JPH09195957A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power loss of a scroll compressor by preventing excessive pressing force to be generated with the revolution of a moving scroll. SOLUTION: A movable scroll 7 and a balance weight 5 are so arranged as to be independently displaced in the radial direction of a rotary shaft 1 in relation to an eccentric part 8 according to the rotational movement of the rotary shaft 1. The moment of inertial of both sides 7, 5 around the rotational center of the rotary shaft 1 are equalized to each other, and a coil spring 12a for making elastic force act in the direction to opposite centrifugal force to act on the balance weight 5, and a coil spring for making elastic force act in the direction to opposite centrifugal force to act on the movable scroll 7 are provided. The centrifugal force of the both sides 7, 5 are canceled, and starting shock in starting is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor, which is suitable for use as a compressor for a vehicle air conditioner.

[0002]

2. Description of the Related Art As is well known, a scroll type compressor has a fixed scroll which has a spiral tooth portion and is fixed to a housing, and a tooth portion which is formed so as to mesh with the tooth portion of the fixed scroll. And a rotary shaft that revolves around the movable scroll. Then, the volume of the working chamber formed by the tooth portions of both scrolls is reduced along with the revolution movement of the orbiting scroll, thereby compressing the fluid such as the refrigerant. Therefore, in order to efficiently compress the fluid, it is necessary to sufficiently secure the airtightness of the working chamber.

As a structure for ensuring the airtightness of the working chamber, there is a structure in which a movable scroll and a balance weight are coupled so as to be displaceable in the radial direction of the rotating shaft. This is because the centrifugal force acting on the orbiting scroll along with the orbiting motion of the orbiting scroll causes the orbiting portion of the orbiting scroll to move outward in the orbital radius until it comes into contact with the teeth of the fixed scroll. The force is used to press the teeth of the movable scroll against the teeth of the fixed scroll (so-called driven crank mechanism).

However, since the movable scroll is displaceable in the radial direction of the rotating shaft, the centrifugal force acting on the movable scroll in addition to the compression reaction force acts between the teeth of both scrolls. As the revolution speed increases, the pressing force of the movable scroll teeth to press the fixed scroll teeth increases. If this pressing force increases excessively, the frictional resistance between the scroll tooth portions increases, which causes power loss, which rather reduces the efficiency of the scroll compressor.

Therefore, a balance weight is provided so that it is displaced and revolves integrally with the movable scroll, and the center of gravity is located on the side opposite to the center of gravity of the movable scroll with the rotary shaft interposed therebetween, and an excessive pressing force is applied. It's suppressed.

[0006]

However, in the scroll type compressor described in the above publication, the balance weight and the movable scroll are displaced integrally, so that the revolution radius of the movable scroll increases with the revolution movement of the movable scroll. Suddenly, the revolution radius of the balance weight becomes smaller. That is, since the moment of inertia (rotational inertia) of the movable scroll increases and the moment of inertia of the balance weight decreases with the revolution of the movable scroll, the difference between the centrifugal force acting on the movable scroll and the centrifugal force acting on the balance weight is , It increases with the revolution of the movable scroll.

Further, a means for setting the inertia moment of the balance weight to be larger than the inertia moment of the movable scroll in consideration of the maximum displacement amount of the revolution radius of the movable scroll is conceivable. This means acts on the balance weight. Since the centrifugal force becomes larger than the centrifugal force acting on the movable scroll, the movable scroll cannot be displaced outward in the radial direction of the rotating shaft even if the movable scroll revolves. That is, the tooth portion of the movable scroll cannot come into contact with the tooth portion of the fixed scroll, and as a result, the airtightness of the working chamber cannot be ensured.

Generally, in a scroll type compressor,
Since the moment of inertia of the movable scroll is set to be larger than the moment of inertia of the balance weight, the difference between the centrifugal force of the movable scroll and the centrifugal force acting on the balance weight increases in proportion to the displacement. Therefore, the scroll compressor described in the above publication cannot prevent an excessive pressing force that accompanies the revolution movement of the movable scroll.

In view of the above points, the present invention has an object to prevent an excessive pressing force due to the revolution of the orbiting scroll and reduce the power loss of the scroll compressor.

[0010]

The present invention uses the following technical means in order to achieve the above object. In the invention according to claim 1, the movable scroll (7) and the balance weight (5) are independent of each other with respect to the eccentric portion (8) in response to the rotational movement of the rotational shaft (1). It is configured to be displaceable in the radial direction of (1). Then, when the relative displacement between the movable scroll (7) and the balance weight (5) becomes maximum, the moment of inertia of the movable scroll (7) around the rotation center of the rotation axis (1) and the rotation axis (1). Is equal to the moment of inertia of the balance weight (5) about the center of rotation of.

According to a second aspect of the present invention, in the scroll compressor according to the first aspect, the movable scroll (7) is provided with a rotating shaft (1) with respect to the eccentric portion (8) via a bush (6). ) Is displaceable in the radial direction.
And the bush (6) and the balance weight (5)
Each of the bushes (6) and the balance weight (5) has contact surfaces (6d, 10a) which are in contact with each other and regulate the maximum relative displacement between the bush (6) and the balance weight (5). It is characterized by

According to a third aspect of the present invention, in the scroll compressor according to the first or second aspect, the elastic force acts in a direction opposite to the centrifugal force (Fb) acting on the balance weight (5). It is characterized by having one elastic member (12a) and a second elastic member (12b) for exerting an elastic force in a direction opposite to the centrifugal force (Fs) acting on the movable scroll (7).

According to a fourth aspect of the present invention, in the scroll compressor according to the first or second aspect, the elastic force is applied so as to oppose the centrifugal force (Fb) acting on the balance weight (5). It has a member (33), a magnet (37) arranged on one side of the movable scroll (7) and the balance weight (5), and a magnetic body part (5a) arranged on the other side. And the magnet (3
7) and the magnetic body part (5a) are characterized in that they are arranged so that an attractive force acts in the radial direction of the rotating shaft (1).

According to a fifth aspect of the present invention, in the scroll type compressor according to the first or second aspect, the elastic force for exerting an elastic force in a direction opposite to the centrifugal force (Fb) acting on the balance weight (5). It is provided between the member (12a) and the movable scroll (7) and the balance weight (5), and is interlocked with the displacement of the balance weight (5) in the direction of decreasing the revolution radius of the balance weight (5). , A cam mechanism (5) for displacing the orbiting scroll (7) in such a direction as to reduce the revolution radius of the orbiting scroll (7).
b, 38, 39).

Next, the function and effect will be described. According to the invention described in claims 1 to 5, the movable scroll (7) and the balance weight (5) are provided in accordance with the rotational movement of the rotary shaft (1).
The rotating shaft (1) independent of each other with respect to the eccentric part (8)
Since it is displaceable in the radial direction of the movable scroll (7)
And the moment of inertia of the movable scroll (7) around the rotation center of the rotation axis (1) and the rotation center of the rotation axis (1) when the relative displacement between the balance weight (5) becomes maximum. The moment of inertia of the balance weight (5) can be made equal.

Therefore, the centrifugal force (Fs) acting on the orbiting scroll (7) and the centrifugal force (Fb) acting on the balance weight (5) are canceled out, so that both (5, 7) will be described later. When the maximum relative displacement occurs and the tooth portions of both scrolls 7 and 18 come into contact with each other, excessive scrolls (7, 1
It is possible to prevent the pressing force between the tooth portions in 8). Therefore, it is possible to reduce the power loss of the compressor due to the orbital movement of the movable scroll (7).

According to the third aspect of the invention, the movable scroll (7) and the first elastic member (12a) for exerting an elastic force in a direction opposing the centrifugal force (Fb) acting on the balance weight (5). ) And a second elastic member (12b) that applies an elastic force in a direction opposite to the centrifugal force (Fs) that acts on each of the elastic members (12a, 12a, The balance weight (5) and the orbiting scroll (7) are located closer to the center of rotation of the rotating shaft (1) than the state after starting by 12b). Therefore, the moments of inertia of the balance weight (5) and the orbiting scroll (7) are equal to each other (5, 7).
Since both are smaller than the state after starting, the starting shock at the moment when the scroll compressor is started can be reduced.

Before the scroll type compressor is activated, the movable scroll (7) is located closer to the center of rotation of the rotary shaft (1) than the state after activation, so both scrolls (7, 8). ) There is a gap between the teeth. Therefore, at the moment of starting the scroll compressor,
Since the compression reaction force becomes small, the starting shock at the moment when the scroll compressor is started can be further reduced.

According to the invention described in claim 4, an elastic member (33) for exerting an elastic force in a direction opposite to the centrifugal force (Fb) acting on the balance weight (5), the movable scroll (7) and The balance weight (5) has a magnet (37) arranged on one side and a magnetic body part (5a) arranged on the other side. Since the magnet (37) and the magnetic body portion (5a) are arranged so that the attraction force acts in the radial direction of the rotating shaft (1), the balance weight (5) and the movable scroll (7) are , Both are located closer to the center of rotation of the rotary shaft (1) than the state after activation. Therefore, the same effect as the third aspect can be obtained.

According to the fifth aspect of the invention, the elastic member (12a) for exerting an elastic force in a direction opposite to the centrifugal force (Fb) acting on the balance weight (5), the movable scroll (7) and The movable scroll (7) is provided between the balance weights (5) and interlocks with the displacement of the balance weights (5) in the direction of decreasing the revolution radius of the balance weights (5).
Of the cam mechanism (5
b, 38, 39), the balance weight (5) and the orbiting scroll (7) are both located closer to the center of rotation of the rotating shaft (1) than the state after starting.
Therefore, the same effect as the third aspect can be obtained.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; (First Embodiment) FIG. 1 is a sectional view showing a detailed structure of a scroll type compressor (hereinafter, simply referred to as a compressor) according to the present embodiment. Reference numeral 3 denotes a front housing. The bearing 2 is press-fitted into the rotating shaft 1
Are rotatably supported. The rotating shaft 1 is configured to rotate by receiving a driving force from a traveling engine via an electromagnetic clutch (not shown) connected to one end side. The rotating shaft 1 may be directly driven by an electric motor or the like without an electromagnetic clutch.

A movable scroll 7 is composed of a spiral tooth portion 7b and an end plate portion 7a. A boss portion 7c is formed substantially at the center of the end plate portion 7a. The boss portion 7c has a boss portion 7c. The bearing 17 is press-fitted. The bearing 17 is a shell-type (type without inner ring) needle roller bearing (needle bearing) including an outer ring and rolling elements arranged along the inner wall surface of the outer ring.

A bush 6 is inserted into the bearing 17, and a drive key 8 (eccentric portion) forming a crank mechanism provided on the rotary shaft 1 is inserted into a drive groove 6b formed in the bush 6. ing. The drive key 8 is provided at a position eccentric from the rotation center of the rotary shaft 1 by a predetermined amount, and the movable scroll 7 rotates by receiving a driving force from the drive key 8 with the eccentric amount of the drive key 8 as the revolution radius. It revolves around the center of rotation of the shaft 1.

Reference numeral 5 denotes a balance weight for canceling out the centrifugal force of the movable scroll 7. The position of the center of gravity of the balance weight 5 is the position of the center of gravity of the movable scroll with the rotary shaft 1 interposed in order to cancel out the centrifugal force of the movable scroll 7. And is located on the opposite side. Then, the balance weight 5 also obtains a driving force from the driving key 8 similarly to the movable scroll 7 to obtain the rotation shaft 1.
Orbits around the center of rotation, and its angular velocity is equal to that of the orbiting scroll. The balance weight 5 and the movable scroll 7 are both configured to be displaceable in the radial direction of the rotary shaft 1 independently of the drive key 8 in accordance with the rotational movement of the rotary shaft 1. (Hereinafter, referred to as a driven crank mechanism.) Will be described later.

Reference numeral 16 is a lip seal that seals the gap between the rotary shaft 1 and the front housing 3 and closes the refrigerant (and the lubricating oil mixed with the refrigerant) inside the compressor from leaking out of the compressor. It is fixed in the front housing 3 by a circlip (retaining ring) not shown. A fixed scroll 18 includes a spiral tooth portion 18b and an end plate portion 18a.
8 is fixed to the front housing 8 by a bolt (not shown) such that its tooth portion 18b meshes with the tooth portion 7b of the movable scroll 7.

Then, the tooth portions 7 of both scrolls 7 and 18
A plurality of working chambers 24 in which the refrigerant is sucked and compressed are formed by b and 18b and the end plate portions 7a and 18a. The working chamber 24 is kept airtight by a tip seal (not shown) attached to the tips of the teeth 7b and 18b. Reference numerals 13 and 14 are rotation preventing pins having the same diameter. The rotation preventing pin 13 is inserted into a plurality of blind holes 3b formed in the end surface 3a of the front housing 3, and the rotation preventing pin 14 is a plurality of blind holes 7d formed in the end plate portion 7a of the movable scroll 7. Has been inserted into. Then, one end sides of the both rotation preventing pins 13 and 14 are inserted into the ring 15 to form a rotation preventing mechanism for preventing rotation of the movable scroll 7 around the well-known bearing 17. By the way, the inner diameter of the ring 15 is equal to that of the movable scroll 7.
Is approximately equal to the sum of the radius of revolution and the diameter of the pin for preventing rotation.

Further, the end plate portion 18a of the fixed scroll 18
A discharge port 27 for discharging the compressed refrigerant from the working chamber 24 is formed in a substantially central portion of the above, and the refrigerant flows back into the working chamber 24 on the end plate portion 18a side of the discharge port 27. The discharge valve 19 for preventing the discharge valve 19 and the valve stopper 20 for restricting the maximum opening degree of the discharge valve 19 are fixed to the end plate portion 1 by the bolt 21.
It is fixed to 8a.

The end plate portion 18 of the fixed scroll 18
A rear housing 23 is attached to the fixed scroll 18 by a bolt (not shown) at a, and a discharge chamber for smoothing pressure pulsation of the refrigerant discharged from the discharge port 19 by the rear housing 23 and the end plate portion 18a. Two
2 are formed. The refrigerant that has been smoothed in the discharge chamber 22 is discharged from the discharge port 26 toward the condenser of the air conditioner (not shown) from the compressor. Also,
The refrigerant flowing out of the evaporator of the air conditioner (not shown) is
The suction chamber is sucked from a suction port (not shown) formed in the front housing 3, passes through a gap between the bearing 2 and the end plate portion 7a of the movable scroll 7, and is sucked from a suction chamber formed at a spiral end portion of the tooth portion 7b. Inhaled into.

Next, the driven cranking mechanism of the balance weight 5 and the movable scroll 7 will be described in detail. FIG.
3 is an exploded perspective view of the rotary shaft 1, the balance weight 5, the bush 6, the movable scroll 7, and the like. The drive key 8 provided on the rotary shaft 1 is parallel to both the radial direction and the axial direction of the rotary shaft 1. A two-face width 8a is formed, and two parallel flat portions 6c are formed in the drive groove 6b of the bush 6 so as to fit into the two-face width 8a. Then, the dimension L of the portion of the drive groove 6b parallel to the plane portion 6c
Is the dimension l of the portion of the drive key 8 parallel to the width across flats 8a.
The bush 6 (movable scroll 7) can be displaced in the radial direction of the rotary shaft 1 by the difference between the dimension L of the drive groove 6b and the dimension l of the drive key 8.

Incidentally, the width across flats 8a of the drive key 8 is as shown in FIG.
As shown in FIG. 6, the centrifugal force direction of the movable crawl 7 intersects at a predetermined angle, and as is well known, the component of the compression reaction force acting on the movable crawl 7 in the direction of the two-face width 8a. Acts as a pressing force between the tooth portions of both scrolls 7 and 18. Further, on one end side of the bush 6, a slide portion 6a in which the bush 6 has a rectangular radial cross section is formed.
On the other hand, the balance weight 5 is formed with a slide groove 10 into which the slide portion 6a is fitted. The balance weight 5 and the bush 6 are relatively displaceable relative to each other in a state where the slide portion 6a is fitted in the slide groove 10, and the maximum relative displacement amount between the two is the outer wall surface of the slide portion 6a. Of the inner wall surfaces of the slide groove 10, the end surface 6d on the radially outer side of the rotary shaft 1 is the rotary shaft 1
Is regulated by being in contact with the end surface 10a on the radially outer side.

Pins 9a and 9b are formed on the rotary shaft 1, while the balance weight 5 has the pins 9a and 9b slid on the balance weight 5, as shown in FIG. Grooves 11a, 1 so that they can move
1b is formed. A coil spring 12a is arranged between the pin 9a and the balance weight 5, and the coil spring 12a allows the balance weight 5 to be formed.
The elastic force acting on the balance weight 5 counteracts the centrifugal force acting on the balance weight 5. On the other hand, a coil spring 12b is arranged between the pin 9b and the sliding portion 6a of the bush 6, and the coil spring 12b causes the movable scroll 7 to generate a centrifugal force acting on the movable scroll 7 via the bush 6. Elastic force acts in the opposite direction. In this embodiment, the coil spring is used as the elastic member, but an elastic material such as rubber may be used.

The spring constants of the coil springs 12a and 12b are selected so that the balance weight 5 and the movable scroll 7 around the center of rotation of the rotary shaft 1 are displaced while maintaining the same moment of inertia. And the end surface 6d of the slide portion 6a is in contact with the end surface 10a of the slide groove 10 (the state in which the relative displacement is maximum).
Also in, the moments of inertia of both 5 and 7 are equal.

Next, the operation of this embodiment will be described with reference to FIG. Note that FIG. 3 shows a cross-sectional view taken along the line AA of FIG.
(A) shows the state before the compressor starts, and (B) shows the state after the compressor starts. Coil spring 12
Since a and 12b apply elastic force in the direction opposite to the centrifugal force, respectively, before activation, (a) of FIG.
Balance weight 5 and bush 6 as shown in FIG.
The (movable scroll 7) is located closer to the center of the rotary shaft 1 than the position after activation. In the present embodiment, the balance weight is adjusted so that the moment of inertia of the balance weight 5 around the rotation center of the rotating shaft 1 and the moment of inertia of the movable scroll 7 around the rotation center of the rotating shaft 1 are equal even in the pre-start state. 5 and the position of the center of gravity are set.

When the compressor is activated, centrifugal forces Fb and Fs act on the balance weight 5 and the movable scroll 7 as shown in FIG. 3 (B), which opposes the elastic forces of the coil springs 12a and 12b, respectively. And is displaced outward in the radial direction of the rotary shaft 1. At this time, since the center of gravity of the balance weight 5 is located on the opposite side of the center of gravity of the movable scroll with the rotary shaft 1 in between, the balance weight 5 and the movable scroll 7 are not displaced relative to each other. It is displaced so that it becomes larger. Then, the relative displacement between the both 5 and 7 increases until the end surface 6d of the slide portion 6a contacts the end surface 10a of the slide groove 10. When the maximum relative displacement is reached, the tooth portions of both scrolls 7 and 18 are in contact with each other.

Incidentally, the maximum relative displacement between both 5 and 7 is
Although it is regulated by the slide portion 6a and the slide groove 10, the displacement of the both 5, 7 with respect to the drive key 8 is not regulated, so that even if the maximum relative displacement is reached, both 5, 7 Can be displaced in the radial direction of the rotary shaft 1 with respect to the drive key 8. Therefore, as described above, depending on the compression reaction force acting on the movable scroll 7, both scrolls 7,
A pressing force acts between the 18 tooth portions.

Next, the features of this embodiment will be described. Since the balance weight 5 and the movable scroll 7 are displaced outward in the radial direction of the rotary shaft 1 so that their relative displacements increase with the activation of the compressor (the orbital radii of both 5 and 7 increase), Even when the relative displacement between 5 and 7 becomes maximum (when the tooth portions of both scrolls 7 and 18 are in contact with each other), the inertia moments of both 5 and 7 around the rotation axis 1 can be made equal. Therefore, when the tooth portions of the scrolls 7 and 18 are in contact with each other, the centrifugal force Fb acting on the balance weight 5 and the centrifugal force Fs acting on the movable scroll 7 can be offset. In the end,
Since it is possible to prevent the pressing force between the tooth portions of both scrolls 7 and 18 from increasing excessively, it is possible to reduce the power loss of the compressor.

Before the compressor is started, the balance weight 5 and the movable scroll 7 are both located closer to the center of rotation of the rotary shaft 1 than the state after the start.
The moment of inertia of both 5 and 7 becomes smaller than that after the start. Therefore, the starting shock at the moment when the compressor is started can be reduced. Before the compressor is started, the movable scroll 7 is located closer to the center of rotation of the rotary shaft 1 than in the state after the start of the compressor. Therefore, a gap is generated between the teeth of the scrolls 7 and 8. There is. Therefore,
Since the compression reaction force becomes small at the moment when the compressor is started, the start shock at the moment when the compressor is started can be further reduced. It should be noted that the movable scroll 7 is displaced toward the radial outside of the rotary shaft 1 due to centrifugal force during several revolutions after starting, and the tooth portions of both scrolls 7 and 18 come into contact with each other, so that the working chamber 24 is not hermetically sealed. Power loss due to is negligible.

Since the balance weights 5 and the movable scrolls 7 have the same moment of inertia about the center of rotation of the rotary shaft 1, the centrifugal forces of the two 5 and 7 are always balanced. Therefore, an unnecessary load does not act on the rotary shaft 1 and the bearing 2, so that the durability of the compressor is improved. By the way, in this embodiment, the movable scroll 7 and the balance weight 5 are revolved by obtaining the driving force from the drive key 8, but the drive key 8 is abolished and the balance weight 5 is driven by the pins 9a and 9b. The movable scroll 7 may be driven by fitting the slide groove 10 and the slide portion 6a.

(Second Embodiment) In the above-described embodiment, the driven crank mechanism which slides in the radial direction of the rotary shaft 1 is used, but in the present embodiment, instead of the drive key 8 which will be described later, a drive pin 28 is provided. A driven crank mechanism that allows the movable scroll 7 to be displaced in the radial direction of the rotating shaft 1 by swinging is used.

FIG. 4 shows an axial cross section of the compressor according to this embodiment. The driven crank mechanism according to this embodiment is provided on the bush 6, the swing pin 29 provided on the bush 6, and the rotary shaft 1. The drive pin 28 and the guide pin 32 provided on the balance weight 5 are provided. Specifically, as shown in FIG.
The drive pin 28 is formed in a columnar shape, and the drive pin 28 is inserted into a deformed groove 30 formed in the balance weight 5. The portion of the deformed groove 30 into which the drive pin 28 is inserted is formed in an elliptic shape with the diameter of the drive pin 28 as the short diameter.

A not-shown through hole is formed in the bush 6 at a position eccentric from the center of the bush 6, and the drive pin 28 is inserted into this through hole. Therefore, the bush 6 (movable scroll 7) is
It can swing around this drive pin 28. Also,
The center of the through hole has a centrifugal force F acting on the movable scroll 7.
It is deviated from the line of action of s, and the swing pin 29 is provided on the line of action of the centrifugal force Fs when viewed from the center of this through hole. Therefore, the bush 6 (movable scroll 7) swings in the centrifugal force Fs side direction.

The swing pin 29 is the drive pin 2
The swing pin 29 is inserted into the irregular groove 30 on the rotation center side of the rotary shaft 1 from the position where 8 is inserted.
The diameter is smaller than that of the drive pin 28. The balance weight 5 is provided in the irregular groove 30 at the portion where the swing pin 29 is inserted.
The centrifugal force Fb acting on
A tapered wall surface 30a is formed whose groove width expands in the direction from the drive pin 28 toward the swing pin 29.

The swing pin 29 is displaced in the centrifugal force Fs side direction along the tapered wall surface 30a when the compressor is activated, and the balance weight 5 and the movable scroll 7 are moved.
The maximum relative displacement therebetween is restricted by contacting the inner wall surface portion 30b of the irregular groove 30. A guide pin 32 is formed on the end surface of the balance weight 5 on the rotary shaft 1 side, while a guide groove 31 into which the guide pin 32 is fitted is formed on the rotary shaft 1. This guide groove 3
The longitudinal direction of 1 corresponds to the radial direction of the rotary shaft 1, and thereby the balance weight 5 is restricted so as to be displaced in the radial direction of the rotary shaft 1.

Then, as shown in FIG. 4, the guide pin 3
2 and a pin 1a provided on the rotary shaft 1, a coil spring 33 is arranged.
An elastic force is applied to the balance weight 5 in a direction opposite to the centrifugal force Fb acting on the balance weight 5.
An elastic material such as rubber may be used instead of the coil spring 33.

The balance weight 5, the movable scroll 7 and the coil spring 33 are set so that the moments of inertia of the balance weight 5 and the movable scroll 7 around the rotation center of the rotary shaft 1 are always equal. Next, the operation of this embodiment and its features will be described. Since the coil spring 33 exerts an elastic force on the balance weight 5 in a direction that opposes the centrifugal force Fb acting on the balance weight 5, the balance weight 5 is, as shown in FIG. 5, before starting the compressor. , Rotating shaft 1 after starting
It is located on the rotation center side.

When the balance weight 5 is displaced from the state shown in FIG. 6A to the state shown in FIG. 5A, the swing pin 29 is displaced along the tapered wall surface 30a, so that it acts on the movable scroll 7. Displacement from the centrifugal force Fs side to the drive pin 28 side (from left to right in FIG. 5). As a result, the movable scroll 7 is displaced toward the center of rotation of the rotary shaft 1.

Therefore, as in the above embodiment, the starting shock at the time of starting the compressor can be reduced. Then, when the compressor is activated, the balance weight 5 is displaced against the elastic force of the coil spring 33 toward the radially outer side of the rotary shaft 1. Further, since the drive pin 28 is not located on the line of action of the centrifugal force Fs acting on the movable scroll 7, the movable scroll 7 swings around the drive pin 28 in the centrifugal force Fs side direction. Therefore, the movable scroll 7 is also displaced radially outward of the rotary shaft 1.

At this time, the relative displacement between the balance weight 5 and the movable scroll 7 is regulated by the contact between the swing pin 29 and the inner wall surface portion 30b of the deformed groove 30 as described above, and acts on the balance weight 5. The centrifugal force Fb and the centrifugal force Fs acting on the movable scroll 7 cancel each other out. (Third Embodiment) In the second embodiment, the swing pin 29 is used.
Is displaced along the tapered wall surface 30a of the irregular groove 30, but in the present embodiment, the swing pin 29 is displaced via the rod 36 extending from the guide pin 32.

As shown in FIG. 7, a communication hole 35, which communicates with the guide groove 31 from the swing hole 34 into which the swing pin 29 formed in the rotary shaft 1 is fitted, is formed.
A rod 36 is arranged inside the member 5 so as to contact the guide pin 32 and the swing pin 29. This rod 36
Of these, a portion where the rod 36 and the swing pin 29 are in contact with each other has a tapered surface similar to the tapered wall surface 30a.

Therefore, this embodiment can obtain the same operation as that of the second embodiment, and the same effect as that of the second embodiment. (Fourth Embodiment) In the present embodiment, the coil spring 12b that causes the elastic force to act on the movable scroll 7 in the direction opposite to the centrifugal force Fs acting on the movable scroll 7 in the first embodiment is eliminated. .

That is, as shown in FIG. 10, the permanent magnet 37 is arranged on the boss portion 7c of the movable scroll 7, and the portion 5a of the balance weight 5 facing the permanent magnet 37 is made of a magnetic material such as iron. It is a thing. As a result, a suction force acts between the balance weight 5 and the movable scroll 7 in the radial direction of the rotating shaft 1. A permanent magnet may be arranged on the balance weight 5 and the boss portion may be made of a magnetic material such as iron.

According to this embodiment, before starting the compressor,
The balance weight 5 is located on the rotation center side of the rotary shaft 1 by the coil spring 12a as in the first embodiment.
Therefore, since the permanent magnet 37 approaches the portion 5a, the movable scroll 7 is displaced toward the center of rotation of the rotary shaft 1 by the attraction force acting between the permanent magnet 37 and the portion 5a. Then, when the compression is activated, the balance weight 5 is displaced toward the radially outer side of the rotary shaft 1 by the centrifugal force Fb acting on the balance weight 5, and the movable scroll 7 is also moved by the centrifugal force Fs acting on the movable scroll 7. It displaces toward the radial outside of the rotating shaft 1 against the attractive force acting between the permanent magnet 37 and the portion 5a.

Therefore, this embodiment operates in the same manner as the first embodiment, so that the same effect as in the first embodiment can be obtained. (Fifth Embodiment) In the fifth embodiment as well, the coil spring 12b that causes the elastic force to act on the movable scroll 7 in the direction opposite to the centrifugal force Fs acting on the movable scroll 7 in the first embodiment is eliminated. .

That is, instead of the coil spring 12b, as shown in FIG. 11, a cam mechanism including a taper projection 5b provided on the balance weight 5 and a taper pin 38 which is displaced along the taper surface of the taper projection 5b is used. It is provided. Specifically, as shown in FIG. 12, a taper protrusion 5b is formed on the end surface 10a side, which is formed with a taper surface 5c that is farther away from the movable scroll 7 as it goes radially outward from the rotation center side of the rotary shaft 1. Has been formed. And
The taper pin 38 is provided on the rotating shaft 1 and is provided on the pin holding portion 3.
9, and the pin holding portion 39 allows the tapered pin 3
The radial displacement of the rotary shaft 1 of 8 is regulated.

Further, the taper pin 38 has taper surfaces 38a and 38b formed at both axial ends of the rotary shaft 1 in a state of being inserted into the pin holding portion 39. And the tapered surface 3
8a is formed so as to be closer to the movable scroll 7 as going radially outward from the rotation center side of the rotary shaft 1 along the taper surface 5c of the taper protrusion 5b, and the taper surface 38b is
It is formed so as to move away from the movable scroll 7 as it goes radially outward from the rotation center side of the rotating shaft 1. Further, the taper surface 38b of the taper pin 38 is, as shown in FIG.
Tapered surface 7 formed on boss portion 7c of movable scroll 7
It touches d.

Before the compressor is started, the taper protrusion 5b has the rotating shaft 1 as shown in FIG. 13 (A).
Is displaced toward the outside of the diameter of. Therefore, the pin holder 3
The taper pin 38 whose radial displacement of the rotary shaft 1 is restricted by 9 is displaced toward the movable scroll 7 side (front side of the drawing), so that the movable scroll 7 moves along the tapered surface 38b (7d) about the rotation center of the rotary shaft 1. Displace to the side.

After the compressor is activated, the centrifugal force Fb acting on the balance weight 5 causes the radial weight of the rotary shaft 1 to be displaced outward. As a result, the tapered protrusion 5b is displaced toward the center of rotation of the rotary shaft 1, as shown in FIG. Therefore, since the taper pin 38 can be displaced to the side opposite to the movable scroll 7, the movable scroll 7
Is displaced radially outward of the rotary shaft 1 by the centrifugal force Fs acting on the movable scroll 7.

Therefore, the present embodiment operates in the same manner as the first embodiment, and the same effect as that of the first embodiment can be obtained. Incidentally, in the second to fifth embodiments, the elastic force of the coil spring is applied to the balance weight 5 to follow the displacement of the balance weight 5 to displace the movable scroll 7. However, the elastic force of the coil spring is applied to the movable scroll 7. The present invention can be carried out even when the balance weight 5 is displaced by acting on the displacement of the movable scroll 7 by acting on.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a scroll compressor according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a driven crank mechanism according to the first embodiment.

FIG. 3 is an explanatory diagram (sectional view taken along the line AA in FIG. 1) for explaining the operation of the first embodiment.

FIG. 4 is an axial sectional view of a scroll compressor according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a state before starting the compressor according to the second embodiment, and FIG. 5A is a sectional view taken along line CC of FIG.
(B) is a BB sectional view of FIG. 4.

FIG. 6 is an explanatory diagram showing a state after the compressor according to the second embodiment has been started, and (A) is a sectional view taken along line CC of FIG. 4;
(B) is a BB sectional view of FIG. 4.

FIG. 7 is an axial sectional view of a scroll compressor according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a state before the compressor is started according to the third embodiment, FIG. 8A is a sectional view taken along line CC of FIG.
(B) is a DD sectional view of FIG. 4.

FIG. 9 is an explanatory diagram showing a state after the compressor according to the third embodiment has been started, and (A) is a sectional view taken along line CC of FIG. 7;
(B) is a DD sectional view of FIG. 4.

FIG. 10 is an axial sectional view of a scroll compressor according to a fourth embodiment of the present invention.

FIG. 11 is an axial sectional view of a scroll compressor according to a fifth embodiment of the present invention.

FIG. 12 is an exploded perspective view of a driven crank mechanism according to a fifth embodiment.

FIG. 13 is an explanatory diagram (F-F cross-sectional view of FIG. 12) for explaining the operation of the fifth embodiment.

[Explanation of symbols]

1 ... Rotary shaft, 2 ... Bearing, 3 ... Front housing, 5 ...
Balance weight, 6 ... bush, 6a ... slide part,
6b ... Drive groove, 7 ... Movable scroll, 8 ... Drive key (eccentric part), 9a, 9b ... Pin, 10 ... Slide groove, 11
a, 11b ... Groove, 12a, 12b ... Coil spring.

Claims (5)

[Claims] 1. A housing (3), a rotating shaft (1) rotatably arranged in the housing (3), and an eccentric portion provided at a position eccentric from a rotation center of the rotating shaft (1). (8) and a movable scroll (7) having a spiral tooth portion (7b) and revolving around the rotation center of the rotation shaft (1) by obtaining a driving force from the eccentric portion (8), The movable scroll (7) has a tooth portion (18b) that meshes with the tooth portion (7b) and is fixed to the housing (3) and a fixed scroll (18) sandwiching the rotating shaft (1). A center of gravity is located on the side opposite to the center of gravity of the scroll (7), and a balance weight (5) is provided which revolves around the rotation center of the rotation shaft (1) by receiving a driving force from the eccentric portion (8). , The movable scroll (7) and the balance weight (5) Is capable of being displaced in the radial direction of the rotating shaft (1) independently of each other with respect to the eccentric part (8) according to the rotational movement of the rotating shaft (1), and the movable scroll (7). And the moment of inertia of the movable scroll (7) around the rotation center of the rotation shaft (1) and the rotation center of the rotation shaft (1) when the relative displacement between the balance weights (5) becomes maximum. A scroll type compressor characterized in that the moment of inertia of the balance weights (5) around it is equal. 2. A bush (6), which is interposed between the movable scroll (7) and the eccentric part (8) and supports the movable scroll (7), the movable scroll (7) comprises: It is displaceable in the radial direction of the rotating shaft (1) with respect to the eccentric portion (8) via the bush (6), and each of the bush (6) and the balance weight (5) is , The bush (6) and the balance weight (5) are in contact with each other to form contact surfaces (6d, 10a) for restricting the maximum relative displacement between the bush (6) and the balance weight (5). The scroll compressor according to claim 1, wherein the scroll compressor is provided. 3. A first elastic member (12a) for exerting an elastic force in a direction opposite to a centrifugal force (Fb) acting on the balance weight (5), and a centrifugal force (acting on the movable scroll (7) ( Fs) second elastic member (12) that applies an elastic force in a direction opposite to
The scroll compressor according to claim 1 or 2, further comprising b). 4. An elastic member (33) for exerting an elastic force in a direction opposing a centrifugal force (Fb) acting on the balance weight (5), the movable scroll (7) and the balance weight (5). It has a magnet (37) arranged on one side and a magnetic body part (5a) arranged on the other side, and the magnet (37) and the magnetic body part (5a) are the rotary shaft ( 3. The scroll compressor according to claim 1, wherein the scroll compressor is arranged so that suction force acts in the radial direction of 1). 5. An elastic member (12a) for exerting an elastic force in a direction opposite to a centrifugal force (Fb) acting on the balance weight (5), the movable scroll (7) and the balance weight (5). The movable scroll (7) is revolved around the orbit of the movable scroll (7) by interlocking with the displacement of the balance weight (5) in the direction of reducing the orbital radius of the balance weight (5). The scroll compressor according to claim 1 or 2, further comprising a cam mechanism (5b, 38, 39) for displacing in a direction of decreasing a radius.