JPS641509Y2 - - Google Patents

Description

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

[Conventional technology]

An example of this type of compressor will be explained with reference to FIGS. 1 to 6.

FIG. 1 is a cross-sectional structural diagram of a scroll type compressor that has already been proposed.

In the figure, this compressor includes a front end plate 11 and a cup-shaped portion 12 installed thereon.
It has a compressor housing 10. The front end plate 11 has a through hole 111 centered on the central axis of the housing 10,
A main shaft 14 is inserted through a ball bearing 13 therein.
We support this. Therefore, the axis of the main shaft 14 coincides with the central axis of the housing 10.
The front end plate 11 also includes a sleeve portion 1 that protrudes forward so as to surround the outer periphery of the main shaft 14.
5, and a shaft seal 16 is disposed within the sleeve portion 15. Further, an electromagnetic clutch device 17 is disposed on the outer periphery of the sleeve portion 15.
This device transmits rotational motion from an external drive source to a pulley 171 via a V-belt (not shown),
Furthermore, the transmission of rotational motion from the pulley 171 to the main shaft 14 is controlled by controlling the energization of the electromagnetic coil 172. In addition, the front end plate 11
is fixed by bolts or the like between flanges (not shown) formed at the front end opening of the cup-shaped portion 12 at intervals in the circumferential direction, and the O-ring 1
8 seals the joint surfaces of the two. The sleeve portion 15 is also fixed onto the end surface of the front end plate 11 with bolts or the like, and the joint surface is
It is sealed by a ring 19.

A fixed scroll member 20, a movable scroll member 21, a movable scroll member drive mechanism, 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 201
It is composed of a spiral body 202 and a leg portion 203 provided on the side plate 201 on the opposite side to the spiral body 202. This fixed scroll member 20
The leg portion 203 is fixed to the inner wall of the bottom portion 121 by a bolt 23 which is screwed through the bottom portion 121 of the cup portion 12 from outside the cup portion 12. Also, the side plate 20 of the fixed scroll member 20
1 partitions the space within the cup-shaped portion 12 into a suction chamber 25 and a discharge chamber 26 by sealing between the outer peripheral surface and the inner wall surface of the cup-shaped portion 20 with an O-ring 24. Furthermore, a communication hole 204 is bored in the center of the side plate 201 to communicate the discharge chamber 26 with the sealed space formed between the scroll members.

The movable scroll member 21 is composed of a side plate 211 and a spiral body 212. The movable scroll member 21 is engaged with the spiral body 212 of the fixed scroll member 20 so that the spiral body 202 of the fixed scroll member 20 has an angular deviation of 180°. The movable scroll member 21 is connected to a drive mechanism and a rotating element mechanism, which will be described later, and revolves around a circular orbit having a radius R _pr by the rotation of the main shaft 14, thereby performing the fluid compression operation described above.

Here, the radius R _pr 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 R _pr . As a result, a line contact part is formed between both spiral bodies, and this line contact part moves toward the center along the spiral body surface, and as a result, the fluid pocket moves toward the center of the spiral body while decreasing its volume. do.

Therefore, the housing 10 is supplied from the external fluid circuit through the suction port provided on the outer periphery of the housing 10.
The fluid that has flowed into the suction chamber 25 inside is taken into the fluid pocket from the outer end of both spiral bodies, and the compressed fluid passes from the fluid pocket at the center of both spiral bodies to the discharge chamber 26 through the communication hole 204. sent to. Further, the fluid flows from the discharge chamber 26 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. 2, which is an exploded view thereof.

A large diameter portion 141 is formed at the inner end of the main shaft 14 that passes through the through hole 111 of the front end plate 11 . I fully support it. 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 side plate 211 of the movable scroll member 21
has an annular boss 213 on the opposite surface from the spiral body 212. A bush 27 in the form of a thick disk or short shaft is fitted into the boss 213 and rotatably supported via a needle bearing 28 . The bush 27 is integrated with a disc-shaped balance weight 2 extending in the radial direction.
71, and also has an axial hole, that is, an eccentric hole 272, at a position offset from the center. The drive pin 142 is fitted into the eccentric hole 272 and rotatably supported by the needle bearing 29.

A bush 27 having such an eccentric hole 272
The advantages of using this will be explained below with reference also 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 eventually moves to the center of the bush as shown in Figure ₃ .
It can be thought of as acting as shown in F _D. By the way, the bush 27 is connected to the drive pin 142.
Since the drive pin 142 is rotatable on the
receives a moment of rotation around the center O _D by force F _D. This moment is in the direction of force F _D
When the angle between the line connecting O _C and O _D is θ as shown in Figure 3, it is expressed as F _D · ε ₂ sin θ. 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, which causes the spiral body 212 to be pressed against the spiral body 202. . This pressing force is F _P
Then, since F _P・ε ₂ cosθ=F _D・ε ₂ sinθ, 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 is automatically obtained at the line contact portion of No. 2, thereby ensuring the heel of the compressor pocket.

Furthermore, as mentioned above, the center of the eccentric bushing 27
Since O _C is rotatable 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. 3, 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 be a circular orbit with a radius R _pr of the movable scroll member 21, the bearing 28, and the bush 27 in addition to the above F _P. Since the centrifugal force F ₁ due to the movement 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 can be obtained while reducing wear on the spiral bodies 202 and 212, allowing smooth movement of the movable scroll member 21.

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,
This is the center of gravity _G1 of the bush 27 and bearing 28 as a whole, and 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 the figure, a counterclockwise moment acts. In order to offset this moment, balance weights 143 and 30 (see FIG. 1) 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. 5, 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. 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 is in contact with the end face so as to cover this fixing race 221, and these are attached to spring pins. 223 to the front end plate 11. On the other hand, regarding the movable part, there is a ring-shaped movable race 214 on the outer periphery of the boss 213 near the side plate 211 of the movable scroll member 21, and a movable ring 215 is abutted against the end surface of the movable race 214 so as to cover it. These are fixed to the side plate 211 by spring pins 216. Note that there is a slight gap between the fixed ring 222 and the movable ring 215.

As shown in FIG.
5 and the fixed ring 222, respectively, have a plurality of pockets 215a, which have the same diameter, pitch, and pitch circle.
222a is drilled in the axial direction.

Now, the rotation prevention effect will be explained with reference to FIG. 6, which shows the relationship between the movable ring and the fixed ring as seen from the movable scroll member side.

The rotating element is located in the pocket 22 of the fixed ring 222.
The edge of 2a and the pocket 215 of the movable ring 215
This is done by sandwiching the ball element 224 with the edges of a. That is, when the movable scroll member is driven clockwise in the figure, the movable ring 215 also moves in a circular orbit so that its center draws a circle with a radius R _pr .
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. Try to rotate in the direction. However, the nine ball elements 224 in the upper part of the figure are attached to the fixing ring 22.
The edge of the second pocket 222a and the movable ring 215
Since the movable ring 215 is pinched by the edge of the pocket 215a, the movable ring 215 cannot rotate, thereby preventing the movable scroll member from rotating.
In the illustrated state, the center of the movable ring 215 is located farthest to the right in the figure, and the rotation blocking force distribution is _C1 to _C5.
become that way. As described above, the ball element at the top of the figure contributes the most, and the further away from it, the smaller the ball elements 224, and the nine ball elements 224 in the lower half of the figure do not serve to prevent rotation.
However, the pressure applied in the axial direction of the movable scroll member due to the reaction force of the compression force is applied to the fixed race 221 through the movable race 214 and all ball elements 224.
is supported in thrust.

[Problem that the invention attempts to solve]

As is clear from the above description, when the movable scroll member moves in a circular orbit, it is necessary to maintain balance so that the compressor main body does not vibrate due to unbalance caused by this movement.

The present invention is an improvement of such a balance mechanism, and aims to provide a scroll compressor that is smaller and lighter.

〔Example〕

Examples of the present invention will be described below.

The improved balance mechanism in the drive mechanism, which is a feature of the present invention, will be explained with reference to FIG.

In explaining the drive mechanism, in a scroll compressor, in order to offset the unbalance caused by the orbital movement of the center of gravity of the movable scroll member,
It was shown that a balance weight is necessary. For example, if the mass of the movable member is m ₁ and the angular velocity of circular orbital motion is ω, then a balance weight is required to offset the unbalance of m ₁ R _pr ω ² . In other words, if the mass of the balance weight is m ₂ and the distance from its center of gravity to the center of the circular orbit is r, then m ₁ R _pr ω ² =
m ₂ rω ² is sufficient, and if the distance r is increased, the mass
m ₂ can be small, and the axial thickness of the balance weight can be reduced accordingly.

In this invention, in order to increase the distance r and mass _m2 without increasing the thickness of the balance weight,
This is an improved version of the front end plate 11 and balance weight 271'. That is, the balance weight 271' is provided with a protrusion that protrudes toward the opposite end of the scroll member, that is, toward the front end plate 11, on the tip side of a substantially semicircular plate body.
This protrusion is accommodated in a raceway groove 112 formed on the inner end surface of the front end plate 11. According to such a structure, the balance weight 271' can be incorporated without increasing the axial length of the compressor main body, which causes unbalance during driving.
As a result, a small and lightweight scroll compressor can be obtained.

FIG. 8 shows another embodiment of the present invention, in which the compressor housing 10 is composed of a front end plate 11 having a cylindrical part 112 and a rear end plate 12' fixed to the cylindrical part 112. .

Moreover, the rotation prevention mechanism includes a plurality of recesses 215a' and 222a' having the same diameter, pitch, and pitch in the movable ring 215' fixed to the side plate 211 and the fixed ring 222' fixed to the front end plate 11, respectively. Forming and composing.

In this embodiment, as in the previous embodiment, a groove for the balance weight 271' is formed in the front end plate 11 and the balance weight 271' is housed therein, thereby making it possible to reduce the size and weight of the compressor body. By configuring it with the fixing ring 222', the number of parts can be reduced and the manufacturing process can be simplified.

In the embodiment, the movable scroll member is driven using an eccentric bushing mechanism that allows the radius of the circular orbit to be changed, but a rigid crankshaft with a fixed radius of the circular orbit may also be used. In this case, by selecting the circular orbit radius so that there is no contact interference between the two spiral bodies, the fourth
There is no fundamental difference from the method of balancing explained in the figure, and the balance weight 143 and the balance weight 271' attached to the crank part may be combined into one balance weight. In this case, since the amount of unbalance of one balance weight must be made larger than in the case of the above-mentioned embodiment, a larger space is required for the rotation of this weight. However, according to the balance weight storage section according to the present invention, it is easy to secure such a space, and further effects can be expected. In this way,
The space required for the balance weight 143 is no longer necessary, and by combining the balance weights into one having a center of gravity at a position with a large distance from the axis, the length dimension can be reduced and the weight can be reduced. Further, by reducing the axial dimension of the crank portion, the moment applied to each bearing can be reduced, and the bearings can also be made smaller.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional structural diagram of a scroll type compressor that has already been proposed, Fig. 2 is an exploded perspective view of the drive mechanism, Fig. 3 is a diagram for explaining the action of the eccentric bushing, and Fig. 4 is a diagram for explaining the action of the eccentric bushing. The figures are for explaining the dynamic balance in Figure 1, Figure 5 is an exploded perspective view of the rotation prevention mechanism in Figure 1, Figure 6 is a diagram for explaining the principle of rotation prevention, and Figure 7. 8 is a sectional structural diagram of the first embodiment of the present invention, and FIG. 8 is a sectional structural diagram of another embodiment. In the figure, 10 is a compressor housing, 11 is a front end plate, 12 is a cup-shaped part, 12'
1 is a rear end plate, 14 is a main shaft, 20 is a fixed scroll member, 21 is a movable scroll member, 2
2 is a rotation prevention mechanism, 224 is a ball element, 30,
143, 271, 271' are balance weights.

Claims (1)

[Scope of utility model registration request] a compressor housing having a fluid inlet and a fluid outlet; a first plate provided on one surface of the first plate;
a fixed scroll member having a spiral body and fixedly disposed within the housing; a second spiral body provided on one surface of a second plate body;
a movable scroll member superimposed on the fixed scroll member such that the spiral body meshes with the first spiral body in an angularly shifted manner to form a closed fluid pocket therebetween; a crankshaft including a supported main shaft and a drive pin eccentrically provided at an 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 a scroll type compressor, the crankshaft moves towards the center of both spiral bodies while decreasing the amount of fluid, thereby compressing the fluid. The balance weight has a balance weight that offsets the unbalance, and the balance weight has a protrusion protruding in a direction opposite to the scroll member on the radial tip side of a substantially semicircular plate body;
A scroll compressor characterized in that the protrusion is accommodated in a raceway groove formed on the inner end surface of the housing.