The present invention is related to a pneumatic tool, and more particularly to an axial flow cylinder of a pneumatic tool. The axial flow cylinder has cooperative movable wheels and fixed wheels for compressing the air so as to provide high rotational speed and high power output.
The above cylinder with eccentric rotor pertains to single-cylinder type. The highest pressure value in the cylinder body is the pressure value of the high-pressure air. Therefore, the output power of such type of pneumatic cylinder is limited. The rotational speed at most is about 10000 rpm and can be hardly enhanced.
The vanes 16 are slidably mounted in the vane slits 18 of the rotor. By means of the centrifugal force, the outer ends of the vanes keep in contact with the wall of the cylinder body 12. However, the vanes 16 repeatedly slide within the vane slits 18 to increase the friction in operation. Also, the outer ends of the vanes contact with the wall of the cylinder body to also create a frictional resistance. These frictional resistances will affect the rotation of the rotor to reduce the rotational speed and output of the pneumatic cylinder.
In order to reduce the frictional resistance, the wall, vane slits and vanes of the cylinder body are all manufactured at precision so that the manufacturing cost is relatively high.
It is therefore a primary object of the present invention to provide an axial flow cylinder of pneumatic tool. Several movable wheels and fixed wheels are disposed in the cylinder chamber of the cylinder and interlaced with each other. The air flows along the axis of the cylinder body between the vents of the movable wheels and fixed wheels to be compressed for increasing output power and rotational speed of the cylinder.
The present invention can be best understood through the following description and accompanying drawings.
Please refer to FIGS. 2 to 4. The pneumatic cylinder 20 of the present invention includes a cylinder body 30 and multiple movable wheels 60 and fixed wheels 70 interlaced with each other and disposed in the cylinder body 30. The movable wheels are rotatable along with a rotary shaft 50. The movable wheels and the fixed wheels serve to compress the air to create a boosting effect for enhancing the output power and rotational speed of the pneumatic cylinder.
The cylinder body 30 of the preferred embodiment is composed of three block bodies, that is, a front block body X, a middle block body Y and a rear block body Z. The front end of the cylinder body is formed with an intake 32. A cylinder chamber 34 is formed in the cylinder body. After the high-pressure air flows into the intake 32, the air can flow through a flow way 35 into the cylinder chamber 34. Then the air is exhausted from one or more exhaust port 38 of rear end of the cylinder body as shown in
Referring to
The rotary shaft 50 is mounted in the cylinder body 30 and fitted through two bearings 52 disposed in the cylinder body. A rear end of the rotary shaft extends out of the cylinder body.
In this embodiment, there are six sets of movable wheels 60 and fixed wheels 70.
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After the rotary shaft with the movable wheels and fixed wheels is mounted into the cylinder body, a first movable wheel 60a is positioned behind the air-conducting member 40. The air-conducting hole 42 is inclined in a direction reverse to the direction in which the vent 72 of the first movable wheel is inclined.
In use, the high-pressure air flows from the intake 32 into the cylinder chamber 34 and flows along the axis of the cylinder body and then flows out from the exhaust ports 38.
Referring to
When the air flows within the vents 62 of the first movable wheel 60a, an oblique airflow is produced. After flowing out of the vents 62, the air flows into the vents 72 of the first fixed wheel 70a. The air obliquely flows within the vents 62, 72 of the first movable wheel 60a and first fixed wheel 70a in different directions. Therefore, in operation, when the high-pressure air flows from the position of the vents of the first movable wheel 60a into the position of the vents of the first fixed wheel 70a, due to change of the direction of the airflow and the variation of the capacity of the vents 62, 72 taking place when the movable wheel rotates, the air is aerodynamically compressed between the vents 62, 72. Such compression is a first-grade compression.
After the compressed airflow flows out from the first fixed wheel 70a, the airflow continuously flows toward the second movable wheel 60b. After passing through the vents 62 of the second movable wheel 60b and the vents 72 of the second fixed wheel 70b, which vents are inclined in different directions, the airflow is further compressed to form a second-grade compression. Then, the compressed airflow further flows through the third movable wheel 60c and third fixed wheel 70c to be third-grade compressed. Accordingly, the compressed airflow continuously flows to the sixth movable wheel 60f and sixth fixed wheel 70f to be sixth-grade compressed. Eventually, the air is exhausted from the exhaust ports 38 of the cylinder body.
Each set of movable wheel and fixed wheel form a compression area. Each grade of compression serves as a cylinder to compress the air. Therefore, the air is six-grade compressed from the initial pressure like the air is continuously compressed by six cylinders to achieve a final pressure value. The pressure value is the product of the six-grade compression. Presuming that the initial air pressure is 2 psi, then 2 psi×1=2 psi (through first-grade compression), 2 psi×2=4 psi (through second-grade compression), 4 psi×3=12 psi (through third-grade compression), 12 psi×4=48 psi (through fourth-grade compression), 48 psi×5=240 psi (through fifth-grade compression) and 240 psi×6=1440 psi (through sixth-grade compression). After the six-grade compression, the air pressure value is 720 times enlarged. Therefore, the present invention can greatly increase the pressure of the air to achieve high output power and high rotational speed. The rotational speed of the conventional cylinder is about 6000˜7000 rpm. Through a simple test of the model of the present invention, the rotational speed of the present invention can easily reach over 25000 rpm.
In this embodiment, the vents 62 have a length equal to that of the vents 72. Therefore, in each grade of compression, the movable wheel and fixed wheel compress the air in a stabilized state. The vents can be inclined straight vents or inclined arched vents.
Referring to
The end face of each movable wheel 120 is formed with multiple openings 122 annularly arranged at equal intervals. An oblique vane 124 rearward extends from one side of each opening. Each two adjacent vanes define an oblique first vent 126. The axis of the vent 126 and the axis of the movable wheel contain a 30-degree angle.
Similarly, the end face of each fixed wheel 130 is formed with multiple openings 132 arranged at equal intervals. An oblique vane 134 rearward extends from one side of each opening. Each two adjacent vanes define an oblique second vent 136. The axis of the vent 136 and the axis of the fixed wheel contain a 45-degree angle. The vents 126 of the movable wheel and the vents 136 of the fixed wheel are inclined in different directions.
An inner spacing plate 140 is fixedly connected with inner circumference of each the movable wheel 120. The inner spacing plate 140 has a hexagonal hole 142 in which the rotary shaft 110 is fitted. The inner spacing plate is synchronously rotatable with the rotary shaft.
The front and rear end faces of each fixed wheel 130 are clamped by outer spacing plates 145 and fixed in the cylinder chamber. The inner spacing plate 140 has a thickness larger than the thickness of the movable wheel and fixed wheel. Therefore, when the fixed wheels and movable wheels are interlaced with each other, the inner spacing plate slightly protrudes from the through hole 138 of the fixed wheel. When two adjacent inner spacing plates 140 are leant on each other, not only the movable wheels 120 are kept at equal intervals, but also a gap is defined in which the fixed wheel 130 is located without touching the movable wheel and the inner spacing plate. Also, the outer spacing plate 145 and the movable wheel will not touch each other.
In use, the high-pressure air is conducted by the air-conducting holes 106 to form oblique airflow flowing into the cylinder chamber. The airflow provides kinetic energy for driving the first movable wheel 120a, whereby the rotary shaft 110 and the movable wheels are synchronously rotated.
After the air flows through the vents 126, 136 of the first movable wheel 120a and the first fixed wheel 130a, the air is first-grade compressed. The compressed airflow then sequentially flows along the axis of the cylinder body 100 through the successive sets of movable wheels and fixed wheels. After reaching the final sixth movable wheel 120f and sixth fixed wheel 130f, the six-grade compression is accomplished. Eventually, the air is exhausted from the exhaust ports 108. Accordingly, high rotational speed and high power output of the rotary shaft 110 can be achieved.
In the cylinder of the present invention, the air flows along the axis of the cylinder body and the high-pressure air serves as the power source for the movable wheels and rotary shaft. The air is compressed by the cooperative movable wheels and fixed wheels to form multi-grade compression. After compressed grade by grade, the air pressure is gradually increased to achieve high power. The power output efficiency of the present invention is much higher than the conventional device. The number of the sets of the movable wheels and fixed wheels is not limited. For example, there can be six sets of movable wheels and fixed wheels to achieve six-grade compression. Alternatively, there can be three sets of movable wheels and fixed wheels to achieve three-grade compression.
In operation, the components of the present invention will not abrade each other so that the frictional resistance can be reduced to reduce power loss.
The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.