JPS631031Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a scroll compressor.

[Conventional technology]

This type of compressor consists of two scroll members each having a spiral body in the form of a single plate, which are meshed with each other with the angles of the spiral bodies shifted, so that one scroll member is fixed and the other is movable. The circular orbital motion of the movable scroll member moves the fluid pocket formed between both scroll members toward the center and reduces the volume, thereby compressing the fluid. When the movable scroll member moves in a circular orbit, a balance mechanism that corrects the unbalance caused by this and prevents abnormal vibration is essential, and this is achieved by installing a weight called a balance weight on the drive shaft of the movable scroll member. This is achieved by

This will be explained below with reference to the drawings.

FIG. 5 is a cross-sectional structural diagram of a conventional scroll compressor. In the figure, the compressor has a compressor housing 10 with a front end plate 11 and a cup-shaped part 12 mounted thereon.

The front end plate 11 is the housing 10
The main shaft 14 is rotatably supported in the through hole 111 via a ball bearing 13. Therefore, the axis of the main shaft 14 coincides with the central axis of the housing 10. The front end plate 11 has a sleeve portion 15 projecting forward so as to surround the outer periphery of the main shaft 14, and a shaft seal 16 is disposed within the sleeve portion 15. Sleeve part 1
An electromagnetic clutch device 17 is disposed on the outer periphery of the clutch 5. This electromagnetic clutch device transmits rotational motion from an external drive source to a pulley 171 via a V-belt (not shown), and further transmits rotational motion from the pulley 171 to the main shaft 14 by controlling energization to an excitation coil 172. control the transmission of The front end plate 11 is fixed with several bolts (not shown) so as to close the front end opening of the cup-shaped portion 12, and the joint surface between the two is sealed with an O-ring 18. are doing. Further, the sleeve portion 15 is also fixed onto the end surface of the front end plate 11 with bolts or the like (not shown), and the joint surface is sealed with an O-ring 19.

A fixed scroll member 20, a movable scroll member 21, a drive mechanism for the movable scroll member, and a rotation prevention mechanism 22 are disposed within the cup-shaped portion 12 whose opening is closed by the front end plate 11.

Here, the fixed scroll member 20 has a side plate 20
1, a spiral body 202 provided on one side of the spiral body 202, and a leg portion 203 provided on the side plate 201 on the opposite side of the spiral body 202. This fixed scroll member 20 is arranged such that the leg portion 203 is attached to the bottom portion 12 of the cup-shaped portion 12 from the outside of the cup-shaped portion 12.
The bottom part 1 is fixed by a bolt 23 that penetrates through the bottom part 1 and is screwed into the bolt 23.
21 is fixed on the inner wall. Furthermore, the side plate 201 of the fixed scroll member 20 seals between its outer peripheral surface and the inner wall surface of the cup-shaped portion 20 with an O-ring 24, thereby dividing the space inside the cup-shaped portion 12 into a suction chamber 25 and a discharge chamber 26. It is divided into moreover,
A communication hole 2 is provided in the center of the side plate 201 to communicate the sealed space formed between the scroll members with the discharge chamber 26.
04 is drilled.

The movable scroll member 21 includes a side plate 211 and a spiral body 212 provided on one side thereof. The movable scroll member 21 is meshed with the spiral body 212 of the fixed scroll member 20 so that the spiral body 202 has an angular deviation of 180°. Moreover, the movable scroll member 21 is
It is connected to a drive mechanism and a rotation prevention mechanism, which will be described later, and revolves around a circular orbit having a radius of Ror by the rotation of the main shaft 14, thereby performing the fluid compression operation described above.

Here, the radius Ror of the circular orbit is generally (pitch of the spiral body) - 2 × (wall thickness of the spiral body)
/2 is given. In addition, the movable scroll member 21
is arranged such that the spiral center of the spiral body 212 is separated from the spiral center of the spiral body 202 of the fixed scroll member 20 by a distance Ror. As a result, a line contact portion is formed between both spiral bodies, and this line contact portion moves toward the center along the surface of the spiral body. As a result, the fluid pocket moves toward the center of the spiral body while decreasing its volume.

In this way, the fluid flowing from the external fluid circuit into the suction chamber 25 in the housing 10 through the suction port provided on the outer periphery of the housing 10 is taken into the fluid pocket from the outer ends of both spiral bodies. The compressed fluid flows from the fluid pocket at the center of both spiral bodies to the discharge chamber 2 through the communication hole 204.
6 will be sent out. Furthermore, the discharge chamber 26 will flow to the external fluid circuit via a discharge port provided on the housing 10.

Next, the drive mechanism of the movable scroll member will be explained with reference to FIG. 6, which is an exploded perspective view thereof.

A large diameter portion 141 is provided at the inner end of the main shaft 14 passing through the through hole 111 of the front end plate 11.
This large diameter portion 141 is connected to the through hole 11.
It is supported by a ball bearing 13 disposed on the inner circumference of 1. Further, a drive pin 142 is provided on the tip end surface of the large diameter portion 141 at a position eccentric from the center so as to protrude in the axial direction.

On the other hand, the spiral body 2 of the movable scroll member 21
On the side plate 211 opposite to the surface having 12,
An annular boss 213 is formed. A thick disk-shaped or short-shaft shaped bush 27 is fitted into the boss 213 and rotatably supported via a needle bearing 28 . Butsuyu 27
has a balance weight 271 integrally extending in the radial direction, and has an eccentric hole 272 on the surface facing the large diameter portion 141 of the main shaft 14. The aforementioned drive pin 142 is fitted into the eccentric hole 272 via the needle bearing 29. As a result, the movable scroll member 21 is rotatably supported on the drive pin 142. Note that the movable scroll member 21
The movement in the rotational direction is prevented by a rotation prevention mechanism shown at 22 in FIG.

Next, the reason for using the bush 27 having the eccentric hole 272 will be explained below with reference to FIG.

As described above, when the fluid is compressed by the circular orbital movement of the movable scroll member 21, the reaction force acts on the spiral body 212, that is, the movable scroll member 21 in the tangential direction of the circular orbit. This force can be thought of as acting on the center of the bush O _C as shown by F _D in Figure 7. By the way, the bush 27 is connected to the drive pin 14.
2, so the drive pin 14
The moment of rotation around the center O _D of 2 is the force F _D
receive by. This moment is expressed as F D ·ε ₂ sin θ, where θ is the angle between the direction of force F _D and the line connecting O _C and O _D as shown _in FIG.
As a result, the movable scroll member 21 supported on the bush 27 receives a moment of rotation around the center O _D of the drive pin 142.
As a result, the whirlpool body 212 becomes the whirlpool body 202.
You will be forced to. This pressing force
If F _P , then F _P・ε ₂ cosθ=F _D・ε ₂ sinθ, so it is given by F _P =F _D・tanθ.

That is, when the movable scroll member 21 is driven using the bush 27 having the eccentric hole 272, both the spiral bodies 212 and 20 are moved by the reaction force of the fluid compression.
A pressing force at the two line contacts is automatically obtained, which ensures the sealing of the fluid pocket.

Furthermore, as mentioned above, the center of the eccentric bushing 27
Since O _C can rotate around the center O _D of the drive pin 142, for example, the spiral body 202 or 212
Even if the pitch of the spiral or the wall thickness of the spiral body changes due to dimensional errors, O _C , O _S
The distance can be changed. That is, as shown in Fig. 7, the O _C point can be moved to the points O _C ′ and O _C ″, for example, on an arc of radius ε ₂ centered on O _D. As a result,
Even with such dimensional errors, the movable scroll member 21 can perform smooth movement.

While obtaining the pressing force F _P of the spiral body 212 of the movable scroll member 21 as described above, the center O _C
The balance weight 271 is not necessary for the bush 27 if only to obtain the followability. However, without this balance weight 271, the pressing force of the spiral body 212 against the spiral body 202 would actually cause the movable scroll member 21, the bearing 28, and the bush 27 to move in a circular orbit with a radius Ror in addition to the above F _P. Since the centrifugal force F ₁ is added, the pressing force becomes large. As a result, Uzumaki body 2
The frictional force between 02 and 212 increases, resulting in increased wear between them. Therefore, balance weight 2
71 is provided, and its centrifugal force F ₂ cancels out the above-mentioned centrifugal force F ₁ . As a result, an appropriate sealing force is obtained while reducing wear on the spiral bodies 202 and 212, and the movable scroll member 21 can be moved without sliding.

The force balance of the entire compressor will be explained with reference to FIG.

The point of action of the force F ₁ is the movable scroll member 21,
Center of gravity of the entire bush 27 and bearing 28 G ₁
Since it is shifted in the axial direction from the point of application of force _F2 , that is, the center of gravity _G2 of the balance weight 271,
In Fig. 8, a counterclockwise moment acts. In order to offset this moment, balance weights 143 and 30 (see FIG. 5) are provided at two points on the main shaft to generate a moment in the clockwise direction in the figure. Their centers of gravity are G ₃ and G ₄ , and their centrifugal forces are F ₃ and F ₄ , respectively. This moment balance is expressed as F ₁ l ₁ +F ₂ l ₂ =0, which prevents vibrations of the compressor.

Furthermore, the rotation prevention mechanism of the movable scroll member will be explained with reference to FIG. 9, which is an exploded view thereof.

The rotation prevention mechanism 22 is composed of a fixed part, a movable part, and a ball element, and includes a boss 2 of the movable scroll member 21.
It is arranged on the outer periphery of 13. First, to explain the fixed part, a ring-shaped fixed ball coupling element 221' is attached to the end surface of the front end plate 11.
is fixed to the front end plate 11 by a spring pin 223. On the other hand, regarding the movable part, a ring-shaped movable scroll side ball coupling element 214' is fixed to the side plate 211 by a spring pin 216 on the outer periphery of the boss 213 of the movable scroll member 21 near the side plate 211. In addition, the fixed ball coupling element 2
A slight gap is provided between the ball coupling element 21' and the movable scroll ball coupling element 214'.

As shown in FIG. 9, the movable scroll side ball coupling element 214' and the fixed ball coupling element 221' each have a diameter.
A plurality of pockets (recesses) 214'a and 221'a with equal pitch and pitch circle are provided.

[Problem that the invention attempts to solve]

By the way, scroll compressors, especially those used as refrigerant compressors for automobile air conditioners, have a wide range of rotation speeds, making it difficult to balance inertia, have a wide load range, and have limited installation space. Due to these constraints, there is a strong demand for a wide range of usage conditions and for smaller size and lighter weight. For this reason, a light alloy such as aluminum is used for the scroll member.
However, the fixed ball coupling element and the movable scroll side ball coupling element require mechanical strength in order to thrust support the ball element, and light alloys such as aluminum cannot be used.

Furthermore, the balance weight 271 requires a predetermined mass in order to offset the inertia force generated due to the circular orbital movement of the movable portion including the movable scroll member 21. In order to secure this predetermined mass, the axial dimension of the balance weight 271 must be increased, that is, the thickness must be increased, or the radial dimension must be increased. However, if the thickness of the balance weight 271 is increased, the distance between the shafts of the bearing 13 and the bush 27 will increase, and a large load will be applied to the bearing 13, which is not preferable. On the other hand, if the radial dimension of the balance weight 271 is increased, the front end plate 11 is shaved by that amount, so the supporting area of the fixed ball coupling element 221' is reduced. This means that the fixed ball coupling element 221' is supported in a so-called cantilevered manner as shown in FIG.
It is necessary to select a material for 21' that has sufficient mechanical strength, which makes it difficult to achieve weight reduction.

Furthermore, for the fixed ball coupling element and the movable scroll side ball coupling element, a pocket (recess) with the same diameter and pitch circle must be formed by cutting on an annular plate of large hardness, which poses the problem of difficulty in machining. be.

Therefore, the purpose of the present invention is to divide the rotation prevention mechanism into rotation prevention parts (fixed ring, movable scroll side ring) and race parts (fixed race, movable scroll side race), and to separate the rotation prevention mechanism from the fixed race and the movable scroll as the race parts. The difference between the outer diameter and the inner diameter of each side race is the minimum size that can secure the transfer area of the ball element, and as a result, the inner diameter of the fixed race can be increased, thereby increasing the width. By improving the shape and housing structure of the balance weight to utilize the space inside the fixed race, the unbalanced moment caused by the axial misalignment between the center of gravity of the movable scroll member and the center of gravity of the balance weight is reduced. An object of the present invention is to provide a scroll type compressor that is designed to be

In the present invention, as mentioned above, the rotation prevention mechanism is divided into rotation prevention parts and race parts, so the number of heavy parts can be minimized to reduce the weight of the compressor. Ease of processing is also achieved.

[Means for solving problems]

According to the present invention, the rotation prevention mechanism includes a ring-shaped movable scroll race fixed to the surface of the second plate of the movable scroll member opposite to the second spiral body, and a ring-shaped movable scroll race that covers the movable scroll race. a movable scroll-side ring fixed to the opposite surface of the second spiral body of the second plate body, and a ring-shaped fixed race whose entire surface is bonded and fixed to the inner wall of the housing facing the movable scroll-side race. and a fixed ring fixed to the inner wall of the housing so as to cover the fixed race and to leave a slight gap between the movable scroll side ring and the movable scroll side ring. and the fixed ring each have a plurality of pockets of the same diameter drilled in the axial direction at respective positions in the circumferential direction that can overlap when the centers of each ring are aligned, and the pockets of the movable scroll side ring and A plurality of ball elements are always held between the pockets of the fixed ring, and the difference between the outer diameter and the inner diameter of the movable scroll side race and the fixed race is the minimum that can secure the transfer area of the ball elements. On the other hand, the second plate of the movable scroll member has a boss formed on a surface opposite to the second spiral body, and a boss is formed in the boss. A bushing having an eccentric hole is rotatably supported, a drive pin is rotatably fitted in the eccentric hole, and the bushing is configured to prevent dynamic imbalance due to the circular orbital movement of the movable scroll member and the bushing. The balance weight has a balance weight that is formed between the outer periphery of the boss and the inner periphery of the fixed race and the fixed ring as the movable scroll member moves in a circular orbit. It is characterized by the provision of an auxiliary balance weight extending within a crescent-shaped space.

〔Example〕

Examples of the present invention will be described below.

FIG. 1 is a cross-sectional structural diagram of a scroll compressor to which the present invention is applied, and the same parts as in FIG. 5 are given the same numbers and explanations are omitted.

First, the improved part of the rotation prevention mechanism, which is the main part of the present invention, will be explained with reference to FIGS. 2 and 3.

The rotation prevention mechanism 22 is composed of a fixed part, a movable part, and a ball element, and includes a boss 2 of the movable scroll member 21.
It is arranged on the outer periphery of 13. To explain the fixing part, it has a ring-shaped fixing race 221 on the end face of the front end plate 11, and a fixing ring 222 that comes into contact with the end face so as to cover the fixing race 221. These are connected to the front end plate 11 by spring pins 223.
is fixed. On the other hand, regarding the movable part, the boss 2 near the side plate 211 of the movable scroll member 21
A ring-shaped movable scroll side race 214 is provided on the outer periphery of the movable scroll side race 213.
The movable scroll side ring 215 is abutted on the end surface of the movable scroll so as to cover the movable scroll 14. These are fixed to the side plate 211 by spring pins 216. Note that a slight gap is left between the fixed ring 222 and the movable scroll side ring 215.

As shown in FIG. 2, a plurality of pockets 215a and 222a having the same diameter, pitch, and pitch circle are bored in the axial direction in the movable scroll side ring 215 and the fixed ring 222, respectively.

To prevent rotation, refer to FIG. 3, fixing ring 2
This is done by sandwiching the ball element 224 between the edge of the pocket 222a of the ring 22 and the edge of the pocket 215a of the movable scroll side ring 215. That is, when the movable scroll member is driven clockwise in the figure, the movable scroll side ring 215 also moves in a circular orbit so that its center draws a circle with a radius Ror. At this time, a rotational force or moment is generated in the movable scroll member in the clockwise direction in the figure due to the misalignment between the point of application of the reaction force of the compressive force and the point of application of the driving force.
The movable scroll member is the movable scroll side ring 2.
It attempts to rotate clockwise around the center of 15. However, the nine ball elements 22 in the upper part of the figure
4 is the edge of the pocket 222a of the fixed ring 222 and the pocket 21 of the movable scroll side ring 215
5a, the movable scroll side ring 215 cannot rotate, thereby preventing the movable scroll member from rotating. In addition, in the illustrated state, the movable scroll side ring 2
15 is located at the far right side in the figure, and the rotation blocking force distribution is as f _C1 to f _C5 . In this way, the ball element 224 at the top of the figure contributes the most to rotation prevention, and the further away from it, the smaller the ball elements 224 in the lower half of the figure no longer have any role in rotation prevention. do not have. However, the pressure applied in the axial direction of the movable scroll member due to the reaction force of the compressive force is thrust supported by the fixed race 221 via the movable scroll side race 214 and all the ball elements 224. From this, the inner and outer diameters of the movable scroll side race 214 and the fixed race 221 need only be large enough to secure the transfer area of the ball element 224, and the difference between the outer diameter and the inner diameter should be the minimum size. It is set so that

As a result, the inner diameter of the fixed race 221 can be increased, thereby expanding the inner space of the fixed race.

Next, an improved part of the balance mechanism in the drive mechanism of the present invention will be explained with reference to FIGS. 1 and 4.

In FIG. 1, a balance weight 271' is joined to the side surface of the bush 27 by means such as press fitting, and an auxiliary balance weight 271'' is integrated with the surface of this balance weight 271' on the movable scroll member 21 side. The reason for using the balance weights 271' and 271'' in this way is that the balance weights 271' and 271'' are used to cancel out the inertia force generated due to the circular orbital movement of the movable parts including the movable scroll member 21, as described above. This is due to the fact that it is difficult to provide sufficient mass eccentricity with only this method.

In the present invention, in particular, as shown in FIG.
A space 40 having an approximately crescent shape in cross section is created between the fixed race 221 and the fixed ring 222 and the boss 213 due to the eccentric movement of the This space 40 is designed to have a sufficient mass eccentricity by extending a balance weight 271'' in the space (wider than that of the compressor). On the other hand, it always occurs on the opposite side across the axis, and the movement of the space 40 and the movement of the balance weight 271'' are synchronized and also match the required position angle of the balance weight 271'' with respect to the center of gravity of the movable part. Balance weights 271', 27
1'' may be integrally formed, and can also be integrally formed with the bush 27 as shown in FIG.

[Effect of idea]

As explained above, according to the present invention, a thrust bearing that also serves as a rotation prevention mechanism for a movable scroll member is connected to rotation prevention parts (fixed ring, movable scroll side ring) and race parts (fixed race, movable scroll side ring). ) is characterized by being configured separately. As a result, the movable scroll side ring 215 and the fixed ring 222 do not need to be as hard as the race member, so they can be made of a light alloy such as aluminum. Since both the movable scroll side race 214 and the fixed race 221 have high mechanical strength, their durability is sufficient, and the axial support force through the ball element is also sufficient. In addition, since the race member can have a larger inner diameter and smaller outer diameter than the coupling element member shown in FIG. 5, this greatly contributes to weight reduction together with the weight reduction of the ring member. In terms of machining, both the movable scroll side race 214 and the fixed race 221 can be obtained by simply punching them into a ring shape, and the surface finishing of the ball element transfer surface is easy and the height can be made uniform. On the other hand, since the movable scroll side ring 215 and the fixed ring 222 can also be obtained by punching, the machining becomes easy.

Further, in the present invention, the rotation prevention mechanism is divided into the rotation prevention part and the race part, and the difference between the outer diameter and the inner diameter of the fixed race and the movable scroll side race as the race parts is the transfer area of the ball element. This makes it possible to increase the inner diameter of the fixed race, thereby increasing the space on the fixed race side. Utilizing this expanded space, the balance weight 271'' can be placed closest to the movable scroll member 21, so that the center of gravity _G1 of the movable part and the balance weight 271'' in FIG.
The distance in the axial direction of the center of gravity _G2 of 1', 271'' can be made the shortest, thereby minimizing the random unbalance moment.Therefore, a stable operating condition with less vibration can be obtained. Further, since the bush 27 and the balance weights 271' and 271'' are made compact, the rotation prevention mechanism is not subject to geometrical positional restrictions due to the balance weights. Specifically, in the example shown in FIG. 5, the fixed ball coupling element 221' has a so-called cantilever structure in which only its outer edge is supported by the front end plate 11. Then, the entire surface of the fixed race 221 is supported by the front end plate 11. This is important in that since the fixed race 221 thrust-supports the entire movable part, a highly durable rotation prevention mechanism can be obtained. Furthermore, the weight of the shaft balance weight 143 and the clutch armature balance weight 30, which are provided at two points on the main shaft to offset the moments caused by the movable part and the balance weights 271' and 271'', can be reduced, and from the above points, compression can be reduced. The entire machine can be made smaller and lighter.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional structural view of a scroll compressor that is an embodiment of the present invention, Fig. 2 is an exploded perspective view of a rotation prevention mechanism thereof, and Fig. 3 is a diagram for explaining the rotation prevention mechanism. Fig. 4 is a sectional view taken along the line A-A in Fig. 1, Fig. 5 is a sectional structural view of the conventional example, Fig. 6 is an exploded perspective view of the conventional drive mechanism, and Fig. 7 is a cross-sectional view of the eccentric bushing in Fig. 5. 8 is a diagram for explaining the dynamic balance in FIG. 5, and FIG. 9 is an exploded perspective view of the rotation prevention mechanism in FIG. 5. In the figure, 10 is a compressor housing, 11 is a front end plate, 12 is a cup-shaped portion, 14 is a main shaft, 20 is a fixed scroll member, 21 is a movable scroll member, 22 is a rotation prevention mechanism, 224 is a ball element, 30, 143,271,271',2
71″ is a balance weight.

Claims (1)

[Scope of utility model registration request] A fixed scroll member having a first spiral body provided on one surface of the first plate body and fixedly disposed within the housing, and a second spiral body provided on one surface of the second plate body. a movable scroll member superimposed with the fixed scroll member such that the second spiral body meshes with the first spiral body in an angularly offset manner to form a closed fluid pocket therebetween; a main shaft rotatably supported by the housing; a drive pin provided eccentrically at the inner end of the main shaft and coupled to the movable scroll member for imparting circular orbital motion to the movable scroll member; and a rotation prevention mechanism that prevents rotation of the movable scroll member during circular orbital motion and thrust-supports the movable scroll member, and the fluid pocket increases in volume due to the circular orbital motion of the movable scroll member. In the scroll type compressor, the rotation prevention mechanism moves toward the center of both the spiral bodies while decreasing the amount of fluid, thereby compressing the fluid. a ring-shaped movable scroll side race fixed to the surface opposite to the spiral body; and a ring-shaped movable scroll side race fixed to the surface of the second plate body opposite to the second spiral body so as to cover the movable scroll side race. A movable scroll side ring, a ring-shaped fixed race whose entire surface is bonded and fixed to the inner wall of the housing opposite to the movable scroll side race, and a slight ring between the movable scroll side ring and the movable scroll side ring so as to cover the fixed race. It is made in a ring shape with a fixing ring fixed to the inner wall of the housing so that there is a gap,
Moreover, the movable scroll side ring and the fixed ring each have a plurality of pockets of the same diameter drilled in the axial direction at respective positions in the circumferential direction where they can overlap when the centers of each ring are aligned. A plurality of ball elements are always held between the pocket of the scroll side ring and the pocket of the fixed ring, and the difference between the outer diameter and the inner diameter of the movable scroll side race and the fixed race is the transfer of the ball element. The second plate body of the movable scroll member has a boss formed on a surface opposite to the second spiral body. A bush having an eccentric hole is rotatably supported in the boss, the drive pin is rotatably fitted in the eccentric hole, and the bush is connected to the movable scroll member and a circle of the bush. It has a balance weight that offsets the dynamic unbalance caused by the orbital motion, and the balance weight includes the outer periphery of the boss, the inner periphery of the fixed race and the fixed ring, and 1. A scroll compressor characterized in that an auxiliary balance weight is provided that extends within a substantially crescent-shaped space formed between the scroll compressor.