JPS596779A - Method and device for operating rotary machine - 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 The present invention relates to multi-speed rotating devices and adjustment of their rotational speeds.

More particularly, the invention is operable at multiple speeds;
The present invention also relates to a rotating device including means for ensuring a lubricating film between the sleeve bearing and the rotating shaft in order to extend the life of the sleeve bearing.

Still more particularly, the present invention relates to fan motor speed control using an autotransformer to power the motor at a variable voltage. The electric motor operates at different speeds, without fear of overheating, depending on the voltage of the electrical power supplied to the electric motor.

In an air conditioning system, it is desirable that cooling operation be possible even when the outdoor temperature is relatively low.

In a typical refrigeration circuit, the condensing temperature and pressure and thus also the evaporator temperature are a function of the ambient air temperature. In order to enable efficient operation of the air conditioning system at low outside temperature conditions e1, the condensation temperature, that is, the temperature at which the refrigerant changes from gas to liquid inside the condenser, must be maintained at a minimum temperature level. . On hot days, the refrigerant changes from gas to liquid.
) A condenser fan is used to circulate ambient air such that heat exchange occurs with the refrigerant within the condenser to transfer thermal energy from the refrigerant to the air. When ambient air temperatures are low, there may be a small volume or no air forced to circulate to the condenser surface to provide adequate heat transfer.

If the condenser fan is operated at full speed and the ambient temperature is low enough, ice can form on the evaporator heat transfer surfaces as the refrigerant is condensed at a lower temperature and cooled to an even lower ν) temperature. . The total system capacity is also reduced because the condensing pressure is reduced and the resulting flow rate of refrigerant through the system is also reduced. In order to maintain full capacity of the air conditioning system under low outdoor temperature conditions, it is desirable to vary the speed of the condenser fan motor to alter the flow of air in heat transfer relationship with the condenser. Fan speed is varied to maintain the condensing temperature at the desired level. Typically, the refrigerant temperature is sensed at a suitable location within a closed refrigeration circuit to determine at what flow rate the air is circulated to the condensing surface.

A speed controller is used to vary the speed of an electric motor connected to drive a propeller-type fan for converting ambient air into a condenser.

It has been found that an economical and efficient system for making such fan speed changes is one that uses tapped transformers to power the motor at various voltages. How many times does this tap I1. The device is 1 to obtain various operating speeds! Allows the use of semi-electric motors. Other systems for using ordinary economical fan motors are:
This is because the system uses electric motors with sleeve bearings rather than expensive ball bearings. Sleeve bearing motors have a rotating shaft supported within a cylindrical sleeve. Lubricant is supplied to the space between the sleeve and the shaft to support the shaft.

It has been found that if the fan motor is operated at a sufficiently high speed, no lubricating film will be established between the shaft and the bearing. If a lubricating film is not established, the life of the bearing is significantly reduced. Furthermore, it has been found that if the shaft is operated at a minimum rotational speed that establishes a lubricating film during start-up, subsequent operation at lower speeds will not destroy the lubricating film. Therefore, operation of the fan motor at reduced speed after the lubricating film is established maintains the lubricating film and
It works to extend the bearing life.

Disclosed herein is a control system operative to energize a fan motor at a minimum speed that may vary between 500 and 800 rpm for a predetermined time interval to establish a lubricating film during startup. Ru. After startup, the fan speed may be reduced while maintaining the lubricating film in relation to the need for ambient air to be circulated to the condenser.

In a typical vapor compression refrigeration circuit using an air-cooled condenser,
Condensers are usually located outdoors and are affected by changes in outside weather conditions. For example, in the summer, the outdoor temperature is relatively I! At times when the temperature and pressure of the refrigerant flowing from the condenser to the system expansion device are relatively high, the temperature and pressure of the refrigerant flowing from the condenser to the system expansion device are relatively high. The reduction in refrigerant pressure between the condenser and the expansion device reduces the amount of refrigerant delivered to the system evaporator by the expansion stage, thereby reducing the system capacity. .

Due to the reduction in the amount of refrigerant flowing to the evaporator, lower radiator temperatures may also result in the formation of ice on the evaporator, which impedes heat transfer between the refrigerant flowing through the evaporator and the air flowing over the evaporator. Exercisebat
ing) resulting in a reduction in system capacity.

To effectively adjust the condensing temperature and pressure, the volume of air circulated through the condenser may be varied to affect the heat transfer between the refrigerant and the air.

As outdoor temperatures drop, you need it to absorb the intense heat you need! ! air flow rate decreases.

Thus, by adapting the flow rate of air to the condenser to the temperature of said air, the temperature and pressure of the condenser are maintained.

It has been found that various methods of speed control are available in condenser fan operation where a motor is used to drive a propeller fan to circulate air through the condenser. One economical method for regulating fan speed is to use a tapped transformer with a standard fan motor. The use of a tapped transformer provides a power source with different voltage levels, and the use of a standard fan motor allows the fan motor to operate at different speeds as a function of the voltage of the power source. The use of a standard fan motor reduces the cost of the motor compared to the use of compound-wound fan motors or other speed control devices such as chopper devices, inverters, or multi-wound motors.

One of the problems with using tapped transformers to power fan motors at various voltages is that standard one-volt motors can overheat when operated at a particular selected voltage. There is a tendency. In certain regions, known as high temperature voltage regions, when a fan motor operates at a given voltage, overheating conditions can occur in the motor windings. This overheating results in reduced fan motor life, premature failure, and additional maintenance problems.

The main object of the present invention is to provide a safe, economical and reliable fan motor control system that can extend the life of the motor.

An aspect of the present invention is to provide an apparatus and method for establishing a lubricating film on a sleeve bearing that supports a shaft of a fan motor when the shaft rotates at a reduced speed.

Another aspect of the invention is to operate the fan motor at a selected speed by changing the voltage of the power supplied to the fan motor while avoiding areas of excessive motor winding temperature. and providing a fan speed control device using a tapped transformer.

This object is achieved according to the invention by providing a control I device for an electric motor having a lubricated sleeve bearing supporting the motor shaft. The motor has a plurality of starting speeds and includes motor speed control means electrically connected to the motor and sensor means for producing a response indicative of the desired motor speed. Circuit means are provided and connected to both the sensor means and the motor speed control means for energizing the motor at a speed indicated by the hinge means.

Starting speed control means for energizing the motor at a predetermined minimum rotational speed for a selected time interval to establish a lubricating film within the bearings prior to operating the machine at a reduced rotational speed. It is included.

A tap one transformer is installed having a series of relays for connecting the motor to the appropriate taps on the transformer.

A control circuit is used to energize the appropriate relay to select the appropriate fan speed based on the resistance developed through the thermistor.

A timing circuit consisting of a resistor and a xepacitance is connected through the integrated circuit to energize the motor that drives the fan at the appropriate speed to establish a lubricating film during start-up.

According to another feature of the invention, this object is a power source for supplying current at a relatively constant voltage as a device for regulating the volume of air circulated by a fan. , an electric motor mechanically coupled to rotate the fan, the electric motor including motor windings;
This is achieved by a device that has at least one operating voltage range that produces high winding tension and is configured to operate at a variable rotational speed in relation to the voltage level of the applied power. The transformer is connected to a power source and has a plurality of voltage taps, each tap being selected to provide a voltage output other than an output voltage within a region that produces high motor winding temperatures. Circuit means are provided for connecting the tap of the transformer to the motor, the circuit means comprising:
Includes a relay means for powering the motor at a selected voltage level by connecting selected transformer taps to the motor to avoid voltage levels that would otherwise cause high motor winding temperatures. A variable volume of air is circulated by the fan by operating the fan motor at a selected speed by supplying a power source with various selected voltage levels.

The present invention will be explained below with reference to the drawings.

The preferred embodiment described herein relates to a condensing fan motor for use with a refrigeration circuit that circulates outside air to the condenser of the refrigeration circuit. Control devices and methods of operation in which a lubricating film is established before operating at a reduced speed, or in which outside air is recycled to the condenser of a refrigeration circuit, may also be used in other applications. It will be appreciated that the present invention may also be used with devices other than electric motors. The purpose of such a fan control circuit in a refrigeration circuit is to maintain a relatively constant head pressure, thereby allowing operation of the refrigeration system at low outdoor humidity. Other motor speed control objectives may also be met by the embodiments described herein.

Referring now to FIG. 1, a vertically mounted motor 10 is schematically shown. This electric motor includes a coater 16, a stator 18, and a casing 12. fan 20
A rain shield 14, which covers the hub 24 and the fan blade 22 mounted on the shaft 30 of the motor, is provided to protect and cover the motor from vertically falling rain. stepped shaft 31,
A biasing spring 40, a grease reservoir 44 and a sleeve bearing 42 are mounted on the upper part of the motor. The lower part of the motor, shown partially in cross-section, includes a grease reservoir 46, a three-one bearing 42, and an end bell 4 of the motor.
9 and lower bearing water slinger (Slillget) 4
8 is provided. Bearing 42G has shaft 30 extending through the motor. The lubricant beam is kept in the I-arm 4G. This lubricant! In order to establish rII slippage, it flows into the space between the shaft and the bearing. The bearing may have an opening for passing lubricant into the space between the rotating shaft and the bearing.

The bearing (j) may have diagonal grooves or similar recesses to facilitate the flow of oil within the bearing. It's good that the material is swirled!, -.

FIG. 2 shows a wiring diagram of a control system for operating the various motors. Power is through the conductor L-
1 and L-2.

Conductor 103 is connected to L-2 and fan motor 10 and transformer 50. Conductor L-1 is connected to normally closed relay contact 3-1 and transformer 50 by conductor 101. Conductor 104 connects normally closed relay contact 3-1 to normally closed relay contact 3-2 and fan motor 10. Fan Tanabata 10 is physically coupled to fan 20.

Conductor 107 connects normally open relay contact K 3-2 to normally open relay contact 2-2 and normally closed relay contact 2-1. Conductor 109 is normally closed relay contact K2-1
is connected to the tap connection to transformer 50. guide m1i1c
Connect 1-1 to the normally open relay contact 1<2-2 and the normally closed relay contact.

The conductor 112 connects the normally closed relay contact 1-'1 to the transformer 5.
Tap connect to 0 and cover connect.

The low voltage side of transformer 50 is connected to the control circuit section previously described and shown in FIG. 2 opposite the power section. Conductor 121 is connected from transformer 50 to diodes D-3 and 1]-2.

Conductor 123 runs from transformer 50 to diodes D-1 and D.
-4 is connected. Conductor 125 is diode D-1
and D-2, resistor R-1, remister R-[, capacitor C-1 and switching 1-transistor Q-1,0
-2 and Q-3 are connected. Conductor 127 connects diodes 0-4 and 0-3 to conductor 129. Four diodes D-1 to (]-4 form a diode bridge for supplying direct current to the rest of the control circuit.Resistor R-2 is connected to resistor R-3. C
and resistor R-3 is connected to resistor R-4,
Thereafter, the resistor R-8 is connected in series in the same manner. In addition, the resistor R-2 is connected to the resistor R'1 through the conductor 131.
-1, K-2 and l<-3 are connected to resistor R-9, resistor R-15, diode D-5 and relay through conductor 129. ing. Resistor R-2 is connected via conductor 141 to resistor R-3 and to terminal 7 of integrated circuit Δ-1. Resistor R-3 is connected by a wire 143 to resistor R-4 and to terminal 1 of integrated circuit A-1. Resistor R-4 is connected via conductor 145 to resistor R-5 and to terminal 7 of integrated circuit A-2. Resistor R-5 is connected via conductor 147 to resistor R-6 and to terminal 1 of integrated circuit Δ-2. Resistor R
-6 is connected to resistor R-7 and integrated circuit A- through conductor 149.
It is connected to terminal 7 of 3. Resistor R-7 is lead wire 15
1 to resistor R-8 and terminal 1 of integrated circuit A-3. Resistor R-9 is connected to resistors R-10, R-11 and R-12 via conductor 150,
These resistors are connected to conductors 153, 155 and 15 respectively.
7 to terminals 8 of integrated circuits A-1, A-2 and A-3. A conductor 150 connects resistor R-9 to thermistor RT. Resistor R-15 is connected to conductor 129 and connected to integrated circuit A-1 by conductor 159.
4 and the capacitor C-1. The resistor R-13 is connected to the resistor R-14 and the terminal 7 of the integrated circuit Δ-4 via a conductor 133.

A conductor 135 connects resistor R-14 to terminal 1 of conductor 125 and to the integrated circuit-4.

Integrated circuit Δ-1 is connected to the base of switching transistor Q-1 via conductor 161.

Integrated circuits A-2 and A-4 are connected to the base of switching transistor Q-2 via conductor 163. Integrated circuit A-a is connected via conductor 165 to the base of switching transistor Q-3. Conductor 167 connects switching transistor Q-3 to relay -3, and conductor 169 connects switching transistor Q-3 to relay -3.
2 is connected to the relay to -2, and a conductor 171 connects switching transistor Q-1 to the relay to -1.

Appropriate pull-up resistors and circuit protection devices are provided with the integrated circuit. These elements are omitted from illustration for the purpose of making the drawings easier to see.

Referring to FIG. 3, there is shown a graph of the relationship between the m1 drop of the power source, the temperature top of the electric m line, and the revolutions per minute of the electric motor. At lower voltage levels, the winding temperature rise is less and the speed is reduced.

As the voltage level increases, the temperature rises rapidly and reaches a high temperature region around 108V to 143V. Thereafter, the humidity increase decreases to the motor's design operating voltage of 230V. The same graph shows that the speed of the motor increases non-linearly with increasing voltage.

The graph also shows three operating positions. The motor tested was designed to operate at 230 volts and had a relatively low winding temperature rise of about 37.5 volts and an operating speed of 10801 volts at such voltage levels. . The reduced voltage level of 170.2V is $
Motor winding temperature upper back to 661.5 and about 920 "rl
It has been selected to have the rotational speed of a river. 230V
It has been found that motors with other predetermined voltages operate in a similar manner.

At a third selected voltage of about 100 V, the upper temperature limit is about 86 K and the rotation speed is about 375 rpm.
It has been found that l. Therefore, with the three speeds selected, the high winding temperature region, which in this case is selected for a warm rise of about 89°C, is avoided, and the motor is forced to maintain a field at a lower wire temperature. It is operated only at the resulting speed. Therefore, high temperature areas are avoided and the life of the fan motor is extended.

Next, I will explain how it works.

The thermistor RT is installed so that heat is transferred from a part of the refrigeration circuit, and responds to the temperature rt1j. Depending on its temperature, a selected resistance is generated by the thermistor. Based on this resistance in combination with the other resistances of resistors R-2 to R-12, the appropriate voltage level is established. Resistor? -2 to R-8 and R-13 and R-14 establish reference level voltages for -1 to 8-4 to the integrated circuit.

The resistance of resistor R-9 and the thermistor is such that the resistance of resistor R-9 and the thermistor has an appropriate voltage drop related to the level of resistance produced by the thermistor.
It acts to generate. Are all integrated circuits A-1-A-4 P1 cogler? RCA circuit 3098 that acts as a pull-schmitt trigger, its output is on bin 8.
goes high when the voltage level at pin 7 exceeds the voltage level at pin 7, and goes low when the voltage level at pin 8 falls to the voltage level at bin 1. Therefore, if a voltage level outside the range of voltage levels between terminals 1 and 7 of integrated circuit A-2 is detected such that it is the resistor of the resistor, integrated circuit Δ-2 is not shown. The switching transistor Q works together with the circuit elements to lower the power.
-2 through 11163 to de-energize relay I<-2.

Relays -1, -2 and -3 are always open.
Relay contacts are shown with these relays unenergized. Upon application of power to the circuit, all of these relays are initially energized and switched from the positions shown.

Therefore, depending on the voltage detected at the various terminals 8 of the integrated circuit A'=1, A-2 and -3, the appropriate switching transistor is deactivated. Therefore, if the voltage drops 3 at the same time as the unit starts up! If the voltage falls within the hysteresis range of any of the two integrated circuits, all three relays will be energized and will move to the opposite position from that shown in Figure 2. , so the fan motor 10 receives no power. If the voltage changes such that the voltage at terminal 8 of integrated circuit A-3 is outside the hysteresis range of the integrated circuit, conductor 165 is energized and switching transistor Q-3 is deenergized. , thereby deenergizing relay 1 (-3. In this condition, K
3-1 is closed and the K3-2 contact is open, so power is drawn from conductor 111101 to the newly closed! This is supplied to the fan motor 1 ( ) through the relay contact 3 - 1 and through the conductor 104 . In this condition, the fan motor is operated at maximum speed C via the voltage between windings E, -1 and L-2.

If the voltage level changes and is detected to be outside the hysteresis range of integrated circuit Δ-2, the Q-2 switching transistor is deenergized, deenergizing I-1<~2 and causing K - Switch one contact of relay 2. The K2-1 contact is now closed and the K2-2 contact is now open. The circuit therefore runs from the transformer 50 via conductor 109 to the now closed relay contact K 2-1 and conductor 107 to the now closed relay contact K 3-2 and conductor 104.
and is connected to operate the fan motor.

In this condition, the fan motor is operated with power having the voltage level at the tap of transformer 50 connected to conductor 109. If terminal 8 of integrated circuit A-1 detects a voltage outside the hysteresis range of that integrated circuit, the 1<-1 relay will likewise be deenergized and the K1-1 contact will be closed. This allows power to be transferred to the fan motor through conductor 112.
The fan motor It operates at a rate represented by the voltage level of the power source connected via winding 112 to the tap of transformer 50.

A starter is provided to establish an initial minimum speed of the motor to establish a lubricating oil film.

Integrated circuit Δ-4 is connected such that a voltage drop outside the hysteresis range between terminals 1 and 7 is detected at start-up. A timing circuit consisting of resistor R-12 and capacitor C-1 acts to create a voltage drop outside the hysteresis range for about 3 seconds during start-up. During this three second period, switching transistor Q-2 is deenergized and 2-1 is also closed, thereby operating the fan motor at intermediate speed through the now closed K3-2 contact. If Q-3)-ransistor is I・1
If not, the fan motor will run at maximum speed.

Accordingly, a control circuit is provided to maintain the fan motor at a selected minimum speed at predetermined time intervals to establish lubrication. (After that, the system is operated at a fan speed determined by the refrigeration circuit conditions.

Referring to FIGS. 2 and 3, the fan [-ta 10 is 1
It can be seen that it is operated at 00v, 170v or 230v. From the power side of the wiring diagram in FIG. 1, it can be seen that when the K3-1 relay contact directly leads the fan motor and is connected between -1 and -2, the fan motor is operated at a line voltage of 230V. If different conditions are required, the power supply is connected to conductor 11.
The appropriate relay will be energized, such as from the voltage tap connected to 0 or the voltage tap connected to conductor 109. In either case, power will be supplied to the fan motor at the appropriate voltage level.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a sleeve bearing type fan motor and fan. FIG. 12 is a wiring diagram of a control system for controlling the operation of the fan motor. FIG. 3 is a graph showing the relationship between motor speed, motor winding temperature, and voltage of power supply to the motor. 10...) 1 motor, 12... casing, 14
...Rain shield, 16... [I-ta, 18... Stator, 20... Fan, 22... Fan blade, 2
4...) Tsutabu. 30... Shaft, 31... Stepped shaft, 40... Offset G, 42... Sleeve bearing, 44.46... Goonose 1 nose nope.

Claims (4)

[Claims] (1) A process for selecting an appropriate rotational operating speed for a machine in a method of extending the life of a sleeve bearing in a machine having multiple operating speeds and at least one lubricated sleeve bearing supporting a rotating shaft. and selecting and urging the machine to operate at a rotational speed sufficient to establish a lubricating film between the sleeve bearing and the rotating shaft. A method for operating a rotating machine, characterized in that the process includes an override process and a process of cutting off the A-palite process after the shed at a time t81 sufficient to establish a lubricating film. (2) regulating the volume of air circulated and discharged by the fan by supplying power at a selected voltage level to a fan motor connected to power the fan and operating the fan motor at a variable speed; , and in a way to extend the life of the fan motor, if the fan motor is operated with a supplied voltage of the power supplied within the high voltage range, the motor will reach an overheating temperature. During the process of determining the high temperature voltage range and ensuring that the fan motor is operated at variable rotational speed without overheating, power is supplied to the fan motor at a power level outside the high temperature range. 1. A method of operating a rotating machine, comprising the step of energizing a rev motor. (3) In a motor control device that has a lubricated bearing that supports a rotating shaft and has multiple operating speeds, a motor speed control means electrically connected to the motor, and a response that indicates a desired motor speed. circuit means connected to the sensor means and the speed control means for energizing the motor at a speed indicated by the sensor means; and starting speed control means for energizing the motor at a predetermined minimum rotational speed at intervals of time to establish a lubricating film in the bearing. (4) In a device for regulating the volume of air circulated by a fan, an electric motor mechanically coupled to a power source supplying current at a relatively constant voltage to rotate the fan. hand,
an electric motor comprising electric m-windings, having at least one operating voltage region producing high winding temperatures and operating at a variable rotational speed in relation to the voltage level of the supplied power; and a power source. a transformer connected to a transformer having a plurality of voltage taps, the taps of which can be selected to provide a voltage output different from a voltage level in an area that produces high motor winding temperatures; , circuit means for connecting a transformer tap to the electric motor, including a relay means for supplying power to the electric motor at a selected voltage level by connecting selected transformer taps to the electric motor; and circuit means whereby a variable air volume is circulated by the fan by operating the motor at a voltage drop selected to avoid voltage drops that would result in high motor winding temperatures. Regulator.