JPH04119378U - rotary compressor - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the tip of the blade 10 from temporarily separating from the outer circumferential surface of the rolling piston 6 during low speed rotation of the compressor, and to prevent the tip of the blade 10 from temporarily separating from the rolling piston 6 when the compressor is rotating at low speed. prevent excessive contact pressure with the outer peripheral surface of the [Structure] The spring force of the spring that presses the blade 10 toward the rolling piston 6 is increased in accordance with the decrease in the difference between suction pressure and discharge pressure.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a rotary compressor.

0002

[Conventional technology]

An example of a conventional rotary compressor is shown in FIGS. 5 and 6. Inside the sealed casing 1 is a motor 2 consisting of a stator 2a and a rotor 2b, and this motor. A rotary compression mechanism 3 driven by the motor 2 is housed below the motor 2. , this rotary compression mechanism 3 is immersed in lubricating oil 17 stored at the inner bottom of the casing 1. It's pickled. The stator 2a of the motor 2 is fixed to the casing 1 by shrink fitting, etc., and the rotor 2b is fixed to the upper end of the crankshaft 4. The rotary compression mechanism 3 includes a crankshaft 4 and a crankshaft of the crankshaft 4. A rolling piston 6 fitted to the rank pin 5 and fixed to the casing 1 Cylinder block 7 and an upper bearing that closes the upper end opening of this cylinder block 7 8, a lower bearing 9 that closes the lower end opening of the cylinder block 7, and a lower bearing 9 that closes the lower end opening of the cylinder block 7. The blade 10 is fitted into the slit 21 formed in the hole 7 and It consists of a pusher spring 11 placed behind the card 10 to push it. cylinder blow The hook 7 is fixed to the casing 1 by plug welding or the like.

0003 Cylinder bounded by cylinder block 7, upper bearing 8 and lower bearing 9 The rolling piston 6 is accommodated in the chamber 12, and the outer peripheral surface of the rolling piston 6 is By bringing the tip of the blade 10 into contact with the suction chamber on one side of the blade 10, 13 is delimited and on the other side a compression chamber 14 is delimited.

0004 The crankshaft 4 has upper bearings 8 and They are each supported by a lower bearing 9. When the crankshaft 4 is rotationally driven by the motor 2, the crank pin 5 The fitted rolling piston 6 has its outer peripheral surface aligned with the inner peripheral surface of the cylinder block 7. It rotates eccentrically in the direction of the arrow within the cylinder chamber 12 while sliding in contact. Inhale at the same time Low pressure gas is sucked into the chamber 13 from the suction pipe 20, and the gas in the compression chamber 14 is compressed. The compressed gas passes through the discharge port 22, pushes up a discharge valve (not shown), and is discharged from the upper shaft. It enters a discharge muffler 27 bounded by a receiver 8 and a cover 26 covering the upper surface thereof. The pulsating component is removed. Next, pass through a hole (not shown) drilled in the cover 26. and enters the first expansion chamber 28 bounded between the motor 2 and the rotary compression mechanism 3. By expanding, the pulsating component is further removed. Next, stator 2a and low It enters the second expansion chamber 15 limited above the motor 2 through the gap with the motor 2b and expands. By doing so, the pulsating component is further removed. Then, it passes through the discharge pipe 16 to the outside. It is discharged.

[0005] The lubricating oil 17 stored in the inner bottom of the casing 1 is incorporated into the crankshaft 4. The oil is pumped up by the centrifugal pump 18, which is drilled into the crankshaft 4. The sliding surfaces of the crankshaft 4 and the upper and lower bearings 8 and 9 pass through the passage 19. The sliding surface between the link pin 5 and the rolling piston 6, and the sliding surface between the rolling piston 6 and the cylinder The sliding surfaces with the double lock 7 are lubricated.

[0006] The advancing state of the blade 10 is shown in FIG. 7, and the force acting on it is shown in FIG. ing. The blade 10 receives the pressure Pi in the suction chamber 13 and the pressure Pm in the compression chamber 14 on both sides thereof. Due to the pressure difference, it tilts as shown in the figure and comes into line contact with the slit 21 at points E and F. It makes line contact with the outer peripheral surface of the rolling piston 6 at point G. Then, from line G on the front end surface Pressure Pi acts on the width a on the suction chamber 13 side, and width b on the compression chamber 14 side from line G. Pressure Pm acts on . The rear end surface of the blade 10 has a gas inside the first expansion chamber 28. The gas pressure, that is, the discharge pressure Pd of the compressor acts.

[0007] Here, the contact pressure Fp between the tip of the blade 10 and the outer peripheral surface of the rolling piston 6 is calculated by the following formula: It is expressed as Fp=[(a+b)・w・Pd+Fs+Fi]−[a・w・Pi+b・w・Pm+Ff+Fe] = [Fs+Fi-Ff-Fe]+a・w・(Pd−Pi) +b・w・(Pd−Pm)〕 However, a is the width over which the pressure Pi acts b is the width on which pressure Pm acts w is the height of blade 10 Fs is the pressing force of pressing spring 11 Fi is the inertial force acting on blade 10 Ff is the friction force at point F Fe is the friction force at point E

[0008]

[Problem that the idea aims to solve]

In the conventional compressor mentioned above, when the rotation speed is reduced, the suction pressure Pi and the discharge pressure As the difference from the force Pd becomes smaller, the inertial force Fi acting on the blade 10 becomes smaller. Then, the sum of the friction force Ff at point F and the friction force Ff at point E is the push force of spring 11. The pressure becomes greater than Fs and the blade 10 stops midway through its advance. And low When the ring piston 6 rotates eccentrically, its outer circumferential surface collides with the tip of the blade 10. do. In this way, the tip of the blade 10 temporarily touches the outer peripheral surface of the rolling piston 6. There was a problem in that the gas could not be compressed during this time because the gas was separated from the gas. Also, the brake When the tip of the cylinder 10 collides with the outer circumferential surface of the rolling piston 6, an impact sound is generated. Both the tip of the blade 10 and the outer peripheral surface of the rolling piston 6 are damaged by this collision. There was a problem with it being damaged. To deal with this, increasing the pressing force of the presser spring 11 causes fatigue of the presser spring 11. damage to the compressor is likely to occur, and the wear of the tip of the blade 10 becomes large, causing damage to the compressor. There was a problem that impeded the lifespan and reliability of the product.

[0009]

[Means to solve the problem]

This invention was proposed to solve the above problems, and its gist is as follows: However, the block is slidably fitted into the slit drilled in the cylinder block. The tip of the blade is pushed by the discharge pressure acting on its rear end face. A rotary that slides into contact with the outer circumferential surface of a rolling piston that rotates eccentrically in the cylinder chamber. In the compressor, the blade is pushed toward the outer peripheral surface of the rolling piston. spring, and the pressing force of this spring increases as the difference between suction pressure and discharge pressure decreases. There is provided a rotary compressor characterized in that a means is provided.

0010

[Effect]

Since this invention has the above configuration, the difference between suction pressure and discharge pressure is reduced. When this occurs, the pressing force of the spring increases and the tip of the blade is pushed around the outer circumference of the rolling piston. Bring it into contact with the surface.

[0011]

【Example】

A first embodiment of the invention is shown in FIG. The outer peripheral surface of the cylinder block 7 has a slit extending in the centripetal direction at a position facing the slit 21. A hole 30 is bored in the hole 30, and a cylindrical block whose openings at both ends are closed by electromagnets 31 and 32 is inserted into the hole 30. Shush 33 is inserted. And the limit is set by electromagnets 31, 32 and bush 33. A cylindrical slider 35 is fitted in the cavity 34 to be movable in the radial direction. Permanent magnets 36 and 37 are buried at both ends of the rider 35, respectively. And this One end of a semicircular spring 38 is locked in the center of the slider 35, and the other end is a blade. It is locked on the rear end surface of 10.

0012 Suction pressure Pi detected by sensor 39 and detected by sensor 40 The discharge pressure Pd is input to the controller 41. Controller 41 controls these differential pressures ΔP is calculated, and this differential pressure ΔP decreases below the set pressure preset by the setting device 42. When this happens, it outputs to switch 43 and turns it on. Then, the electromagnet is connected via the electric wire 44. A current flows through the electromagnet 32 and the electromagnet 32 attracts the permanent magnet 37. Thus, Sly The driver 35 moves radially to take up the position shown, and the spring force of the spring 38 increases accordingly. The force increases and the tip of the blade 10 is pressed against the outer peripheral surface of the rolling piston 6.

[0013] When the differential pressure ΔP between the suction pressure Pi and the discharge pressure Pd exceeds the set pressure, the controller The switch 45 is turned on by the command from 41. Then, the electric wire 46 connects to the electromagnet 31. A current flows and the electromagnet 31 attracts the permanent magnet 36. Thus, slider 35 is centripetal As the blade 10 moves in this direction, the pressing force exerted on the blade 10 by the spring 38 becomes smaller. Other configurations and operations are similar to the conventional ones shown in FIGS. 5 and 6, and corresponding members are given the same symbol.

[0014] FIG. 2 shows a second embodiment of the invention. An O-ring 47 is wrapped around the outer circumference of the slider 35, and the slider 35 is sealed inside the hole 30. By slidingly fitting the chamber 48a, the chamber 48a is limited to the back of the slider 35, and the chamber 48a is Chamber 48b is restricted. Suction pressure Pi is introduced into the chamber 48a through the through hole 52a. Then, the discharge pressure Pd is introduced into the chamber 48b through the through hole 52b. installed in chamber 48a The slider 35 is pushed in the radial direction by the tabular spring 49 and is prevented from coming into contact with the stopper 50. It is prevented from coming out of the hole 30 by. The centripetal movement of slider 35 is It is regulated by a stopper 51. However, when the differential pressure between the suction pressure Pi and the discharge pressure Pd becomes smaller, the slider 35 It moves in the radial direction and comes into contact with the stopper 50 and occupies the position shown, and the brake is activated by the spring 38. Increase the pressing force of door 10. When the discharge pressure Pd increases and the pressure difference between it and the suction pressure Pi increases, the slider 35 The blade 10 moves in the centripetal direction against the elastic force of the spring 49, and the pressing force of the blade 10 by the spring 38 decrease. Other configurations and functions are similar to those of the first embodiment shown in FIG. 1, and corresponding members are the same. Reference numerals are given and explanations thereof are omitted.

0015] FIG. 3 shows a third embodiment of the invention. A bore 54 is bored in the cylinder block 7, communicating with the back of the hole 30 and perpendicular thereto. A taper slider 55 is slidably fitted into the bore 54. taper sura A permanent magnet 56 buried in one end of the ider 55 is supplied with an electromagnet 58 via an electric wire 60. When excited by the current, it is attracted to this, and the other end of the taper slider 55 A permanent magnet 57 embedded in the When it is magnetized, it is attracted to it. Then, a slide is slidably fitted into the hole 30. The tip of the slider 35 contacts the tapered surface 62 formed on the central part 1 side of the taper slider 55. are doing. Therefore, the electromagnet 58 is activated by a command from the controller 41 (not shown). Or if you move the taper slider 55 to the left or right by energizing 59, Along with this, the slider 35 moves along the radial direction and changes the spring force of the spring 38. Ru.

[0016] A fourth embodiment is shown in FIG. A taper slider 55 with an O-ring 68 wrapped around its outer circumference can be sealed and slid freely within the bore 55. By fitting the taper slider 55 into the chamber 63a on one side and the chamber 63b on the other side. It is limited. Suction pressure Pi is introduced into chamber 63a through hole 64a, and is introduced into chamber 63b. A discharge pressure Pd is introduced through the through hole 64b. And the taper slider 55 is chamber 63a is biased to the left by a coil spring 67 disposed inside the stopper 65, 66, its movement is restricted. On the center part 1 side of this taper slider 55 The tip of the slider 35 is in contact with the formed tapered surface 62. However, when the differential pressure between the suction pressure Pi and the discharge pressure Pd becomes smaller, the taper slider 55 assumes the position shown, and the slider 35 moves radially to release the spring 38. Increase the spring force of.

[0017]

[Effect of the idea]

In this invention, when the difference between suction pressure and discharge pressure decreases, the pressing force of the spring is increased. The tip of the blade is brought into contact with the outer circumferential surface of the rolling piston, so it is compressed. Even when the machine rotation speed decreases, the tip of the blade remains on the outer circumferential surface of the rolling piston. Therefore, due to this, there is a reduction in compression performance, the generation of impact noise, and Damage caused by this impact can be prevented. Additionally, the spring force of the spring can be reduced during normal compressor operation, reducing spring fatigue. This prevents damage caused by blades and abnormal wear of the blade tips, extending the life of the compressor. It is possible to increase the length and improve the reliability.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing one embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a second embodiment of the present invention.

FIG. 3 is a partial cross-sectional view showing a third embodiment of the present invention.

FIG. 4 is a partial cross-sectional view showing a fourth embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a conventional rotary compressor.

FIG. 6 is a sectional view taken along line AA in FIG. 5;

FIG. 7 is a partially enlarged view of FIG. 5;

FIG. 8 is an explanatory diagram showing the force acting on the blade.

[Explanation of symbols]

7 Cylinder block 21 slit 10 blades 12 Cylinder chamber 6 rolling piston 38 Spring 35 Pressure force variable means

Claims (1)

[Scope of utility model registration request] 1. A rolling piston whose tip rotates eccentrically within a cylinder chamber when a blade slidably fitted into a slit bored in a cylinder block is pushed by discharge pressure acting on its rear end surface. In a rotary compressor that slides on the outer peripheral surface of the rolling piston, a spring pushes the blade toward the outer peripheral surface of the rolling piston, and means for increasing the pressing force of the spring in accordance with a decrease in the difference between suction pressure and discharge pressure. A rotary compressor characterized by being equipped with.