JPH04143468A - Rotary balance adjusting device of wobble plate type compressor - Google Patents

Abstract

PURPOSE:To reduce the vibration caused by dislocation of the center of gravity from the rotational center by furnishing a counter-weight on the way of a communication path formed in a rotary member, and allowing the counter-weight to move in accordance with the size of the differential pressure between a crank chamber and a low pressure chamber in the direction of varying the distance from the driving shaft. CONSTITUTION:A rotary member 9 for transmitting the power is provided with an accommodation chamber 47 on the way of a transverse hole 40a, and this chamber 47 accommodates a counter-weight 48 which can only slide in the radial direction of the rotary member 9. The two ends of this counter-weight 48 are energized in opposite directions by springs 49, 50 arranged in the accommodation chamber 47, and the differential pressure with a low pressure chamber 28 increases with higher pressure in a crank chamber 4 to generate a motive as approaching the counter-weight 48 to the driving shaft 7. When the stroke of a piston 23, i.e., the capacity of compressor 1, enlarges, the differential pressure between the crank chamber 4 and low pressure chamber 28 decreases to move the counter-weight 48 apart from the drive shaft 7-when the capacity of the compressor 1 lessens, the counter-weight 48 approaches the driving shaft 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a wobble plate type variable displacement compressor used in the cooling cycle of an air conditioner, and more particularly to a device for adjusting the center of gravity of a rotating member.

(Prior Art) As shown in FIG. 5, a conventional wobble plate type variable capacity compressor includes a rotating member 9 for power transmission that rotates together with a drive shaft 7 in a crank chamber 4 inside the compressor.
The rotating member 9 is connected to the rotating member 9 via a link mechanism, and the swing angle can be varied via a hinge ball 10 fitted onto the drive shaft 7. It has a rotating member 11 for supporting the bull plate,
A wobble plate 19 for moving the piston 23 is attached to the rotating member 11 via a bearing so as to allow only rocking.

When the swing angle of the rotating member 11 for supporting the wobble plate is large, the stroke l of the piston 23 is large, and conversely, when the swing angle of the rotating member 11 for supporting the wobble plate is small, the stroke is large. The lid becomes smaller and this rotating member 1
The swing angle of 1 is controlled by a pressure control valve 32 that adjusts the pressure inside the crank chamber.

(Problem to be Solved by the Invention) However, in general, in this type of compressor &S, in order to place the center of gravity of the entire rotating member 9.11 on the axis of the drive boat 7, drive shaft 7
A balancer 9a is provided at a position opposite to the link mechanism, but even if such a fixed balancer 9a is provided, changes in the stroke of the piston 23, that is, changes in the rotation member 11 for supporting the wobble plate, may occur. It is difficult to always maintain the center of gravity on the axis of the drive shaft 7 even when the inclination angle changes.

According to the results of actually measuring the balance state of the rotating element with respect to the stroke amount (maximum stroke is 100%), as shown in Figure 3 (a), the side with the link mechanism (A) and the drive shaft 7 on the side opposite to the link mechanism (B
) increases almost linearly as the stroke amount increases, but the method of change is not the same, and when these are summed, the stroke amount increases as shown in Figure 3 (b). As the size increases, the rotating members 9, 11
The overall center of gravity shifted from the link mechanism side to the opposite side, making it impossible to maintain rotational balance throughout the entire stroke range.

For this reason, the center of gravity of the rotating member deviates from the axis of the drive shaft 7, causing vibrations in the compressor itself, especially when this compressor is used in an automobile air conditioner.
The disadvantage was that the compressor's vibration frequency matched the engine's idle speed, causing resonance and causing the vehicle floor to vibrate.

Therefore, in this invention, the above-mentioned drawbacks are solved, and the position of the center of gravity of the entire rotating member is maintained on the axis of the drive shaft by correcting the position of the entire rotating member according to the stroke amount. It is an object of the present invention to provide a rotational balance adjustment device for a wobble plate compressor that can prevent or reduce the amount of damage.

(Means for Solving the Problems) Therefore, the gist of the present invention is to include a rotating member that transmits rotation of a drive shaft in a crank chamber formed inside, and a rotating member that is swingably connected to the rotating member, and a rotating member that transmits rotation of a drive shaft. A rotating member is provided that supports a wobble plate connected to the piston via a rod and rotates with respect to the wobble plate, and the reciprocating motion of the piston compresses the fluid sucked into the low pressure chamber to create a high pressure chamber. a wobble that changes the swing angle of the wobble plate by transmitting the pressure in the crank chamber to a pressure control valve that IM-controls the communication state between the crank chamber and the low pressure chamber; In the plate type compressor, a communication path is provided to communicate the crank chamber and the low pressure chamber via the rotating member and the drive shaft, and a communication path from the drive shaft is provided in the middle of the communication path formed in the rotating member. A counterweight is provided that moves in a direction that changes the distance depending on the magnitude of the differential pressure between the crank chamber and the low pressure chamber.

(Function) Therefore, when the swing angle of the wobble plate is changed, the overall center of gravity of the rotating member is about to change, but the distance from the drive shaft of the counterweight is the pressure difference between the crank chamber and the low pressure chamber. Since the moment of inertia of the rotating member is changed by this counterweight, the deviation between the center of rotation and the center of gravity can be corrected and made to coincide with each other. Therefore, the above object can be achieved.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a wobble plate type variable displacement compressor l has a bottomed cylindrical housing 2, a cylinder block 3 is fixed to the open end of the housing 2, and one end of the housing 2 and the cylinder block 3 are connected to each other. The crank chamber 4 is surrounded by. Also, cylinder block 3
A cylinder head 5 is fixed to the other end with a valve plate 6 interposed therebetween.

The drive shaft 7 is rotatably supported via bearings 44.45 by cylindrical bearing members 42.43 fitted in the bottom center of the housing 2 and the recess 41 in the center of the cylinder block 3, respectively. A rotating member 9 for transmitting power, which is a thrust flange rotatably maintained in the housing 2 via a thrust bearing 8, is fixed to the drive shaft 7 within the crank chamber 4. In addition, the drive shaft 7
A rotary member 11 for supporting a wobble plate, which will be described later, is also rotatably and swingably supported within the crank chamber 4 via a hinge ball IO that is loosely fitted onto the outside. The supporting rotating member 11 is connected to the power transmitting rotating member 9 via a link mechanism.

In this link mechanism, the supporting rotating member 11 is inserted into the elongated hole 13 of the lug plate provided in the rotating member 9 for power transmission.
The pin 15 of the arm 14 provided at In particular, in this embodiment, the distance between the pin 15 and the drive shaft 7 is the maximum in the maximum inclination state, and the distance between the pin 15 and the drive shaft 7 is the minimum in the minimum inclination state. .

The shapes of these rotating members 9, 11 are determined in advance so that the center of gravity of the entire rotating members 9, 11 is located approximately on the axis of the drive shaft 7.

The hinge ball 10 is provided around the drive shaft 7,
A first member whose one end abuts the rotating member 9 for power transmission and the other end abuts the end of the hinge ball 10 facing the rotating member 9.
an elastic member 16, and a receiving plate 1 whose one end is provided on the drive shaft 7.
7, both sides of the hinge ball 10 are pressed by a second elastic member 18 whose other end is in contact with the end opposite to the receiving plate 17 of the hinge ball 10, allowing movement in the axial direction.

In addition, the wobble plate 19 is rotatably supported in the crank chamber via a radial and thrust bearing 20, 21 with respect to the rotating member 11 for supporting the wobble plate, and is supported with respect to the housing 2 via a slider 22. They are engaged and are only allowed to swing about the hinge ball 11 as a fulcrum.

In this wobble play) 19, a plurality of pistons 23 (for example, 7 pistons in a 7-cylinder compressor) are attached to the rod 2.
They are connected via 4. These pistons 23 are slidably inserted into cylinder bores 25 formed in the cylinder block 3, and a compression chamber is formed in a space surrounded by the end of the piston 22 and the cylinder bore 25. There is.

When the piston 23 is in the suction stroke, the suction valve 26 is opened and the compression chamber communicates with the low pressure chamber 28 in the cylinder bed 5 through the suction hole 27 formed in the valve plate 6. 23 is in the discharge stroke, the discharge valve 29 is opened and the low pressure chamber 28 is discharged in the cylinder head 5 through the discharge hole 30 also formed in the valve plate 6.
It communicates with a high pressure chamber 31 defined by. The above low pressure chamber 28
and the high pressure chamber 31 are connected to an inlet port and a discharge port (not shown) formed in the cylinder head 5, respectively.

Further, in the compressor l, a pressure control valve 32 constituting a capacity variable means is inserted and fixed into a control valve insertion hole 33 formed in the cylinder head 5.

The control valve insertion hole 33 is connected to the crank chamber 4 through the pressure control valve 32 through a communication hole 34 formed in the cylinder head 5, valve plate 6, and cylinder block 3, and the pressure control valve 32 and the control valve insertion hole In a portion surrounded by the inner surface of the hole 33, there is a suction chamber 3 that communicates with the low pressure chamber 28.
5 is formed.

The pressure control valve 32 includes a valve body 36 that adjusts the communication state between the suction chamber 35 and the crank chamber 4, a pressure responsive member 37 that moves the valve body 36 according to the pressure within the suction chamber 35, and the valve body. 36 is forcibly moved by the amount of electricity applied to the electromagnetic coil 38, and when the current flowing through the electromagnetic coil 38 increases and the magnetic force of the solenoid 39 increases, communication between the crank chamber 4 and the suction chamber 35 is established. A force is applied to the valve body 36 in the direction of constricting the valve body.

Furthermore, the rotating member 9 for power transmission and the drive shaft 7 are located on the opposite side of the link mechanism with respect to the drive shaft 7 in the radial direction, one end extends to the center of the drive shaft 7, and the other end rotates. A horizontal hole 40a facing the crank chamber 4 from the peripheral edge of the member 9 is formed, and in the axial direction of the drive shaft 7, one end is connected to the horizontal hole 40a, and the other end is connected to the cylinder block of three examples of the drive shaft 7. A vertical hole 40b is formed that extends to the support end and opens into a space 46 formed by being surrounded by the recess 41 of the cylinder block 3, the bearing member 42, and the end of the drive shaft 7. This space 46 communicates with the low pressure chamber 28 via a connecting hole 40c formed in the cylinder block 3 and pulp plate 6, and these horizontal holes 40a, vertical holes 40b, space 46, and connecting hole 40c communicate with the crank chamber. A communication path 40 is formed that communicates from the low pressure chamber 28 to the low pressure chamber 28 .

The rotating member 9 for power transmission has the horizontal hole 40a.
A storage chamber 47 is formed with an enlarged diameter in the middle, and a counterweight 48 that is only allowed to slide in the radial direction of the rotating member 9 is stored in this storage chamber 47. This counterweight 48 has both ends pressed in opposite directions by springs 49 and 50 disposed in the storage chamber 47, and the higher the pressure in the crank chamber 4, the lower the pressure in the low pressure chamber 47.
The pressure difference between the counterweight 48 and the drive shaft 8 increases, and a large force is applied to bring the counterweight 48 closer to the drive shaft 7.

Therefore, when the current flowing through the electromagnetic coil 38 is small, a large amount of refrigerant gas leaks from the crank chamber 4 to the suction chamber 35 (
As a result, the pressure in the crank chamber decreases and the force acting on the back surface of the piston 23 becomes smaller, causing the wobble plate 19 to rotate together with the rotating member 11 about the hinge ball 10 in a direction that increases the rocking angle. The stroke of the piston 23, that is, the capacity of the compressor 1 increases. In such a case, the difference between the pressure in the crank chamber 4 and the pressure in the low pressure chamber 28 is small, and the counterweight 48 moves away from the drive shaft 7.

On the other hand, when the current flowing through the electromagnetic coil 38 is large, there is less refrigerant gas leaking from the crank chamber 4 to the suction chamber 35, and so-called blow-by gas leaking from between the piston 23 and the cylinder bore 25 to the crank chamber 4 causes the crank chamber 4 pressure increases. As the pressure in the crank chamber 4 increases, the force acting on the back surface of the piston 23 increases, causing the wobble play (19) to occur on the rotating member 11.
At the same time, the piston 23 rotates about the hinge ball 10 as a fulcrum in a direction in which the swing angle becomes smaller, and the stroke of the piston 23, that is, the capacity of the compressor 1 becomes smaller.

In such a case, since the pressure inside the crank chamber 4 is high, the pressure difference between the crank chamber 4 and the low pressure chamber 28 becomes large.
The counterweight 48 approaches the drive shaft 7.

Therefore, at the maximum swing angle of the wobble plate 19, that is, when the counterweight 48 moves away from the drive shaft 7, the moment of inertia of the portion of the rotating member 9 on the opposite side of the link mechanism with respect to the drive shaft 7 is increased. Therefore, at the minimum swing angle of the wobble plate 19, that is, when the counterweight 48 is closest to the drive shaft 7, an increase in the moment of inertia of the portion opposite to the link mechanism can be suppressed. Therefore, this counterweight 48
The position of the center of gravity of the entire rotating member is determined by the movement of
As shown by the dotted line, the position can be corrected to be on or close to the axis of the drive shaft 7, and as a result, smooth rotation of the rotating members 9 and 11 can be realized, and vibrations of the compressor l can be suppressed. It can be suppressed.

(Effects of the Invention) As described above, according to the present invention, the crankshaft prevents the center of gravity of the entire rotating member from moving from the center of rotation due to changes in the stroke of the piston, that is, the swing angle of the wobble plate. This can be suppressed by adjusting the distance of the counterweight from the drive shaft using the pressure difference between the chamber and the low-pressure chamber, so that vibration can be prevented or reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a wobble plate compressor according to the present invention, Fig. 2 is a characteristic diagram showing the stroke of the piston and the balance state of rotating members, and Fig. 3 is a cross-sectional view showing a conventional wobble plate compressor. FIG. l... Wobble plate type compressor, 4... Crank chamber, 9.11... Rotating member, 19... Wobble plate, 23... Piston, 24... Rod, 28
...Low pressure chamber, 31...High pressure chamber, 32...Pressure control valve, 40...Communication path, 48...Counterweight.

Claims (1)

[Claims] A rotating member that transmits the rotation of a drive shaft and a wobble plate that is swingably connected to the rotating member and connected to the piston via a rod are supported in a crank chamber formed inside. and a rotary member that rotates with respect to the wobble plate, and the reciprocating motion of the piston compresses the fluid sucked from the low pressure chamber and sends it to the high pressure chamber, and the pressure in the crank chamber is changed between the crank chamber and the high pressure chamber. A wobble plate type compressor in which a swing angle of the wobble plate is varied by adjusting a communication state with a low pressure chamber with a pressure control valve, the crank chamber being connected to the crank chamber via the rotating member and the drive shaft. and a low pressure chamber, and a pressure difference between the crank chamber and the low pressure chamber is increased in a direction in which the distance from the drive shaft is changed in the middle of the communication path formed in the rotating member. A rotational balance adjustment device for a wobble plate type compressor, characterized in that it is provided with a counterweight that moves according to the rotation.