JPS5820901A - Rotary blade type expansion machine - Google Patents

Abstract

PURPOSE:To prevent reliably a separation of the edge of a blade from the internal circumferential surface of a cylinder, by forming a pressure equalizing groove on a high pressure side surface of a blade provided with a pressurizing device of back pressure. CONSTITUTION:Back pressure grooves 12 and 13 which lead back pressure to a blade groove 5 and are confronted with each other are formed on a front and a rear walls 2 and 3 of a cylinder 1, and a pressure equalizing pipe 7 which connects the blade groove 5 with an expansion space is formed on a high pressure side surface of a blade 6. In this constitution, high pressure actuation gas is filled evenly in the blade groove 5 through the back pressure grooves 12 and 13 and the blade 6 is pushed forcibly against the internal circumferential surface of the cylinder 1, in the vicinity of a rotary position P1 where a separation phenomenon is easy to occur. Then, when the blade 6 advances in a direction of a position P2, the pressure equalizing groove 7 of the blade 6 is opened into the expansion space 16 and a high pressure working fluid in the blade groove 5 is made to flow into the expansion space 16.

Description

[Detailed description of the invention] In the conventional method, a rotor is provided with a plurality of blade grooves, blades are inserted into the blade grooves, and the rotor with blades is eccentrically supported in a cylinder to rotate the rotor. In positive displacement rotary vane type expanders, high pressure flowing into the expander is installed at the bottom of the vanes as a means of preventing the phenomenon in which the tips of the vanes come loose from the inner circumferential wall of the cylinder during rotation of the rotor (vane detachment phenomenon). Measures have been taken to introduce part of the working gas to apply back pressure to the bottom of the blade, but the centrifugal force of the blade itself is not dynamically sufficient at low speed rotation, and the expander is forced to rotate at low speed. The present invention is intended to improve the above-mentioned problems, and improves the means for using the pressure of high-pressure working gas as a back pressure urging force for the blades, so that even when the expander rotates at low speed, the blades can be sufficiently The purpose is to obtain back pressure urging force.

The present invention will be explained below with reference to the drawings showing one embodiment thereof.

1 is a cylinder, 2 is a front wall, 3 is a rear wall, 4 is a rotor, and the rotor 4 is eccentrically mounted in the cylinder so as to rotate. A blade groove 5 is formed in the rotor 4, and a blade 6 is inserted into the blade groove 6.

A pressure balancing groove 7 is formed in one surface of the blade 6.

The cylinder 1 is also provided with an inflow head 8 and an inflow hole 9.
The rear wall 3 includes a back pressure inlet 10, a back pressure communication hole 11, an arcuate rear wall back pressure groove 12, and a discharge hole 14 and a discharge head 1.
7, and the front wall 2 is provided with an arc-shaped front wall back pressure groove 13 in a portion corresponding to the rear wall back pressure groove 12, and is composed of a cylinder 1, a front wall 2, and a rear wall 3. rotor 4 in space
rotates, the bottom of the vane groove 6 being able to communicate with the rear wall backpressure groove 12 and the front wall backpressure groove 13.

The high-pressure working gas is separated at the branch point A, and the main flow of the reservoir that causes the expansion process passes from the inlet head 8 through the inlet hole 9 of the cylinder 1 and is surrounded by the cylinder 1, the front wall 2, the rear wall 3, and the vane 6. The rotor 4 and external output shaft 16
is rotated in the direction of arrow M to generate power on the external output shaft 16, and then exits to the outside through the discharge head 71 through the discharge hole. It passes through the attachment 12 at the bottom and is introduced through the bottom of the vane groove 5 into the front wall back pressure groove 13 of the front wall 2. The high pressure working gas introduced into the front wall back pressure groove 13 and the rear wall back pressure groove 12 acts as a back pressure on the blade 6 to prevent the blade 6 from coming loose. Further, the high pressure working gas from the back pressure inflow portion 1o not only exerts a back pressure urging force on the blade 6, but also a part of it flows into the expansion space 15 through the pressure balancing groove of the blade 6, thereby causing the cylinder 1 It compensates for the decrease in the flow rate of the working gas caused by the fluid resistance that occurs in the inflow hole 9, and serves to prevent a decrease in the efficiency of the expander. After completing the expansion process, the working gas has a low pressure and exits the expander through the discharge head 17.

Although the blade 6 is prone to release phenomenon near the rotational position P1, the rear wall back pressure groove 12 and from there, the front wall back pressure groove 13 via the blade groove 6 are filled with even high-pressure working gas, and the bottom of the blade 6 is By applying a back pressure biasing force, a reaction force is generated between the tips of the vanes 6 and the inner circumferential surface of the cylinder 1, thereby preventing the rotor 4 from coming loose when rotating at low speed. Next, when the rotational position of the blade 6 advances from Pl to around P2, the blade 6 leaves the range where the separation phenomenon is likely to occur. At this time, the pressure balancing groove 7 provided on the high-pressure side side surface of the blade 6 opens into the expansion space 15.
The high-pressure working gas is opened into the expansion space 15 and the high-pressure working gas is introduced into the expansion space 15 . In this way, the high pressure working gas is
At a rotational angle position exceeding the release phenomenon range, the pressure balancing groove 7 of the blade 6 opens into the expansion space 16, and the suction process (the rotational angle range in which the expansion space 16 also opens the inflow hole 9VC) ends. At the same time, the bottom of the blade groove 5 and the front wall back pressure groove 1
3 and the rear wall back pressure groove 12 are cut off,
The working gas from the back pressure inlet 10 is stopped from being introduced into the expansion space 15. Also, the blade 6 moves from the rotational position P3 to P
4, the pressure balancing groove 7 of the blade 6 is installed to prevent the high-pressure working gas remaining at the bottom of the blade groove 6 from excessively pressing the tip of the blade 6 against the inner surface of the cylinder 1 and causing mechanical loss. The high pressure working gas at the bottom of the blade groove 5 is released through the blade groove 5.

As is clear from the above embodiments, in the rotary vane expander of the present invention, high-pressure working gas is always supplied to the front wall back pressure groove through the rear wall back pressure groove and the rotor blade groove, regardless of the rotation angle of the rotor. stagnates, and when the bottom of the blade groove opens into the rear wall back pressure groove, a back pressure biasing force is applied to the blade bottom without delay at the starting rotation angle of the blade release phenomenon range, and conventionally, the rear wall back pressure It is possible to apply back pressure evenly to the bottom of the blade near the front wall, where the back pressure force is difficult to transmit due to the distance from the groove, and it is possible to prevent the blade from coming loose during low speed rotation. In addition to improving the efficiency of the expander, pressure is applied to the blades symmetrically from both sides of the front and rear walls, so that no deflection load is applied to the blades, so that at the opening rotation angle of the back pressure groove (
In addition, part of the volume of the front wall back pressure groove serves as a retention function for the lubricating oil that circulates with the high pressure working gas, and the front wall side This has the effect of promoting lubrication on the surfaces of the expansion mechanism parts.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a rotary vane type expander showing an embodiment of the present invention, FIG. 2 is a front view taken along line n-n' in FIG. 1,
FIG. 3 is a front view taken along line m-m' in FIG. 1, and FIG. 4 is a perspective view of the blades of the expander. 1...Cylinder, 2...Front wall, 3...
... Rear wall, 4 ... Rotor, 5 ... Vane groove, 6 ... Vane, 7 ... Pressure balance groove, 9 ...・Inflow hole, 11... Back pressure communication hole, 1
2... Rear wall back pressure groove (back pressure groove), 13...
... Front wall back pressure groove (back pressure groove), 16... Expansion space. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure m'-1 Figure 2

Claims (1)

[Claims] A front wall and a rear wall are attached to both ends of the cylinder to form a space inside the cylinder, and a rotor having blade grooves and blades inserted into the blade grooves is disposed in this trace, and a high pressure is placed in this space. An inflow hole through which working gas flows is provided, a back pressure communication hole is provided on one of the front wall or the rear wall, and an arcuate back pressure groove that guides a portion of the high pressure working gas from the back pressure communication hole to the bottom of the blade groove. , and another arc-shaped back pressure groove facing this back pressure groove is provided on the other side, and a pressure balancing groove is formed on the high-pressure side side surface of the blade, and the working gas from the back pressure communication hole is directed to the bottom of the blade. A rotary vane expander that uses working gas for urging and expansion.