JPH0243117B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a main blower which has been improved in order to achieve variable speed control of a blower fan with a large inertia load, and to achieve continuous automatic control operation for a long period of time outdoors. Regarding electric motors.

More specifically, the present invention relates to an improvement in a variable speed blower system that transmits variable speed power to a blower fan purely mechanically and controls the speed purely electrically or electronically.

[Prior art]

Conventionally, it has been considered as a technical idea to apply a mechanical transmission as a method of changing the speed of the blower fan, but none of these methods has reached practical use.

FIG. 1A shows a block diagram of the technical idea. In the figure, 1 is a cooling tower, 2 is a water sprinkler, 3 is a filler, 4 is a water tank, 5 is a cooling water inlet pipe, 6 is an outlet pipe, and 7 is an air flow. The principle is that heated cooling water is sprayed by a sprinkler 12, cooled by an air flow 7 from below, and then returned to the outlet 6. This is intended to control the speed of the blower in order to continuously change the amount of airflow 7.

10 is a stepless reducer, 11 is a blower motor, 12 is a gear reducer, 13 is a blower fan, 14 is a power source, 1
5 is a computer, and 16 is a sensor.

Here, it is processed by the computer 15 and a speed change signal is given to the stepless reducer 10 to control the rotational speed of the blower fan 13.

On the other hand, as an example of the stepless reducer 10, FIG.
There is a structure shown in . In this figure, only a cross-sectional view of the half side from the axis center is drawn. In the figure, A is the input shaft, B is the output shaft, C is the sun wheel, and the fixed side car C ₁ and the moving side car C ₂ constantly sandwich the planet wheel E with the spring D, while the planet wheel E and the carrier F are interlocked. do. G is the gear ratio control section, which consists of fixed ring G ₂ and moving cam G ₁
This makes the planetary wheel E movable in the radial direction. In this structure, the planet wheel E plays the role of a variable planet, and the gear ratio is controlled by the interval between the cracks by operating the moving cam _G1 .

〔problem〕

However, when this type of friction transmission type stepless reducer 10 between metal wheels C and E is applied to a large inertial load such as a blower, the following phenomenon occurs.

Originally, the stepless reducer 10 is a device that reduces input power while increasing output torque and supplies it to a load. This is consistent with the torque expansion property of the stepless reducer 10 since the blower is in the direction of increasing torque when a speed increase command is given, but when a deceleration command is given, the relationship between the two is completely opposite. Become. From the perspective of the stepless reducer 10, this means that even though torque continues to be supplied from the input shaft A to the output shaft B even when a speed increase command or a deceleration command is issued, when a deceleration command is issued Only when , means that the inertial torque is reversely transmitted from the output shaft B to the input shaft A at the same time.

However, when power is transmitted from the input shaft A to the output shaft B, the fan starts to speed up slowly due to inertia, but in the stepless reducer 10, the planetary wheel rotates the contact point X in a tangential direction with the Z point as the fulcrum. The torque is transmitted smoothly due to the viscous resistance in the lubricating oil, although there may be some slippage at the X and Z points. However, on the other hand, with a large inertia load, when moving vehicle _G1 is operated to the deceleration side, inertia remains on the load side, so power transmission is not normally performed, and input shaft A is also transmitted from output shaft B side.
Power is simultaneously reversely transmitted to the side. During this reverse transmission, the planetary wheel E has its fulcrum as the Z point and the Y point as the point of action, so at the original transmission point, the X point, as a result of receiving an external force for speed change, the viscous transmission by lubricating oil is not properly carried out. This does not work, and the metal contact surfaces of the planetary wheel E and the sun wheel C are instantly damaged.

In particular, since another reducer 12 is interposed between the stepless reducer 10 and the fan 13 as shown in FIG. 1A, the inertia of the fan 13 is transmitted to the output shaft B of the stepless reducer 10. The torque is magnified by the speed ratio of the speed reducer 12 and is directly applied to the metal friction points of the planetary wheel E. At this time, the torque input from input shaft A is
Approximately several times the inertia torque input from the output shaft
Since it is about ten times smaller, the friction transmission point between metals
The Z had a fundamental defect in that it could not transmit torque properly and the entire device would be scrapped after a short period of use.

To solve this drawback, it is necessary to significantly increase the output capacity of the stepless reducer 10 and the electric motor 11 that is input to it, and to create a design that can overcome the reversely transmitted inertia torque. Therefore, extremely large and large-capacity stepless reducer 10 and electric motor 11 are required, which is practically not economically viable.
In addition, as a method to prevent the inertia torque from increasing, it is conceptually possible to place the reducer 12 in the first stage and the stepless reducer 10 in the next stage, but in this case as well, Since the normal torque from the electric motor 11 is magnified and input, an extremely large and large-capacity stepless reducer is required, and although it is technically possible to eliminate the reverse transmission of inertial torque, As a result, as in the above example, this is not economically viable.

This has made it impossible to apply a point-contact friction transmission type stepless reducer between metals to inertial loads. As a result, the conventional technical idea shown in FIG. 1A is nothing more than a mere idea, and in a practical sense, there has been a strong desire to realize a long-term continuous automatic control operation system for fans.

〔the purpose〕

The first object of this invention is to eliminate the above-mentioned drawbacks and absorb the reverse transmission of inertial torque from the fan by using a variable diameter belt transmission device that can increase and decrease speed using a line or surface contact friction transmission method using a belt. It is an object of the present invention to provide an air blowing control device that realizes long-term continuous automatic control operation of an air blower outdoors by eliminating the problem and ensuring proper torque transmission.

The second object of the present invention is to simplify and speed up maintenance due to automatic control, which increases the frequency of belt replacement due to accelerated belt wear during long-term continuous automatic control operation. It is an object of the present invention to provide a ventilation control device in which input and output shafts are arranged coaxially.

Furthermore, the third object of the present invention is to promote heating in the line or surface contact friction transmission section during long-term continuous automatic control operation, and to eliminate the phenomenon of belt material deterioration by introducing a forced cooling blower. The present invention provides a blower control device that ensures long-term stable operation.

The fourth object of the present invention is to introduce a startup control circuit that always starts from the lowest speed when starting, which is likely to cause the belt to break as the starting impact is absorbed by the belt material in a large inertia blower fan. It is an object of the present invention to provide an air blowing control device that can more completely perform continuous automatic control operation over a long period of time.

[Technical means to solve problems]

The blower control device of the first invention includes a blower fan, a main blower electric motor, an increasing/decelerating type variable diameter belt transmission, a pilot control device converting an electrical signal of a gear ratio into a mechanical signal, a housing, and a decelerating motor. It is composed of a variable diameter belt transmission and a pilot control device, and the former is used for power transmission, and the latter and the electronic adjustment circuit are used for speed change control. It is.

In the air blow control device of the second invention, in addition to the above configuration of the first invention, the input shaft and the output shaft are coaxial, and the speed reduction device is also formed by a belt speed reduction device with an intermediate shaft interposed.

In the air blow control device of the third invention, in addition to the above configuration of the first invention, a blower device is built into a variable diameter belt transmission, and a forced cooling air flow is formed indoors within the transmission. be. Further, in the blower control device of the fourth invention, in addition to the above configuration of the first invention, a starting control circuit is provided which gives a forced deceleration command to the variable diameter belt transmission when the main blower motor is stopped.

[Effect]

According to the first invention, it is variable not only in the case of normal transmission of forward torque from the traction motor, but also in both cases, even when inertial torque from the fan is expanded and reversely transmitted to the line or surface contact transmission part. The ability of the diameter belt transmission to absorb large inertia loads guarantees the basic smoothness of torque transmission, and the combination of the pilot control device and the transmission allows for outdoor installation with a fan. Since the electronic adjustment circuitry controls the transmission ratio, dangerous remote control of the blower fan is achieved. Therefore, it is only through the present invention that a configuration in which the power system can be operated mechanically and the speed change control system can be operated electronically has become a reality and has reached the level of practical use.

According to the second invention, based on the first invention described above, two types of transmissions are housed in a single housing, thereby achieving miniaturization of the entire power plant. Furthermore, in practical terms, simplification of belt replacement and maintenance has been achieved.
In terms of advantages, mass production at factories is ensured, and unmanned and automated fan control is further promoted.

According to the third invention, as a result of promoting a longer belt life, frequent maintenance is not required, and this has the effect of further promoting the practical application of automatic operation of the blower fan. Furthermore, according to the fourth invention, since the belt material is synthetic resin, it is possible to recover the shock at the time of startup,
This helps extend the life of the belt, and as a result, it works to improve the reliability of the blower control device.

〔Example〕

The air blow control device of the present invention will be described as an example in which a blower installed in a cooling tower is controlled in variable speed.

FIG. 2 shows the relationship between the suction type countercurrent cooling tower, the electronic control device, and the centrifugal chiller.

Reference numeral 10 is a countercurrent cooling tower, which has an FRP body side plate 11 and a water tank 12, which are formed into a tapered shape in consideration of fluid dynamics, and a punched metal louver 13 is provided between the two to suck air. form the mouth. Inside, the usual filling material 14, watering conduit 17, watering pipe 15 and eliminator 16 are arranged in a known manner. Cooling water flows from the inlet 18 to the water conduit 1
7. The water passes through the four pipes 15, passes through the filler 14, and flows from the water tank 12 through the drop tank 20 to the outlet 19.

Above the tower body 11, there is an air outlet 21,
Eight tube stays 23 are arranged radially there, and a blower device 25 is attached to the center thereof.
This blower device 25 includes a three-phase induction motor 29, a belt power transmission device 26 sealed with a box-shaped frame 27 and a lid 26, and an axial blower fan 24.
are assembled together. Further, in order to insulate indoor heat generated by the sealed transmission device 25, cooled outside air with little moisture is introduced into the sealed chamber from the inlet 32 via the piping 31, and is discharged from the discharge port 33. With the exception of the blower 25 and piping 31, cooling towers of this type are known. A centrifugal blower fan may be used as the blower fan. Such a cooling tower 10 is used in various fields such as the chemical industry, the steel manufacturing field, and the electric power field, but here, as an example in the air conditioning field, a turbo chiller 4 is used.
The cooling water is circulated between the condenser 42 and the cooling tower 10 by a pump 49. Turbo chiller 4
As is well known, compressor finger 41, condenser 42, expansion valve 43 and evaporator 44 are connected to refrigerant pipe 4.
5, 46, 47 and 48. Here, this refrigerator 4
0 will be omitted, but it should be noted that the condenser 42 needs to release the heat generated therein to the outside, that is, to the cooling water.

On the other hand, the blower device 25, which constitutes the main part of the present invention, is
Wiring 30 including three-phase power line a, signal lines b and p
is connected to a three-phase AC power source 37 and an electronic regulator 50 via. The regulating device 50 supplies a signal for proportionally controlling the gear ratio of the transmission device 26 via the signal line b according to the temperature signal of the dry temperature sensor 51 of the outlet cooling water, and also sends a switch output signal to the power line 39. The power is also supplied to a contact switch 39 provided to perform automatic control such that the operation of the main motor 29 and the operation of the adjustment device 50 and transmission device 26 are in harmony with each other. Further, the signal for controlling the gear ratio of the transmission device 26 may be based only on the temperature of the outlet cooling water, but the adjusting device 50 can be modified in various ways. For example, as shown in FIG. It is also possible to compensate and control the cooling capacity of the cooling tower 10 depending on weather conditions. For this purpose, it is possible to add an outside air condition detector 52 to the bridge circuit in the adjustment device 50, and furthermore, an outside air wet bulb temperature detector or an outside air enthalpy detector may be used to detect this outside air condition. As shown in FIG. 2, as an inexpensive detector, a combination of an outside air temperature detector 53 and an outside air humidity detector 54 may be used for outside air compensation.

Next, the configuration of a blower device 50 that constitutes a part of the blower control device of an apparatus according to an embodiment of the present invention will be explained with reference to FIGS. 3A to 3F.

FIG. 3A shows a blower device 2 which is the main part of the present invention.
5 is disclosed. Note that the same reference numerals are used for the same components as in FIG. 2.

The variable air blow control device 26 is composed of the usual induction motor 29, the belt power transmission device 26, and the air blow fan 24 as described above. In this embodiment, these three elements are assembled together, but as will be described later, the blower fan 24 is installed at the cooling tower air outlet 21, and the electric motor 29 and part of the transmission device 26 are connected to the air. It is also possible to install it near the outside of the air outlet 21 and connect the two. Since the normal three-phase AC induction motor 29 is placed in a humid atmosphere inside the cooling tower air outlet 21, a closed type is used, and a small heat-insulating fan 55 is provided. As is well known, there are a stator 56 and a rotor 57 inside the electric motor 29, and an input rotating shaft 60 is supported by two bearings 58. The electric motor 29 is bolted to the box-shaped frame 27 of the belt transmission device 26 via a flange 59, and its rotating shaft 60 projects and extends into the frame as a power input shaft. On the other hand, in order to reduce the weight of the belt power transmission device 26, a sealed chamber 61 is formed by a frame body 27 and a lid body 28 which are formed by casting an aluminum alloy. A drive-side pulley device 62 is attached via a key to the tip of the input shaft 60 that has entered the sealed chamber. This pulley device 62
forms an initial stage transmission, that is, a variable diameter belt continuously variable transmission 65 together with a driven pulley device 64 connected via a variable belt 63, and an intermediate rotating shaft 66.
It transmits rotational power to. The drive side and driven side pulley devices 62 and 64 include fixed pulleys 62a and 64d and a sliding pulley 6 having conical inclined contact surfaces 62c and 64c, respectively, as shown in the figure.
2b and 64b, and a variable belt 63 is formed between each pulley.
The inclined surfaces of the fixed and sliding pulleys are arranged so as to face each other so that the fixed pulley and the sliding pulley can be clamped. However, the vertical positions of the fixed pulley and the sliding pulley are reversed between the driving side and the driven side, so that the belt 63 can be maintained horizontally even when the variable belt 63 moves from side to side. Furthermore, a speed change controller 67 is integrally attached to the drive pulley device 62 for forcibly externally controlling the distance between the inclined surfaces of the fixed pulley 62a and the sliding pulley 62b. This controller 67 has a control column 7 supported via bearings 68a and 68b between a cylindrical portion 62d of a pulley 62a and a cylindrical portion 62e of a pulley 62b that are fitted together via oilless metal.
0, and a screw groove 71 provided in this column 70.
It also has a guide 72 screwed together. control pillar 7
At the tip of the sprocket 7, there is a sprocket 7 for connecting to a pilot controller, which will be described later, via a chain 74.
3 is fixed. When the control column 70 rotates with the rotation of the sprocket 73, the thread groove 7
1, the guide 72 moves up and down with respect to the column 70. Accordingly, only the moving pulley 62b
Because it slides up and down with respect to the fixed pulley 62a,
The radius of the contact circle between the belt 63 and the pulley device 62 can be variably controlled. On the other hand, in the driven pulley device 64, the sliding pulley 64b is always maintained at a predetermined spring pressure by the coil spring 69 to the fixed pulley 64a.
When the belt 63 moves due to the operation of the driving pulley device 62, the sliding pulley 64b automatically moves up and down against the spring 69, and as a result, the driving side and the driven side The speed of rotation of the intermediate shaft 66 is changed by both pulleys. Such a variable diameter belt transmission 65 functions both as a speed increaser and a speed reducer at the point where the radius of contact with the belt on the drive side and the driven side match, that is, at a speed ratio of 1:1. . In particular, as a transmission device for a cooling tower, it is advantageous to provide such a variable diameter transmission 65 at the first stage and to operate this transmission 65 as a speed increaser, as will be described later.

Next, the intermediate shaft 66 connects its center portion to the cylindrical support 8 through two bearings 81a and 81b.
0, and further this support 80
As described in FIG. 2F, it is slidable on a stand 86 indicated by a broken line, and a take-up mechanism 84 consisting of a stud bolt 82, a nut 83, and a protrusion 85 on the bottom of the frame allows the input and intermediate shafts to be moved. The distance can be easily adjusted by removing the lid 28.

Further, a small-diameter constant-speed pulley 91 is attached to the lower free end of the intermediate shaft 66, and three V-belts 92a, 92b, and 92c are attached to the output rotating shaft 95 in three belt grooves provided on the side wall of the pulley. It is also wound around a large diameter constant speed pulley 93 to form a speed reducer 90 with a constant speed reduction ratio. Furthermore, in this embodiment, since the output shaft 95 and the input shaft, that is, the motor rotor 60, are axially aligned, the take-up mechanism 84 is used to adjust the belt tension and perform other maintenance work. It can be done easily.

On the other hand, the output shaft 95 is supported at its center by an output flange 99 via two bearings 96a and 96b. This flange 99
are upper and lower flanges 99a and 99c.
are fixed to the frame 27 and a circular installation stand 100 provided at the center of the stay 23, respectively. It also protrudes downward through the through hole of the installation base 100 and passes through the protruding holder 99b, and at its tip, the output shaft 99 is connected to the oil seal 97 and stopper lid 98.
The fan mounting portion 95' of No. 5 is extended. This mounting part 95' has four blade bodies 101 and a mounting tool 1.
A conventional blower fan 24 having a 02 is mounted by means of two nuts.

In addition, the sliding pulley 62 of the drive-side pulley device 62
A heat-insulating blower device 67 consisting of an impeller 77 that rotates together with the pulley and an eccentric casing 76 is attached to the back side of b, and serves to introduce outside air with little moisture into the room 61. On the other hand, the air heat-exchanged in the room 61 is exhausted to the outside through the discharge port 33 arranged on the top surface of the lid 28. Since the static pressure in the room 61 is high, high humidity outside air will not flow backward through the discharge port 33 and enter. casing 76
may be a spiral-shaped sirotsk fan.

FIG. 3B shows a sectional view taken along line B-B' of FIG. 3A. Re-explanation of the portion described in FIG. 2A will be omitted here. FIG. 3B shows the relationship between the speed change controller 67 and the pilot electric controller 110 and the cylindrical support 80.
The structure is mainly described. The frame 23 has an elliptical shape, and a part 23 of the frame 23 partially protrudes for installing the tension pulley mechanism 120, and a reference numeral 27'' is open for the cover 28.The frame 23 has a pilot An electric control unit 110 is installed, and includes a known recycling electric motor 111 held in a cover 114, a gear reducer 112, and a small diameter sprocket 113. When the electric motor 111 is driven by an external proportional signal, which will be described later. Accordingly, the sprocket 113 is connected to the chain conductor 74.
is rotated and transmitted to the large-diameter sprocket 73, and the speed change controller 67 continuously and steplessly controls the speed change ratio of the transmission 65. On the other hand, the cylindrical support 80 has a horizontally protruding plate-like fixed arm 80a, in which three elongated holes 87a, 87b, and 87c are bored. Further, the stud bolts provided on the standing pillars 86a, 86b, and 86c, which protrude from the bottom of the frame 23 and are pressed into a platform shape at their tips, are connected to the fixed arms 80a.
By inserting the elongated holes 877a, 87b and 87c, the support body 80 is fitted with nuts 88a, 88b and 87c.
It is fixed with 8b. Long holes 87a, 87b and 8
7c is for belt conversion and tension adjustment.

FIG. 3C is an external perspective view showing the relationship between the heat-insulating centrifugal blower device 75 and the driving pulley device 62 already disclosed in FIG. 3A. In the figure, casing 7
6 is a cylinder part 76a, a spiral part 76b and a discharge part 7
6c, and a flexible pipe 31' that communicates with the introduction pipe 31 shown in FIG. 3A is attached to the cylindrical portion. One side wall of the spiral portion 76b is connected to the pulley 62
b itself functions as a wall. The blower device 75 configured in this manner supplies cold air in the direction of the arrow as the pulley device 62 rotates. Note that the blower device 75 is not limited to the one in this embodiment, and any device may be used as long as it can introduce less humid outside air into the room. For example, a sirotsko fan with a DC motor may be installed on the frame, or only a suction type fan may be placed on the frame and the power of the input shaft 60 may be driven by a belt speed increaser.

FIG. 3D shows a configuration diagram of the pilot electric control section 110 shown in FIG. 3B. Vertical and horizontal plate portions 116a and 116 are provided on the arm 114a of the cover 114.
A motor 111, a reduction gear 112, a gear transmission body 113, and a sprocket 73 are installed on one side of the T-shaped holding plate 116 formed by b, and a terminal chamber 118 is formed on the other side. A lead wire can be connected to this terminal chamber 118 from the outside through an open end 119 of an operation lid 117. Terminal room 11
8 is provided with a potentiometer 131, which will be described later. Note that this control section 110 may be replaced with a known hydraulic mechanism.

FIG. 3E shows a sectional view taken along the line E-E' of FIG. 3A. FIG. 2E mainly shows the configuration of the constant speed ratio belt reducer 90 and the tension adjustment pulley mechanism 120. The belt speed reducer 90 is configured as a speed reducer in which two pulleys 91 and 93 have a large radius so that as much power as possible can be transmitted. On the other hand, the tension adjustment pulley mechanism 120 compensates for the elongation of the belt 92, and the arm 12 is supported by a shaft 121 that is erected on the bottom surface of the frame 27.
A support column 123 is attached to 2, and a pulley body 124 that presses the back surface of the belt 92 is supported thereon. An adjustment rod 127, which is pressed against a coil spring 126, is pivoted to the tip 125 of the arm 122. The adjustment rod 127 is attached to the belt 9 using an adjustment screw 128 attached to the frame 27.
It works to adjust the pressing force on 2, one end of which is
It protrudes outside the room through a tapered hole in the screw 128, and the magnitude of the pressing force can be visually observed and measured through a transparent drip-proof cover 130.

FIG. 3F is a perspective view showing the relationship between the cylindrical support 80 and the frame 27, already described in FIGS. 3A and 3B. As already mentioned, the support body 80 that supports the intermediate shaft 66 equipped with the pulley device 64 and the small diameter pulley 91 has stud bolts 89a, 89b and 89c inserted into the three elongated holes provided in the fixed arm 80a.
are secured by nuts 88a, 88b, and 88c, and the positioning of the bearing 80 is effected by the take-up mechanism 84 described in FIG. 3A when the nuts are loosened.

The variable air blow control device 26 shown in this embodiment has 1
Although the variable diameter belt transmission 65 is housed together with the constant speed ratio reducer 90 in two small diameter closed rooms 61, these may be separated and the belt transmission 65 and main motor 29 may be installed outside the fan stack of the cooling tower 10. . In addition, in this embodiment, the belt reducer 9 is used as the constant speed ratio reducer.
0 is used, but this can also be configured with a known gear reduction gear.

The operation of the blower device shown in FIGS. 2A to 2F can be understood from the details already described, but here we will explain that the blower control device of the present invention is a stepless reducer that has been devised merely as an idea. In contrast, we will describe the basis for its ability to withstand long-term continuous automatic control operation, and also describe the advantages and functions of this blower control device.

In the air blow control device of the present invention, as described above, the first stage transmission is equipped with an increase/decrease type variable diameter belt transmission.
The second stage is also combined with a speed reduction device with a constant reduction ratio. Here, the variable-diameter belt transmission of speed-up/deceleration type refers to one that can change the speed of the intermediate shaft 52 both in the direction of speeding up and in the direction of decelerating the input rotational speed of the electric motor. Therefore, as shown in FIG. 1B, this is different from a continuously variable reducer which can only change speed in the deceleration direction in response to input.

It has been found that the combination of such an increase/decrease type variable diameter belt transmission and a speed reducer has the following synergistic effect, and works as a sufficiently stable and advantageous transmission even with a load of large inertia.

First, with a large inertial load, even if the large inertial capacity of the load is reversely transmitted when a deceleration command is issued from the pilot control device during operation, the elastic force of the belt itself and the spring of the driven pulley device can be used to avoid ,
The advantage is that the stress can be avoided by three simultaneous interactions with the slip between the belt and pulley, and this guarantees durability when continuously operating a large inertial load.

Second, in a combination of an acceleration/deceleration type variable diameter belt transmission and a reduction gear, especially in the speed increase region, the pulley devices 54 and 55 once increase the input rotation speed, and then the reduction gear 2 Although it may seem like a waste of time to decelerate the vehicle, this makes it possible to achieve downsizing, economy, and ease of maintenance when selecting a variable diameter belt transmission. It is working very advantageously.

From the first point, when the electric motor 27 is stopped, the pilot electric controller 29
It has also stopped (described later). Therefore, it is thought that the rotational force in the opposite direction applied from the blower fan 101 via the deceleration device 90 is merely transmitted through the belt 63 and rotates the rotor of the electric motor 29, but when a deceleration command is issued during operation, the fan is not yet commanded. While maintaining the previous high-speed inertia, the electric motor 29 also applies a large rotational force to the input pulley 62 while the pilot control device 110 forcibly acts on the belt 63 together with the spring 69. Therefore, even in this case, the stress of the speed between the high-speed inertia of the load before the command and the rotational force of the electric motor increases by the speed ratio of the reduction gear 90, causing the belt 63 and pulleys 62, 64 to each line Otherwise, it will be applied directly to the surface contact area. In this case, since the belt transmission body is mainly made of synthetic rubber such as neoprene, its elastic force absorbs this stress, and if this stress cannot be absorbed, slips occur between the belt and pulley due to avoidance of the pulley spring 69, and the belt Even if the material wears out, it has the effect of absorbing this speed stress.
This is fundamentally different in principle from the metal friction type stepless reducer mentioned earlier, and the invention does not cause damage to the metal transmission wheel itself, but rather the belt. The warranty function actively takes advantage of the fact that it is a consumable item. In other words, the variable diameter belt transmission 65 always provides appropriate slip absorption even when there is a delay in fan startup due to inertia during a speed increase command, or when stress is generated due to reverse transmission of habitual torque during a deceleration command. It has the advantage of being effective.

Furthermore, compared to the point contact type transmission of the continuously variable reducer shown in Figure 1B, in the line or surface contact type variable diameter belt transmission, the expanded torque in the forward and reverse directions is applied to the line or surface contact portion. Because it is dispersed, it does not concentrate at a point like a point contact type, and because one of the belts is made of synthetic rubber, it achieves almost completely stable power transmission against any external torque, and it can be used for long periods of time. Ensure continuous automatic control operation for hours.

Furthermore, as a second advantageous condition, the variable diameter belt transmission itself can be made smaller and more economical. In other words, as a characteristic of the blower fan itself, its shaft horsepower W is proportional to the cube of the rotation speed N, and the maximum power is required at maximum speed increase, so the belt transmission and All you have to do is select the capacity of the reduction gear. In other words, in a normal belt transmission, if the transmitted horsepower Wo is constant, the horsepower is proportional to the product (N・T) of the rotation speed N and belt tension T, so if a transmission that acts as a speed increaser is used, the rotation Since the number N is large, the tension T applied to the belt can be reduced accordingly. This means that the first stage transmission can use extremely small and inexpensive belts and pulleys. This simplifies the structure of the tower itself since it is placed at the top of the tower.
The economic effect is great because maintenance is also easier. In particular, it is significantly cheaper and more stable than the metal friction transmission type.

Next, the configuration and operation of the electronic adjustment circuit device 50 shown in FIG. 3A will be explained. The electronic regulation circuit device 50 includes:
Here, an example of a servo regulator is disclosed for automatically controlling the cooling water temperature, and together with the blower device 25 of FIGS. 3A to 3F, the blower control device of the present invention is achieved. Note that the temperature control circuit used in the present invention may be a known controller that manually sets the cooling water temperature and controls it based on the deviation from the actually measured temperature.

In FIG. 4A, the regulating circuit device 50 includes a proportional regulating circuit 130, a part of the pilot electric controller 110,
Furthermore, it consists of three circuit parts including a soft start starting control circuit ₁₆₀ , and as shown in _{FIG .} ing. A power supply line 155 is connected to the regulating circuit device 50 from the three-phase power lines R and S phases.
Power is supplied from 156 and 156 via a voltage doubler rectifier circuit 153. The start control circuit 160 has start and stop switches 161 and 162 and three relays 1R, 2R and 3R. Electric power is also supplied from this control circuit 160 to the recycling motor 111 of the pilot electric controller 110. Note that a three-phase electric motor may be used as the electric controller 110.

The proportional adjustment circuit 130 includes two bridge circuits 1
32 and 135 are connected via a ground point 133, and the upper bridge circuit 132 is provided with a feedback potentiometer 131 (hereinafter referred to as FBP) for adjusting the gear ratio of the transmission device 26.
Also connected to the lower bridge circuit 135 is a cooling water outlet temperature detector, that is, a temperature measuring resistor 51 such as a Pt valve. This proportional adjustment circuit 130
Here, an example is shown in which the rotational speed of the blower fan is controlled only by the cooling water outlet temperature. On the other hand, the outputs of each bridge circuit 132 and 135 are supplied to operational amplifiers 137 and 138, respectively, and after being preamplified there, the respective outputs x and y receive a deviation signal at a connection point 141 via a resistor. is generated and further applied to operational amplifier 142. Note that the state of the gear ratio or cooling water temperature is indicated by an indicator 140 via a changeover switch 139. The deviation signal output of the amplifier 143 is input to the operational amplifier 144 via the filter 143. The non-inverting input of this operational amplifier 144 receives positive feedback from its output via a resistor, and the inverting input receives negative feedback via a known dead band circuit 145 consisting of four diodes. This is to prevent output hunting.

The output of the amplifier 144 is further supplied to a speed-increasing drive circuit 146 and a decelerating-side drive circuit 147,
The activation of relays 150 and 151 is controlled via respective semiconductor switches 148 and 149. Further, the speed increase side circuit 146 has a contact 2R4 in series with the transistor switch 148, and the speed reduction side circuit 147 has a contact 2R4 in series with the transistor switch 148.
A contact 2R2 is connected in parallel with 49, respectively. On the other hand, relays 150 and 151 have output contacts 150a and 151a, and control the rotation of recycling motor 111. Electric motor 111
1 is a known electric motor composed of drive coils 111a and 111b and a capacitor 112. Limit switches HS and LS are connected to the motor to prevent excessive rotation of its output, and control power supply from a power supply terminal 157.

On the other hand, the starting control circuit 160 performs a function of regulating the mutual relationship between the traction motor 29 and the pilot motor 111, and a soft start function of starting the transmitter 26 from the lowest speed, that is, a light load state. It is something. There are relay 1R with normally open contacts 1R1 and 1R2, relay 2R with normally open contacts 2R1, 2R2 and normally closed contacts 2R3 and 2R4, and relay 3R with normally open contacts 3R1, 3R2, 3R3 and 3R4. It controls three circuits: the proportional adjustment circuit 130, the pilot electric control section 110, and the main motor 29. Reference numeral 163 is a thermal protector.

Next, before explaining the operation of FIG. 4A, FIG. 4B will be described. Figure 4B shows the electronic proportional adjustment circuit 1.
30 shows another embodiment in which the cooling device 30 has a function of compensating the cooling capacity of the cooling device, that is, the cooling tower, based on the outside air weather condition signal. This embodiment has almost the same configuration as FIG. 4A, so only the different circuit parts are shown.
In addition to 1, an outside air dry bulb temperature detector 53 and an outside air relative humidity detector 54 are connected as shown. As already mentioned, cooling towers are usually affected by the amount of outside air enthalpy or the outside air wet bulb temperature.
The detectors 53 and 54 used here are intended to provide compensation that substantially approximates these quantities. In addition, in order to perform rough control with low precision, the humidity detector 54 may be omitted and control may be performed simply based on the difference between the cooling water outlet temperature and the outside air temperature. , outside temperature detector 5
3, an outside air condition detector 52 (see FIG. 2), such as a known outside air wet bulb temperature sensor or an outside air enthalbi detector, is used between terminals m and n, and the output signal of the amplifier 138 is output from the cooling water outlet. It is obvious to those skilled in the art that the difference between the temperature and these outside air state quantities may be used as a control input. However, these outside air condition detectors 52 need to be able to convert the outside air condition quantity into an electrical signal, for example, a change in resistance value. Furthermore, those skilled in the art will be able to perform control based on the difference signal between the cooling water inlet water temperature and the outlet water temperature, and further, depending on the type of equipment to which this cooling device is applied, such as a refrigerator, It is well known that there are cases where it is advantageous to control the

Next, the operations in FIGS. 4A and 4B will be briefly described.
If the source switch 38 is turned on in advance and then the start switch 161 is pressed and turned on, the contacts 2R3,
Since the relay 3R is energized via the protector 163, it is self-held by the contact 3R1. Contact 3
The main motor 29 is started by closing R2, and the contact 3R
Power is supplied to the regulating circuit 130 via the power supply interlock 3R4, and also to the pilot section 110 by closing the power supply interlock contact 3R4. At this time, relay 2R
has been deactivated, but the low limit switch LS
is closed and the adjustment circuit 160 enters the proportional control operation, the relay 1R is energized, the contact 1R2 is closed, and the pilot section 110 also starts operating.

First, when the cooling water outlet temperature of the cooling tower shown in FIG. 2 is relatively high, the output y of the bridge circuit 135 is
Since is higher than the output x of the bridge circuit 132, a positive signal appears at the output z of the amplifier 142, and the proportional switch output is supplied from the amplifier 144, and the speed increaser circuit 14
6 relay 150 is driven. Along with this, contact 15
0a is reversed, the recycle electric motor 110 rotates in the direction in which the transmission 65 increases the speed, and this signal is transmitted to the speed change control section 67 of the transmission 65 via the chain transmission body 74, and the pulley devices 62 and 64 and the belt The radius of the contact circle with the air blower 63 changes as described above, and the rotational speeds of the output shaft 95 and the blower fan increase continuously and proportionally accordingly. The output of the amplifier 142 gradually becomes smaller and the dead band circuit 1
45, the relay 150 is deenergized, the operation of the pilot section 110 is also stopped, and only the main motor 29 rotates. Conversely, when the cooling water outlet temperature gradually decreases, and as a result, the output x becomes larger than the output y, a negative signal is generated in the amplifier 142 and reaches a predetermined value, the deceleration command circuit 147 is activated. Relay 151 is energized, and only its contact 151a is closed this time. Then, contrary to the above, the electric motor 111 rotates in a direction that reduces the speed of the transmission 65. Therefore, the transmitter output shaft 95
The rotational speed of the blower fan gradually decreases continuously and proportionally, and when it reaches a predetermined dead zone, the deceleration operation is stopped and only the main blower motor 29 rotates.

Such an operation is always performed as the coolant temperature changes within a predetermined proportional band determined by the adjustment circuit 160, and functions to keep the coolant temperature always within a predetermined range. Also, bridge circuit 1 in Figure 4B
35' also responds to changes in outside weather conditions; for example, when the outside wet bulb temperature is substantially low, the cooling efficiency of the cooling tower also increases, so the rotational speed of the blower fan 24 changes accordingly. The adjustment circuit 160 operates to lower the amount of water.

Next, when the stop switch 162 is pressed, the relay 2R is energized via the contact 3R1 and the switch 162, and is self-held at the contact 2R1, and the relay 2R is held at the contact 2R3.
will be developed. Furthermore, contact 2R2 is transistor 1
49, the relay 151 is energized, and since the contact 2R4 is opened, the relay 150 is forcibly de-energized. At this time, the relay 3R is also energized, the main motor 29 continues to rotate, and the contact 3R4 is also closed, so the pilot section 11
0 is the transmission 65 due to the reversal of the contact 151a.
control to forcibly shift to a deceleration state.
Therefore, in the end, the low speed limit switch
Recycled motor 1 reached the point where LS was opened.
11 is stopped, and furthermore, relay 1R is deenergized and contact 1R1 is opened, so relay R is also deenergized, rotation of main fan motor 29 is stopped, power supply to adjustment circuit 130 is also blocked, and contact R1 is closed. Due to the release, relay 2R is also released from self-holding, and the entire control system is stopped.

That is, the activation control circuit 160
The drive pulley device 64 functions to stop in a state where the reduction ratio is the largest, that is, in a state where it is held in the vicinity of the outermost periphery of the driven pulley device 64. This has the advantage of making maintenance work such as belt replacement or tension adjustment extremely easy, and also provides a soft start function to ensure that the next restart starts from a light load or lowest speed condition. There is. Therefore, not only the power consumption of the main motor 29 is reduced, but also an auxiliary starter such as a motor starter may be unnecessary in some cases. Further, even if the low speed switch LS is open at the time of startup, the speed increase command circuit 146 operates first, so the switch LS is closed thereafter, and the proportional operation of the adjustment circuit 160 is not hindered. Note that relays 1R, 2R, and 3R may be known solid state switches.

[Other Examples]

Although the air blow control device of the present invention has been explained using a cooling tower blower, it goes without saying that the technical idea can be applied to other blowers.

Furthermore, in the embodiment, a combination of a variable diameter belt transmission and a belt deceleration device has been described as the best embodiment, but if an increase/deceleration type variable belt transmission is placed on the first stage side, it is possible to The speed reducer may be of any type. For example, it is extremely easy for those skilled in the art to assemble a known planetary gear reducer. It is also obvious that the pilot control device may be of any other type.

[Effect]

Conventionally, it has been difficult to perform long-term interlocking automatic speed change control on a large inertial load such as a blower fan, and only ideas have been developed, but the present invention uses a variable diameter belt speed change device that increases and decreases speed. Even if inertia torque due to the inertia of the blower fan is transmitted in reverse to the normal forward torque applied from the electric motor, active slip occurs at the line or surface contact area between the belt and the pulley, and any of these Even if torque is applied to the friction transmitting portion, in any case, there is a sufficient effect of absorbing these irregular external forces, and transmission of shifting power to a large inertial load can be accomplished extremely smoothly. Moreover, since this variable diameter belt transmission is not just a stepless speed reducer but an increasing/decelerating type, there is no need to select a large, large-capacity transmission as described in the conventional technology, but rather it acts as a speed increaser. Therefore, even if the variable diameter belt transmission device itself is made small and small in capacity, it can sufficiently perform the transmission function, and as a result, an inexpensive variable speed air blowing system can be realized. In addition, since the pilot control device is incorporated into the variable diameter belt transmission device, remote automatic control operation can be almost ideally realized by assembling these together with an outdoor blower. Along with this basic speed change operation, the following derivative effects occur.

Firstly, torque transmission is performed properly despite large inertia because the fan torque follows even if the rotational speed is changed arbitrarily, so it is necessary to improve the rotation accuracy of the fan or the target object to be controlled (for example, cooling water in a cooling tower). This means that it can be controlled with extremely high precision.

Second, it is now possible to rotate the blower as needed and as much as necessary, resulting in energy savings.

Thirdly, since it is a belt, there is no radio noise or noise unlike thyristor transmissions.

Fourth, since the first stage variable diameter belt transmission can be downsized, the entire system can be constructed at low cost.

The above are the effects common to all of the second to third inventions, centering on the first invention.

Next, as a special effect of the second invention, since the input shaft and the output shaft are arranged coaxially, the entire transmission can be integrated and miniaturized, and mass production in factories can be easily achieved. It also has the added advantage of being inexpensive to form as a transmitter. Furthermore, each belt in the upper and lower stages can be converted by simply moving the intermediate shaft at the same time.
This simplifies and speeds up maintenance, and has the effect of quickly responding to belt wear, which accelerates more than expected during long-term continuous automatic control operation.

In the third invention, although frictional heat between the belt and the pulley is unavoidable, long-term continuous automatically controlled operation is further guaranteed by creating a cooling air flow within the belt transmission. Particularly, as mentioned above, since the main torque transmission is active slip operation in both speed-up and deceleration operations, the effect of reducing belt deterioration and extending its life increases the industrial value.

In the fourth invention, as in the third invention, the belt protection measures are taken, but in this case as well, the life of the belt made of synthetic resin material can be extended by performing slow startup under large inertia loads. As a result, reliability and durability are improved and effective for long-term continuous automatic control operation.

[Brief explanation of drawings]

FIG. 1A is a conceptual configuration diagram of a conventional air blowing control device that has been considered as a mere idea, and FIG. 1B is a sectional configuration diagram of a continuously reduced speed reducer used therein. FIG. 2 is a schematic configuration diagram of a cooling device to which an embodiment of the ventilation control device of the present invention is applied, and FIG.
3A to 3F are structural diagrams of air blowers forming part of the control device, and FIG. 3A is an overall configuration diagram of the air blower. Also, Figure 3B is B of Figure 3A.
3C is a partial perspective view of the drive-side pulley device, FIG. 3D is a sectional view of the pilot electric control section, and FIG. 3E is a sectional view of the −
3F is a sectional view taken along the line E', FIG. 3F is a partial perspective view of the driven pulley device, and FIGS.
Figure A is a connection diagram of the electronic adjustment circuit that constitutes another part of the control device. Figure A shows the left side connection diagram of the connection diagram, and Figure A shows the right side connection diagram of the connection diagram. FIG. 4B, shown in half, further shows a bridge circuit diagram of another embodiment of the regulating circuit. In the figure, 10...cooling device, that is, a cooling tower, 25
...Air blower, 40...Turbo chiller, 50...
Electronic adjustment circuit device, 65... Variable diameter belt transmission, 90... Constant reduction ratio speed reduction device, 110... Pilot control device, 130... Adjustment circuit, 160...
Soft start activation control circuit.

Claims (1)

[Scope of Claims] 1. (a) A blower fan attached to the output shaft; (b) A main blower motor serving as a rotational power source for the input shaft; (c) A steplessly increasing fan that is directly connected to the main blower motor. a variable diameter belt transmission capable of both speeding and deceleration operations, and (d) a pilot control that is mechanically connected to the variable diameter belt transmission and converts an input electrical control signal into a mechanical speed change signal. (e) a housing for housing the pilot control device and the variable diameter belt transmission; and (f) a stepless speed increase or deceleration output of the variable belt transmission to be decelerated and supplied to the output shaft. and (g) an electronic adjustment circuit device connected to the pilot control device to supply an electric signal for determining a gear ratio of the variable diameter belt transmission device. 2. The blower control device according to claim 1, wherein the main blower motor is an AC induction motor powered by a three-phase AC power source. 3 In claim 2, the variable diameter belt transmission device includes the belt and a variable pulley device that combines a fixed pulley and a sliding pulley to sandwich the belt, and the belt and the variable pulley A ventilation control device that has a variable contact radius with the device. 4. The air blowing control device according to claim 3, wherein the pilot control device has a reversible control motor, is installed on the wall of the housing, and is connected to the variable pulley device within the housing chamber. 5 In claim 4, the blower fan is directly connected to the output rotating shaft of a power transmission device formed by integrally forming the variable diameter belt transmission and the speed reducer, and the main blower motor and A blower control device comprising the power transmission device disposed at an air outlet of the blower fan. 6 (a) A blower fan attached to the output shaft, (b) A main blower motor that serves as a rotational power source for the input shaft, and (c) A fan that is directly connected to this main blower motor and capable of both stepless speed increase and deceleration operation. (d) a pilot control device that is mechanically connected to the variable diameter belt transmission and converts an input electrical control signal into a mechanical speed change signal; a belt reduction device that connects the continuously increasing or decelerating output of the variable diameter belt transmission via a movable intermediate shaft for belt replacement; (f) the pilot control device and the variable diameter belt transmission; Furthermore, a housing housing the belt speed reduction device and having the input shaft and the output shaft arranged coaxially, and (g) an electric signal connected to the pilot control device to determine the gear ratio of the variable diameter belt transmission A ventilation control device consisting of an electronic adjustment circuit device that supplies 7 In claim 6, the variable diameter belt transmission device includes first and second variable pulley devices configured by combining a fixed pulley and a sliding pulley for sandwiching a speed change belt. An air blowing control device in which the speed change belt is wound between the speed change belt and the contact circumference radius between the speed change belt and the pulley device is variable. 8 In claim 7, the variable speed and constant speed belts can pass between each free end of the output shaft of the belt reduction device and the input shaft on which the variable pulley device is installed. A ventilation control device that is spaced apart. 9. An air blow control device according to claim 8, wherein the belt speed reduction device includes a tension pulley device for application to a constant speed belt. 10 In claim 9, the power transmission device integrally formed with the variable diameter belt transmission and the belt speed reducer has a holder that rotatably supports the intermediate rotating shaft, The above-mentioned holding body supports the above-mentioned intermediate rotating shaft between both mounting portions of the above-mentioned intermediate rotating shaft to which the above-mentioned variable diameter belt transmission device and the above-mentioned belt reduction gear device are mounted. 11. In claim 10, the holder is bolted to the pedestal that protrudes from the housing, and the pedestal is fixed to the pedestal by loosening the bolt when changing the speed or constant speed belt. A blower control device connected to a hoisting device for sliding in the direction of the input/output axis. 12 In claim 11, the housing is provided with a lid above the stand and around the intermediate shaft, and when the lid is opened, the variable pulley device and the fixed pulley An air blowing control device in which the intermediate shaft is detachable from the housing while the intermediate shaft is installed. 13. The air blowing control device according to claim 12, wherein the pilot control device is installed in the housing, and the pilot control device and the variable pulley device are interlocked by a variable speed power transmission body. 14 In claim 13, the tension pulley device includes a tension adjuster and a tension indicator, and the tension adjuster and tension indicator are operable and visible from outside the housing. Air blow control device installed. 15 (a) A blower fan attached to the output shaft, (b) A main blower motor that serves as a rotational power source for the input shaft, and (c) A fan that is directly connected to this main blower motor and capable of both stepless speed increase and deceleration operation. (d) a pilot control device that is mechanically connected to the variable diameter belt transmission and converts an input electrical control signal into a mechanical speed change signal; (f) a housing that houses the pilot control device and the variable diameter belt transmission device, and has a blower device attached to a path for taking in cooling air from the outside and discharging it to the outside in order to radiate heat generated indoors; a reduction gear that decelerates the stepless speed increase or deceleration output of the transmission and supplies it to the output shaft; A ventilation control device consisting of an electronic adjustment circuit device that supplies air. 16. The blower control device according to claim 15, wherein the blower device includes a centrifugal blower comprising a casing and a blade driven by the rotational power of the main blower motor. 17 In claim 16, the housing containing a power transmission device integrally formed with the variable belt transmission and the speed reduction device is installed at the air outlet of the blower fan, and the housing The air blowing control device is provided with piping that communicates between an air inlet provided outside the air outlet and the inside of the housing. 18 (a) A blower fan attached to the output shaft, (b) A main blower motor that serves as a rotational power source for the input shaft, and (c) A fan that is directly connected to this main blower motor and capable of both stepless speed increase and deceleration operation. (d) a pilot control device that is mechanically connected to the variable diameter belt transmission and converts an input electrical control signal into a mechanical speed change signal; (f) a deceleration device that decelerates the stepless speed increase or deceleration output of the variable diameter belt transmission and supplies it to the output shaft; g) an electronic regulating circuit device connected to the pilot control device and supplying an electrical signal to determine the gear ratio of the variable diameter belt transmission; A blower control device comprising: a startup control circuit that later stops the main blower motor and supplies a maximum deceleration command signal to the pilot control device at the predetermined time. 19 In claim 18, the adjustment circuit device includes a potentiometer that detects the speed change ratio of the variable diameter belt transmission, and a speed change signal of the potentiometer and a speed change signal of the blower fan. A blower control device comprising a servo adjustment device for adjusting the pilot control device by comparing the output signal with a set output signal for setting the rotation speed to an arbitrary value. 20 In claim 18, the adjustment circuit device includes a potentiometer for detecting a gear ratio of the variable diameter belt transmission, and a gear ratio signal of the potentiometer and a state detector. It has a comparison circuit that compares the status signal and the deviation output signal of the set output signal, and uses the output signal of this comparison circuit to send an electrical speed change signal of each output circuit for a speed increase command or a deceleration command to the pilot control device. A blower control device configured with a servo adjustment device that supplies air and adjusts a gear ratio. 21. The air blow control device according to claim 19 or 20, wherein the state detector is a temperature detector of circulating cooling water in a cooling tower. 22. The air blow control device according to claim 21, wherein the regulating circuit device further includes a detector that substantially and electrically detects the amount of outside air enthalpy. 23. The ventilation control device according to claim 19 or 20, wherein the setting output signal of the adjustment circuit device is an output signal of a program setting device that changes over time.