JP2014040837A - Unrefuel screw compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an unrefuel screw compressor which achieves high reliability.SOLUTION: A unrefuel screw compressor includes: a compressor body having a screw rotor which rotationally compresses in a non contact manner with no oil supply; a lubrication oil path that supplies a lubrication oil for lubricating a gear which drives the screw rotor or a bearing; an air-cooling type cooler for the lubrication oil; a cooling fan 25 which supplies cooling air to the compressor body and the air-cooling type cooler; a first sensor 29 which detects a temperature of the lubrication oil; a storage part which stores a setting temperature of the lubrication oil; and cooling fan control means which outputs a control signal for increasing a rotation speed of the cooling fan 25 when a lubrication oil temperature detection value from the first sensor 29 becomes higher than the setting temperature of the lubrication oil stored in the storage part.

Description

  The present invention relates to an oil-free screw compressor capable of controlling the rotation of a cooling fan, and more specifically, an oil-free type capable of appropriately maintaining the temperature of compressed air and lubricating oil in response to changes in environmental temperature. It relates to a screw compressor.

  An oil-free screw compressor having a pair of male and female screw rotors that can rotate in a non-contact and oil-free manner and compresses air by the screw rotors is known. The air-cooled oil-free screw compressor includes a lubricating oil that lubricates bearings, gears, and the like, and an air-cooled cooler that cools the compressed air, and the outside air is taken into the air-cooled cooler by a cooling fan. , And a structure for performing heat exchange with compressed air (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 1-116297

  In the air-cooled, oil-free screw compressor, a pair of male and female screw rotors in the compressor body is supported by the compressor body by bearings, and is provided with a rotational power from a motor by a gear. Moreover, it is set as the structure by which lubricating oil is supplied to the bearing and gear used for the drive part inside and outside a compressor main body.

  This type of air-cooled, oil-free screw compressor is sometimes installed in a place where the environmental temperature changes greatly with respect to a set specification. In this case, when the temperature of the lubricating oil becomes lower than the appropriate temperature due to the ambient temperature, the mechanical power loss of the bearings and gears increases as the viscosity of the lubricating oil increases. In addition, an increase in the temperature of the lubricating oil shortens the life of the lubricating oil itself.

  Also, in the compressed air discharged from the compressor body, the discharge compressed air temperature fluctuates depending on the environmental temperature, but the increase in the temperature of the discharged compressed air due to the increase in the environmental temperature reduces the life of the air-cooled cooler, When the set temperature of the compressor protection device is exceeded, the compressor stops to prevent accidents. Further, if the environmental temperature is significantly lower than the appropriate temperature, the generation and increase of condensed water in the compressed air leads to a reduction in the amount of compressed air and failure of equipment inside and outside the compressor.

  However, since the air-cooled cooling device for the lubricating oil and compressed air described above exchanges heat with the cooling air taken from the outside of the compressor by the cooling fan, the lubricating oil depends on the ambient temperature if the rotation speed of the cooling fan is constant. And the problem that the temperature of compressed air will fluctuate occurs.

  The present invention has been made based on the above-described matters, and is an oil-free screw compressor that can maintain the reliability of the lubricating oil and the intake air properly and maintain high reliability even when the environmental temperature fluctuates. The purpose is to provide.

  In order to achieve the above object, the first invention provides a compressor body having a screw rotor that rotates and compresses in a non-contact and oil-free manner, and lubrication that supplies lubricating oil that lubricates a gear or a bearing that drives the screw rotor. A first sensor for detecting the temperature of the lubricating oil, comprising: an oil path; an air-cooled cooler for the lubricating oil; and a cooling fan that supplies cooling air to the compressor body and to the air-cooled cooler. And a storage unit that stores the set temperature of the lubricant, and the cooling fan when the detected value of the lubricant temperature from the first sensor is higher than the set temperature of the lubricant stored in the storage unit. And a cooling fan control means for outputting a control signal for increasing the number of rotations.

  In addition, the second invention provides a compressor body having a screw rotor that rotates and compresses in a non-contact and oil-free manner, an air-cooled cooler for compressed air, and cooling air in the compressor body and the air-cooled cooler. A cooling fan for supplying the air, a second sensor for detecting the intake air temperature, a storage unit for storing the set temperature of the intake air, and an intake air temperature detection value from the second sensor in the storage unit And a cooling fan control means for outputting a control signal for increasing the number of revolutions of the cooling fan when the stored temperature of the intake air becomes higher.

  Furthermore, a third invention is characterized in that, in the first or second invention, the rotation speed of the cooling fan is controlled by an inverter dedicated to the cooling fan.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the cooling fan is speed-controlled by a compressor inverter.

  The fifth invention is characterized in that, in any one of the first to fourth inventions, the cooling fan control means takes in the temperature inside and outside the compressor unit and controls the rotation speed of the cooling fan.

  Furthermore, a sixth invention is any one of the first to fifth inventions, wherein the cooling fan control means takes in the temperature in the control panel such as a start panel and controls the number of revolutions of the cooling fan. And

  In a seventh aspect based on the first aspect, the cooling fan control means controls the number of rotations of the cooling fan so that the temperature of the lubricating oil is maintained within a preset temperature range. And

  According to the present invention, even if the environmental temperature fluctuates, the temperature of the lubricating oil and the intake air can be maintained appropriately, and therefore a highly reliable oil-free screw compressor can be provided.

1 is a system diagram showing an overall configuration of an embodiment of a two-stage air-cooled oil-free screw compressor of the present invention. It is a figure which shows the structure of the cooling fan control means which comprises one Embodiment of the two-stage air-cooling non-lube type screw compressor of this invention shown in FIG. It is a systematic diagram which shows the whole structure of other embodiment of the two-stage air-cooling type oil-free screw compressor of this invention. It is a figure which shows the structure of the cooling fan control means which comprises one Embodiment of the two-stage air-cooled oil-free screw compressor of this invention shown in FIG.

  Embodiments of an oil-free screw compressor according to the present invention will be described below with reference to the drawings.

  As an embodiment of the present invention, a compressor body having a pair of male and female screw rotors that can rotate in a non-contact and non-lubricating manner with a timing gear, an air-cooled cooling device that cools compressed air discharged from the compressor body, Cooling that has an air cooling type cooling device that cools the bearing and gear lubricating oil used in the drive part inside and outside the compressor body, and that allows the rotation speed control to adjust the amount of cooling air flow to this cooling device An oil-free screw compressor composed of a fan will be described.

  Specifically, it has an inverter dedicated to the cooling fan and this control unit, and the temperature sensor detects any of the lubricating oil temperature, suction compressed air temperature, compressor unit internal / external temperature, or starter panel internal temperature, and the cooling fan Rotational speed control is performed. In addition, it is possible to control the rotational speed of the cooling fan in synchronization with the capacity control of the compressor.

  FIG. 1 is a system diagram showing an overall configuration of an embodiment of a single-stage air-cooled oil-free screw compressor according to the present invention. In FIG. 1, an oil-free screw compressor 1 includes a single-stage compressor body 2A and a single-stage compressor body 2B in a housing 1A. The compressor main bodies 2 </ b> A and 2 </ b> B are attached in the gear casing 3. A pair of screw rotors of a male rotor 4 and a female rotor 5 are provided in the compressor main bodies 2A and 2B. Timing gears 6 and 7 are attached to shaft ends on one side of these rotors.

  A pinion gear 9 is attached to one shaft end of the male rotor 5. The pinion gear 9 meshes with a bull gear 10 connected to the drive shaft. The pinion gear 9 and the bull gear 10 are accommodated in the gear casing 3. A lower part of the gear casing 3 is an oil sump 12. The rotor and the drive shaft are both supported by a bearing 8. A drive belt 11 is stretched between a pulley attached to the end of the drive shaft having the bull gear 10 and a sheave attached to the end of the motor shaft. Using the compressor driving gear 10 and the belt 11, the output of the motor 13 is transmitted to the compressor main bodies 2A and 2B.

  As the flow of compressed air, the outside air taken in and compressed by the first-stage compressor body 2A passes through the discharge pipe 16A and is cooled by the first-stage compressed air cooler 17A, and then passes through the discharge pipe 16B and is compressed in two stages. It is compressed by the machine body 2B. The air compressed by the two-stage compressor body 2B passes through the discharge pipe 18, is cooled by the two-stage compressed air cooler 17B, and then passes through the discharge pipe 19 and is supplied to the pipe connected to the outside of the compressor unit. Is done. A check valve 15 is provided in the discharge pipe 18.

  As the flow of the lubricating oil, the lubricating oil collected in the oil sump 12 in the gear case 3 passes through the lubricating oil pipe 21 and is cooled by the lubricating oil cooler 20, and then the oil connected to the lubricating oil pipe 23. After passing through the filter 22, it is supplied to the drive unit bearing 8 and the gears 9 and 10 including the first-stage compressor body 2A and the two-stage compressor body 2B.

  A starting and control panel 24 is provided inside the casing 1A of the compressor 1 (lower left side in FIG. 1). A cooling fan 25 is provided inside the casing 1A of the compressor 1 (upper right side in FIG. 1). The cooling fan 25 is rotationally controlled by a motor 26. By the rotation of the cooling fan 25, outside air is taken in from the intake holes 27 formed in the housing 1A. This outside air cools the inside of the unit, and then heat exchanges with the compressed air coolers 17A and 17B and the lubricating oil cooler 20, and then is discharged from the exhaust hole 28 formed in the housing 1A.

  The lubricating oil pipe 23 on the outlet side of the lubricating oil cooler 20 has a first sensor 29 for detecting the temperature of the lubricating oil, and the suction side of the one-stage compressor body 2A and the two-stage compressor body 2B is suctioned. Second sensors 30A and 30B for detecting the air temperature are provided. The detection signals of these sensors 29, 30A, 30B are taken into the cooling fan control means 31 described later.

  FIG. 2 shows the configuration of the cooling fan control means 31 constituting one embodiment of the two-stage air-cooled oil-free screw compressor of the present invention. In FIG. 2, the same reference numerals as those in FIG. 1 are the same. Since it is a part, the detailed description is abbreviate | omitted.

  The cooling fan control means 31 includes a storage unit 31A for storing the set temperature of the lubricating oil and the set temperature of the intake air, and the setting of the lubricating oil in which the detected value of the lubricant temperature from the first sensor 29 is stored in the storage unit 31A. When the temperature becomes higher than the temperature, a control signal for increasing the number of revolutions of the cooling fan 25 is calculated, and the intake air temperature detection values from the second sensors 30A and 30B are stored in the storage unit 31A. A calculation unit 31B that calculates a control signal for increasing the rotation speed of the cooling fan 25 when the temperature becomes higher than the set temperature is provided. The control signal from the calculation unit 31B is transmitted to the cooling fan dedicated inverter 32. Based on this, the cooling fan dedicated inverter 32 is output to the motor 26 of the cooling fan 25, and the motor 26 controls the rotation speed of the cooling fan 25.

Next, the operation of one embodiment of the above-described two-stage air-cooled oil-free screw compressor of the present invention will be described with reference to FIGS.
The temperature of the lubricating oil is taken into the arithmetic unit 31B of the cooling fan control means 31 by the first sensor 29, and the intake air temperature is taken by the second sensors 30A and 30B. When the temperature of the lubricating oil rises due to the influence of the surrounding environment such as the installation location of the oil-free screw compressor 1 and becomes higher than the set temperature of the lubricating oil stored in the storage unit 31A, the cooling fan control means 31 The calculation unit 31B outputs a control signal to the motor 26 of the cooling fan 25 via the cooling fan dedicated inverter 32 so as to increase the rotation speed of the cooling fan 25. As a result, the increase in the rotational speed of the cooling fan 25 increases the amount of cooling air, suppresses the temperature rise of the lubricating oil, and keeps the lubricating oil at an appropriate temperature.

  Further, when the temperature of the intake air rises due to the influence of the surrounding environment due to the installation location of the oilless screw compressor 1 or the like and becomes higher than the set temperature of the intake air stored in the storage unit 31A, the cooling fan control means The calculation unit 31 </ b> B 31 outputs a control signal to the motor 26 of the cooling fan 25 via the cooling fan dedicated inverter 32 so as to increase the rotation speed of the cooling fan 25. As a result, the increase in the number of rotations of the cooling fan 25 increases the amount of cooling air, suppresses the rise in the temperature of the intake air, and keeps the intake air at an appropriate temperature.

  In this embodiment, the cooling fan control due to the rise in the temperature of the lubricating oil and the cooling fan control due to the rise in the intake air temperature are controlled with priority given to any of these set values. Alternatively, the control unit 31B performs control so that the lubricating oil and the intake air temperature are maintained within a preset temperature range.

  As described above, in this embodiment, even if the environmental temperature fluctuates, the temperature of the lubricating oil can be kept appropriate, and the compressed air temperature can be kept appropriate by keeping the temperature of the intake air appropriate. Therefore, the high reliability of the oil-free screw compressor can be maintained.

3 and 4 show another embodiment of the two-stage air-cooled oil-free screw compressor of the present invention. FIG. 3 is a system diagram showing the overall configuration, and FIG. 4 is a diagram of the cooling fan control means. 3 and 4, the same reference numerals as those in FIGS. 1 and 2 denote the same parts, and detailed description thereof will be omitted.
In this embodiment, in addition to the cooling fan control due to the rise in the temperature of the lubricating oil and the cooling fan control due to the rise in the intake air temperature in the above-described embodiment, the inside and outside of the compressor unit affected by the fluctuation of the environmental temperature, and the start In order to suppress the temperature rise of the control panel 24, the third sensor 33 that detects the temperature inside and outside the casing 1A is provided in the casing 1A, and the fourth sensor that detects the temperature inside the casing 1A. 34, the detection signals of these sensors 33 and 34 are taken into the cooling fan control means 31, and when the detection value exceeds the set value by the cooling fan control means 31, as in the above-described embodiment, The number of rotations of the cooling fan 25 is increased so that the temperature inside and outside the compressor unit and the temperature of the starting and control panel 24 are properly maintained. Thereby, it is possible to reduce the heat load caused by the temperature rise on the motor and the equipment in the start panel.

  Further, by synchronizing the volume control of the discharge compressed air and the rotation speed control of the cooling fan in the unloader, compressor with an automatic stop function or inverter control compressor of FIG. 1, the above-described lubricating oil temperature, discharge compressed air temperature, It is also possible to adopt a configuration in which the temperatures in the compressor unit and the start panel are maintained at appropriate temperatures. At this time, when the compressor is stopped by the capacity control, the cooling fan 25 can be rotated or stopped at the lowest inverter frequency after confirming the temperature in the unit.

  In the above-described embodiment, the rotation speed of the cooling fan 25 is controlled by the cooling fan dedicated inverter 32. However, the rotation speed can also be controlled by the compressor inverter.

DESCRIPTION OF SYMBOLS 1 Oilless type screw compressor 2A Single stage compressor main body 2B Two stage compressor main body 3 Gear casing 4 Male rotor 5 Female rotor 13 Motor 17A Single stage compressed air cooler 17B Single stage compressed air cooler 18 Discharge pipe 19 Discharge pipe 20 Lubricating oil cooler 21 Lubricating oil pipe 23 Lubricating oil pipe 24 Start and control panel 25 Cooling fan 26 Motor 27 Intake hole 28 Exhaust hole 29 First sensor 30A Second sensor 30B Second sensor 31 Cooling fan control means

Claims (7)

A compressor body having a screw rotor that rotates and compresses in a non-contact and non-lubricated manner, a lubricating oil passage that supplies lubricating oil that lubricates a gear or a bearing that drives the screw rotor, and an air-cooled cooler for the lubricating oil; A cooling fan that supplies cooling air to the compressor body and the air-cooled cooler,
A first sensor for detecting a temperature of the lubricating oil;
A storage unit for storing a set temperature of the lubricating oil;
Cooling fan control means for outputting a control signal for increasing the number of revolutions of the cooling fan when the detected value of the lubricating oil temperature from the first sensor becomes higher than the set temperature of the lubricating oil stored in the storage unit. An oil-free screw compressor characterized by comprising: A compressor body having a screw rotor that rotates and compresses in a non-contact and oil-free manner, an air-cooled cooler for compressed air, and a cooling fan that supplies cooling air in the compressor body and to the air-cooled cooler ,
A second sensor for detecting the intake air temperature;
A storage unit for storing the set temperature of the intake air;
Cooling fan control means for outputting a control signal for increasing the number of rotations of the cooling fan when the detected value of the intake air temperature from the second sensor becomes higher than the set temperature of the intake air stored in the storage unit An oil-free screw compressor characterized by comprising:   The oilless screw compressor according to claim 1 or 2, wherein the cooling fan is controlled in rotational speed by an inverter dedicated to the cooling fan.   The oilless screw compressor according to any one of claims 1 to 3, wherein the cooling fan is rotationally controlled by a compressor inverter.   The oil-free screw compressor according to any one of claims 1 to 4, wherein the cooling fan control means takes in the temperature inside and outside the compressor unit and controls the number of revolutions of the cooling fan. Oil-free screw compressor.   The oilless screw compressor according to any one of claims 1 to 5, wherein the cooling fan control means takes in a temperature in a control panel such as a start panel and controls the number of rotations of the cooling fan. An oil-free screw compressor.   2. The oil-free screw compressor according to claim 1, wherein the cooling fan control means controls the number of rotations of the cooling fan so that the temperature of the lubricating oil is maintained in a preset temperature range. Oil-free screw compressor.

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