JP2006291800A - Vane rotary air pump - Google Patents

Abstract

An object of the present invention is to provide a vane rotary type air pump in which a cylinder is reduced in the axial direction while securing a suction volume.
A part of the inner wall of a cylinder 3 has a curved inner wall concentric with the rotor 4, and both ends of the curved inner wall and a minimum gap between the cylinder 3 and the rotor 4 are non-circular curved surfaces such as an elliptical shape. By providing the cylinder curved inner wall formed by connecting the cylinder 3 and the cylinder 3, the cylinder 3 can be reduced in the axial direction while ensuring the suction volume, and the pump can be downsized.
[Selection] Figure 2

Description

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

  Conventionally, many vane rotary pumps of this type have a cylinder inner wall having a perfect circular cylindrical shape and a rotor having a perfect circular cylindrical shape whose diameter is smaller than that of the cylinder (see, for example, Patent Document 1). ).

  3 and 4 show a conventional vane rotary pump described in Patent Document 1. FIG. A cylindrical rotor 4 having a diameter smaller than that of the cylinder 3 is disposed in the cylindrical cylinder 3 so as to be close to each other by shifting the central axes thereof, and the rotor 4 is provided with a plurality of slits 5 in the direction of the central axis. The plate-like vanes 6 are slidably fitted to each other, and the front plate 1 and the end plate 2 are arranged on both end faces of the cylinder 3 so as to sandwich the rotor 4 and the vanes 4. , And a mechanical shaft 10 is provided on the central axis of the rotor 4 to constitute a pump mechanism unit 8. Then, by driving the mechanical shaft 10, the rotor 4 rotates, and the vane 6 reciprocates in the slit 5, while the tip of the vane 6 slides along the inner wall of the cylinder 3. No. 7 produces an expansion / contraction action and repeats the suction, compression and discharge of air.

Here, the suction port 17 is formed so as to end up to a position where the pump space 7 is maximized, and the discharge port 20 is formed in the vicinity where the cylinder 3 and the rotor 4 are close to each other so as to obtain a predetermined discharge pressure. Has been.
JP 62-276291 A

  However, in the conventional configuration, the distance between the inner wall of the cylinder and the outer wall of the rotor approaches in the vicinity of the suction port and the discharge port, and it is difficult to make a large pump space. As a result, in order to secure the suction volume, the entire length of the cylinder has to be expanded in the axial direction, which has the problem that the pump becomes large.

  An object of the present invention is to solve the above-described conventional problems, and to provide a small vane rotary air pump by providing a large pump space by providing a curved inner wall concentric with the rotor on a part of a cylinder inner wall. It is.

  In order to solve the above-described conventional problems, the vane rotary type air pump of the present invention has a curved inner wall concentric with the rotor on a part of the inner wall of the cylinder. As a result, the distance between the cylinder inner wall and the rotor outer wall near the suction port and the discharge port can be increased. Therefore, a large pump space can be taken and the suction volume can be expanded. Therefore, the entire length of the cylinder can be shortened in the axial direction while ensuring a necessary suction volume.

The vane rotary type air pump of the present invention is provided with a curved inner wall concentric with the rotor on a part of the inner wall surface of the cylinder, and connects both ends of the curved inner wall and the minimum clearance between the cylinder and the rotor with a non-circular curved surface. By having the constructed cylinder curved inner wall, a large pump space can be obtained, the entire length of the pump can be shortened in the axial direction, and the pump can be miniaturized.

  1st invention provides the cylinder curved inner wall which comprised the curved inner wall concentric with a rotor in a part of cylinder inner wall, and connected the both ends of this curved inner wall, and the minimum clearance gap between a cylinder and a rotor by the ellipse. Thus, the distance between the inner wall of the cylinder and the outer wall of the rotor in the vicinity of the suction port and the discharge port can be increased, so that the pump space can be increased and the suction volume can be increased. Therefore, the entire length of the cylinder can be shortened in the axial direction while ensuring a necessary suction volume.

  In the second invention, in particular, in the first invention, the cylinder curved inner wall concentric with the rotor is provided in the compression stroke, so that the frictional force acting on the vane tip generated in the conventional cylinder is not generated. In the range of 180 degrees in the rotation direction of the rotor from the smallest gap between the cylinder and the rotor, the force to push the vane back into the slit can be reduced, so that the vane is difficult to separate from the cylinder inner wall, Noise generated by vane jump, which is a phenomenon of recontact after leaving the inner wall of the cylinder, can be suppressed.

  At the same time, in the range of 180 degrees in the rotational direction of the rotor from the point where the smallest gap between the cylinder and the rotor is 180 degrees, the force to press the vane against the cylinder inner wall can be reduced, so the vane tip wear Can be reduced and the life of the vane can be extended.

  In particular, the third aspect of the present invention is the first or second aspect of the present invention, wherein the curved inner wall concentric with the rotor provided in the cylinder and the minimum inner clearance between the cylinder and the rotor are connected by a non-circular curved surface. By providing the starting point of the discharge port in the discharge stroke, the pressure acting on the vane tip and the pressure acting on the back of the vane can be balanced in the discharge stroke, and the force that presses the vane tip against the cylinder inner wall can be eliminated by the pressure difference. The force that pushes the tip against the inner wall of the cylinder is reduced, wear on the vane tip can be reduced, and the life of the vane can be extended.

  According to a fourth aspect of the present invention, in particular, in any one of the first to third aspects, the outer diameter of the rotor is compared with the radial slit arrangement by disposing the slit provided in the rotor offset from the rotor center. Are the same, it is possible to increase the slit cutting length and to increase the cost of the vane. In addition, when securing the same allowance as the radial slit arrangement, the outer diameter of the rotor can be reduced, and the inner diameter and outer diameter of the cylinder can also be reduced while securing the suction volume. it can.

  In the fifth aspect of the invention, in particular, in the fourth aspect of the invention, when the pump is reduced in the radial direction, the slit provided in the rotor is offset in the rotational direction of the rotor, thereby disposing the frictional force acting on the vane tip. Force is generated to press the vane tip against the cylinder inner wall. This force compensates for the reduction in the vane tip pressing force due to the decrease in the centrifugal force acting on the vane, and can suppress the noise generated by the vane jump.

  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. FIG. 1 is an axial section, and FIG. 2 is a radial section. In FIG. 1, the vane rotary type air pump includes a pump mechanism unit 8 and a DC motor 9.

In FIG. 2, a section from the suction completion point 23 to the discharge start point 25 is configured by a perfectly circular curved inner wall concentric with the rotor 4, and a section from the discharge start point 25 to the minimum gap portion 22 between the cylinder 3 and the rotor 4, and A cylindrical rotor 4 is arranged in a cylinder 3 in which a section from the minimum gap portion 22 to the suction completion point 23 is connected by an elliptical inner wall, and the rotor 4 is arranged by being offset in the direction of the rotor rotation direction 26. The plate-shaped vane 6 made of a self-lubricating carbon material is slidably fitted in these slits 5, and the suction port 17 and the surface desired for the pump space 7 are provided. The front plate 1 and the end plate 2 provided with the discharge port 20 and the back pressure groove 21 are respectively attached to the end surfaces of the cylinder 3 so as to sandwich the rotor 4 and the vane 6. 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 8 is configured by being rotatably supported by the ball bearing 11 press-fitted into the ball 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 also serving as the motor shaft integrally formed with the motor rotor 13 is rotatably supported by the ball 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. 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 and 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. Flows into the pump space 7 from the two locations. The inflowing air is compressed in the pump space 7 as the rotor 4 rotates, and is discharged through the discharge port 20.

  The distance between the inner wall of the cylinder 3 in the vicinity of the suction port 17 and the discharge port 20 and the outer wall of the rotor 4 can be increased by the inner wall shape combining the perfect circular shape and the elliptical shape of the cylinder 3. be able to. As a result, the suction volume can be increased as compared with the conventional circular cylinder inner wall shape. Therefore, the entire length of the cylinder 3 can be shortened in the axial direction while ensuring a necessary suction volume.

  Further, by providing the curved inner wall concentric with the rotor 4 in the compression stroke, the component force of the frictional force acting on the tip of the vane 6 generated in the conventional perfect cylinder is not generated during the compression, and the suction completion point In the range from 23 to the maximum clearance 24 between the conventional perfect cylinder and the rotor 4, the force to push the vane 6 back into the slit 5 can be reduced, so that the vane 6 is difficult to separate from the inner wall of the cylinder 3. Thus, the noise generated by the vane jump, which is a phenomenon in which the vane 6 re-contacts after separating from the inner wall of the cylinder 3, can be suppressed.

  At the same time, even in the range from the maximum clearance 24 between the conventional circular cylinder and the rotor 4 to the discharge start point 25, no component force of the frictional force acting on the tip of the vane 6 is generated, and the vane 6 is connected to the inner wall of the cylinder 3. Since the force for pressing the blade 6 can be reduced, wear at the tip of the vane 6 can be reduced, and the life of the vane 6 can be extended.

Further, the discharge start which is the starting point of the discharge port 20 is made at the contact point of the curved inner wall formed by connecting the curved inner wall concentric with the rotor 4 provided in the cylinder 3 and the minimum clearance 22 between the cylinder 3 and the rotor 4 by an ellipse. By providing the point 25, the pressure acting on the tip of the vane 6 and the pressure acting on the back surface of the vane 6 guided from the discharge port 20 to the back surface of the vane 6 through the discharge groove 22 are balanced in the discharge stroke. It is possible to reduce the force of pressing the tip of the cylinder to the inner wall of the cylinder 3. As a result, wear at the tip of the vane 4 can be reduced, and the life of the vane 4 can be extended.

  The slit 5 provided in the rotor 4 is arranged to be offset from the center of the rotor 4 so that the cut length of the slit 5 is increased as long as the outer diameter of the rotor 4 is the same as compared to the radial slit arrangement. The cost of the vane 6 can be increased. Further, when the same allowance as the radial slit arrangement is secured, the outer diameter of the rotor 4 can be reduced, and the inner diameter and the outer diameter of the cylinder 3 can be reduced while securing the suction volume. Can also be miniaturized.

  In addition, by offsetting the slit 5 provided in the rotor 4 in the rotor rotation direction 26, a force for pressing the tip of the vane 6 against the inner wall of the cylinder 3 is generated by the component force of the friction force acting on the tip of the vane 6. This force compensates for the reduction in the pressing force of the tip of the vane 6 against the inner wall of the cylinder 3 due to the reduction of the centrifugal force acting on the vane 6 that occurs when the pump mechanism 8 is contracted in the radial direction. Can be suppressed.

  As described above, since the vane rotary type air pump according to the present invention is small and has a long life, the vane rotary type air pump can be applied to applications such as leisure goods and medical treatment instruments used outdoors.

Sectional drawing of the axial direction of the vane rotary type | mold air pump in Embodiment 1 of this invention Sectional drawing of the radial direction of the vane rotary type | mold air pump in Embodiment 1 of this invention Radial sectional view of a conventional vane rotary air pump A sectional view in the axial direction of a conventional vane rotary type 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 17 Suction port 20 Discharge port 22 Minimum clearance part 23 Suction completion point 24 Maximum clearance part 25 Discharge start point 26 Rotor rotation direction

Claims (5)

A cylindrical rotor is disposed in a cylinder having a curved inner wall, and the rotor is provided with a plurality of slits in the direction of the central axis, and plate-like vanes made of a carbon material having self-lubricating properties are provided in these slits. A front plate and an end plate having a suction port are fitted in a slidable state and arranged on both end faces of the cylinder so as to sandwich the rotor and the vane to form a pump space, and a central axis of the rotor Is provided with a mechanical shaft, and a pump mechanism portion is configured, and a motor is disposed on the side opposite to the mechanical mechanism of the end plate. When the motor drives the mechanical shaft, the rotor rotates, and the vane As the vane tip slides along the inner wall of the cylinder while reciprocating in the slit, the pump space expands and contracts. An oilless air pump that repeats suction, compression, and discharge, and has a curved inner wall concentric with the rotor on a part of the inner wall of the cylinder, and both ends of the curved inner wall and a minimum gap between the cylinder and the rotor A vane rotary type air pump characterized by having a cylinder curved inner wall formed by connecting a portion with a non-circular curved surface. 2. The vane rotary air pump according to claim 1, wherein a cylinder inner wall has a curved inner wall concentric with the rotor in a section from immediately after completion of suction to immediately before discharge start. 3. The vane rotary air pump according to claim 1, wherein the discharge port is formed from a position where the inner wall of the cylinder and the inner wall of the concentric circle are in contact with the non-circular curved surface. The vane rotary type air pump according to any one of claims 1 to 3, wherein the slit provided in the rotor is arranged offset from the center of the rotor. The vane rotary type air pump according to claim 4, wherein a slit provided in the rotor is arranged to be offset in a rotation direction of the rotor.