JPH11141472A - Scroll type fluid machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the uneven wear of a sliding bearing even when a slide bush is inclined by forming the sliding surface of either one of a cylindrical member and a bearing part constituting a sliding part with the bearing part of a movable scroll into a crowning form protruded to the other sliding surface side. SOLUTION: A movable scroll 3 to which the rotating force of a roller 10 by a motor M is transmitted through the eccentric part 2a of a crank shaft 2 is rotated around it by an Oldham's coupling 6. The crank shaft 2 has a collar part 2b and an eccentric part 2a on the upper end part, and a slide bush 1 with balance weight is loosely fitted to the eccentric part 2a. In operation, a moment is generated in the slide bush 1 by the force added from each part, and the slide bush 1 is inclined to a sliding bearing 5. When the outer circumferential surface of the slide bush 1 has a crowning form, the end part of the sliding bearing 5 never make uneven contact with the outer circumferential surface of the cylinder part 1a of the slide bush 1 even if the slide bush 1 is inclined, and the uneven wear thereof can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine, and more particularly, to a slide which is loosely fitted to an eccentric portion of a drive shaft and forms a sliding portion with a bearing portion of a movable scroll. The present invention relates to a scroll type fluid machine having a bush.

[0002]

2. Description of the Related Art A scroll type fluid machine having a slide bush is disclosed, for example, in Japanese Patent Application Laid-Open No. 4-175486. Hereinafter, a scroll type fluid machine disclosed in this publication will be described as a conventional example. In addition, about the name of each member disclosed by the said gazette, for convenience of explanation,
Modified as appropriate.

FIG. 9 is a schematic sectional view partially showing the structure of a conventional scroll type fluid machine, and FIG.
It is a schematic sectional drawing which follows the A line.

Referring to FIGS. 9 and 10, an eccentric portion 2a is provided at an upper end of a crankshaft 2 connected to a drive source (not shown) of a scroll type fluid machine. A slide bush 201 with a balance weight is loosely fitted to the eccentric portion 2a so as to have a gap with the eccentric portion 2a.

The slide bush 201 has an eccentric portion 2
and a balance weight 201c attached to the outer periphery of the cylindrical portion 201a on the opposite side of the eccentric direction of the eccentric portion 2a. This slide bush 2
01, the torque of the crankshaft 2 can be transmitted to the compression element CF.

[0006] The compression element CF has a movable scroll 3 that can revolve while keeping its attitude relatively, and a fixed scroll 4 fixed to a casing (not shown) via a housing (not shown). doing. Movable scroll 3
Has a mirror plate 3a, a spiral tooth portion 3b protruding from the front surface of the mirror plate 3a, and a boss 3c protruding from the rear surface of the mirror plate 3a. The slide bush 20 is provided in the boss 3c.
The eccentric portion 2a into which the first bush 1 is loosely fitted is received, and the slide bush 201 is provided on the inner peripheral surface of the boss portion 3c.
Is mounted. The fixed scroll 4 has a head plate 4a and a spiral tooth portion 4b projecting from the front surface of the mirror plate 4a and engaging with the spiral tooth portion 3b of the movable scroll 3 to constitute a compression chamber.

Here, the role of the slide bush 201 is as follows. In order to partition between the two compression chambers in the compression element CF so that there is no leakage of the refrigerant, the spiral teeth 3b and 4b of the movable scroll 3 and the fixed scroll 4 are spaced from each other between the two compression chambers. Must be in contact with each other. Since the slide bush 201 is fitted (with loose fit) in the eccentric portion 2a of the crankshaft 2 with a gap, the movable scroll 3 can be slid by the gas force in the compression chamber. The spiral tooth portions 3b, 4b of the movable scroll 3 and the fixed scroll 4 can be brought into contact with each other without any gap between the two compression chambers. That is, the slide bush 201 is
Is loosely fitted to the eccentric portion 2a, and serves to make the movable scroll 3 slidable so that refrigerant does not leak between the compression chambers.

In this scroll type fluid machine, the balance weight 201c provided on the slide bush 201
Generates a centrifugal force in the direction opposite to the centrifugal force acting on the movable scroll 3 during the orbital movement of the movable scroll 3. The centrifugal force generated by the orbital motion of the orbiting scroll 3 can be offset by the centrifugal force generated by the balance weight 201c. Therefore, it is possible to suppress the contact pressure between the spiral teeth 3b and 4b from becoming excessive, and to prevent the spiral teeth 3b and 4b from being damaged.

[0009]

However, in the conventional scroll type fluid machine, various forces act on the slide bush 201 from various parts during operation. Also,
The points of action of these forces acting on the slide bush 201 are in the axial direction of the slide bush 201 (dashed line C-
C). For example, the axial position of the bearing load applied to the slide bush 201 during operation and the balance weight 201 connected to the slide bush 201
The position of c in the centrifugal force axial direction is shifted. For this reason, a moment is generated in the slide bush 201 due to the displacement of the point of action of each force. Since the slide bush 201 is fitted in the eccentric portion 2a of the crankshaft 2 with a gap, the slide bush 201 is inclined with respect to the slide bearing 5 by this moment. Due to this inclination, there is a problem that the sliding bearing 5 causes a partial contact with the slide bush 201 to cause uneven wear.

Therefore, an object of the present invention is to provide a scroll-type fluid machine in which even if the slide bush is tilted by a moment generated during operation, the sliding bearing does not hit the slide bush and uneven wear can be prevented. .

[0011]

According to a first aspect of the present invention, there is provided a scroll type fluid machine having a cylindrical member which is loosely fitted to an eccentric portion of a drive shaft and forms a sliding portion between the eccentric portion and a bearing portion of a movable scroll. , Wherein one of the sliding surface of the cylindrical member forming the sliding portion and the bearing portion has a crowning shape protruding toward the other sliding surface.

According to the scroll type fluid machine of the first aspect, one of the sliding surfaces has a crowning shape protruding toward the other sliding surface, that is, the center of the one sliding surface is on the other side than the both ends. Has a shape protruding toward the sliding surface side. For this reason, even if the cylindrical member is tilted by the moment during operation, the end of the other sliding surface does not have a one-sided contact, and uneven wear can be prevented.

In the scroll-type fluid machine according to the second aspect, the sliding surface of the tubular member has a crowning shape.

According to the scroll type fluid machine according to the second aspect, no one-side contact occurs at the end of the sliding portion of the movable scroll, and uneven wear can be prevented.

[0015] In the scroll-type fluid machine according to the third aspect, the crowning shape is generally curved.

According to the scroll type fluid machine of the third aspect, even when the inclination of the tubular member is large, it is easy to secure the bearing load capacity necessary for the operation of the scroll type fluid machine.

In the scroll-type fluid machine according to the fourth aspect, the central portion of the crowning shape has a straight portion in cross section.

According to the scroll-type fluid machine of the fourth aspect, when the inclination of the tubular member is small, a relatively large bearing load capacity can be secured.

In the scroll type fluid machine according to the fifth aspect, the cylindrical member has a balance weight on an outer periphery thereof for balancing when the drive shaft is driven.

According to the scroll type fluid machine of the fifth aspect, when the tubular member has a balance weight and is easily inclined, uneven wear due to one-side contact can be more effectively prevented.

[0021]

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

FIG. 1 is a sectional view schematically showing the structure of a scroll compressor according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view illustrating a configuration of a slide bush.

Referring to FIG. 1 and FIG. 2, a motor M and a compression element CF are mainly disposed in the closed container 13.

The motor M has a stator 9 fixed to the inner wall of the closed casing 13 and a rotor 10 facing the stator 9 at a predetermined interval. This rotor 10
Is connected to the crankshaft 2. The upper end of the crankshaft 2 is provided with a flange 2b and an eccentric portion 2a located above the flange 2b and eccentric with respect to the crankshaft 2. The slide bush 1 with the balance weight is loosely fitted to the eccentric portion 2a so as to be supported from below by the flange portion 2b.

Slide bush 1 with balance weight
Has a tubular portion 1a, a flange portion 1b, and a balance weight 1c. The cylindrical portion 1a is loosely fitted with a gap with the outer peripheral surface of the eccentric portion 2a, and the balance weight 1c is
The eccentric portion 2a is mounted on the outer peripheral surface of the lower end portion in the direction opposite to the eccentric direction of the eccentric portion 2a. The flange portion 1b is an outer peripheral surface of a lower end portion of the cylindrical portion 1a and has at least a balance weight 1
c.

The axial movement of the slide bush 1 with the balance weight is regulated by, for example, a C-shaped retaining ring mounted on the eccentric portion 2a.

The crankshaft 2 is connected to the upper housing 7
And a rolling bearing (not shown) provided in a lower housing (not shown).

A compression element CF is provided to apply a rotational force from the eccentric portion 2a of the crankshaft 2 via the slide bush 1 with a balance weight.

The compression element CF has a movable scroll 3 and a fixed scroll 4. The movable scroll 3
End plate 3a, spiral tooth portion 3b projecting from the front surface of end plate 3a
And a boss 3c protruding from the back surface of the end plate 3a. The eccentric part 2a and the cylindrical part 1a of the slide bush 1 with balance weight are received in the boss part 3c. Further, a sliding bearing 5 constituting a sliding portion with the outer peripheral surface of the cylindrical portion 1a is attached to the inner peripheral surface of the boss portion 3c. The movable scroll 3 is supported by an Oldham coupling 6 so as to revolve while receiving a rotational force from the crankshaft 2 while keeping its attitude relatively. Fixed scroll 4
Has a mirror plate 4a and spiral teeth 4b protruding from the mirror plate 4a. The spiral teeth 4b mesh with the spiral teeth 3b of the orbiting scroll 3 to form a compression chamber. The fixed scroll 4 includes an upper housing 7
Are fastened and fixed by, for example, bolts.

The closed container 13 is provided with a suction pipe 11 for sucking the refrigerant gas from the outside to the inside, and a discharge pipe 12 for discharging the refrigerant gas from the inside to the outside.

Of particular note in the scroll compressor of the present embodiment is the shape of the outer peripheral surface of the cylindrical portion 1a of the slide bush 1 with the balance weight. The shape of the outer peripheral surface of the cylindrical portion 1a is, both end portions of the cylindrical portion 1a (P _1, P _2: 2) bearing 5 slip towards the center portion sandwiched between the opposite ends thereof than (P _1, P ₂₎ It has a so-called crowning shape protruding to the side. In particular, in the present embodiment, the outer peripheral surface has a shape that is entirely curved (a whole crowning shape).

Next, the operation of the scroll compressor shown in FIG. 1 will be described. Referring to FIG. 1, when the motor M is energized, the rotor 10 rotates, and this rotational force is applied to the movable scroll 3 via the eccentric portion 2 a of the crankshaft 2. The orbiting scroll 3 revolves with the Oldham's joint 6 while keeping its attitude relatively.

The revolving motion of the movable scroll 3 causes the spiral teeth 3 of the movable scroll 3 and the fixed scroll 4 to rotate.
The compression chamber constituted by b and 4b moves from the outer peripheral side to the inner peripheral side while gradually reducing the volume. Thereby, the refrigerant gas introduced into the closed container 13 by the suction pipe 11 and reaching the outermost compression chamber is gradually compressed, reaches the innermost compression chamber, and is discharged from the discharge hole 4c there. .
The refrigerant gas discharged from the compression element CF is discharged to the outside of the closed container 13 by the discharge pipe 12.

At the time of this operation, a moment is generated by the force applied from each part to the slide bush 1 with the balance weight as described above, and the slide bush 1 is inclined with respect to the slide bearing 5.

As shown in the comparative example of FIG. 3, when the outer peripheral surface of the cylindrical portion 101a of the slide bush 101 has a normal cylindrical (straight) shape, the slide bush 101 is
When tilted as shown in the figure, the ends (regions R ₁ , R
₂ ) One-sided contact occurs and uneven wear occurs.

On the other hand, when the outer peripheral surface of the slide bush 1 has a crowning shape as in this embodiment,
Even when the slide bush 1 is inclined as shown in FIG. 5, the end of the slide bearing 5 does not come into contact with the outer peripheral surface of the cylindrical portion 1a of the slide bush 1. Therefore, uneven wear is prevented.

In this embodiment, the case where the outer peripheral surface of the cylindrical portion 1a of the slide bush 1 is entirely crowned as shown in FIGS. 1 and 2 has been described. However, the present invention is not limited to this. As shown, the outer peripheral surface of the cylindrical portion 1a may have a so-called partial crowning shape.

Here, as shown in FIG. 6, the partial crowning shape means that the central portion sandwiched between both ends (P ₁ , P ₂ ) is more than the both ends (P ₁ , P ₂ ) of the cylindrical portion 1a. It is a shape that protrudes toward the slide bearing and that has a straight portion in the center at the center.

In the case of the partial crowning shape shown in FIG. 6, even if the slide bush 1 is tilted as shown in FIG. 7, no one-side contact occurs at the end of the slide bearing 5, thereby preventing uneven wear. You.

It is effective to use the slide bush 1 having the entire crowning shape shown in FIGS. 1 and 2 and the partial crowning shape shown in FIG. 6 according to each application. This will be described in detail below.

FIG. 8 shows the relationship between the inclination angle of the slide bush and the bearing load capacity when the outer peripheral surface of the cylindrical portion has a straight shape (FIG. 3), a full crowning shape (FIG. 2) or a partial crowning shape (FIG. 6). FIG.

Referring to FIG. 8, in the case of the entire crowning shape (FIG. 2), the bearing load capacity when the inclination angle of the slide bush is small is small, but the decrease in the bearing load capacity with the increase in the inclination angle. Is small. On the other hand, in the case of the partial crowning shape, when the inclination angle of the slide bush is small, the bearing load capacity is larger than that in the case of the full crowning shape. Larger than the shape.

For this reason, it is preferable to use a partially crowned slide bush in applications where the inclination angle of the slide bush is relatively small and a large bearing load capacity is required. For applications in which the inclination angle of the slide bush is large but a bearing load capacity is not so high, it is preferable to use a slide bush having a crowning shape over the entire surface.

As described above, by appropriately using the slide bush having the entire crowning shape and the partial crowning shape according to each application, uneven wear can be prevented and a more stable operation of the scroll compressor can be realized.

In this embodiment, the case where the outer peripheral surface of the slide bush 1 has a crowning shape has been described. However, the outer peripheral surface of the slide bush 1 is straight and the sliding surface (inside The peripheral surface may have a crowning shape protruding toward the slide bush 1.

In the above-described embodiment, the scroll compressor has been described. However, the present invention is not limited to the scroll compressor, but can be applied to a scroll expander.

The embodiment disclosed this time is an example in all respects, and should be considered as not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0048]

According to the first aspect of the present invention, one of the sliding surfaces of the cylindrical member and the bearing constituting the sliding portion has a crowning shape protruding toward the other sliding surface. Therefore, even if the tubular member is tilted by a moment during operation, the end of the other sliding surface does not have a partial contact, and uneven wear can be prevented.

According to the second aspect of the present invention, since the sliding surface of the tubular member has a crowning shape, there is no one-side contact at the end of the sliding portion of the movable scroll. Wear can be prevented.

According to the third aspect of the present invention, since the crowning shape is a curved shape as a whole, that is, a so-called overall crowning shape, even when the inclination of the tubular member is large, the operation of the scroll type fluid machine can be performed. It is easy to secure the bearing load capacity required for the vehicle.

According to the fourth aspect of the present invention, the central portion of the crowning shape has a so-called partial crowning shape having a linear portion in cross section, so that when the inclination of the tubular member is small, it is relatively large. Bearing load capacity can be secured.

According to the fifth aspect of the present invention, uneven wear due to one-sided contact can be effectively prevented even when the balance weight is used to easily tilt.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view schematically showing a configuration of a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing a configuration of a slide bush of the scroll compressor according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of a comparative example of a slide bush.

FIG. 4 is a schematic cross-sectional view showing a state where uneven wear occurs in a slide bush of a comparative example.

FIG. 5 is a schematic cross-sectional view for explaining that uneven wear does not occur in the slide bush of the scroll compressor according to one embodiment of the present invention.

FIG. 6 is a schematic sectional view showing a configuration of a slide bush having a partially crowned shape.

FIG. 7 is a schematic cross-sectional view for explaining that uneven wear does not occur in a slide bush having a partially crowned shape.

FIG. 8 is a graph showing a relationship between a bearing load capacity and an inclination angle of a slide bush in each of slide bushes having a straight shape, a partial crowning shape, and a full crowning shape.

FIG. 9 is a partial sectional view showing a configuration of a conventional scroll type fluid machine.

FIG. 10 is a schematic sectional view taken along the line AA of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slide bush with balance weight 1a Cylindrical part 1b Flange part 1c Balance weight 2 Crankshaft 2a Eccentric part 2b Cylindrical part 3 Movable scroll 5 Slide bearing

Claims (5)

[Claims] 1. A tubular member (1) which is loosely fitted to an eccentric part (2a) of a drive shaft (2) and constitutes a sliding part with a bearing part (5) of a movable scroll (3). A scroll-type fluid machine, wherein one of the cylindrical member (1) and the bearing portion (5) forming the sliding portion protrudes toward the other sliding surface. A scroll type fluid machine having a crowning shape. 2. The scroll-type fluid machine according to claim 1, wherein a sliding surface of the tubular member has the crowning shape. 3. The scroll-type fluid machine according to claim 1, wherein the crowning shape has a generally curved shape. 4. The scroll type fluid machine according to claim 1, wherein the central portion of the crowning shape has a straight portion in a cross section. 5. The scroll type according to claim 1, wherein the cylindrical member has a balance weight on an outer periphery thereof for balancing when the drive shaft is driven. Fluid machinery.