contactor 14 that controls the operation of the fan motor 21 of the blower 10 is a normally open contact 1 of the compressor electromagnetic contactor 11.
6 is connected in series, and the auxiliary relay 17 is connected in series with a switch 18 controlled by the delay timer 13 and a normally open contact 19 of the auxiliary relay 17. The blower electromagnetic contactor 14 is also connected in series with the normally open contact 19, and the auxiliary relay 17 and the switch 18 are also connected in series with the normally open contact 16.

The low-pressure switch 12 senses the pressure on the suction side of the compressor 2 and closes the contact when the compressor 2 is operated and the suction side becomes low pressure, and when the compressor 2 stops and the pressure on the suction side rises. It opens the contact. Also, delay timer 1
The switch 3 opens the switch 18 and closes it again after a predetermined period (for example, 5 minutes) after being energized.

The operation of the above configuration will be described below. The compressor 2 is controlled to be operated / stopped by a thermostat or the like provided in an indoor unit (not shown), and the delay timer 13 closes the switch 18. And the compressor 2
Is activated, the pressure on the suction side decreases, so that the low-voltage switch 12 closes the contact. As a result, the electromagnetic contactor 11 for the compressor is energized and the normally closed contact 15 is opened, so that the delay timer 13 is not energized. On the other hand, since the normally open contact 16 is closed, the blower electromagnetic contactor 14 is energized, and thereby the fan motor 21 is started. The fan 20 is rotated by the operation of the fan motor 21, and air is circulated in the condenser 8 as indicated by the arrow in FIG. Further, since the switch 18 is closed, the auxiliary relay 17 is also energized, thereby closing the normally open contact 19.

Next, when the compressor 2 is stopped by the thermostat, the pressure on the suction side rises.
The low voltage switch 12 opens the contacts. As a result, the electromagnetic contactor 11 for the compressor is de-energized, so that the normally closed contact 15 is closed, whereby the delay timer 13 starts operating. On the other hand, the normally open contact 16 is opened, but the normally open contact 19 of the auxiliary relay 17 is closed, so that the blower electromagnetic contactor 14 is closed.
Is still energized, so that the fan motor 21 of the blower 10 continues to operate. Then, the delay timer 13
When a predetermined period (5 minutes) has passed after the start of energization to the relay, the delay timer 13 opens the switch 18, so that the energization to the auxiliary relay 17 is cut off and the normally open contact 19 is opened. As a result, the power supply to the blower electromagnetic contactor 14 is cut off, and the fan motor 21 is stopped. As described above, in the present invention, the fan motor 21 is stopped with a delay of a predetermined period from the stop of the compressor 2.

Here, since the high-temperature and high-pressure gas refrigerant is supplied to the condenser 8 while the compressor 2 is operating, it is circulated to the condenser 8 by the operation of the blower 10 and rises from there to blower. Although the temperature of the air passing around 10 is higher than that of the outside air, the heat generated from the fan motor 21 is also taken away by this circulating air, so that the upper and lower bearings 28, 23 of the fan motor 21 while the blower 10 is operating. The temperature is kept constant at about + 78 ° C.

However, during the delay period, since the refrigerant is not supplied from the compressor 2 to the condenser 8, the temperature of the condenser 8 rapidly decreases toward the outside air temperature and the blower 10 causes the condenser 8 to cool. The temperature of the air passing through the air drops almost as much as the outside air temperature. Therefore, during the delay period after the compressor 2 is stopped, the air having a low temperature passes around the fan motor 21 due to the operation of the blower 10, and the fan motor 21 is cooled by the circulating air having a low temperature. Will be.

Further, the fan boss 26 of the fan 20 to which the shaft 24 of the fan motor 21 is attached is
Since it projects from the base portion 29 of 0 in the direction opposite to the fan motor 21, heat generated from the windings is generated by the upper and lower bearings 28, 23.
Via the shaft 24, further transmitted to the fan boss 26, and dissipated from the portion protruding upward from the base portion 29,
After that, the cooling air of the blower 10 is taken and discharged upward. Therefore, the heat from the shaft 24 can be smoothly dissipated, so that the upper and lower bearings 28, 23.
It becomes possible to remarkably lower the temperature of (particularly the upper bearing 28), and in the experiment, the upper bearing 28 of the fan motor 21 is
In the above, it was confirmed that the temperature decreased by about 2 ° C. during the operation of the blower 10 as compared with the case where the fan boss 26 was not projected. Then, due to the heat dissipation effect and the delayed stop, the fan motor 2
The temperature of bearings 28 and 23 when stopped at 1 is 15 ° C higher than before.
It was suppressed to as low as + 75 ° C.

Thus, according to the present invention, the fan motor 2
It becomes possible to remarkably suppress the temperature rise during and immediately after the stop of No. 1, thereby suppressing the deterioration of grease between the bearings 28 and 23 and the shaft 24 and their expansion, resulting in wear and seizure, and further The occurrence of burnout of the winding of the fan motor 21 can be eliminated.

Further, the operation of the fan motor 21 after the compressor 2 is stopped completely condenses and liquefies the refrigerant (superheated steam, saturated steam state) in the condenser 8 which was being condensed when the compressor 2 was stopped. The compressor 2
It is possible to suppress the pressure increase at the time of restarting and reduce the starting load.

[0027]

As described above in detail, according to the present invention, the fan motor continues to be operated by the control device even after the compressor is stopped, and the fan motor is stopped with a delay for a predetermined period. The low temperature air that has passed through the condenser whose temperature is lowered due to the lack of supply of air can cool the fan motor of the blower. In particular, the fan boss with good heat conductivity for attaching the shaft of the fan motor is projected from the fan in the direction opposite to the fan motor, so the heat from the shaft is conducted to this fan boss, and from the protruding part. It will spread smoothly. Therefore, it becomes possible to remarkably suppress the temperature rise during the operation of the fan motor and immediately after the stop, and it is possible to prevent the wear of the bearing and the shaft of the fan motor and the burnout due to the overheating of the winding.
The useful life of the fan motor can be extended. Further, at this time, since the inside of the fan motor is not modified, the cost increase can be prevented.

Further, by operating the fan motor after stopping the compressor, it is possible to completely condense and liquefy the refrigerant in the condenser that was in the middle of condensation when the compressor was stopped, so that the compressor is restarted. It is also possible to suppress the pressure increase at the time and reduce the starting load.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a cooling unit of the present invention.

FIG. 2 is a partially cutaway side view of the blower.

FIG. 3 is an electric circuit diagram of a cooling unit controller.

[Explanation of symbols]

 1 Cooling Unit 2 Compressor 8 Condenser 10 Blower 20 Fan 21 Fan Motor 24 Shaft 26 Fan Boss

Claims (1)

[Claims] 1. A compressor that constitutes a refrigeration cycle, a condenser that condenses the refrigerant discharged from the compressor, a fan and a fan motor that rotates the fan, and causes air to flow through the condenser. In a cooling unit including a blower, the fan motor is operated during operation of the compressor, and after the compressor is stopped, a controller for delaying the fan motor for a predetermined period is provided and the fan is provided. Is provided with a heat-conductive fan boss for mounting the shaft of the fan motor, and the fan boss is projected from the fan in a direction opposite to the fan motor.