JP2010133290A - Vacuum pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum pump, which is compact with a direct-current motor capacity of 2 KW or lower and is capable of attaining a vacuum easily at any location. <P>SOLUTION: In a vacuum pump 10 including a positive displacement pump P equipped with a pair of pump rotors within a pump casing, a DC motor M for rotationally driving the pair of pump rotors, a driver for driving the DC motor M and a controller, there is provided a cooling means (a fan 22) for cooling a compression heat generated by a pumping action of the pump operation, and heat generated from the DC motor M, the driver, and the controller by air cooling. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a positive displacement vacuum pump having a pair of pump rotors in a pump casing driven by a DC motor.

  In recent years, dry vacuum pumps that can operate from atmospheric pressure and can easily obtain a clean vacuum environment have been used in a wide range of fields. Normally, such a vacuum pump is operated in a state where the intake side is close to the deadline, and therefore consumes power to maintain the differential pressure between the intake port side and the exhaust port side. That is, the degree of vacuum on the intake port side is maintained by continuing to exhaust the gas that flows back into the pump from the exhaust port side. For this reason, most of the power consumed by the vacuum pump operation is converted into heat on the exhaust port side. Although depending on the capacity of the vacuum pump, measures against heat generation have conventionally been provided by providing a water cooling jacket or the like in the casing and radiating heat to the water passing through the water cooling jacket.

  Further, as shown in FIG. 11, the vacuum pump includes a power supply unit 1 including a circuit breaker 2, a noise filter 3, a rectifier 4, a smoothing capacitor 5, and a DC / DC converter 6, and a driver 7. By turning on (closing) the AC power of the AC power supply (AC100V / 200V) 8 through the noise filter 3, noise is removed and converted to DC (DC141V / 248V) by the rectifier 4, and further by the DC / DC converter 6. A constant voltage is supplied to the driver 7. The driver 7 supplies a pulse having a predetermined frequency to the motor M of the vacuum pump 10 under the control of a control unit (not shown), and activates the motor M to drive the pump P.

The noise filter 3, the rectifier 4, the smoothing capacitor 5, the DC / DC converter 6, the driver 7, and the control unit have heating units, and the heat generated by the vacuum pump operation including the heat from these heating units is mainly water-cooled. The heat is dissipated.
JP-A-8-319967

  However, cooling the vacuum pump with water cooling requires a cooling water facility for obtaining cooling water, which not only increases the burden on the user, but also restricts the place where the vacuum pump can be used. There is a problem that a vacuum cannot be easily obtained.

  The present invention has been made in view of the above points, and does not require a cooling water facility, and can easily obtain a vacuum at an arbitrary place with a small pumping speed of 2000 L / min or less and a DC motor capacity of 2 KW or less. An object of the present invention is to provide a vacuum pump.

  In order to solve the above problems, the present invention provides a positive displacement pump having a pair of pump rotors in a pump casing, a direct current motor that rotationally drives the pair of pump rotors, a driver that drives the direct current motor, and a control The vacuum pump provided with a section is characterized by comprising cooling means for cooling by air cooling the compression heat generated by the pump action by the operation of the pump and the heat generated from the DC motor, driver, and control section.

  Further, the present invention is a magnet coupling type DC brushless motor that includes a pair of magnet rotors of a DC motor in a vacuum pump and reverses in synchronization with each other, and the pair of pump rotors of the pump mesh with each other and rotate. A male rotor and a female rotor are provided, and a pair of magnet rotors of a magnetic coupling type DC brushless motor are respectively connected to a pair of pump rotors of a pump, and the pair of pump rotors are synchronized without using a timing gear. It is characterized by being inverted.

  Further, according to the present invention, in the vacuum pump described above, the pumping speed of the pump is 2000 L / min or less, the capacity of the DC motor is 2 KW or less, and the output voltage from the power supply unit supplied to the DC motor is the size of the power supply unit. It is characterized by a high voltage that does not increase.

  According to the present invention, in the above vacuum pump, a power factor improving unit for improving the power factor is provided in a power source unit that supplies electric power to the DC motor.

  Further, the present invention is characterized in that the vacuum pump includes a heat sink for heat dissipation, and at least a part of heat generated from heat generating portions of the pump, the DC motor, the driver, and the controller is radiated by the heat sink for heat dissipation.

  In the vacuum pump, the heat sink for heat dissipation includes a pump, a DC motor, a driver, and a control unit, and a heat sink for heat dissipation is provided with a flow path plate to form an air flow path through which cooling air passes. A pump package is provided, and a fan for introducing cooling air into the air flow path of the pump package is provided.

  Further, according to the present invention, in the vacuum pump, the heat radiation heat sink mounting rank of the pump package, the DC motor, the driver, and the control unit is the one with a small heat generation amount upstream of the air flow path, and the heat generation amount downstream. It is characterized by arranging a large one.

  Further, the present invention is the above vacuum pump, wherein the cooling air inlet and outlet for guiding the air flow path of the pump package are provided on the rear surface and / or front surface of the pump package, and a plurality of pump packages are provided. The plurality of pump packages are arranged with their side surfaces adjacent to each other.

  According to the present invention, the compression heat generated by the pump action and the heat generated from the DC motor, driver, and controller are cooled by the cooling means. A vacuum pump that can easily obtain a vacuum can be provided.

  In addition, according to the present invention, the DC motor includes a pair of magnet rotors and uses a magnet coupling type DC brushless motor that is reversed in synchronization with each other, and the pair of pump rotors are engaged with each other and the pair of male rotors rotate. And the female rotor, and the pair of pump rotors are synchronously reversed without using the timing gear, so that the mechanical loss is reduced and the air cooling means is suitable for cooling.

  Further, according to the present invention, since the output voltage from the power supply unit supplied to the DC motor is set to a high voltage within a range in which the size of the power supply unit does not increase, the current is reduced accordingly, heat generation is reduced, and air cooling means is used. The configuration is more suitable for cooling.

  In addition, according to the present invention, since the power factor improving unit that improves the power factor is provided in the power source unit that supplies power to the DC motor, the peak current can be suppressed by the amount of the improved power factor. This is a more suitable configuration for cooling by air cooling means.

  Further, according to the present invention, since the heat sink for heat dissipation is provided and the heat generated from the heat generating portion is dissipated by the heat sink for heat dissipation, heat can be efficiently radiated.

  Further, according to the present invention, a pump, a DC motor, a driver, and a control unit are mounted on a heat sink for heat dissipation to form a pump package, and a fan that guides cooling air to the air flow path of the pump package is provided. Heat can be dissipated.

  Further, according to the present invention, the heat dissipation heat sink mounting order of the pump, the DC motor, the driver, and the control unit of the pump package is the one having a small heat generation amount upstream of the air flow path and the one having a large heat generation amount downstream. Since the cooling air is arranged, the cooling air flows from a low temperature region to a high region, and heat can be radiated more efficiently.

  Further, according to the present invention, since the cooling air inflow and outflow ports leading to the air flow path of the pump package are provided on the rear surface and / or front surface of the pump package, the side surface of the pump package is hardly cooled. Even if a plurality of pump packages are arranged with their side surfaces adjacent to each other, the cooling efficiency does not decrease, and a large number of pump packages can be installed in a small installation area.

  Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are diagrams showing a configuration example of a vacuum pump according to the present invention. FIG. 1A is a plan view, FIG. 1B is a cross-sectional view taken along line AA, and FIG. As shown in the figure, this vacuum pump includes a heat sink 12, and a flow path plate 13 is attached to the lower surface of the heat sink 12, and between the fins 12a and the fins 12a of the heat sink 12 and both side bent portions of the flow path plate 13 and the fins 12a. An air flow path 14 through which cooling air passes is formed. In FIG. 1A, the left end of the heat sink 12 is the rear end and the right end is the front end. On the upper surface of the heat sink 12, there are a power supply component 15, a driver component 16, a motor M, and a pump P in order from the rear end. It is installed. An air outflow hole 18 is formed between the driver component 16 of the heat sink 12 and the motor M.

  As described above, the power supply component 15, the driver component 16, the motor M, and the pump P are mounted on the upper surface of the heat sink 12 to constitute the pump package 20, and the fin 12 a and the fin 12 a of the heat sink 12 of the pump package 20 are configured. When the cooling air is allowed to flow from the rear end to the air flow path 14 as shown by the arrow B, the cooling air flows into the air flow path 14 and between the bent portions on both sides of the flow path plate 13 and the fins 12a. It flows through the passage 14 and flows upward through an air outlet hole 18 provided between the driver component 16 and the motor M. The heat generated in the heat generating parts of the power supply component 15 and the driver component 16 and transmitted to the main body of the heat sink 12 and the fins 12a and 12a is efficiently radiated to the cooling air passing through the air flow path 14. In the above example, the cooling air is forcibly introduced into the air channel 14. However, the cooling air may flow in the air channel 14 by natural convection.

  2A and 2B are diagrams showing a configuration example of a vacuum pump according to the present invention, in which FIG. 2A is a plan view, FIG. 2B is a cross-sectional view along AA, and FIG. 2C is a left side view. . This vacuum pump is different from the vacuum pump shown in FIG. 1 in that a fan 22 is provided at the front end of the heat sink 12 as a means for guiding cooling air to the air flow path 14. By operating the fan 22, the cooling air flows through the air flow path 14 as indicated by an arrow B, and passes through the air outflow hole 18 provided between the driver component 16 of the heat sink 12 and the motor M. And then flows around the motor M and the pump P and flows out from the air outlet 23 where the fan 22 is provided. Here, the front end of the air flow path 14 is closed by the front panel 24.

FIG. 5 is an example of a block diagram showing the configuration of the power supply unit of the vacuum pump according to the present invention. As shown in the figure, the power supply unit of this vacuum pump has a configuration in which a power factor correction circuit (PFC) 25 is provided on the output side of the rectifier 4. A power supply component 15 shown in FIG. 1 is a component constituting a power factor correction circuit (PFC) 25, and a driver component 16 is a component constituting a driver 7. They are arranged in consideration of the current flow. The heat generation amount H ₁₅ of the heat generating portion of the power supply component 15 is smaller than the heat generation amount H ₁₆ of the heat generating portion of the driver component 16, and the heat generation amount H ₁₆ of the heat generating portion of the driver component 16 is the heat generation amount of the motor M. less than the heating value H _M, but more heat value H _M of the heat generating portion of the motor M is preferably a is smaller than the heating value H _P of the heat generating portion of the pump _{P (H 15 <H 16 <} H M <H P) Depends on the load condition of the pump. That is, the air flow path 14 and the cooling air flow upstream are arranged with a small amount of heat generation and the downstream side with a large heat generation amount. As a result, the cooling air flows from the low temperature region to the high temperature region of the vacuum pump, and heat can be radiated more efficiently.

  Since the peak current can be suppressed by improving the power factor of the input portion of the AC power supply (AC100V / 200V) 8, heat generation due to the peak current can be reduced. As a method for improving the power factor, as shown in FIG. 5, a power factor improving circuit (PFC) 25 is provided on the output side of the rectifier 4 to improve the power factor, or the output side of the rectifier 4 as shown in FIG. There is a method of improving the power factor by providing a direct current reactor (DCL) 26 in the main body.

  4 is provided with a step-up chopper or voltage doubler rectifier 21 to boost the DC voltage rectified by the rectifier 4 (DC 360 V in this case), so the DC voltage supplied to the driver 7 Can be increased and the current can be reduced accordingly, so that the amount of heat generated in the heat generating portion of the driver 7 and the motor M can be suppressed.

  FIG. 3 is a side sectional view (corresponding to a sectional view taken along line AA in FIG. 1A) of another configuration example of the vacuum pump according to the present invention. This vacuum pump is different from the vacuum pump shown in FIG. 2 in that the front end of the air flow path 14 is opened. By operating the fan 22, as shown by the arrow C, cooling air flows from the front end opening of the air flow path 14, and the cooling efficiency is further improved.

  FIG. 7 shows (air cooling member volume) / (cooling heat volume), (water cooling structure volume) with respect to the motor capacity of a vacuum pump having a positive displacement pump having a pair of pump rotors in a pump casing driven by a DC motor. It is a figure which shows the relationship of / (cooling calorie | heat amount). In FIG. 7, a solid line A indicates (air cooling member volume) / (cooling heat amount), and a dotted line B indicates (water cooling structure volume) / (cooling heat amount). As is apparent from the figure, when the motor capacity is about 2000 (W) or less, the air cooling member volume is superior to the water cooling structure part volume with respect to the cooling heat quantity. Therefore, an air cooling method is adopted as a cooling method of a vacuum pump having a capacity transfer type pump having a motor having a capacity of about 2000 (W) or less and a pair of pump rotors, and the above structure is adopted in the air cooling part. Thus, an excellent cooling effect can be exhibited.

  FIG. 8 is a view showing a configuration example of the motor M and the pump P of the vacuum pump according to the present invention, FIG. 8 (a) is a plan sectional view, FIG. 8 (b) is an AA sectional view, and FIG. 8 (c). FIG. 8D is a cross-sectional view taken along the line B-B, and FIG. 8D is a view showing the pump casing of FIG. As shown in the figure, the present vacuum pump is composed of a pump P and a motor M. A casing 33 (pump casing) of the pump P includes an intake port 31 and an exhaust port 32, and a rotor housing space 39 in which a pair of rotors (a pair of pump rotors) 35 is rotatably housed. Is formed. The cross section of the rotor accommodating space 39 has a shape in which both sides are arc-shaped and convex portions 40 are formed at portions located between the pump rotors 35. Further, each pump rotor 35 disposed in the rotor accommodating space 39 is rotatably supported by bearings 37 and 38 at both ends thereof.

  The motor M includes a casing (motor casing) 41 attached to an end of the pump casing 33, and a motor stator 42 is disposed in the casing 41. A rotor storage space 44 in which the two motor rotors 43 are rotatably arranged is formed in the motor stator 42. The end of the motor rotor 43 of the motor M is connected to the shaft end of each pump rotor 35. As will be described in detail later, the motor M uses a two-axis synchronous inversion drive motor in which two axes are synchronously inverted. By starting the two-axis synchronous reversal drive motor, a pair of pump rotors 35 of the pump P are driven to be synchronously reversed.

As described above, the pair of pump rotors 35 of the pump P are synchronously inverted, and the gas in the space surrounded by the pump rotor 35 and the pump casing 33 is compressed. The pump casing 33 is provided with the intake port 31 and the exhaust port 32 as described above, and the exhaust port 32 can exhaust the intake port to 10 ⁻³ to 10 Torr under atmospheric pressure.

  FIG. 9 is a diagram showing an example of the configuration of a two-axis synchronous inversion drive motor, that is, a motor M, which synchronously inverts a pair of pump rotors 35 of the pump P. As shown in the figure, the two-axis synchronous inversion drive motor includes a pair of magnet rotors (motor rotors) 43 and 43 having the same configuration, and reversely drives a pair of pump rotors 35 and 35 as a brushless DC motor. At the same time, synchronous reversal of the pump rotors 35 and 35 is secured by magnet coupling. As shown in the drawing, each magnet rotor 43 has a ring-shaped magnet 43a around the outer periphery of a magnetic material yoke 43b. In the present embodiment, a magnetized magnet 43a is provided on the outer periphery of the magnet rotor 43, and is opposed to each other so that the different magnetic poles of the magnet rotors 43 and 43 are attracted to each other and with a clearance F maintained. ing. The number of poles of the magnet rotor 43 is an even number such as 4, 6, 8,...

Due to the magnet coupling action of the pump rotors 35 and 35 and the magnet rotors 43 and 43, they rotate synchronously in the opposite direction. Thus, a screw pump capable of stable two-axis synchronous reversal without a timing gear is configured. Further, the absence of the timing gear means that no lubricating oil is required, non-contact rotation including a safe biaxial synchronization mechanism is possible, and high speed operation of the screw pump is possible. That is, a contact-type synchronous mechanism using timing gears are synchronized inverted high-speed rotation of 10000～30000Min ^-1 using magnetic coupling of the magnet rotor 43 at rotational speeds which is a 6-pole 6000～7000Min ^-1 Thus, even if the vacuum pump is made small, it is possible to achieve an improvement in exhaust performance such as a high ultimate vacuum.

  Close to a part of the outer peripheral surface of each magnet rotor 43, a three-phase (U, V, W) motor stator 42 including an iron core 42a and a winding 42b is disposed. The three-phase motor stator 42 is disposed on the side opposite to the side where the magnet rotors 43 are coupled to each other with respect to the rotation axis. Thereby, the magnet coupling force that the magnet rotors 43 attract each other can be canceled by the attraction force that acts on the magnet rotor 43 and the iron core 42a of the motor stator. Further, the three-phase motor stator magnetic pole corresponds to the number of magnetic poles of the magnet rotor 43, and a magnetic field is applied to the four poles of the magnet rotor 43 as indicated by arrows G and H in FIG. By supplying a direct current having a required rectangular pulse waveform to the three-phase winding 42b, the pair of pump rotors 35 of two shafts can be synchronously inverted and driven at an arbitrary rotational speed.

  1 and 2 show a vacuum pump 10 including a motor M, which is a magnetic coupling type DC brushless motor having the above-described configuration, and a volume transfer type pump P including a pair of rotors (a pair of pump rotors) 35. 3, the heat sink 12 is mounted on the front end side (downstream side of the cooling air flow) of the upper surface of the heat sink 12, and the power supply component 15 and the driver component 16 are further rear end side (downstream of the cooling air flow). By mounting in the case, since the amount of heat generated from the heat generating part of the motor M is small, it is possible to sufficiently cool even by air cooling. Further, as shown in FIG. 4, the power supply unit 1 is provided with a boost chopper or voltage doubler rectifier 21 to boost the voltage supplied to the driver 7, thereby reducing the current, and the amount of heat generated by the driver 7 and the heat generating part of the motor M. Becomes smaller. Further, as shown in FIGS. 5 and 6, a power factor correction circuit (PFC) 25 and a direct current reactor (DCL) 26 are provided to improve the power factor, thereby suppressing the peak current and reducing the peak current from the heat generating portion. The calorific value can be reduced.

  FIG. 10 is a view showing a case where a plurality (four in the figure) of vacuum pumps according to the present invention configured as described above are arranged, FIG. 10 (a) is a plan view, and FIG. 10 (b) is a front view ( FIG. The inflow and discharge of the cooling air in each vacuum pump VP is performed through the inlet provided on the rear end surface (back surface) of the vacuum pump VP and the exhaust port provided on the front end surface (front surface). The surface hardly contributes to cooling. Therefore, both side surfaces of each vacuum pump VP can be arranged close to each other so as to come into contact with each other (side-by-side arrangement), and a space-saving space for installing a plurality of vacuum pumps VP can be achieved. Moreover, since each vacuum pump VP can be lightened and miniaturized so that it can be conveyed by human power, it can be easily conveyed and arranged by attaching the handle 50 to a predetermined position on the upper surface.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Can be modified. Note that any shape or structure not directly described in the specification and drawings is within the technical scope of the present invention as long as the effects of the present invention are achieved.

It is a figure which shows the structural example of the vacuum pump which concerns on this invention. It is a figure which shows the other structural example of the vacuum pump which concerns on this invention. It is a figure which shows the other structural example of the vacuum pump which concerns on this invention. It is a block diagram which shows the structural example of the power supply part of the vacuum pump which concerns on this invention. It is a block diagram which shows the other structural example of the power supply part of the vacuum pump which concerns on this invention. It is a block diagram which shows the other structural example of the power supply part of the vacuum pump which concerns on this invention. It is a figure which shows the relationship of (air cooling member volume) / (cooling calorie | heat amount), (water cooling structure part volume) / (cooling calorie | heat amount) with respect to the motor capacity | capacitance in a vacuum pump. It is a figure which shows the structural example of the motor M and pump P of the vacuum pump which concerns on this invention. It is a figure which shows the structural example of the motor M of the vacuum pump which concerns on this invention. It is a figure which shows the example of arrangement | positioning of the several vacuum pump which concerns on this invention. It is a block diagram which shows the structural example of the power supply part of the conventional vacuum pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply part 2 Circuit breaker 3 Noise filter 4 Rectifier 5 Smoothing capacitor 6 DC / DC converter 7 Driver 8 AC power supply 10 Vacuum pump M Motor P pump 12 Heat sink 13 Flow path plate 14 Air flow path 15 Power supply part component 16 Driver component 18 Air Outlet 20 Pump Package 21 Boost Chopper or Voltage Rectifier 22 Fan 23 Air Outlet 25 Power Factor Correction Circuit (PFC)
26 DC reactor (DCL)
DESCRIPTION OF SYMBOLS 31 Intake port 32 Exhaust port 33 Pump casing 35 Pump rotor 37 Bearing 38 Bearing 39 Rotor accommodating space 40 Convex part 41 Motor casing 42 Motor stator 43 Motor rotor (magnet rotor)
44 Rotor storage space 50 Handle

Claims (8)

In a volumetric pump having a pair of pump rotors in a pump casing, a DC motor that rotationally drives the pair of pump rotors, a vacuum pump that includes a driver and a control unit that drive the DC motor,
A vacuum pump comprising cooling means for cooling the air generated by the compression heat generated by the pumping action by the operation of the pump and the heat generated from the DC motor, driver, and control unit. The vacuum pump according to claim 1, wherein
A magnet coupling type DC brushless motor comprising a pair of magnet rotors of the DC motor and reversing in synchronization with each other;
The pair of pump rotors of the pump includes a pair of male and female rotors that mesh with each other and rotate,
The pair of magnet rotors of the magnet coupling type DC brushless motor are respectively connected to the pair of pump rotors of the pump, and the pair of pump rotors are synchronously reversed without using a timing gear. A vacuum pump characterized by The vacuum pump according to claim 1 or 2,
The capacity of the DC motor is 2 KW or less, and the output voltage from the power supply unit supplied to the DC motor is a high voltage within a range where the size of the power supply unit does not increase. The vacuum pump according to any one of claims 1 to 3,
A vacuum pump characterized in that a power factor improving section for improving a power factor is provided in a power supply section for supplying electric power to the DC motor. The vacuum pump according to any one of claims 1 to 4,
It has a heat sink for heat dissipation,
A vacuum pump, wherein at least a part of heat generated from heat generating portions of the pump, the DC motor, the driver, and the controller is radiated by the heat sink for heat radiation. The vacuum pump according to claim 5,
The pump, a DC motor, a driver, and a control unit are mounted on the heat sink for heat dissipation, and a flow path plate is provided on the heat sink for heat dissipation to form an air flow path through which cooling air passes to form a pump package.
A vacuum pump comprising a fan for introducing cooling air into an air flow path of the pump package. The vacuum pump according to claim 6,
The heat dissipation heat sink mounting order of the pump, the DC motor, the driver, and the controller of the pump package is such that the one with a small heat generation amount is arranged upstream of the air flow path and the one with a large heat generation amount is arranged downstream. A vacuum pump characterized by The vacuum pump according to claim 6 or 7,
A configuration in which an inlet and an outlet of cooling air led to the air flow path of the pump package are provided on the rear surface and / or the front surface of the pump package;
A vacuum pump comprising a plurality of the pump packages, wherein the plurality of pump packages are arranged with their side surfaces adjacent to each other.

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