Tip seal and scroll fluid machine using same

Abstract

Provided is a tip seal that makes it possible to improve the durability of a tip seal installed on the tooth tip of a wall even when a continuously inclined section is provided to the wall. The tip seal is provided with: a tip seal inclined section (7A) installed in a groove section of a wall in which the height changes continuously in a spiral direction; and a tip seal flat section (7B) that is installed in a groove section of the wall in which the height is fixed in the spiral direction and that is adjacent to the tip seal inclined section (7A). A recess (8) is formed at a position away from the adjacent area between the tip seal inclined section (7A) and the tip seal flat section (7B).

Claims

1. A tip seal which is installed in a groove portion formed on a tooth tip of a spiral first wall and a spiral second wall of a scroll fluid machine and is formed of a resin, the scroll fluid machine comprising: a first scroll member having a first end plate on which the spiral first wall is provided; a second scroll member having a second end plate on which the spiral second wall is provided, the second end plate being disposed to face the first end plate and the spiral second wall meshing with the spiral first wall such that the second scroll member performs a revolution orbiting movement relative to the first scroll member, the tip seal comprising: a tip seal inclined portion which is installed in the groove portion of each of a wall inclined portion of the spiral first wall and a wall inclined portion of the spiral second wall whose heights are continuously changed in a spiral direction; and a tip seal flat portion which is installed in the groove portion of each of a wall flat portion of the spiral first wall and a wall flat portion of the spiral second wall whose heights are constant in the spiral direction and is adjacent to the tip seal inclined portion, wherein the tip seal inclined portion is inclined to the tip seal flat portion so as to come into contact with a tooth bottom of each of an end plate inclined portion of the first end plate and an end plate inclined portion of the second end plate even if a tip clearance between the tooth tip of each of the wall inclined portion of the spiral first wall and the wall inclined portion of the spiral second wall and the tooth bottom of each of the end plate inclined portion of the first end plate and the end plate inclined portion of the second end plate is changed during the revolution orbiting movement; and wherein a concave portion is formed on a surface of the tip seal at a position away from a connection position between the tip seal flat portion and the tip seal inclined portion by twice or more width of the tip seal flat portion, the concave portion being recessed from the surface of the tip seal.

2. The tip seal according to claim 1, wherein a height of the tip seal inclined portion is higher than a height of the tip seal flat portion.

3. The tip seal according to claim 2, wherein the tip seal inclined portion is formed of a material having wear resistance higher than that of the tip seal flat portion.

4. The tip seal according to claim 2, wherein the tip seal is divided into the tip seal inclined portion and the tip seal flat portion at a connection position therebetween.

5. A scroll fluid machine comprising: a first scroll member having a first end plate on which a spiral first wall is provided; a second scroll member having a second end plate on which a spiral second wall is provided, the second end plate being disposed to face the first end plate and the spiral second wall meshing with the spiral first wall such that the second scroll member performs a revolution orbiting movement relative to the first scroll member; and an inclined portion in which an inter-facing surface distance between the first end plate and the second end plate facing each other continuously decreases from outer peripheral sides of the spiral first wall and the spiral second wall toward inner peripheral sides thereof, wherein the tip seal according to claim 3 which comes into contact with a facing tooth bottom to perform sealing for a fluid is provided in the groove portion formed on each tooth tip of the spiral first wall and the spiral second wall corresponding to the inclined portion.

6. The tip seal according to claim 1, wherein the tip seal inclined portion is formed of a material having wear resistance higher than that of the tip seal flat portion.

7. The tip seal according to claim 6, wherein the tip seal is divided into the tip seal inclined portion and the tip seal flat portion at a connection position therebetween.

8. A scroll fluid machine comprising: a first scroll member having a first end plate on which a spiral first wall is provided; a second scroll member having a second end plate on which a spiral second wall is provided, the second end plate being disposed to face the first end plate and the spiral second wall meshing with the spiral first wall such that the second scroll member performs a revolution orbiting movement relative to the first scroll member; and an inclined portion in which an inter-facing surface distance between the first end plate and the second end plate facing each other continuously decreases from outer peripheral sides of the first wall and the second wall toward inner peripheral sides thereof, wherein the tip seal according to claim 4 which comes into contact with a facing tooth bottom to perform sealing for a fluid is provided in a groove portion formed on each tooth tip of the spiral first wall and the spiral second wall corresponding to the inclined portion.

9. The tip seal according to claim 1, wherein the tip seal is divided into the tip seal inclined portion and the tip seal flat portion at a connection position therebetween.

10. A scroll fluid machine comprising: a first scroll member having a first end plate on which a spiral first wall is provided; a second scroll member having a second end plate on which a spiral second wall is provided, the second end plate being disposed to face the first end plate and the spiral second wall meshing with the spiral first wall such that the second scroll member performs a revolution orbiting movement relative to the first scroll member; and an inclined portion in which an inter-facing surface distance between the first end plate and the second end plate facing each other continuously decreases from outer peripheral sides of the spiral first wall and the spiral second wall toward inner peripheral sides thereof, wherein the tip seal according to claim 5 which comes into contact with a facing tooth bottom to perform sealing for a fluid is provided in the groove portion formed on each tooth tip of the spiral first wall and the spiral second wall corresponding to the inclined portion.

11. A scroll fluid machine comprising: a first scroll member having a first end plate on which a spiral first wall is provided; a second scroll member having a second end plate on which a spiral second wall is provided, the second end plate being disposed to face the first end plate and the spiral second wall meshing with the spiral first wall such that the second scroll member performs a revolution orbiting movement relative to the first scroll member; and an inclined portion in which an inter-facing surface distance between the first end plate and the second end plate facing each other continuously decreases from outer peripheral sides of the spiral first wall and the spiral second wall toward inner peripheral sides thereof, wherein the tip seal according to claim 1 which comes into contact with a facing tooth bottom to perform sealing for a fluid is provided in the groove portion formed on each tooth tip of the spiral first wall and the spiral second wall corresponding to the inclined portion.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1A is longitudinal sectional view showing a fixed scroll and an orbiting scroll of a scroll compressor according to an embodiment of the present invention.

(2) FIG. 1B is a plan view when the fixed scroll is viewed from a wall side.

(3) FIG. 2 is a perspective view showing the orbiting scroll of FIGS. 1A and 1B.

(4) FIG. 3 is a plan view showing an end plate flat portion provided in the fixed scroll.

(5) FIG. 4 is a plan view showing a wall flat portion provided in the fixed scroll.

(6) FIG. 5 is a schematic view showing a wall which is displayed to extend in a spiral direction.

(7) FIG. 6 is a partially enlarged view showing a region indicated by a reference sign Z in FIG. 1B in an enlarged manner.

(8) FIG. 7A is a side view showing a tip seal clearance of a portion shown in FIG. 6 and a state where the tip seal clearance relatively decreases.

(9) FIG. 7B is a side view showing the tip seal clearance of the portion shown in FIG. 6 and a state where the tip seal clearance relatively increases.

(10) FIG. 8 is a horizontal sectional view around a tooth tip in the wall.

(11) FIG. 9 is a perspective view showing a periphery of a connection portion between an inclined portion and a flat portion of a tip seal.

(12) FIG. 10 is a perspective view showing a modification example of FIG. 9.

(13) FIG. 11 is a longitudinal section view showing a combination with a scroll which does not have a step portion.

(14) FIG. 12 is a longitudinal section view showing a combination with a stepped scroll.

DESCRIPTION OF EMBODIMENTS

(15) Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.

(16) In FIGS. 1A and 1B, a fixed scroll (first scroll member) 3 and an orbiting scroll (second scroll member) 5 of a scroll compressor (scroll fluid machine) 1 are shown. For example, the scroll compressor 1 is used as a compressor which compresses a gas refrigerant (fluid) which performs a refrigerating cycle of an air conditioner or the like.

(17) Each of the fixed scroll 3 and the orbiting scroll 5 is a metal compression mechanism which is formed of an aluminum alloy or steel, and is accommodated in a housing (not shown). The fixed scroll 3 and the orbiting scroll 5 suck a fluid, which is introduced into the housing, from an outer peripheral side, and discharge the compressed fluid from a discharge port 3c positioned at a center of the fixed scroll 3 to the outside.

(18) The fixed scroll 3 is fixed to the housing, and as shown in FIG. 1A, includes an approximately disk-shaped end plate (first end plate) 3a, and a spiral wall (first wall) 3b which is erected on one side surface of the end plate 3a. The orbiting scroll 5 includes an approximately disk-shaped end plate (second end plate) 5a and a spiral wall (second wall) 5b which is erected on one side surface of the end plate 5a. For example, a spiral shape of each of the walls 3b and 5b is defined by using an involute curve or an Archimedes curve.

(19) The fixed scroll 3 and the orbiting scroll 5 are assembled to each other such that centers thereof are separated from each other by an orbiting radius ρ, the walls 3b and 5b mesh with each other with phases deviated from each other by 180°, and a slight clearance (tip clearance) in a height direction is provided in the room temperature between tooth tips and tooth bottoms of the walls 3b and 5b of both scrolls. Accordingly, a plurality pairs of compression chambers which are formed to be surrounded by the end plates 3a and 5a and the walls 3b and 5b are symmetrically formed about a scroll center between both scrolls 3 and 5. The orbiting scroll 5 performs a revolution orbiting movement around the fixed scroll 3 by a rotation prevention mechanism such as an Oldham ring (not shown).

(20) As shown in FIG. 1A, an inclined portion is provided, in which an inter-facing surface distance L between both end plates 3a and 5a facing each other continuously decrease from an outer peripheral side of each of the spiral walls 3b and 5b toward an inner peripheral side thereof.

(21) As shown in FIG. 2, in the wall 5b of the orbiting scroll 5, a wall inclined portion 5b1 whose height continuously decreases from an outer peripheral side toward an inner peripheral side is provided. In a tooth bottom surface of the fixed scroll 3 facing a tooth tip of the wall inclined portion 5b1, an end plate inclined portion 3a1 (refer to FIG. 1A) which is inclined according to an inclination of the wall inclined portion 5b1 is provided. A continuously inclined portion is constituted by the wall inclined portion 5b1 and the end plate inclined portion 3a1. Similarly, a wall inclined portion 3b1 whose height is continuously inclined from the outer peripheral side toward the inner peripheral side is provided on the wall 3b of the fixed scroll 3, and an end plate inclined portion 5a1 facing a tooth tip of the wall inclined portion 3b1 is provided on the end plate 5a of the orbiting scroll 5.

(22) In addition, the meaning of the continuity in the inclined portion in the present embodiment is not limited to a smoothly connected inclination but also includes an inclined portion in which small step portions inevitably generated during processing are connected to each other in a stepwise fashion and the inclined portion is continuously inclined as a whole. However, the inclined portion does not include a large step portion such as a so-called stepped scroll.

(23) Coating is applied to the wall inclined portions 3b1 and 5b1 and/or the end plate inclined portions 3a1 and 5al. For example, the coating includes manganese phosphate processing, nickel phosphorus plating, or the like.

(24) As shown in FIG. 2, wall flat portions 5b2 and 5b3 each having a constant height are respectively provided on the innermost peripheral side and the outermost peripheral side of the wall 5b of the orbiting scroll 5. Each of the wall flat portions 5b2 and 5b3 is provided over a region of 180° around a center O2 (refer to FIG. 1A) of the orbiting scroll 5. Wall inclined connection portions 5b4 and 5b5 which become curved portions are respectively provided at positions at which the wall flat portions 5b2 and 5b3 and the wall inclined portion 5b1 are connected to each other.

(25) Similarly, in the tooth bottom of the end plate 5a of the orbiting scroll 5, end plate flat portions 5a2 and 5a3 each having a constant height are provided. Each of the end plate flat portions 5a2 and 5a3 is provided over a region of 180° around the center of the orbiting scroll 5. End plate inclined connection portions 5a4 and 5a5 which become curved portions are respectively provided at positions at which the end plate flat portions 5a2 and 5a3 and the end plate inclined portion 5a1 are connected to each other.

(26) As shown by hatching in FIGS. 3 and 4, similarly to the orbiting scroll 5, in the fixed scroll 3, end plate flat portions 3a2 and 3a3, wall flat portions 3b2 and 3b3, end plate inclined connection portions 3a4 and 3a5, and wall inclined connection portions 3b4 and 3b5 are provided.

(27) FIG. 5 shows the walls 3b and 5b which are displayed to extend in a spiral direction. As shown in FIG. 5, the wall flat portions 3b2 and 5b2 on the innermost peripheral side are provided over a distance D2, and the wall flat portions 3b3 and 5b3 on the outermost peripheral side are provided over a distance D3. Each of the distance D2 and the distance D3 is a length corresponding to the region which becomes 180° around each of the centers O1 and O2 of the respective scrolls 3 and 5. The wall inclined portions 3b1 and 5b1 are provided over the distance D1 between the wall flat portions 3b2 and 5b2 on the innermost peripheral side and the wall flat portions 3b3 and 5b3 on the outermost peripheral side. If a height difference between each of the wall flat portions 3b2 and 5b2 on the innermost peripheral side and each of the wall flat portions 3b3 and 5b3 on the outermost peripheral side is defined as h, an inclination φ of each of the wall inclined portions 3b1 and 5b1 is represented by the following Expression.
φ=tan.sup.−1(h/D1)  (1)

(28) In this way, the inclination φ of the inclined portion is constant in a circumferential direction in which each of the spiral walls 3b and 5b extends.

(29) FIG. 6 is an enlarged view showing a region indicated by a reference sign Z in FIG. 1B in an enlarged manner. As shown FIG. 6, a tip seal 7 is provided in the tooth tip of the wall 3b of the fixed scroll 3. The tip seal 7 is formed of a resin such as Polyphenylenesulfide (PPS) and comes into contact with the tooth bottom of the end plate 5a of the facing orbiting scroll 5 so as to perform sealing for a fluid. The tip seal 7 is accommodated in a tip seal groove 3d which is formed on the tooth tip of the wall 3b in the circumferential direction. A compressed fluid enters the tip seal groove 3d, presses the tip seal 7 from a rear surface thereof to push the tip seal 7 toward the tooth bottom side, and thus, the tip seal 7 comes into contact with the facing the tooth bottom. In addition, a tip seal is also provided in the tooth tip of the wall 5b of the orbiting scroll 5.

(30) As shown in FIGS. 7A and 7B, a height Hc of the tip seal 7 in the height direction of the wall 3b is constant in the circumferential direction.

(31) If both the scrolls 3 and 5 perform the revolution orbiting movement relative to each other, the positions of the tooth tip and the tooth bottom are relatively deviated by an orbiting diameter (orbiting radius ρ×2). In the inclined portion, the tip clearance between the tooth tip and the tooth bottom is changed due to the positional deviation between the tooth tip and the tooth bottom. For example, in FIG. 7A, a tip clearance T is small, and in FIG. 7B, the tip clearance T is large. Even when the tip clearance T is changed by an orbiting movement, the tip seal 7 is pressed toward the tooth bottom side of the end plate 5a by the compressed fluid from the rear surface, and the tip seal 7 can follow the tooth bottom so as to perform sealing for the tooth bottom.

(32) FIG. 8 is a horizontal sectional view around the tooth tip when viewed from a sectional plane of the wall 3b of the fixed scroll 3 orthogonal in the spiral direction. In addition, the tooth tip of the orbiting scroll 5 and the tip seal 7 are similarly configured. The tip seal 7 is accommodated in the tip seal groove 3d formed on the tip of the wall 3b. A horizontal cross section of the tip seal 7 has a substantially rectangular shape, and includes a facing end plate side surface, that is, tooth tip side surface 7a, a back surface 7b, and side surfaces 7c. The surface 7a of the tip seal 7 comes into contact with a tooth bottom of the facing end plate so as to perform sealing.

(33) FIG. 9 shows a periphery of a connection region between a tip seal inclined portion 7A and a tip seal flat portion 7B of the tip seal 7. The tip seal inclined portion 7A is installed in the wall inclined portions 3b1 and 5b1 (refer to FIG. 5), and the tip seal flat portion 7B is installed in the wall flat portions 3b2, 3b3, 5b2, and 5b3 (refer to FIG. 5).

(34) The tip seal inclined portion 7A and the tip seal flat portion 7B are integrally formed and are fixed to each other at a connection position C1. Moreover, in the connection position C1, the surface 7a and the back surface 7b may be chamfered so as to be smoothly connected to each other.

(35) A plurality of concave portions 8 are formed on the surface 7a of the tip seal 7 at predetermined intervals along a longitudinal direction of the tip seal 7. When the tip seal 7 is resin-molded and released from a mold, each concave portion 8 is formed as a trace of a head shape of an extrusion pin on the surface 7a of the tip seal 7 when the tip seal 7 is pressed by the extrusion pin and taken out of the mold.

(36) As described with reference to FIGS. 7A and 7B, the tip clearance T is changed according to the orbiting movement of the scrolls 3 and 5, the tip seal inclined portion 7A moves toward or away from the facing tooth bottom. Accordingly, repeated stress is generated at the connection position C1 between the tip seal inclined portion 7A and the tip seal flat portion 7B, due to bending. In consideration of this, as shown in FIG. 9, each concave portion 8 is provided so as to avoid the adjacent regions across the connection position C1. The adjacent region is set to a region which is twice tip seal width Tw, which is a dimension orthogonal to the longitudinal direction of the tip seal 7, away from the connection position C1. Accordingly, the concave portion 8 is provided at a position away from the connection position C1 by twice or more tip seal width Tw.

(37) The above-described scroll compressor 1 is operated as follows. The orbiting scroll 5 performs the revolution orbiting movement around the fixed scroll 3 by a drive source such as an electric motor (not shown). Accordingly, the fluid is sucked from the outer peripheral sides of the respective scrolls 3 and 5, and the fluid is taken into the compression chambers surrounded by the respective walls 3b and 5b and the respective end plates 3a and 5a. The fluid in the compression chambers is sequentially compressed while being moved from the outer peripheral side toward the inner peripheral side, and finally, the compressed fluid is discharged from a discharge port 3c formed in the fixed scroll 3. When the fluid is compressed, the fluid is compressed in the height directions of the walls 3b and 5b in the inclined portions formed by the end plate inclined portions 3a1 and 5a1 and the wall inclined portions 3b1 and 5b1, and thus, the fluid is three-dimensionally compressed.

(38) According to the present embodiment, the following operational effects are exerted. The concave portion 8 is formed at the position avoiding the adjacent region between the tip seal inclined portion 7A and the tip seal flat portion 7B, and thus, the repeated stress in the adjacent region is reduced, and a risk of damages in the adjacent region can be reduced.

(39) Moreover, the configuration in which the concave portions 8 are formed on the surface 7a of the tip seal 7 is described. However, the concave portion 8 may be provided on the back surface 7b or the side surface 7c of the tip seal 7.

(40) In addition, as shown in FIG. 10, in a modification example of the present embodiment, a height of the tip seal inclined portion 7A may be set higher than a height of the tip seal flat portion 7B, that is, a thickness of the tip seal inclined portion 7A may increase to improve wear resistance.

(41) Moreover, the tip seal inclined portion 7A may use a material having the wear resistance higher than that of the tip seal flat portion 7B. For example, PolyEtherEtherKetone (PEEK) or polytetrafluoroethylene (PTFE) may be applied to the tip seal inclined portion 7A, or Diamond-LikeCarbon (DLC) coating or PTFE coating may be applied to a base material such as Polyphenylene sulfide (PPS). In this case, PPS or the like is used as a material of the tip seal flat portion 7B.

(42) In addition, the tip seal 7 may be divided into the tip seal inclined portion 7A and the tip seal flat portion 7B at the connection position C1 therebetween. Accordingly, it is possible to avoid occurrence of the repeated stress due to the bending at the connection position C1.

(43) Moreover, in the present embodiment, although the end plate inclined portions 3a1 and 5a1 and the wall inclined portions 3b1 and 5b1 are provided on both the scrolls 3 and 5. However, they may be provided in any one of the scrolls 3 and 5. Specifically, as shown in FIG. 11, in a case where the wall inclined portion 5b1 is provided in one wall (for example, orbiting scroll 5) and the end plate inclined portion 3a1 is provided in the other end plate 3a, the other wall and one end plate 5a may be flat. In addition, as shown in FIG. 12, a shape combined with a stepped shape of the related art may be adopted, that is, the shape in which the end plate inclined portion 3a1 is provided in the end plate 3a of the fixed scroll 3 may be combined with a shape in which the step portion is provided in the end plate 5a of the orbiting scroll 5.

(44) In the present embodiment, the wall flat portions 3b2, 3b3, 5b2, and 5b3 and the end plate flat portions 3a2, 3a3, 5a2, and 5a3 are provided. However, the flat portions on the inner peripheral side and/or the outer peripheral side may be omitted, and the inclined portion may be provided so as to extend to the entire walls 3b and 5b.

(45) In the present embodiment, the scroll compressor is described. However, the present invention can be applied to a scroll expander which is used as an expander.

REFERENCE SIGNS LIST

(46) 1: scroll compressor (scroll fluid machine) 3: fixed scroll (first scroll member) 3a: end plate (first end plate) 3a1: end plate inclined portion 3a2: end plate flat portion 3a3: end plate flat portion 3a4: end plate inclined connection portion 3a5: end plate inclined connection portion 3b: wall (first wall) 3b1: wall inclined portion 3b2: wall flat portion 3b3: wall flat portion 3b4: wall inclined connection portion 3b5: wall inclined connection portion 3c: discharge port 3d: tip seal groove (groove portion) 5: orbiting scroll (second scroll member) 5a: end plate (second end plate) 5a1: end plate inclined portion 5a2: end plate flat portion 5a3: end plate flat portion 5a4: end plate inclined connection portion 5a5: end plate inclined connection portion 5b: wall (second wall) 5b1: wall inclined portion 5b2: wall flat portion 5b3: wall flat portion 5b4: wall inclined connection portion 5b5: wall inclined connection portion 7: tip seal 7a: surface 7b: back surface 7c: side surface 7A: tip seal inclined portion 7B: tip seal flat portion 8: concave portion C1: connection position L: inter-facing surface distance T: tip clearance Tw: tip seal width φ: inclination