JP2005069163A - Air cooled dry vacuum pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air cooled dry vacuum pump that is superior in a heat exchange property, capable of performing a clean exhaust, and small in size and compact in design, small in installation area, lightweight, and further achieves reduction in noise, inexpensive in manufacture cost and equipment cost, unlike only an air cooled dry vacuum pump that achieves a heat radiation by providing a fan in the outside of the heating part of a vacuum pump to increase a heat radiating area for cooling. <P>SOLUTION: A vacuum pump has a rotor 2 to rotate by the driving force of an electric motor M as a rotating drive source, housed in a casing 1 having a suction port 1a and a discharge port 1b of a fluid. An air supply means is provided in one side 1c in an axial direction I of the casing, and the casing is formed in a double pipe construction that consists of an internal pipe portion 4 in which the rotor 2 is rotatably housed and an external pipe portion 5 provided in the surrounding of the internal pipe portion. An air passage 7 passing a cooled air W through between the internal pipe and the external pipe by the air supply means is provided along the axial direction I. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air-cooled dry vacuum pump used in, for example, medical equipment, food machinery, electrical equipment, electronic equipment, optical equipment, packaging equipment, semiconductor device-using equipment, etc., and has excellent heat exchange and clean exhaust. In addition, it is small and compact, has a small installation area, is lightweight, and achieves low noise.

  Normally, since the vacuum pump is operated with the fluid suction side closed and the degree of sealing increased, the rotational driving force from the motor is almost exchanged for heat. At this time, since the generated heat has a large calorific value, unless any countermeasure is taken, the vacuum pump itself is burned out due to the heat generation, and the operation cannot be continued.

  When the vacuum pump is operated in a vacuum state and the compression ratio of the compressed fluid becomes high, the driving force of the motor that drives the vacuum pump is converted into heat and a large amount of heat is generated. There was a wet-type vacuum pump that was cooled by injecting oil or sealed water, but the cooling water or oil was connected to the suction side of the vacuum pump, not the discharge side of the vacuum pump. Backflow to the chamber side to be made, and there was a disadvantage that the vacuum state was damaged. Moreover, in recent years, dry vacuum pumps have begun to attract attention in place of wet vacuum pumps from the viewpoints of protecting and preserving the global environment, preventing pollution of toxic chemicals, and improving precision and precision.

  By the way, as a countermeasure against the burning of the vacuum pump due to heat generation, the dry type vacuum pump is provided with a jacket part in the casing of the vacuum pump and is cooled by sending the refrigerant liquid to the jacket part to generate heat by the refrigerant liquid. It was a liquid-cooled vacuum pump that removed and took heat balance.

However, since this liquid-cooled vacuum pump uses a coolant such as pure water or industrial water as the coolant, equipment and equipment such as a pump for feeding the piping and coolant are required. In addition, a treatment facility for draining the coolant has become necessary. Moreover, if the coolant is to be used in a circulating manner, a cooling device or a rust prevention treatment facility is required when necessary, and a lot of facilities are required for production. There were many difficulties.
JP-A-7-167091

  However, since the above conventional liquid-cooled vacuum pump uses a coolant such as pure water or industrial water as the coolant, equipment and equipment such as a pump for supplying piping and coolant are not available. In addition, a treatment facility for draining the coolant has become necessary. Moreover, if the coolant is to be used in a circulating manner, a cooling device or a rust prevention treatment facility is required when necessary, and a lot of facilities are required for production. There were many difficulties.

  Thus, as a result of many years of research and development, the present inventor has focused on an air-cooled vacuum pump in order to cool the heat generated in the heat generating part of the vacuum pump in place of the water-cooled vacuum pump. It is a thing.

  And the present invention is excellent in heat exchanging performance unlike a simple air-cooled dry vacuum pump that attempts to cool down by providing fins outside the heat generating part of the vacuum pump to increase the heat radiation area and to radiate heat. The purpose is to provide an air-cooled dry vacuum pump that can perform clean exhaustion, is small and compact, has a small installation area, is lightweight, has low noise, and has low manufacturing and equipment costs. To do.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the invention according to claim 1 houses a rotor rotated passively by a driving force of a motor as a rotational driving source in a casing having a fluid inlet and outlet. In the vacuum pump, an air supply means is provided on one side in the axial length direction of the casing, and the casing includes an inner tube portion in which the rotor is rotatably accommodated and an outer tube portion provided around the inner tube portion. A ventilation path through which the cool air supplied by the air supply means passes is provided along the axial length direction between the inner pipe part and the outer pipe part. Adopted the feature means.

  According to a second aspect of the present invention, in the first aspect, the ventilation path includes a motor as a rotational drive source, a speed increasing gear that transmits a driving force from the motor to the rotor, a timing gear, and the like. The heat transmission member, the rolling bearing means for rotatably supporting the shaft of the rotor, and a heat generating member comprising the rotor and the like meshing with each other are provided along the axial length direction and generated from the heat generating member. The means is characterized in that the heat and the cold air generated by the air supply means passing through the air passage flow in a convection and exchange heat.

  The invention according to claim 3 of the present invention employs means according to claim 1 or claim 2, wherein the air supply means is an air supply fan or a suction fan.

  According to a fourth aspect of the present invention, the speed increasing gear chamber according to the first, second, or third aspect of the present invention includes the casing that houses the rotor and the speed increasing gear chamber that houses the speed increasing gear as the rotation transmission component. And the timing gear chamber that houses the timing gear, the air passage is formed jointly by communicating with the double pipe structure of the inner pipe portion and the outer pipe portion via a communicating portion. Adopted the means characterized by.

  According to a fifth aspect of the present invention, in the first, second, third, and fourth aspects, the speed-up gear chamber and the timing gear chamber are arranged in two upper and lower sides through a partition wall. The two chambers are formed so as to be divided into chambers, and the inside of the two chambers is provided so as to communicate with each other through a passage so that lubricating oil is provided so as to allow convection.

  According to a sixth aspect of the present invention, in the first, second, third, fourth, and fifth aspects, the rotor is fixed to one side of the casing. The first rolling bearing means disposed on the first end is attached to a rotor shaft that is rotatably supported at one end side.

  According to a seventh aspect of the present invention, in the first, second, third, fourth, fifth, and sixth aspects, the rotor is sealed by providing the suction port. The rotor shaft is attached to the rotor shaft in the vicinity of the other side of the casing, and the rotor shaft is rotatably supported at the other end by a second rolling bearing means disposed in a small-diameter holding cylinder fixed to the one side of the casing. Adopted a feature characterized by being supported.

  Further, an invention according to an eighth aspect of the present invention is the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, the sixth aspect, the seventh aspect, the casing, the motor, The means is characterized in that at least one outer periphery of the air supply means is covered with a sound absorbing member as necessary.

  The present invention is excellent in heat exchange, can perform clean exhaust, is small and compact, has a small installation area, is light in weight, has low noise, and has low manufacturing costs and equipment costs.

  Details of the present invention will be described below with reference to specific examples of embodiments according to the drawings.

[Embodiment 1]
FIG. 1 is a longitudinal sectional view showing Embodiment 1 of an air-cooled dry vacuum pump according to the present invention, FIG. 2 is a perspective view, FIG. 3 is a front view, FIG. 4 is a plan view, and FIG. It is.

  The first embodiment is a vacuum pump in which a rotor 2 that is rotated by passively driving a driving force of a motor M as a rotational drive source is housed in a casing 1 having a fluid G suction port 1a and a discharge port 1b. Is the same configuration and operation as the conventional vacuum pump described in Patent Document 1, for example.

  However, in the first embodiment, an air supply fan 3 as an air supply means is provided on one side of the casing 1 in the axial length direction I, and the casing 1 is an inner pipe portion in which the rotor 2 is rotatably accommodated. 4 and an outer tube portion 5 provided around the inner tube portion 4.

  Further, in the present embodiment shown in the figure, the rotor 2 includes two inner tubes 4, 4 which are provided in the casing 1 symmetrically in the diameter direction Q as shown in FIG. 4 in the present embodiment. A biaxial axial flow type vacuum pump including the rotors 2A and 2B is configured.

  The two rotors 2A and 2B have different twisting directions. For example, if one rotor 2A is a right screw, the other rotor 2B has a left screw formed on the outer periphery. The screws having different torsional directions are formed from the pitch length 6a in which the rotors 2A and 2B form a large pitch from the suction side to the discharge side of the vacuum pump and the pitch length 6b having a pitch smaller than the pitch length 6a. The suction gas is adiabatically compressed by the pitch lengths 6a and 6b.

  Reference numeral 7 denotes a ventilation path provided between the inner pipe sections 4 and 4 and the outer pipe sections 5 and 5. The ventilation paths 7 and 7 are casings through which the cool air W from the air supply fan 3 passes. 1 along the axial direction I.

  The ventilation path 7 includes a motor M as a rotational drive source, a rotation transmission component 10 such as a speed increasing gear 8 and timing gears 9A and 9B for transmitting a driving force from the motor M to the rotor 2A, and the rotor. Rolling bearing means 12A, 12B for rotatably supporting the rotor shafts 11A, 11B of 2A, 2B; 12A, 12B and the heat generating member comprising the rotors 2A, 2B etc. meshing with each other along the axial length direction I So that it penetrates vertically. In FIG. 4, two rotors 2A and 2B are provided in a substantially flat elliptical shape according to two biaxial axial flow type vacuum pumps, but the planar shape is a representative example. However, the present invention is not limited to this, and an appropriate shape may be used.

  That is, the casing 1 for housing the rotors 2A and 2B, the speed increasing gear chamber 13 for storing the speed increasing gear 8 as the rotation transmission component 10 and the timing gear chamber 14 for storing the timing gears 9A and 9B are the inner pipe. The air passages 7 and 7 are integrally formed by communicating between the double tube structure of the portion 4 and the outer tube portion 5 through a communication portion.

  Then, the heat generated from the heat generating member and the cold air W from the air supply fan 3 passing through the ventilation paths 7 and 7 flow oppositely to exchange heat.

  The speed increasing gear chamber 13 and the timing gear chamber 14 are divided into two upper and lower chambers through a partition wall, and the two chambers are disposed on the outer peripheral side with a passage 15A arranged in the inner peripheral central portion. Lubricating oil O is provided so as to be convectively communicated with each other through a passage 15B. Of these, the passage 15 </ b> A disposed in the central portion of the inner periphery has a short cylindrical shape to promote convection of the lubricating oil O.

  The rotors 2A and 2B include a main shaft whose one end 16a is rotatably supported by first rolling bearing means 12A and 12A disposed in a speed increasing gear chamber 13 fixed to one side 1c of the casing 1. Attached to the rotor shafts 11A and 11B as the auxiliary shafts using mechanical lock members m and m.

  Moreover, the rotors 2A and 2B are attached to the rotor shafts 11A and 11B as described above in the vicinity of the other side 1d of the casing 1 forming the closed wall surface except that the suction port 1a is provided, so that airtightness on the suction side is achieved. Sex is measured.

  The rotor shafts 11A and 11B are rotatably supported at the other end 16b by second rolling bearing means 12B and 12B disposed in a small diameter holding cylinder 17 fixed to the one side 1c of the casing 1. Is done. As these rolling bearing means 12A, 12A; 12B, 12B, for example, a ball bearing is used as shown in FIG. 1, and a roller bearing is used.

  Reference numeral 18 denotes a sound absorbing member that is provided as necessary when noise is low or required. The sound absorbing member 18 may be provided as necessary, but the sound absorbing member 18 is the casing 1, the motor M, and the air supply fan. 3, all of the outer periphery is covered as shown in the first embodiment.

  As the sound absorbing member 18, a porous material having a high sound absorbing property such as polyurethane foam, sponge rubber, felt, non-woven fabric, synthetic resin fiber or fabric laminated with natural fibers is optimally used. .

  Reference numeral 19 denotes a fin formed on the outer periphery of the outer tube portion 5 of the casing 1 for radiating heat.

  Reference numeral 20 denotes a plurality of suspension fittings mounted on the upper surface of the casing 1, and is intended to be easily moved by a suspension machine such as a crane by placing a wire during transportation and storage.

  21 is a level gauge and 22 is an air breather.

  The first embodiment of the present invention has the above-described configuration. When the motor M is driven, the rotors 2A and 2B are driven by the speed increasing gear 8 and the timing gears 9A and 9B meshing with each other. Since the rotor shafts 11A and 11B rotate passively via the rotation transmission component 10, the rotors 2A and 2B provided on the outer periphery with screws attached to the rotor shafts 11A and 11B and having different twist directions are provided on the casing 1. The inner pipe portions 4 and 4 are rotated in mutually different rotation directions while meshing with a pitch length 6a having a large pitch and a pitch length 6b having a small pitch. At this time, the fan motor is driven at the same time as the motor M is driven, and the air supply fan 3 as the air supply means is rotated.

  Then, a gas as a fluid is introduced into the inner pipe portion 4 of the casing 1 from the suction port 1a provided on the other side 1d (upper surface in FIG. 1) of the casing 1, and then the pitch length of the large pitch is increased. 6a and a pitch length 6b of a small pitch are adiabatically compressed to the downstream while being introduced from the primary rotor 2A rotating while meshing with each other to the secondary rotor 2B, and provided on the side surface of the casing 1 It is discharged from the discharged outlet 1b.

  At this time, the motor M as a rotational drive source, the rotation transmission parts 10 such as the speed increasing gear 8 and the timing gears 9A and 9B for transmitting the driving force from the motor M to the rotor 2A, and the rotors of the rotors 2A and 2B From the heat generating member comprising the rolling bearing means 12A, 12B; 12A, 12B for rotatably supporting the shafts 11A, 11B and the rotors 2A, 2B rotating in mesh with each other to compress the fluid G, a vacuum pump Heat is generated during the operation.

  When the air supply fan 3 starts rotating as described above, the cold air W is a casing having a double-pipe structure composed of the inner tube portion 4 and the outer tube portion 5 that rotatably accommodate the rotors 2A and 2B. 1, the air passes through the ventilation passages 7 and 7 provided so as to be vertically penetrated between the inner tube portion 4 and the outer tube portion 5 along the axial length direction I, and is discharged.

  Then, when the cold air W from the air supply fan 3 rises through the air passages 7 and 7 having a double wall structure, the heat generated from the heat generating member is cooled through the air passages 7 and 7. Heat exchange is performed.

  At the same time, the cooling function by the cold air W supplied from the air supply fan 3 is efficiently performed by the convection function (chimney effect) accompanying the temperature rise of the ventilation paths 7 and 7 themselves.

  Further, by the cold air W supplied from the air supply fan 3, for example, as shown in FIG. 1, rotational driving of the rotors 2 </ b> A and 2 </ b> B of the vacuum pump provided in the lower part of the casing 1 facing the air supply fan 3 in the left-right direction The motor M as a source can also be directly cooled.

  Further, the speed increasing gear chamber 13 and the timing gear chamber 14 are provided so as to communicate with each other via a short cylindrical passage 15A disposed in the central portion of the inner periphery and a passage 15B disposed on the outer peripheral side. Therefore, since the lubricating oil O accommodated in the speed increasing gear chamber 13 and the timing gear chamber 14 is convected, the temperature of the lubricating oil O is suppressed from rising as the vacuum pump is operated and cooled. In addition, lubricity of each component such as the speed increasing gear 8, the meshed timing gears 9A and 9B, and the rotor shafts 11A and 11B is ensured, and wear can be prevented. Further, since the lubricating oil O is pumped up by pressurization when the speed increasing gear 8 rotates, convection between the speed increasing gear chamber 13 and the timing gear chamber 14 is promoted.

  At least one outer periphery of the casing 1, the motor M, and the air supply fan 3, all of which are covered by the sound absorbing member 18 as required in the first embodiment as shown in the figure, the motor serving as the main noise generation source M, noise generated from the air supply fan 3 and the like is absorbed by the sound absorbing member 8 and is prevented from leaking outside, and noise is reduced.

  At this time, even if the outer periphery of the casing 1, the motor M, and the air supply fan 3 are all covered with the sound absorbing member 18, the heat generated from the heat generating member as described above is the inner tube portion 4 and the outer tube portion 5. Since heat is exchanged by supplying the cold air W from the air supply fan 3 into the air passages 7 and 7 provided so as to be vertically penetrated along the axial length direction I of the casing 1. Heat exchange is performed smoothly and quickly without the sound absorbing member 18 getting in the way.

  In the first embodiment shown in the figure, the heat generating member is formed by supplying the cold air W to the ventilation paths 7 and 7 provided between the inner tube portion 4 and the outer tube portion 5 by using the air supply fan 3 as the air supply means. However, the present invention is not limited to this. For example, although not shown in the drawing, the suction fan is connected to the other side 1d of the casing 1 and the ventilation paths 7 and 7 are not shown. By installing the air in the air passages 7 and 7 by this suction fan, fresh air is introduced into the air passages 7 and 7 from the outside to form the cold air W, which is generated from the heat generating member. It is also within the scope of the present invention to perform heat exchange with heat.

  In the illustrated first embodiment, a two-axis axial flow type vacuum pump in which the two rotors 2A and 2B are rotatably accommodated in the two inner tube portions 4 and 4 is meshed. However, this is merely an example, and the present invention is also applicable to a vacuum pump having a uniaxial axial flow type in which the rotor and the inner tube portion 4 accommodating the rotor are one. In the above embodiment, the case where gas is compressed as the fluid G is representatively described. However, this is an example, and the case where a liquid is compressed as the fluid G is also within the scope of the present invention.

  In the present invention, cold air is supplied into the communication path of the double-pipe structure provided in the casing in the vicinity of the heat generating member, so that the heat exchange is excellent and the cold air is supplied. Equipment and equipment such as pumps for feeding the liquid, as well as a treatment facility for draining the cooling liquid, and a cooling device and rust prevention treatment equipment for reusing the refrigerant are also required. Clean exhaust can be done without need. In addition, it is small and compact, has a small installation area, is lightweight, and has low noise, making it ideal for medical equipment, food machinery, electrical equipment, electronic equipment, optical equipment, packaging machinery, semiconductor device equipment, etc. Used for.

It is sectional drawing which shows Embodiment 1 of the air-cooling type dry vacuum pump of this invention. It is a perspective view similarly. It is also a front view. It is also a plan view. It is a bottom view similarly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 1a Intake port 1b Outlet 1c One side 1d Other side 2 Rotor 2A Rotor 2B Rotor 3 Air supply fan 4 Inner pipe part 5 Outer pipe part 6a Pitch length 6b Pitch length 7 Ventilation path 8 Speed increase gear 9A Timing gear 9B Timing Gear 11A Rotor shaft 11B Rotor shaft 12A Rolling bearing means 12B Rolling bearing means 13 Speed increasing gear chamber 14 Timing gear chamber 18 Sound absorbing member I Shaft length direction M Motor

Claims (8)

  In a vacuum pump in which a rotor rotated passively by a driving force of a motor as a rotational drive source is housed in a casing having a fluid suction port and a fluid discharge port, an air supply means is provided on one side in the axial direction of the casing. And the casing is formed in a double pipe structure including an inner tube portion in which the rotor is rotatably accommodated and an outer tube portion provided around the inner tube portion, and the inner tube portion and the outer tube portion are formed. An air-cooled dry vacuum pump characterized in that a ventilation path through which the cold air supplied by the air supply means passes is provided along the axial length direction between the pipe section and the pipe section.   The ventilation path includes a motor as a rotational drive source, rotation transmission parts such as a speed increasing gear and a timing gear for transmitting a driving force from the motor to the rotor, and rolling bearing means for rotatably supporting the shaft of the rotor. And the heat generated by the heat generating member formed by the rotor and the like meshing with each other along the axial length direction, and the convection between the heat generated from the heat generating member and the cold air by the air supply means passing through the ventilation path. The air-cooled dry vacuum pump according to claim 1, wherein the air-cooled dry vacuum pump is flowed and exchanged.   The air-cooled dry vacuum pump according to claim 1 or 2, wherein the air supply means is an air supply fan or a suction fan.   The casing for housing the rotor, the speed increasing gear chamber for storing the speed increasing gear as the rotation transmission component, and the timing gear chamber for storing the timing gear have a double tube structure of the inner tube portion and the outer tube portion. The air-cooled dry vacuum pump according to claim 1, 2, or 3, wherein the ventilation path is formed jointly by communicating with each other via a communication portion.   The speed increasing gear chamber and the timing gear chamber are divided into two upper and lower chambers through a partition wall, and the two chambers are provided in communication with each other through a passage so that lubricating oil can be convected. The air-cooled dry vacuum pump according to claim 1, 2, 3, or 4, wherein the air-cooled dry vacuum pump is provided.   2. The rotor according to claim 1, wherein the rotor is attached to a rotor shaft whose one end is rotatably supported by a first rolling bearing means disposed in a timing gear chamber fixed to one side of the casing. The air-cooled dry vacuum pump according to claim 2, claim 3, claim 4, or claim 5.   The rotor is attached to a rotor shaft adjacent to the other side of the sealed casing provided with the suction port, and the rotor shaft is disposed in a small-diameter holding cylinder fixed to the one side of the casing. 7. The air-cooled dry vacuum pump according to claim 1, 2, 3, 4, 5, or 6, wherein the other end side is rotatably supported by the rolling bearing means. .   The outer periphery of at least one of the casing, the motor, and the air supply means is covered with a sound absorbing member as necessary, and further comprises a sound absorbing member. The air-cooled dry vacuum pump according to claim 5, claim 6, or claim 7.

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