JPS5862302A - Rotary blade type expander - Google Patents

Abstract

PURPOSE:To easily machine pressure balancing holes which are drilled in a blade by communicating said balancing holes with long holes which are made from the base part to the end of the blade. CONSTITUTION:Long holes 15 are formed from the base part 13 to the vicinity of the extremity 14 of a blade body 12. Short holes 18 are formed from the high pressure gas face 16 of the blade body 12 and communicated with the long holes 15. The long holes 15 and the short holes 18 constitute pressure balancing holes. Each pressure balancing hole 15 and 18 can be drilled with ease.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary vane type (positive displacement type) expander having a plurality of blades on a rotor, and an object thereof is to provide a blade structure of the expander that is easy to manufacture and has excellent performance. In a rotary vane type expander, it is necessary to keep the blade tip pressed against the inner circumference of the cylinder at all times during rotation, and during the exhaust stroke, the purpose is to release the back pressure from the bottom of the blade. Conventionally, a groove 2 was formed on one side of the blade 1 as shown in Fig. 1, but there were problems such as difficulty in precision machining and large gas leakage during movement, so the present invention was developed. An embodiment of the present invention which eliminates all of these drawbacks will be described below with reference to the drawings.

FIG. 2 is an overall view of an expander using one embodiment of the present five-way valve. High-pressure gas from the inlet passage 3 passes through the inlet port 6 of the cylinder 4 and flows into the working space 6, and expands to rotate the rotor in the direction of the arrow. multiple feathers 8
Among the blades A to 8D, the blade 8 is likely to cause a floating phenomenon in which the tip of the two blades separates from the inner peripheral surface of the cylinder 4. So, I/T°4. A high-pressure gas introduction hole 9 is provided in the rear plate (not shown) on the third side behind the rotor, and high-pressure gas is forced through the blade groove bottom 10 of the rotor 7 to the bottom of the blade 498A to push out the eight blades. The distal end cylinder 4 is brought into close contact with the inner circumferential surface of the cylinder 4 to generate a reaction force between the inner circumferential surface of the cylinder 4 and the tip of the blade 8 to prevent the detachment phenomenon. When the rotation angle of the blade 8D advances a little further, the bottom of the blade groove communicates with the high pressure gas introduction hole 9, and the blade 8D is pushed out along the inner peripheral surface of the cylinder 4.

. The high pressure introduction hole 9 is configured so that the rotation angle of the blade 8M advances and no trenching force is required at the position of the blade 8B, and the connection with the high pressure introduction hole 9 is removed. Although the Wi root 8B has passed through the high pressure introduction hole 9 as described above, high pressure gas still remains at the bottom 1dK of the blade groove, and this pressure pushes out the blade 8B more forcefully than necessary.

Therefore, a pressure balancing hole 11 is formed inside the blade 8B to prevent wear of the tip of the blade 8B and increase the mechanical efficiency of the expander by discharging the high-pressure gas in the bottom 1σ of the blade groove that is no longer needed.
through to the working space. Further, when the rotation angle of the blade 8B advances a little, the working space d enters the exhaust stroke, and the low-pressure gas that has completed expansion flows out from the exhaust portion 12 together with the blade 8C, which is already in the exhaust stroke.

The release phenomenon is less likely to occur when the pressure between the bottom and the tip of the blade aB (with a slightly advanced rotation angle) and the blade 8G are dynamically balanced during the discharge stroke, and the pressure balancing hole formed in the blade 8B is 11 to balance the pressure and obtain good operation.

FIGS. 3 and 4 show a component diagram and a cross section of the expander blade (8m to 8D in FIG. 2) according to this embodiment. From the bottom 13 of the vane structure 12 to the tip 14. In addition, a short hole 18 is formed from the high-pressure gas surface 16 of the blade structure 12 (high-pressure gas always acts on the high-pressure gas surface 17 of the blade 8B in FIG. 2) and communicates with the long hole 16. 16 and the short hole 18 constitute a pressure balancing hole (11 in FIG. 2). The short diameter 18 is in contact with the inner surface of the blade groove of the rotor 7, so after it is drilled with a drill, the machining holes are removed using a larger drill, and the edge 19 is chamfered and a pressure balancing hole is machined. It can be easily opened with a simple drill,
Manufacturing costs are significantly lower than conventional methods that require precision machining throughout.

Only the short hole 18 is exposed on the high-pressure gas surface of the blades 8mm to 8D, and compared to the conventional method in which the high-pressure gas surface is grooved, the high-pressure gas surface of the blade has no edges and is smoother. ~
8D easily slides in the blade groove of the rotor 7, increasing mechanical efficiency.

By configuring the long hole 16 inside the blade structure, the short hole 1
No other gas leaks until reaching the opening of 8.
Pressure relief and pressure parallelization at the tips and bottoms of the blades are effectively performed, and the efficiency of the expander is increased overall.As described above, according to the present invention, manufacturing costs are reduced and efficiency is also increased.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional example, FIG. 2 is a sectional view showing an embodiment of the present invention, and FIGS. 3 and 4 are a perspective view and an enlarged sectional view of a blade. 4...Cylinder, 7...Ronita, 8m~8D...Pa. ...Blade, 11...Pressure balance hole, 16...
...Long hole, 18...Short hole.

Claims (1)

[Claims] Cylinder 1) A rotor is rotatably provided in the cylinder, and this rotor is provided with blades that come into contact with the inner surface of the cylinder.This blade has an elongated hole from the bottom to the tip, and a short hole is connected to the elongated hole from the high-pressure gas surface of the blade. A rotary vane expander with communicating holes to form a pressure balancing hole.