JP2005264802A - Vane rotary vacuum pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems in a conventional vane rotary vacuum pump in which the material of a motor case storing a motor part is formed of an aluminum alloy wherein since the material of the core of a stator fitted to the inside of the motor case is an iron, when the pump is operated and the motor is heated, the elongation of the motor case in the radial direction is increased more than that by heat in the radial direction of the stator due to a difference in the coefficient of thermal expansion of the aluminum alloy and the iron, a clearance is produced between the stator and the motor case, and the stator cannot be fixed to the motor case. <P>SOLUTION: This vacuum pump is formed such that the motor case is firmly fixed to the stator even if the coefficients of thermal expansion of the stator and the motor case are different from each other by fitting an iron ring with an inner diameter smaller than the outer diameter of the motor case onto the outer peripheral part of the motor case where the stator is disposed to press the motor case toward the center part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vacuum pump, and more particularly to a vacuum pump in which a compression mechanism and a motor for driving the compression mechanism are integrally formed.

  Conventionally, this type of pump or compressor is fixed by shrinking the stator of the electric motor to the inner periphery of the compressor container or the casing of the electric motor, fitting and welding, or bolting. Yes. As a result, a predetermined air gap is maintained between the rotor supported in the container or the casing, and the operation is performed efficiently and stably (see, for example, Patent Document 1).

A conventional vane pump will be described with reference to FIGS. The vane pump is composed of a pump unit and a drive unit such as a motor unit. The pump unit houses an eccentric rotor 2 in the cylinder 1, and the rotor 2 slides on the inner peripheral surface 3 of the cylinder 1. A plurality of moving vanes 4 are slidably provided in the radial direction, and the gas in the pump chamber 6 surrounded by the cylinder 1, the rotor 2, the vanes 4, and the end plate 5 is supplied from a driving unit such as a motor to the rotating shaft 7. As the rotor 2 rotates through the suction, the air is sucked from the suction port and discharged to the discharge port. The rotating shaft 7 is supported by a bearing 8 and a bearing 9. The bearing 8 is attached to the end plate 5, and the bearing 9 is attached to the motor plate 10. The end plate 5 and the motor plate 10 are disposed at both ends of a motor case 11 to which a motor stator is attached. The stator 12 is fixed to the motor case 11 by shrink fitting or screwing.
JP-A-1-177478

  However, in the conventional configuration, when the material of the motor case is made of aluminum alloy in order to reduce the weight, the material of the stator core is iron. Due to the difference in thermal expansion coefficient between the alloy and iron, the expansion of the motor case in the radial direction is larger than the expansion of the stator in the radial direction, creating a gap between the stator and the motor case. It has become a problem that rattling and vibration are generated.

  The present invention solves the above-described problems, and an object of the present invention is to provide a highly reliable vane rotary vacuum pump that prevents backlash and vibration.

In order to solve the above-mentioned problems, a vane rotary small vacuum pump according to the present invention includes a pump mechanism section, a drive motor section for driving the pump mechanism section, a cylinder having a cylindrical inner surface, A cylindrical rotor is arranged in an eccentric state from the central axis, the rotor has a plurality of vane grooves in the direction of the central axis, a rotating shaft that rotates integrally with the rotor, and the plurality of vanes A plate-shaped vane made of a material having a self-lubricating property inserted slidably into the groove, an end plate attached to an end surface of the cylinder on the drive motor side so as to sandwich the rotor and the vane, and the drive motor The pump mechanism portion is constituted by a front plate attached to the end surface opposite to the side, and a plurality of pump spaces are formed in the pump mechanism portion, and the rotating shaft is Supported by a rolling bearing attached to the end plate and a rolling bearing attached to a motor plate provided on the opposite side of the drive motor with respect to the end plate, and the stator of the drive motor is The vane rotary vacuum pump is disposed inside a cylindrical motor case connecting the end plate and the motor plate, and the volume of the pump space is changed by driving the rotary shaft with the drive motor. By attaching an iron ring having an inner periphery smaller than the outer periphery of the motor case to the outer periphery of the motor case, the motor case is prevented from being deformed in the radial direction. Even when the aluminum alloy has a large diameter, the motor case diameter is extended outwardly due to the heat generated by the motor. It can be suppressed, prevented from becoming impossible retain stator to the motor case.

  In the vane rotary type vacuum pump of the present invention, even if the motor case material is an aluminum alloy having a large thermal expansion coefficient, it is impossible to fix the stator to the motor case by suppressing the extension of the motor case in the circumferential direction due to the heat generated by the motor. This can prevent the occurrence of rattling and vibration.

  The first invention has a pump mechanism section and a drive motor section for driving the pump mechanism section. The pump mechanism section is decentered from a central axis in the cylinder and a cylinder having a cylindrical inner surface. A cylindrical rotor, a rotating shaft that rotates integrally with the rotor, an end plate on the drive motor side of the cylinder, and the drive motor disposed so as to sandwich the rotor and the cylinder The rotor is provided with a plate-like vane made of a self-lubricating material that is slidably inserted into each of a plurality of vane grooves formed in the central axis direction of the rotor. A plurality of pump spaces are formed between the cylinder and the cylinder, and the rotating shaft is connected to a rolling bearing attached to the end plate and the end plate. The stator of the drive motor is supported inside a cylindrical motor case that connects the end plate and the motor plate, and is supported by a rolling bearing mounted on a motor plate provided on the opposite side across the drive motor. Is a vane rotary vacuum pump that changes the volume of the pump space by driving the rotary shaft with the drive motor, and is made of iron having an inner circumference smaller than the outer circumference of the motor case A ring is attached to the outside of the motor case to suppress radial deformation of the motor case. Even when the motor case is made of an aluminum alloy having a large coefficient of thermal expansion, the motor case heats out of the diameter of the motor case. It is possible to prevent the stator from being unable to be held in the motor case.

  In the second invention, in particular, the motor case of the first invention is provided with a notch in the axial direction. The ring can easily deform the diameter of the motor case in the center direction, and the motor Cooling can be facilitated.

  In the third invention, in particular, the outer peripheral surface of the ring according to the first or second invention is formed with a shape that enlarges the surface area, and the area of the outer peripheral surface of the ring can be increased to enhance the heat dissipation effect. Can be suppressed.

  In a fourth aspect of the invention, in particular, in any one of the first to third aspects of the invention, the outer diameter of the motor case located near the pump mechanism side end portion of the stator of the motor is increased stepwise. Positioning when inserting the ring into the pump case makes it easy to assemble.

  According to a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, there is provided a fastening tool that cuts out a part of the circumference of the ring and freely adjusts the diameter of the ring at both ends with the notch interposed therebetween. With this, the inner diameter of the ring can be adjusted, and the accuracy of the outer diameter of the motor case and the inner diameter of the ring can be relaxed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a side sectional view of a vane rotary type vacuum pump according to Embodiment 1 of the present invention, and FIG. 2 is a front sectional view of the same pump mechanism section.

  1 and 2, the vane rotary type vacuum pump 90 of the present invention includes a pump mechanism unit 100, a motor unit 200, and a cooling circuit unit 300.

  The pump mechanism 100 includes a cylinder 111 having a cylindrical inner wall, a cylindrical rotor 121, a vane 131 made of a self-lubricating material, and a front plate 141 and an end plate that sandwich them to form a plurality of pump spaces 161. 151. The rotor 121 is arranged in a state of being eccentric from the central axis of the cylinder 111, and the vane 131 is slidably fitted in a plurality of grooves 122 provided in the direction of the central axis of the rotor 121. A front plate 141 and an end plate 151 are arranged adjacent to each other to form a pump space 161.

  In addition, a mechanical shaft 123 is provided at the central axis of the rotor 121, and the rotor 121 is also rotated integrally with the rotation of the mechanical shaft, and the vane 121 is moved inside the groove 122 accordingly. During operation, the tip of the vane 121 rotates in contact with the inner wall of the cylinder 111, so that the pump space 161 is partitioned, and suction, compression, and discharge are repeated to perform the pump function.

  The motor unit 200 includes a stator 211, a rotor 221, a motor case 231 and the like. The motor case 231 is made of an aluminum alloy to reduce the weight and improve the heat dissipation of the motor. The stator 211 is fixed inside the motor case 231 by shrink fitting, and the motor case is sandwiched between the end plate 151 and the motor plate 232 from both sides. A motor shaft 222 is provided at the central axis of the motor rotor 221, and both ends thereof are supported by rolling bearings 152 and 233. Further, since the motor shaft 222 and the mechanical shaft 123 are integrated, the rotation of the motor rotor 221 directly becomes the rotation of the rotor 121, so that no power transmission loss occurs.

  The cooling circuit unit 300 includes a cooling fan 311 and an air guide 321. A cooling fan 311 is attached to the end of the motor shaft 222 on the side opposite to the pump mechanism and is surrounded by an air guide 321 to prevent wind from being dispersed. In addition, a plurality of through holes are provided in the end surface of the motor case 231 in the axial direction, and the motor unit 200 is cooled by forming a wind circuit.

  Here, a ring 411 is arranged on the outer peripheral portion where the stator 211 of the motor case 231 is located. The material of the ring 411 is iron. The inner diameter of the ring 411 is made smaller than the outer diameter of the motor case 231. By inserting this ring 411 into the outer peripheral portion where the stator 211 of the motor case 231 is located by shrink fitting or the like, the motor case 231 is pressed toward the center and is more firmly fixed to the stator 211. . As described above, since the motor case 231 is pressed against the stator 211 by the ring 411, the iron ring 411 is regulated even if the motor generates heat during operation and the motor case 231 made of aluminum alloy tries to expand in the outer circumferential direction due to heat. Thus, only the thermal expansion is extended, and the motor case 231 can continue to fix the stator 211.

(Embodiment 2)
FIG. 3 is a side view of the vane rotary type vacuum pump according to the second embodiment of the present invention.

  Here, the motor case 231 includes a plurality of notches 234 in the axial direction including a portion where the stator 211 is located. As a result, the ring 411 can easily deform the motor case 231 inward, and the motor case 231 and the stator 211 can be more firmly fixed. Further, the expansion of the motor case 231 in the radial direction due to heat can also be suppressed. In addition, the heat dissipation of the motor is facilitated by the notch.

(Embodiment 3)
FIG. 4 is a front view of the ring according to the third embodiment of the present invention.

  Here, protrusions 413 are formed on the outer peripheral surface of the ring 412 to enlarge the area of the outer peripheral surface of the ring 412. Thereby, the heat radiation effect of the ring 412 is enhanced, and the heat of the stator 211 is radiated by the ring 412 through the motor case 231, and the temperature of the stator 211 can be suppressed.

(Embodiment 4)
FIG. 5 is a side sectional view of the vane rotary type vacuum pump according to the fourth embodiment of the present invention. A stepped portion 235 in which a part of the outer periphery of the motor case 231 is made larger than the inner diameter of the ring 411 is configured. As a result, when the ring 411 is inserted into the motor case 231 by shrink fitting, the ring can be positioned by the stepped portion 235, and the ring 411 is not inserted in a shifted manner, thereby improving the assemblability.

(Embodiment 5)
FIG. 6 is a front view of a ring according to the fifth embodiment of the present invention. A part of the circumference of the ring 414 is cut out, and plates 415 having the same width as the ring are attached to both ends of the cutout so as to be almost radially outward. The distance between the two plates 415 can be freely adjusted by a screw 416, whereby the inner diameter of the ring 414 can be adjusted, the accuracy of the outer diameter of the motor case 231 and the inner diameter of the ring 414 can be relaxed, and the ring It is possible to adjust the tightening degree of 414 to the motor case 231.

  As described above, the vane rotary type vacuum pump according to the present invention can be applied to uses such as pumps other than the vacuum pump.

Side sectional view of a vane rotary type vacuum pump according to Embodiment 1 of the present invention. Front sectional view of the pump mechanism The figure of the vane rotary type vacuum pump in Embodiment 2 of this invention Diagram of the ring according to the third embodiment of the present invention Sectional drawing of the vane rotary type vacuum pump in Embodiment 4 of this invention Diagram of the ring in the fifth embodiment of the present invention Sectional drawing which shows the pump part of the conventional vane pump Partially cut sectional view showing a fuel pump in which a conventional vane pump is used

Explanation of symbols

90 Vane rotary type vacuum pump 100 Pump mechanism part 111 Cylinder 121 Rotor 122 Groove 123 Mechanical shaft 131 Vane 141 Front plate 151 End plate 152 Rolling bearing 161 Pump space 200 Motor part 211 Stator 221 Motor rotor 222 Motor shaft 231 Motor plate 232 Motor plate 233 Rolling bearing 234 Notch 235 Stepped 300 Cooling circuit unit 311 Cooling fan 321 Air guide 411 Ring 412 Ring 413 Ring 414 Plate 415 Plate 416 Screw

Claims (5)

A pump mechanism section, and a drive motor section for driving the pump mechanism section. The pump mechanism section has a cylinder having a cylindrical inner surface, and a cylindrical shape that is eccentric from the central axis in the cylinder. A rotor, a rotating shaft that rotates integrally with the rotor, an end plate on the drive motor side of the cylinder, and a front side opposite to the drive motor, disposed so as to sandwich the rotor and the cylinder A plate-like vane made of a material having a self-lubricating property and slidably inserted in each of a plurality of vane grooves formed in the central axis direction of the rotor. A plurality of pump spaces are formed between the rotating shaft and the rotating shaft mounted on the end plate, and the drive motor with respect to the end plate. It is supported by a rolling bearing attached to a motor plate provided on the opposite side, and a stator of the drive motor is disposed inside a cylindrical motor case that connects the end plate and the motor plate. A vane rotary vacuum pump in which the volume of the pump space is changed by driving the rotating shaft with the drive motor, and an iron ring having an inner circumference smaller than the outer circumference of the motor case A vane rotary vacuum pump characterized in that the motor case is prevented from being deformed in the radial direction. 2. The vane rotary vacuum pump according to claim 1, wherein the motor case is provided with an axial notch. The vane rotary vacuum pump according to claim 1 or 2, wherein a shape for enlarging a surface area is formed on an outer peripheral surface of the ring. The vane rotary type vacuum according to any one of claims 1 to 3, wherein an outer diameter of the motor case located in the vicinity of the end of the stator on the side of the pump mechanism is increased with a step. pump. 5. The fastener according to claim 1, wherein a part of the circumference of the ring is cut out, and a fastener for freely adjusting the diameter of the ring is provided at both ends with the notch interposed therebetween. The vane rotary vacuum pump described in 1.

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