[Technical Field]
[0001] The present invention relates to a scroll fluid machine.
[Background Art]
[0002] Generally, there is known a scroll fluid machine in which a fixed scroll member and
an orbiting scroll member provided with respective spiral walls on respective end
plates are engaged and revolved to compress or expand fluid.
[0003] As such a scroll fluid machine, a so-called stepped scroll compressor disclosed in
PTL 1 is known. In this stepped scroll compressor, respective step sections are provided
at positions along the spiral directions of tooth tip surfaces and tooth bottom surfaces
of spiral walls of a fixed scroll and an orbiting scroll, and the height of the outer
circumferential side of the wall is made higher than the height of the inner circumferential
side of the wall with each step section as a boundary. The stepped scroll compressor
performs compression not only in the circumferential direction of the walls, but also
in the height direction (three-dimensional compression), and therefore it is possible
to increase displacement and increase compressor capacity compared to a general scroll
compressor with no step section (two-dimensional compression).
[Citation List]
[Patent Literature]
[0004] [PTL 1] Japanese Unexamined Patent Application, Publication No.
2015-55173
[Summary of Invention]
[Technical Problem]
[0005] However, the stepped scroll compressor has a problem that fluid leakage at the step
sections is large. Further, there is a problem that stress is concentrated on root
portions of the step sections, and strength is reduced.
[0006] To cope with the above, the inventors are considering providing continuous inclined
sections in place of the step sections provided on the walls and the end plates.
[0007] However, even when the inclined sections are provided, it is not yet established
what is a proper degree of inclination for each inclined section.
[0008] The present invention has been made in view of such a circumstance, and an object
of the present invention is to provide a scroll fluid machine having inclined sections
in a wall and an end plate capable of effectively exhibiting performance.
[Solution to Problem]
[0009] In order to solve the aforementioned problems, a scroll fluid machine of the present
invention employs the following solutions.
[0010] That is, a scroll fluid machine according to an aspect of the present invention is
a scroll fluid machine including: a first scroll member provided with a spiral first
wall on a first end plate; and a second scroll member that is provided with a spiral
second wall on a second end plate disposed so as to face the first end plate, and
that relatively revolves by engagement between the second wall and the first wall,
wherein an inclined section that continuously reduces an inter-facing-surface distance
between the first end plate and the second end plate facing each other, from an outer
circumferential side toward an inner circumferential side of each of the first wall
and the second wall is provided, each of the inclined sections is provided over a
range of 180° or more around a spiral center, a groove section formed in a tooth tip
of each of the first wall and the second wall corresponding to the inclined sections
is provided with a tip seal that comes into contact with a facing tooth bottom to
seal fluid, where an orbiting radius of the scroll member that orbits is denoted by
ρ, and an inclination in a spiral direction of the inclined section is denoted by
ϕ, a tip clearance change amount ΔT is defined by an expression as follows:
and
the tip clearance change amount ΔT is 50% or less of a height dimension of the tip
seal in a height direction of the wall.
[0011] The inclined section that continuously reduces the inter-facing-surface distance
between the first end plate and the second end plate from the outer circumferential
side toward the inner circumferential side of each wall is provided, and therefore
fluid sucked from the outer circumferential side is not only compressed by reduction
of compression chambers in accordance with the spiral shape of the wall, but also
further compressed by reduction of the inter-facing-surface distance between the end
plates, toward the inner circumferential side.
[0012] The inclined sections are provided, and therefore the tip clearance between the tooth
tip and the tooth bottom changes in accordance with orbiting movement. Where the orbiting
radius of the scroll member that orbits is denoted by p, and the inclination in the
spiral direction of the inclined section is denoted by ϕ, the tip clearance change
amount ΔT in accordance with this orbiting movement is obtained by the expression
as follows:
[0013] The tip seal advances and retreats in the height direction from the groove section
by an amount in accordance with this tip clearance change amount ΔT. Therefore, when
the tip clearance change amount ΔT is large, the tip seal may be detached from the
groove section.
[0014] To cope with the above, the tip clearance change amount ΔT is made to be 50% or less
of the height dimension of the tip seal, so that drop of the tip seal is prevented.
[0015] More preferably, the tip clearance change amount ΔT is made to be 20% of less of
the height dimension of the tip seal.
[0016] A scroll fluid machine according to an aspect of the present invention is a scroll
fluid machine including: a first scroll member provided with a spiral first wall on
a first end plate; and a second scroll member that is provided with a spiral second
wall on a second end plate disposed so as to face the first end plate, and that relatively
revolves by engagement between the second wall and the first wall, wherein an inclined
section that continuously reduces an inter-facing-surface distance between the first
end plate and the second end plate facing each other, from an outer circumferential
side toward an inner circumferential side of each of the first wall and the second
wall is provided, each of the inclined sections is provided over a range of 180° or
more around a spiral center, where an orbiting radius of the scroll member that orbits
is denoted by ρ, and an inclination in a spiral direction of the inclined section
is denoted by ϕ, a tip clearance change amount ΔT is defined by an expression as follows:
and
a value obtained by dividing the tip clearance change amount ΔT by a height of an
outermost circumference of the wall is 0.01 or less.
[0017] The inclined section that continuously reduces the inter-facing-surface distance
between the first end plate and the second end plate from the outer circumferential
side toward the inner circumferential side of each wall is provided, and therefore
fluid sucked from the outer circumferential side is not only compressed by reduction
of compression chambers in accordance with the spiral shape of the wall, but also
further compressed by reduction of the inter-facing-surface distance between the end
plates, toward the inner circumferential side.
[0018] The inclined sections are provided, and therefore the tip clearance between the tooth
tip and the tooth bottom changes in accordance with orbiting movement. Where the orbiting
radius of the scroll member that orbits is denoted by p, and the inclination in the
spiral direction of the inclined section is denoted by ϕ, the tip clearance change
amount ΔT in accordance with this orbiting movement is obtained by the expression
as follows:
[0019] An oil film seal by lubricating oil is formed between the tooth tip and the tooth
bottom. However, when the tip clearance change amount ΔT is increased, the oil film
seal between the tooth tip and the tooth bottom may be broken, seal performance of
a compression chamber may be deteriorated, and efficiency may be reduced.
[0020] As a result of keen examination by the present inventors, it is found that when the
value obtained by dividing the tip clearance change amount ΔT by the height of the
outermost circumference of the wall is 0.01 or less, the oil film seal is maintained,
significant performance deterioration does not appear, and expected efficiency can
be maintained.
[0021] A scroll fluid machine according to an aspect of the present invention is a scroll
fluid machine including: a first scroll member provided with a spiral first wall on
a first end plate; and a second scroll member that is provided with a spiral second
wall on a second end plate disposed so as to face the first end plate, and that relatively
revolves by engagement between the second wall and the first wall, wherein an inclined
section that continuously reduces an inter-facing-surface distance between the first
end plate and the second end plate facing each other, from an outer circumferential
side toward an inner circumferential side of each of the first wall and the second
wall is provided, each of the inclined sections is provided over a range of 180° or
more around a spiral center, and a tip clearance between a tooth tip of the wall and
a tooth bottom of the end plate is set larger than a tip clearance reduction amount
based on a torsion angle around a center of the scroll member due to an assembly error.
[0022] The inclined section that continuously reduces the inter-facing-surface distance
between the first end plate and the second end plate from the outer circumferential
side toward the inner circumferential side of each wall is provided, and therefore
fluid sucked from the outer circumferential side is not only compressed by reduction
of compression chambers in accordance with the spiral shape of the wall, but also
further compressed by reduction of the inter-facing-surface distance between the end
plates, toward the inner circumferential side.
[0023] In the scroll fluid machine, when the first scroll member and the second scroll member
are assembled, an assembly error inevitably occurs due to dimensional accuracy of
an Oldham ring, or location accuracy of a centering pin or the like. When the assembly
error occurs, the scroll member is twisted around the center, and the tip clearance
between the tooth tip and the tooth bottom of the inclined sections is reduced on
the basis of the torsion angle.
[0024] To cope with the above, the tip clearance between the tooth tip and the tooth bottom
is set larger than the tip clearance reduction amount based on the torsion angle around
the center of the scroll member due to the assembly error, and interference between
the tooth tip and the tooth bottom is avoided.
[Advantageous Effects of Invention]
[0025] The tip clearance change amount ΔT (= 2ρ × tan ϕ) is made to be 50% or less of the
height dimension of the tip seal, so that it is possible to prevent drop of the tip
seal. Consequently, even when the wall and the end plate have the inclined sections,
it is possible to exhibit performance.
[0026] The value obtained by dividing the tip clearance change amount ΔT (= 2ρ × tan ϕ)
by the height of the outermost circumference of the wall is 0.01 or less, so that
the oil film seal is maintained, significant performance deterioration does not appear,
and expected efficiency can be maintained.
[0027] The tip clearance between the tooth tip and the tooth bottom is set larger than the
tip clearance reduction amount based on the torsion angle around the center of the
scroll member due to an assembly error, so that it is possible to avoid interference
between the tooth tip and the tooth bottom.
[Brief Description of Drawings]
[0028]
[Fig. 1A] Fig. 1A is a longitudinal sectional view illustrating a fixed scroll and
an orbiting scroll of a scroll compressor according to one embodiment of the present
invention.
[Fig. 1B] Fig. 1B is a plan view of the fixed scroll of Fig. 1A viewed from a wall
side.
[Fig. 2] Fig. 2 is a perspective view illustrating the orbiting scroll of Fig. 1.
[Fig. 3] Fig. 3 is a plan view illustrating end plate flat sections provided in the
fixed scroll.
[Fig. 4] Fig. 4 is a plan view illustrating a wall flat section provided in the fixed
scroll.
[Fig. 5] Fig. 5 is a schematic diagram illustrating a wall represented so as to extend
in the spiral direction.
[Fig. 6] Fig. 6 is a partially enlarged view illustrating an enlarged region of reference
symbol Z in Fig. 1B.
[Fig. 7A] Fig. 7A is a side view illustrating a tip seal clearance of a portion illustrated
in Fig. 6, and illustrating a state in which the tip seal clearance is relatively
small.
[Fig. 7B] Fig. 7B is a side view illustrating the tip seal clearance of the portion
illustrated in Fig. 6, and illustrating a state in which the tip seal clearance is
relatively large.
[Fig. 8] Fig. 8 is a graph illustrating an efficiency change rate to a tip clearance
change amount, according to a second embodiment of the present invention.
[Fig. 9A] Fig. 9A is a partially enlarged sectional view illustrating a portion between
a tooth tip and a tooth bottom, and illustrating a state in which an oil film seal
is formed.
[Fig. 9B] Fig. 9B is a partially enlarged sectional view illustrating a portion between
the tooth tip and the tooth bottom, and illustrating a state in which the oil film
seal is destroyed.
[Fig. 10] Fig. 10 is a plan view illustrating a fixed scroll and an orbiting scroll
according to a third embodiment of the present invention, viewed from a wall side
of a fixed scroll.
[Fig. 11A] Fig. 11A is a longitudinal sectional view illustrating a modified example,
and illustrating combination of scrolls having no step section.
[Fig. 11B] Fig. 11B is a longitudinal sectional view illustrating a modified example,
and illustrating combination of stepped scrolls.
[Description of Embodiments]
[First Embodiment]
[0029] Hereinafter, a first embodiment according to the present invention will be described
with reference to the drawings.
[0030] Fig. 1 illustrates a fixed scroll (first scroll member) 3 and an orbiting scroll
(second scroll member) 5 of a scroll compressor (scroll fluid machine) 1. The scroll
compressor 1 is used as a compressor that compresses a gas refrigerant (fluid) for
performing refrigerating cycle of an air conditioner or the like, for example.
[0031] The fixed scroll 3 and the orbiting scroll 5 are a compression mechanism made of
metal such as aluminum alloy and iron, and are housed in a housing (not illustrated).
The fixed scroll 3 and the orbiting scroll 5 suck, from the outer circumferential
side, fluid guided into the housing, and discharge the compressed fluid from a discharge
port 3c at the center of the fixed scroll 3 to the outside.
[0032] The fixed scroll 3 is fixed to the housing, and includes a substantially disk-shaped
end plate (first end plate) 3a, and a spiral wall (first wall) 3b erected on a side
surface of the end plate 3a, as illustrated in Fig. 1A. The orbiting scroll 5 includes
a substantially disk-shaped end plate (second end plate) 5a, and a spiral wall (second
wall) 5b erected on a side surface of the end plate 5a. The respective spiral shapes
of the walls 3b, 5b are each defined by using, for example, an involute curve or an
Archimedes curve.
[0033] The center of the fixed scroll 3 and the center of the orbiting scroll 5 are separated
by an orbiting radius p, are engaged such that the phases of the walls 3b, 5b are
shifted by 180°, and are assembled so as to have slight clearances (tip clearances)
in the height direction between tooth tips and tooth bottoms of the walls 3b, 5b of
both the scrolls at normal temperature. Consequently, a plurality of pairs of compression
chambers formed so as to be surrounded by the end plates 3a, 5a and the walls 3b,
5b are formed between the scrolls 3, 5 so as to be symmetrical with respect to the
scroll centers. The orbiting scroll 5 revolves around the fixed scroll 3 by a rotation
prevention mechanism such as an Oldham ring (not illustrated).
[0034] As illustrated in Fig. 1A, inclined sections that continuously reduce an inter-facing-surface
distance L between the facing end plates 3a, 5a from the outer circumferential sides
toward the inner circumferential sides of the spiral walls 3b, 5b are provided.
[0035] As illustrated in Fig. 2, a wall inclined section 5b1 having a height that continuously
reduces from the outer circumferential side toward inner circumferential side is provided
in the wall 5b of the orbiting scroll 5. An end plate inclined section 3a1 (see Fig.
1A) that inclines in accordance with inclination of the wall inclined section 5b1
is provided in a tooth bottom surface of the fixed scroll 3 facing a tooth tip of
this wall inclined section 5b1. The continuous inclined section is formed by these
wall inclined section 5b1 and end plate inclined section 3a1. Similarly, a wall inclined
section 3b1 having a height that continuously inclines from the outer circumferential
side toward inner circumferential side is provided in the wall 3b of the fixed scroll
3, and an end plate inclined section 5a1 facing a tooth tip of this wall inclined
section 3b1 is provided in the end plate 5a of the orbiting scroll 5.
[0036] The meaning of "continuously" in the inclined section mentioned in this embodiment
is not limited to smoothly connected inclination, but includes inclination that is
formed by stepwisely connecting small steps inevitably generated in machining, and
that is an inclined section continuously inclined as a whole. However, the above meaning
does not include a large step such as a so-called stepped scroll.
[0037] The wall inclined sections 3b1, 5b1 and/or the end plate inclined sections 3a1, 5a1
are coated. Examples of the coating include manganese phosphate treatment, and nickel-phosphorus
plating.
[0038] As illustrated in Fig. 2, wall flat sections 5b2, 5b3 each having a constant height
are provided on the innermost circumferential side and the outermost circumferential
side of the wall 5b of the orbiting scroll 5, respectively. These wall flat sections
5b2, 5b3 are each provided over a region of 180° around the center 02 (see Fig. 1A)
of the orbiting scroll 5. Wall inclined connecting sections 5b4, 5b5 serving as bent
sections are provided at respective positions where the wall flat sections 5b2, 5b3
and the wall inclined section 5b1 are connected.
[0039] Similarly, end plate flat sections 5a2, 5a3 each having a constant height are provided
on a tooth bottom of the end plate 5a of the orbiting scroll 5. These end plate flat
sections 5a2, 5a3 are also each provided over a region of 180° around the center of
the orbiting scroll 5. End plate inclined connecting sections 5a4, 5a5 serving as
bent sections are provided at respective positions where the end plate flat sections
5a2, 5a3 and the end plate inclined section 5a1 are connected.
[0040] As illustrated by hatching in Fig. 3 and Fig. 4, end plate flat sections 3a2, 3a3,
wall flat sections 3b2, 3b3, end plate inclined connecting sections 3a4, 3a5, and
wall inclined connecting sections 3b4, 3b5 are provided in the fixed scroll 3, like
the orbiting scroll 5.
[0041] Fig. 5 illustrates the walls 3b, 5b represented so as to extend in the spiral direction.
As illustrated in Fig. 5, the wall flat sections 3b2, 5b2 on the innermost circumferential
sides are each provided so as to extend over a distance D2, and the wall flat sections
3b3, 5b3 on the outermost circumferential sides are each provided so as to extend
over a distance D3. The distance D2 and the distance D3 are equivalent to the lengths
of the regions of 180° (180° or more and 360° or less, preferably 210° or less) around
the centers O1, O2 of the scrolls 3, 5. The wall inclined sections 3b1, 5b1 are provided
between the wall flat sections 3b2, 5b2 on the innermost circumferential sides and
the wall flat sections 3b3, 5b3 on the outermost circumferential sides so as to extend
over a distance D1. Where each of height differences between the wall flat sections
3b2, 5b2 on the innermost circumferential sides and the wall flat sections 3b3, 5b3
on the outermost circumferential sides is denoted by h, the inclination ϕ of each
of the wall inclined sections 3b1, 5b1 is expressed by the following expression.
[0042] Thus, the inclination ϕ in the inclined section is constant with respect to the circumferential
direction in which each of the spiral walls 3b, 5b extends. The distance D1 is longer
than the distance D2, and is longer than the distance D3.
[0043] For example, in this embodiment, the specifications of the scrolls 3, 5 are as follows.
- (1) Orbiting radius ρ [mm]: 2 or more and 15 or less, preferably 3 or more and 10
or less
- (2) The number of turns of each of the walls 3b, 5b: 1.5 or more and 4.5 or less,
preferably 2.0 or more and 3.5 or less
- (3) Height difference h [mm]: 2 or more and 20 or less, preferably 5 or more and 15
or less
- (4) h/Lout (wall height on outermost circumferential side): 0.05 or more and 0.35
or less, preferably 0.1 or more and 0.25 or less
- (5) Angular range of inclined section (angular range equivalent to distance D1) [°]:
180 or more and 1080 or less, preferably 360 or more and 720 or less
- (6) Angle Φ [°] of inclined section: 0.2 or more and 4 or less, preferably 0.5 or
more and 2.5 or less
[0044] In Fig. 6, an enlarged view of a region indicated by reference symbol Z in Fig. 1B
is illustrated. As illustrated in Fig. 6, a tip seal 7 is provided on the tooth tip
of the wall 3b of the fixed scroll 3. The tip seal 7 is made of resin, and comes into
contact with the tooth bottom of the end plate 5a of the facing orbiting scroll 5
to seal fluid. The tip seal 7 is housed in a tip seal groove 3d formed in the circumferential
direction of the tooth tip of the wall 3b. Compressed fluid enters this tip seal groove
3d, and the tip seal 7 is pressed from a back surface, and pressed out to the tooth
bottom side to be brought into contact with the facing tooth bottom. Similarly, a
tip seal is provided on the tooth tip of the wall 5b of the orbiting scroll 5.
[0045] When both the scrolls 3, 5 relatively revolve, the respective positions of the tooth
tip and the tooth bottom relatively shift by an orbiting diameter (orbiting radius
ρ × 2). In the inclined section, a tip clearance between the tooth tip and the tooth
bottom changes due to this position shift between the tooth tip and the tooth bottom.
A tip clearance change amount Δh [mm] is, for example, 0.05 or more and 1.0 or less,
preferably 0.1 or more and 0.6 or less. For example, the tip clearance T is small
in Fig. 7A, and the tip clearance T is large in Fig. 7B. Even when this tip clearance
T changes due to the orbiting movement, the tip seal 7 is pressed to the tooth bottom
side of the end plate 5a from the back surface by compressed fluid, and therefore
can seal following this pressing.
[0046] As illustrated in Fig. 7, a tip clearance change amount ΔT in which the tip clearance
T changes during a single orbit can be expressed by the following expression.
[0047] Herein, ρ denotes an orbiting radius.
[0048] The tip clearance change amount ΔT is 50% or less of the height dimension Hc of the
tip seal in the height direction of each of the walls 3b, 5b.
[0049] The aforementioned scroll compressor 1 is operated as follows.
[0050] The orbiting scroll 5 revolves around the fixed scroll 3 by a driving source such
as an electric motor (not illustrated). Consequently, fluid is sucked from the outer
circumferential sides of the scrolls 3, 5, and is taken in the compression chambers
surrounded by the walls 3b, 5b and the end plates 3a, 5a. The fluid in the compression
chambers is sequentially compressed in accordance with movement from the outer circumferential
side to the inner circumferential side, and the compressed fluid is finally discharged
from the discharge port 3c formed in the fixed scroll 3. When the fluid is compressed,
the fluid is compressed also in the height direction of the walls 3b, 5b in the inclined
sections formed by the end plate inclined sections 3a1, 5a1 and the wall inclined
sections 3b1, 5b1, and is three-dimensionally compressed.
[0051] According to this embodiment, the following working effects are exhibited.
[0052] To cope with the above, the tip clearance change amount ΔT is made to be 50% or less
of the height dimension Hc of the tip seal 7. Consequently, even when the tip seal
7 advances and retreats in the height direction from the tip seal groove 3d by an
amount in accordance with the tip clearance change amount ΔT, it is possible to avoid
detachment of the tip seal 7 from the tip seal groove 3d, and prevent drop of the
tip seal 7.
[0053] The tip clearance change amount ΔT may be 20% or less of the height dimension Hc
of the tip seal 7.
[Second Embodiment]
[0054] Now, a second embodiment of the present invention will be described.
[0055] This embodiment is different in a way of thinking about setting an upper limit of
a tip clearance change amount ΔT, and other configurations are similar. Therefore,
in the following description, only differences from the first embodiment will be described.
Other configurations are similar, and therefore description thereof will be omitted.
[0056] In this embodiment, ΔT/Lout which is a value obtained by dividing a tip clearance
change amount ΔT by the height of an outermost circumference of each of walls 3b,
5b (see reference symbol Lout of Fig. 2) is 0.01 or less. The reason will be described
with reference to Fig. 8 and Fig. 9.
[0057] In Fig. 8, a horizontal axis indicates ΔT/Lout, and a vertical axis indicates an
efficiency change rate. The efficiency change rate indicates a rate of efficiency
at predetermined ΔT/Lout in a case where the tip clearance change amount ΔT is zero,
that is, in a case where efficiency in a case of no inclination in a wall height,
a so-called two-dimensional scroll is 1. As illustrated in Fig. 8, when ΔT/Lout is
0.01, reduction of the efficiency change rate is less than 1%. Therefore, when ΔT/Lout
is 0.01 or less, the reduction of the efficiency change rate can be limited to be
less than 1%.
[0058] As illustrated in Fig. 9A, it is considered that in a range where ΔT/Lout is 0.01
or less, each tip clearance T is made to be a predetermined value or less, so that
oil film seals OS by lubricating oil are formed between tooth tips of the walls 3b,
5b and tooth bottoms of facing end plates 5a, 3a. Thus, since the oil film seal OS
in each tip clearance T is secured, fluid leakage in compression chambers is reduced,
and reduction of the efficiency change rate becomes small.
[0059] On the other hand, when ΔT/Lout becomes larger than 0.01, the tip clearance T increased,
and as illustrated in Fig. 9B, an oil film in each tip clearance T is separated, and
the oil film seal OS (see Fig. 9A) disappears, and fluid leakage in the compression
chambers occurs. Consequently, the efficiency change rate is significantly reduced.
[0060] As described above, according to this embodiment, ΔT/Lout is made to be 0.01 or less,
so that the oil film seal OS in each tip clearance T is maintained. Consequently,
it is possible to maintain expected efficiency.
[Third Embodiment]
[0061] Now, a third embodiment of the present invention will be described.
[0062] In this embodiment, setting of a lower limit of a tip clearance T will be described.
Other configurations are similar to those of each of the aforementioned embodiments.
Therefore, in the following description, only differences from each of the aforementioned
embodiments will be described. Other configurations are similar, and therefore description
thereof will be omitted. This embodiment can be used by combination with the first
embodiment or the second embodiment.
[0063] In this embodiment, as to setting of tip clearances T between tooth tips of walls
3b, 5b and tooth bottoms of end plates 5a, 3a, a torsion angle δθ around the center
of each of scrolls 3, 5 due to an assembly error is considered. As illustrated in
Fig. 10, when the scrolls 3, 5 are assembled to be operated, an assembly error inevitably
occurs due to dimensional accuracy of an Oldham ring, or location accuracy of a centering
pin or the like, and the torsion angle δθ is generated due to backlash generated around
the centers of the scrolls 3, 5. Fig. 10 is a diagram similar to Fig. 1B. Gas pressure
inside compression chambers is added during operation, and therefore the tooth tips
of the inclined sections of the walls 3b, 5b, and the tooth bottoms of the end plates
5a, 3a approach each other due to the backlash around the centers of the scrolls 3,
5, so that the tip clearances T reduce. Each of these tip clearance reduction amounts
δT is expressed by the following expression.
[0064] Herein, r denotes a radius on an outer circumferential side where an inclined section
starts, that is, a radius at each of wall inclined connecting sections 3b5, 5b5 (see
Figs. 2 and 5) on the outer circumferential sides of the walls 3b, 5b. ϕ denotes an
inclination of the inclined section (see Fig. 5). The torsion angle δθ can be obtained
by measurement of an actual object. The dimensions of portions that cause torsion
of the scrolls such as the dimensional accuracy of the Oldham ring and the location
accuracy of the centering pin are individually measured, and the torsion angle δθ
can be also obtained by calculation from these dimension.
[0065] In this embodiment, when the scrolls 3, 5 are assembled, each tip clearance T is
made larger than the tip clearance reduction amount δT obtained from the aforementioned
expression (3) obtained by considering the radius on the outer circumferential side
where the inclined section starts, the lip clearance reduction amount, and the inclination
ϕ of the inclined section. Consequently, it is possible to avoid interference between
the tooth tips and the tooth bottoms.
[0066] The end plate inclined sections 3a1, 5a1 and the wall inclined sections 3b1, 5b1
are provided in both the scrolls 3, 5 in each of the aforementioned embodiments, but
may be provided in either one.
[0067] Specifically, as illustrated in Fig. 11A, in a case where a wall inclined section
5b1 is provided in a first wall (for example, an orbiting scroll 5), and an end plate
inclined section 3a1 is provided in a second end plate 3a, a second wall and a first
end plate 5a may be flat.
[0068] As illustrated in Fig. 11B, a shape formed by combination with a conventional stepped
shape, that is, a shape, in which while an end plate inclined section 3a1 is provided
in an end plate 3a of a fixed scroll 3, a step section is provided in an end plate
5a of an orbiting scroll 5, may be combined.
[0069] In each of the aforementioned embodiment, the wall flat sections 3b2, 3b3, 5b2, 5b3
and the end plate flat sections 3a2, 3a3, 5a2, 5a3 are provided. However, the flat
sections on the inner circumferential sides and/or the outer circumferential sides
may be omitted, and the inclined sections may be provided so as to extend over the
entire walls 3b, 5b.
[0070] The present invention is applied to a scroll compressor in each of the aforementioned
embodiments, but can be also applied to a scroll expander used as an expander.
[Reference Signs List]
[0071]
1 scroll compressor (scroll fluid machine)
3 fixed scroll (first scroll member)
3a end plate (first end plate)
3a1 end plate inclined section
3a2 end plate flat section (inner circumferential side)
3a3 end plate flat section (outer circumferential side)
3a4 end plate inclined connecting section (inner circumferential side)
3a5 end plate inclined connecting section (outer circumferential side)
3b wall (first wall)
3b1 wall inclined section
3b2 wall flat section (inner circumferential side)
3b3 wall flat section (outer circumferential side)
3b4 wall inclined connecting section (inner circumferential side)
3b5 wall inclined connecting section (outer circumferential side)
3c discharge port
3d tip seal groove
5 orbiting scroll (second scroll member)
5a end plate (second end plate)
5a1 end plate inclined section
5a2 end plate flat section (inner circumferential side)
5a3 end plate flat section (outer circumferential side)
5a4 end plate inclined connecting section (inner circumferential side)
5a5 end plate inclined connecting section (outer circumferential side)
5b wall (second wall)
5b1 wall inclined section
5b2 wall flat section (inner circumferential side)
5b3 wall flat section (outer circumferential side)
5b4 wall inclined connecting section (inner circumferential side)
5b5 wall inclined connecting section (outer circumferential side)
7 tip seal
Hc height dimension of tip seal
L inter-facing-surface distance
OS oil film seal
T tip clearance
ΔT tip clearance change amount
δT tip clearance reduction amount
ϕ inclination
δθ torsion angle