JP2006194163A - Rotary vane air pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary vane air pump in which the surface roughness in vane and cylinder inner peripheral surfaces is prevented from worsening to implement the low noise and low input not only at an operation initial stage but after an elapse of time. <P>SOLUTION: The inner peripheral surface of the cylinder is surface-treated with a nickel phosphorous polytetrafluorethylene resin based coating and the average surface roughness is within the range of not less than 0.05 μm to 0.15 μm so that the surface roughness can be prevented from worsening to enable the low noise and low input not only at the operation initial stage but after the elapse of time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vane rotary type air pump used for an air supply device of a mobile information terminal device using a fuel cell.

  Conventionally, there has been a vane rotary pump of this type in which a vane is subjected to a surface treatment having self-lubricating properties (see, for example, Patent Document 1).

  6 and 7 show a conventional vane rotary pump described in the above document. A cylinder 3 having a cylindrical inner wall closed at both ends by a front plate 1 and an end plate 2 is provided. Inside the cylinder 3, a rotor 4 is arranged in which a part of the outer periphery forms a small gap with the inner wall of the cylinder 3.

A plurality of slits 5 are formed on the outer peripheral surface of the rotor 4, and one end of a vane 6 is slidably inserted into each slit 5. The vane 6 forms a pump space 7 together with the cylinder 3, the rotor 4, the front plate 1, and the end plate 2. The base material of the vane is magnesium or phenol resin, and the surface is impregnated with a solid lubricant.
JP 2003-113785 A

  However, the conventional configuration has a problem in that, when the surface roughness of the inner peripheral surface of the cylinder is deteriorated due to the sliding of the vane during long-time operation, vane jumping occurs and noise increases. In addition, since the cylinder inner peripheral surface with deteriorated surface roughness further deteriorates the surface roughness of the vane tip, the surface roughness of the vane and the cylinder inner peripheral surface deteriorates at an accelerated rate, and noise due to sliding of both increases. It had a problem of coming.

  The present invention solves the above-mentioned conventional problem, and suppresses deterioration of the surface roughness of the vane and the inner peripheral surface of the cylinder, and realizes low noise and low input not only in the initial operation but also after the lapse of time. The purpose is to provide an air pump.

  In order to solve the above-described conventional problems, a vane rotary type air pump according to the present invention has a nickel phosphor having an average surface roughness in a range of 0.05 μm or more and 0.15 μm or less on a cylinder inner peripheral surface and provided with minute grooves. This is a polytetrafluoroethylene resin-based surface treatment. The purpose of this surface treatment of the cylinder is to suppress deterioration of surface roughness due to sliding of the vane and the cylinder.

  The vane rotary pump of the present invention can realize low noise and low input not only in the initial operation but also after the lapse of time by suppressing the deterioration of surface roughness due to sliding of the vane and the cylinder.

The first invention suppresses noise generated by sliding between the cylinder inner peripheral surface and the vane tip by setting the average surface roughness of the cylinder inner peripheral surface in the range of 0.05 μm to 0.15 μm, Noise during the initial operation can be suppressed. At the same time, since the carbon at the vane tip can be worn moderately, the sliding state between the cylinder inner peripheral surface and the vane tip can be improved, and the input can be reduced.

  In the second invention, in particular, by providing a groove in the same direction as the sliding track of the vane on the inner peripheral surface of the cylinder of the first invention, noise generated by sliding between the inner peripheral surface of the cylinder and the tip of the vane is effective. It is possible to further reduce noise at the beginning of operation.

  In particular, the third invention is caused by “burrs” at the time of machining by machining the groove of the second invention in the same direction as the rotation of the rotor and matching the shear direction of the material and the moving direction of the vane tip. The noise caused by the sliding between the inner peripheral surface of the cylinder and the tip of the vane can be suppressed, and the noise in the initial operation can be further reduced.

  According to a fourth aspect of the invention, a nickel phosphorus polytetrafluoroethylene resin-based surface treatment is applied to the cylinder inner peripheral surface of the first to third inventions so that the polytetrafluoroethylene resin slides between the cylinder inner peripheral surface and the vane tip. The dynamic state can be further improved, wear of the vane tip and deterioration of the surface roughness can be suppressed, and increase in noise and input after time can be suppressed.

  In the fifth aspect of the invention, in particular, by making the film thickness of the surface-treated nickel phosphorus polytetrafluoroethylene resin film of the fourth aspect in the range of 3 μm or more and 10 μm or less, deterioration of the surface shape caused by the surface treatment is prevented. It is possible to keep the inner peripheral surface of the cylinder and the vane tip in a good sliding state, to suppress the wear of the vane tip and deterioration of the surface roughness, and to effectively suppress the increase in noise and input after time. it can.

  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)
1 and 2 are sectional views of a vane rotary type air pump according to Embodiment 1 of the present invention.

  1 and 2, the vane rotary type air pump includes a pump mechanism unit 8 and a DC motor 9.

  A cylindrical rotor 4 is disposed in a cylinder 3 having a cylindrical inner wall in a state of being eccentric from the central axis of the cylinder 3, and the rotor 4 is provided with a plurality of slits 5 in the direction of the central axis. Is fitted with a slidable plate-like vane 6 made of a self-lubricating carbon material, and the front plate 1 and the end plate 2 are arranged on the end face of the cylinder 3 so as to sandwich the rotor 4 and the vane 6 therebetween. A plurality of pump spaces 7 are formed, and a mechanical shaft 10 that also serves as a motor shaft of a DC motor 9 disposed on the opposite side of the end plate 2 is coupled to the central axis of the rotor 4. The pump mechanism unit 8 is configured to be rotatably supported by the press-fitted ball bearing 11 and the ball bearing 12 press-fitted into the end plate 2.

  In the DC motor 9, a stator 14 is disposed on the outer periphery of a motor rotor 13, and a mechanical shaft 10 that also serves as a motor shaft is supported by a bearing 15 and a bearing 16.

According to this configuration, the motor rotor 13 obtains rotational torque and rotates by the magnetic action between the motor rotor 13 and the stator 14. The mechanical shaft 10 serving as a motor shaft integrally formed with the motor rotor 13 is rotatably supported by the bearings 11 and 12, so that the rotational force can be transmitted to the pump mechanism unit 8.

  The rotational force output by the DC motor 9 is transmitted to the rotor 4 coupled to the mechanical shaft 10 that also serves as the motor shaft. Along with the rotation of the rotor 4 that has obtained the rotational force, the vane 6 jumps out along the slit 5 provided in the central axis direction of the rotor 4 by the centrifugal force, thereby forming the pump space 7. At the same time, the air sucked from the suction port 17 flows directly into the pump space 7, the route flows into the pump space 7 from the stepped portion 19 provided in the end plate 2 through the through hole 18 provided in the cylinder 3, It flows into the pump space 7 from three places of the path flowing into the pump space 7 from the communication passage 20 provided in the center of the cylinder through the through hole 18.

  The inflowing air is compressed in the pump space 7 as the rotor 4 rotates, and is discharged from the discharge port 22 through the discharge port 21.

  FIG. 3 is a perspective view of a cross section of the cylinder 3. In the present embodiment, a nickel phosphorous layer 23 is laminated on the inner peripheral surface of the cylinder 3, and a nickel phosphorous polytetrafluoroethylene resin layer 24 is laminated thereon. The nickel phosphorus layer 23 can improve the corrosion resistance of the inner peripheral surface of the cylinder, and the nickel phosphorus polytetrafluoroethylene resin layer 24 can improve the sliding property of the tip of the vane 6 and the inner peripheral surface of the cylinder 3. 6 can suppress wear of the tip and deterioration of surface roughness, and can suppress an increase in noise and input after the passage of time.

  Further, when the nickel phosphorus polytetrafluoroethylene resin layer 24 is laminated thickly, undulation is generated on the surface of the layer, and the tip of the vane 6 and the inner peripheral surface of the cylinder 3 are not in contact with each other. May leak to the suction side and reduce volumetric efficiency. At the same time, a noise may be generated when the vane 6 and the cylinder 3 come into contact again, and the noise during the pump operation may increase. Therefore, the lamination thickness of the nickel phosphorus polytetrafluoroethylene resin layer 24 is 10 μm or less, and the minimum necessary lamination thickness is 3 μm.

  FIG. 4 shows the relationship between the average surface roughness of the inner peripheral surface of the cylinder 3, noise, and input. The larger the average surface roughness value of the inner surface of the cylinder 3, the higher the noise value at the initial stage of operation. Therefore, it is desirable that the average surface roughness value is smaller from the viewpoint of noise reduction. On the other hand, as the average surface roughness value of the inner surface of the cylinder 3 is decreased, the wear of the vane 6 is suppressed, the self-lubricating action is less likely to work, and the input at the initial stage of operation shows a higher value. From the viewpoint, it is desirable that the average surface roughness is large. The average surface roughness that can achieve both low input and low noise is in the range of 0.05 μm or more and 0.15 μm or less, and the average surface roughness of the nickel phosphorus polytetrafluoroethylene resin layer 24 is 0.10 μm.

(Embodiment 2)
FIG. 5 is a perspective view of a cylinder cross section of the vane rotary type air pump according to the second embodiment of the present invention. In the present embodiment, a plurality of grooves 25 in the same direction as the vane sliding locus are provided on the surface of the nickel phosphorus polytetrafluoroethylene resin layer 24 having a thickness of 10 μm. The processing direction 27 of the groove 25 is the same as the rotation direction 26 of the rotor 4. When the rotor 4 rotates in the clockwise direction, the vane 6 slides in contact with the inner peripheral surface of the cylinder 3 by centrifugal force. Therefore, the shear direction of the material when the groove 25 is processed and the moving direction of the tip of the vane 6 are matched. Thus, it is possible to suppress noise due to sliding between the inner peripheral surface of the cylinder 3 and the tip of the vane 6 due to “burr” during processing, and noise in the initial stage of operation can be further reduced.

  As described above, since the vane rotary type air pump according to the present invention has low noise and low input, it can be applied to uses such as household health appliances and medical treatment appliances.

Sectional drawing of the axial direction of the vane rotary type | mold air pump in Embodiment 1 of this invention Sectional drawing of radial direction of vane rotary type air pump in Embodiment 1 of this invention The perspective view of the section of the cylinder in Embodiment 1 of the present invention The characteristic view which shows the relationship between the average surface roughness of the cylinder internal peripheral surface in Embodiment 1 of this invention, noise, and an input The perspective view of the section of the cylinder in Embodiment 2 of the present invention. A sectional view in the axial direction of a conventional vane rotary type air pump Radial sectional view of a conventional vane rotary air pump

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front plate 2 End plate 3 Cylinder 4 Rotor 5 Slit 6 Vane 7 Pump space 8 Pump mechanism part 9 DC motor 10 Mechanical shaft 13 Motor rotor 14 Stator 23 Nickel phosphorus layer 24 Nickel phosphorus polytetrafluoroethylene resin layer 25 Groove 26 Rotor rotation Direction 27 Groove processing direction

Claims (5)

A cylindrical rotor is disposed in a cylinder having a cylindrical inner wall with the center line of the cylindrical inner wall of the cylinder being eccentric from the central axis of the cylinder, and the rotor has a plurality of slits in the direction of the central axis. A plate-like vane made of a self-lubricating carbon material is slidably fitted in these slits, and a front plate and an end plate having a suction port are sandwiched between the rotor and the vane. As described above, a pump space is formed by arranging on the end face of the cylinder, a pump shaft is formed by providing a mechanical shaft on the central axis of the rotor, and a motor is disposed on the opposite side of the end plate. When the motor drives the mechanical shaft, the rotor rotates, and the vane tip reciprocates in the slit while the vane tip is moved to the shaft. The oilless air pump that repeatedly expands and contracts the air by causing the pump space to expand and contract by sliding along the inner wall of the cylinder. The average surface roughness of the inner peripheral surface of the cylinder is 0 A vane rotary air pump characterized by having a range of 0.05 μm or more and 0.15 μm or less. The vane rotary type air pump according to claim 1, wherein a groove in the same direction as a sliding locus of the vane is provided in the inner peripheral portion of the cylinder. The vane rotary type air pump according to claim 2, wherein the groove is machined in the same direction as the rotation direction of the rotor. The vane rotary type air pump according to any one of claims 1 to 3, wherein a nickel phosphorus polytetrafluoroethylene resin-based surface treatment is applied to the inner peripheral surface of the cylinder. 5. The vane rotary air pump according to claim 4, wherein a film thickness of the surface treatment of the nickel phosphorus polytetrafluoroethylene resin system is in a range of 3 μm to 10 μm.

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