CN2351598Y

CN2351598Y - Air motor

Info

Publication number: CN2351598Y
Application number: CN98208471U
Authority: CN
Inventors: 郑相建
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-04-23
Filing date: 1998-04-09
Publication date: 1999-12-01
Anticipated expiration: 2008-04-09
Also published as: TW352796U; KR200185309Y1; KR19980063966U

Abstract

The utility model relates to an air motor for a driving device of a pneumatic grinding mill in industries. Two grooves are formed along the circumferential surface of a through hole of a bearing box which is communicated with an air supply passage on the bearing box and are corresponding to the lowest end of a rotor elongated groove which is inserted with blades, and a plurality of shaft bearings, such as two, are arranged and used for supporting rotating shafts. The utility model shortens the reaching time of the pneumatic power in the maximum number of rotating, maintains a certain rotating numbers of the air motor, quickly discharges the air used for rotating a rotor into atmosphere, and prevents the rotating shaft from the eccentricity.

Description

Air motor

The present invention relates to an air motor as a driving device of an industrial air pressure grinding machine, and more particularly, to an air motor in which a plurality of blades inserted into a rotor elongated slot are floated by forming the elongated slot from a through hole of a bearing housing along a circumferential surface of the bearing housing.

The air motor can be used for polishing the surface of a small-sized workpiece or polishing a pipe coupling portion. In recent years, the present invention is widely used as a driving device for a medical grinding machine for grinding or excavating teeth. The protection period of the related patents and utility models has also expired, and the above-mentioned techniques are well known to those skilled in the art and are publicly available.

Sho 46-19845 discloses a reversible rotary air motor having a piston rotated by compressed air. The air motor includes: a cylindrical stator 1 disposed in the housing 2; a rotor 4 rotatably disposed in the stator 1; four vanes 5 embedded in the peripheral groove; a longitudinal deep hole 18 formed in the center of the rotor 4 with its branched end open at the bottom of the groove; two longitudinal deep holes 15, 21 are formed in the wall surface of the stator 1.

Compressed air is fed through the holes 15 into the stator 1 gap to turn the rotor 4 and through the holes 18 into the slot to lift the vanes. When the rotor 4 rotates, compressed air is discharged through the hole 21.

However, this prior art has the following disadvantages: it is difficult to drill the longitudinal

long holes

15, 18, 21; since the passage is narrow, compressed air cannot be smoothly supplied and discharged, noise is generated, and a large back pressure hinders the operation of the rotor 4.

The utility model aims to overcome the problem that prior art exists, its aim at provides an air motor, avoids processing the slot hole, enables gaseous smooth and easy flowing in the passageway, reduces the noise to obtain required rotational speed fast.

Another object of the present invention is to provide an air motor, which can maintain a constant rotation speed.

Yet another object of the present invention is to provide an air motor which can rapidly discharge air for rotating a rotor into the atmosphere.

Still another object of the present invention is to provide an air motor, which can prevent the rotation shaft from being eccentric.

The object of the utility model is to realize like this, provide an air motor promptly, include: a cylindrical body portion having front and rear ends open; a rotary shaft passing through the open front end of the body portion and threadedly coupled to the tool; a rotor rotating with the rotating shaft, the outer peripheral surface of the rotor being provided with a plurality of elongated slots, the plurality of blades being inserted into the plurality of elongated slots, respectively; a cylinder in which a plurality of injection holes are formed to receive the rotor, and a plurality of exhaust holes are formed at positions opposite to the plurality of injection holes; a bearing supporting the rotating shaft and the rotor; a bearing housing in which a bearing for supporting the rotor is fixed, the bearing housing having a through hole and a groove connected to the through hole and formed along a circumferential surface; a valve tube integrally connected to the body part and having an air supply hose inserted therein, the valve tube being formed with air supply passages respectively communicating with the through-hole of the bearing housing, the groove and the cylinder injection hole; and an air supply amount adjusting clamp which is connected with the periphery of the valve pipe by screw thread and is provided with an exhaust path communicated with the exhaust hole of the cylinder, on one hand, the air supply path of the valve pipe is opened and closed; the rotating shaft, the rotor, the bearing box and the valve pipe are arranged in the body part.

The utility model has the advantages that the volume of the exhaust path is increased, the noise elimination effect and the exhaust effect are improved, and the exhaust pressure is fully reduced; the double bearings are adopted to support the rotating shaft, so that the eccentricity of the rotating shaft is prevented, and severe vibration and high heat caused by the eccentricity are avoided. In addition, because the groove connected with the through hole of the bearing box corresponds to the lowest end of the long groove on the rotor, the long hole does not need to be processed, and the blade is floated out by the initially inflowing compressed air, thereby shortening the time required by the air motor to reach the highest rotating speed. Further, the vane continues to float during the operation of the air motor, so that the number of revolutions can be kept constant.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Wherein,

FIG. 1 is a perspective view of an air motor of the present invention;

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1;

FIG. 3 is an enlarged cross-sectional view of portion A of FIG. 2;

FIG. 4 is an enlarged cross-sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a plan view of the air motor bearing housing of FIG. 1;

FIG. 6 is a perspective view of the air motor of FIG. 1 partially cut away to show the components in a joined relationship.

As shown in fig. 1 to 6, the air motor 30 according to the present invention injects compressed air from an air supply hose 34 (connected to a rear end portion of an air motor body a) into the cylinder 6 installed in the housing 1 through an air supply passage, thereby rotating the rotor 5, the rotary shaft 9 linked with the rotor 5, and the tool 32 at a high speed. At the same time, the gas passing through the cylinder 6 is discharged to the outside through an exhaust passage 11 at the rear end of the air motor body a.

Fig. 2 is a cross-sectional view of fig. 1, showing a state in which a tool 32 is coupled.

The substantially pencil-shaped case 1 is made of metal, has a polygonal outer shape, is detachably screwed to the cylindrical body portion 1a, and has an intermediate portion formed with a knob portion having a tapered concave-convex portion. Two bearings 15 are provided in the rotor, and the rotor 5 and the rotary shaft 9 are supported along the axial center.

The rotor 5 and the rotary shaft 9 are inserted and coupled, and the support shaft at the rear end of the rotor 5 is fitted into the bearing 15a of the bearing housing 14 from the rear, and the rotary shaft 9 is fitted into the bearing 15a of the coupling portion of the housing 1, thereby supporting the rotor 5 and the rotary shaft 9 for coaxial rotation in the housing 1.

The rotor 5 is formed with a plurality of elongated slots 5a, for example, three elongated slots 5a, and a vane 5b is inserted into each elongated slot.

As shown in fig. 3 to 5, a groove 14b is formed on the circumferential surface of the bearing housing 14 from the through hole 14 a; the groove 14b extends to a position corresponding to the lowermost end portion of the long groove 5a of the rotor 5. The groove 14b is formed along the circumferential surface of the bearing housing 14 for a length of at least 1/3(120 °).

A chuck is provided at the front end of the rotary shaft 9, and a tool 32 is detachably attached thereto.

The cylinder 6 to which the rotor 5 is attached is formed with injection holes 7 arranged in a row on the circumferential surface, and exhaust holes 8 are formed at positions opposed to the injection holes 7. The cylinder 26 has a predetermined eccentricity with the rotor 5 and is mounted in a clearance fit between the bearing housing 14 and the inner wall of the housing barrel la.

The injection hole 7 is circular in shape, and the exhaust hole is rectangular in shape.

The flange 3a at the front end of the valve tube 3 is screwed to the inner portion of the rear end of the housing body la, and the bearing housing 14 is pushed forward. The flange portion 3a is formed integrally with the housing 1.

The valve tube 3 is a small-diameter tube for introducing the compressed air in the air supply hose 34 into the housing 1. The valve tube 3 is internally formed with a gas supply passage C1 whose intermediate portion is closed by a partition wall. The valve tube 3 is provided at the front end thereof with a flange portion 3a and at the rear end thereof with a connecting portion 3b for connecting an air supply hose 34.

A valve 12a having a guard pattern is provided around the outer periphery of the partition wall portion of the valve tube 3, and an air supply amount adjusting valve 12 is formed between the valve portion 12a and a step portion 12b of the inner cylinder 2 b.

The air supply adjusting clip 2 is constructed in a double-layered tube structure by an inner tube body 2b screwed to the outer periphery of the valve tube 3 and an outer tube body partitioned by a gap serving as an air exhaust path 11.

The inner and outer

tubular bodies

2a, 2b are integrally connected by a post 2c at the rear end; the inner cylinder 2b is coupled to the outer circumference of the valve tube 3 through a packing and to the screw part 13 of the middle part of the valve tube 3.

In the aforementioned state, the front end portion of the inner cylinder 2b is inserted into the rear end portion of the case body 1a, and the front end portion of the outer cylinder 2a is coupled to the outer periphery of the rear end portion of the case body la.

A stepped portion 12b is formed on the inner periphery of the inner cylinder 2b, and the stepped portion 12b faces the valve portion 12a of the valve tube 3 to constitute an air supply amount adjusting valve 12.

Therefore, when the supply air adjusting clip 2 is rotated to move in the axial direction, the gap between the step portion 12b and the valve portion 12a changes, and the amount of compressed air flowing through the supply air amount adjusting valve 12 in the vent hole 18 is adjusted.

Compressed air is supplied from the connecting portion 3b of the valve tube 3 to an air supply passage of the injection hole 7 of the cylinder 6. The compressed air passes through the

ventilation holes

18 and 18a from the air supply passage C1 inside the valve tube 3, bypasses the air supply amount adjusting valve 12, passes through a through hole 14a, a ventilation hole C2, and a recessed groove 14b formed in the bearing housing 14, and then reaches the vertical through hole C3 along the outer peripheral portion of the cylinder 6, thereby forming the air supply passage.

The compressed air is injected into the cylinder through the air supply passage and the longitudinal injection hole 7, provides a rotational force to the rotor 5, and is then discharged to the exhaust passage through the longitudinal exhaust hole 98.

The exhaust passage is formed by communicating with the exhaust passage 11 through vertical through holes C3 formed along the outer sides of the exhaust holes 8, through holes D1, D2, and D3 in the outer periphery of the flange portion 3a of the bearing housing 14 and the valve tube 3.

As described above, the air supply adjusting clip 2 is coupled to the outside of the case trunk la, so that the inner diameter of the outer cylinder 2a can be increased by at least the thickness of the case 1.

Therefore, the volume in the exhaust passage 11 is increased, and the expansion rate of exhaust gas therein is increased, whereby the noise cancellation effect and the exhaust efficiency are improved, and the pressure generated in the exhaust passage 11 can be sufficiently reduced.

As described above, the front end outer peripheral portion of the outer cylinder 2a coupled to the outer periphery of the rear end portion of the case trunk 1a is coupled in a sealed manner to the rear end portion of the packing cover 4 matching the outer periphery of the case 1.

The packing cover 4 is made of synthetic resin having excellent heat insulation properties, is divided into two halves in the same manner as the case 1, is fitted around the knob portion 1b and the body portion la, and is formed by bulging the rear end 4a of the body portion 1a side to protrude from the outer periphery of the case 1 and by closely contacting the rear end 4a to the outer periphery of the front end of the outer cylinder 2a as described above, thereby preventing the exhaust gas leakage in the exhaust passage 11.

Although the air tightness of the sealing portion is not as high as that of the airtight portion, the packing can increase the exhaust efficiency of the exhaust path 11 and sufficiently reduce the pressure in the exhaust path 11, thereby preventing the air from leaking from the sealing portion and causing noise.

The sealing portion partitions the exhaust passage 11 by the rear end portion of the case body 1a and the rear end portion of the exhaust passage 11, thereby preventing direct contact with the exhaust gas flowing through the exhaust passage 11 at a high speed as in the conventional art and reducing air leakage. This effect is also complementary to the above-described noise-reducing effect, and further reduces the exhaust noise.

In addition, the housing 1 made of metal tends to be overheated or cooled depending on the use conditions. However, as described above, since the case 1 is covered with the packing cover 4 made of synthetic resin having excellent heat insulation, the outer circumferential surface of the air motor main body a which is in contact with the user can be prevented from being excessively overheated or cooled.

Further, the packing cover 4 has a function of blocking the transmission of the resonance sound of the rotor 5 from the casing 1, thereby reducing the rotor noise leaking to the outside.

Since excessive external force is generated by grinding or cutting the tool 32 rotating at a high speed while pressing the surface of the workpiece, the two bearings 15 for supporting the rotary shaft 9 prevent the eccentric center of the rotary shaft 9 from being increased, thereby preventing generation of very severe vibration and high heat. Therefore, the defects of about 80-90% of the product maintenance reasons can be fundamentally overcome.

Since the exhaust hole of the cylinder 6 is formed in a long and narrow rectangular shape, the compressed air flowing from the injection hole can be quickly discharged to the outside after the rotor 5 is rotated.

Since the groove 14b connected to the through hole 14a of the bearing housing 14 corresponds to the lowermost end portion of the long groove 5a of the rotor 5, the vane 5b can be floated by the compressed air that initially flows in, and the time until the maximum number of revolutions is shortened. And the air motor 30 is operated while the vane 5b is continuously lifted, so that the same number of revolutions can be maintained.

Claims

1. An air motor comprising:

a cylindrical body portion having front and rear ends open;

a rotary shaft passing through the open front end of the body portion and threadedly coupled to the tool;

a rotor rotating with the rotating shaft, the outer peripheral surface of the rotor being provided with a plurality of elongated slots, the plurality of blades being inserted into the plurality of elongated slots, respectively;

a cylinder in which the rotor is installed, the cylinder having a plurality of injection holes formed thereon, the cylinder having a plurality of exhaust holes formed thereon at positions opposite to the plurality of injection holes;

a plurality of bearings supporting the rotating shaft and the rotor;

a bearing housing in which a bearing for supporting the rotor is fixed, the bearing housing having a through hole and a groove connected to the through hole and formed along a circumferential surface;

a valve tube integrally connected to the body part and having an air supply hose inserted therein, the valve tube being formed with air supply passages respectively communicating with the through-hole of the bearing housing, the groove and the cylinder injection hole; and

an air supply amount adjusting clamp which is in threaded connection with the periphery of the valve pipe and is provided with an exhaust path communicated with an exhaust hole of the cylinder;

the rotating shaft, the rotor, the bearing box and the valve pipe are arranged in the body part.

2. The air motor as claimed in claim 1, wherein the groove formed along the circumferential surface of the bearing housing is located at a position corresponding to a lowermost end of the elongated slot of the rotor.

3. The air motor as claimed in claim 1, wherein there are two bearings for supporting the rotating shaft.