U.S. patent application number 15/561141 was filed with the patent office on 2018-02-22 for wobble plate type variable displacement compressor.
The applicant listed for this patent is SANDEN HOLDINGS CORPORATION. Invention is credited to Kenji SUGINO.
Application Number | 20180051682 15/561141 |
Document ID | / |
Family ID | 57006786 |
Filed Date | 2018-02-22 |
United States Patent
Application |
20180051682 |
Kind Code |
A1 |
SUGINO; Kenji |
February 22, 2018 |
Wobble Plate Type Variable Displacement Compressor
Abstract
The whirling vibration of a rotating main shaft is reduced to
decrease abnormal wear of a wobble plate rotation preventing
mechanism, so that durability is improved. A inner ring 27 of a
wobble plate rotation preventing mechanism 21 has a first support
portion 52 of which an outer peripheral surface is supported by an
inner peripheral surface of a guide hole 2A of a cylinder block 2
and a second support portion 53 of which an inner peripheral
surface supports the rotating main shaft via a plain bearing 51,
and the first support portion 52 and the second support portion 53
are arranged to overlap within a range from a minimum inclination
angle of a swash plate 8 to a maximum inclination angle of the
swash plate 8 in an axial direction of a rotating main shaft 5.
Inventors: |
SUGINO; Kenji; (Isesaki-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SANDEN HOLDINGS CORPORATION |
Isesaki-shi |
|
JP |
|
|
Family ID: |
57006786 |
Appl. No.: |
15/561141 |
Filed: |
March 15, 2016 |
PCT Filed: |
March 15, 2016 |
PCT NO: |
PCT/JP2016/058123 |
371 Date: |
September 25, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 27/0895 20130101;
F04B 27/1063 20130101; F04B 27/12 20130101; F04B 27/16 20130101;
F04B 27/18 20130101; F04B 27/10 20130101; F04B 27/1072
20130101 |
International
Class: |
F04B 27/12 20060101
F04B027/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2015 |
JP |
2015-071563 |
Claims
1. A wobble plate type variable displacement compressor comprising:
a rotating main shaft of which a front end side and a rear end side
are rotatably supported by a housing; a swash plate which
synchronously rotates with the rotating main shaft and is
inclinable with respect to the rotating main shaft; a wobble plate
which swings along with the rotation of the swash plate with
respect to the rotating main shaft to reciprocate a piston in a
cylinder bore; and a wobble plate rotation preventing mechanism
which is disposed at a middle portion of the rotating main shaft,
and prevents the wobble plate from rotating at the time of rotating
the rotating main shaft, an inclination angle of the swash plate
with respect to the rotating main shaft being varied to control a
stroke amount of the piston, wherein the wobble plate rotation
preventing mechanism including: a guide member which includes a
first support portion of which an outer peripheral surface is
supported by an inner peripheral surface of a guide hole in the
housing to be movable in an axial direction of the rotating main
shaft and prevented from rotating around the rotating main shaft;
and a connecting mechanism which connects the wobble plate to the
guide member so that the wobble plate is swingable with respect to
the guide member and rotation preventing force of the guide member
is transmitted, the guide member further including a second support
portion of which an inner peripheral surface supports the rotating
main shaft, and the first support portion and the second support
portion being arranged to overlap in the axial direction of the
rotating main shaft.
2. The wobble plate type variable displacement compressor according
to claim 1, wherein the first support portion and the second
support portion is arranged to overlap within a range from a
minimum inclination angle of the swash plate to a maximum
inclination angle of the swash plate in the axial direction of the
rotating main shaft.
3. The wobble plate type variable displacement compressor according
to claim 1, wherein the connecting mechanism which connects the
wobble plate to the guide member is a constant velocity universal
joint.
4. The wobble plate type variable displacement compressor according
to claim 3, wherein the connecting mechanism includes: a plurality
of guide grooves formed on the guide member for guiding balls
provided for power transmission; a supporting member which has a
plurality of guide grooves for guiding the balls at positions
facing the respective guide grooves of the guide member and which
fixedly supports the wobble plate on an outer peripheral portion of
the supporting member and rotatably supports the swash plate on an
outer peripheral portion of the supporting member via a bearing; a
plurality of balls which is held by the guide grooves facing each
other and performs power transmission by being compressed between
the guide grooves; and a sleeve which swingably supports the
supporting member and is engaged with the guide member to be
movable in the axial direction together therewith on the rotating
main shaft, and of which an inner peripheral surface supports the
rotating main shaft.
5. The wobble plate type variable displacement compressor according
to claim 1, wherein the connecting mechanism which connects the
wobble plate to the guide member is a universal joint.
Description
TECHNICAL FIELD
[0001] The present invention relates to a wobble plate type
variable displacement compressor in which a piston is reciprocated
by a wobble plate which swings along with the rotation of a
rotating main shaft, and specifically, relates to a wobble plate
type variable displacement compressor used in a refrigerant
circulating device for a vehicle air conditioning system, and the
like.
BACKGROUND ART
[0002] As this type of wobble plate type variable displacement
compressor, a compressor disclosed in Patent Document 1 has been
proposed. In the wobble plate type variable displacement compressor
disclosed in Patent Document 1, a piston support is swung along
with rotation of a swash plate synchronously rotating with a main
shaft of which a front end side and a rear end side are rotatably
supported by a housing via bearings, to thereby reciprocate the
piston in a cylinder bore. Furthermore, by providing a rotation
preventing mechanism of the piston support on a middle portion of
the main shaft, and devising a structure of the rotation preventing
mechanism, the whirling vibration of the main shaft occurring when
the compressor is driven and noise occurring therefrom are
reduced.
REFERENCE DOCUMENT LIST
Patent Document
[0003] Patent Document 1: JP H05-99137 A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0004] In the rotation preventing mechanism of the wobble plate
type variable displacement compressor disclosed in Patent Document
1, onto the outer periphery of a swash plate sleeve which is
installed so as to be movable in an axial direction with respect to
a main shaft and rotatable integrally with the main shaft, a
support sleeve is externally fitted to be rotatable relative to the
swash plate sleeve, and the support sleeve is supported in the
guide hole of a cylinder block (constituting a part of the housing)
to be movable only in the axial direction of the main shaft. That
is, the main shaft is supported on the inner peripheral surface of
the support sleeve via the swash plate sleeve, and the support
sleeve is supported in the guide hole of the cylinder block.
However, since the supporting portion of the support sleeve which
supports the main shaft and the supported portion of the support
sleeve which is supported in the guide hole of the cylinder block
do not overlap in the axial direction of the main shaft, with
respect to the whirling vibration of the main shaft occurring when
the compressor is driven, the support sleeve is supported by a
cantilever structure, and thus, the effect of reducing the whirling
vibration of the main shaft is insufficient.
[0005] The present invention has been made by focusing on the
abovementioned problem, and it is an object of the invention to
provide a wobble plate type variable displacement compressor which
is able to sufficiently reduce the whirling vibration of the
rotating main shaft by modifying the mounting structure of the
rotation preventing mechanism.
Means for Solving the Problems
[0006] Thus, a wobble plate type variable displacement compressor
of the present invention includes: a rotating main shaft of which a
front end side and a rear end side are rotatably supported by a
housing; a swash plate which synchronously rotates with the
rotating main shaft and is inclinable with respect to the rotating
main shaft; a wobble plate which swings along with the rotation of
the swash plate with respect to the rotating main shaft to thereby
reciprocate a piston in a cylinder bore; a wobble plate rotation
preventing mechanism disposed at a middle portion of the rotating
main shaft and prevents the wobble plate from rotating at the time
of rotating the rotating main shaft. In the wobble plate type
variable displacement compressor, an inclination angle of the swash
plate with respect to the rotating main shaft is varied to thereby
control a stroke amount of the piston. The wobble plate rotation
preventing mechanism includes: a guide member which has a first
support portion of which an outer peripheral surface is supported
on an inner peripheral surface of a guide hole in the housing to be
movable in an axial direction of the rotating main shaft and
prevented from rotating around the rotating main shaft; and a
connecting mechanism which connects the wobble plate to the guide
member so that the wobble plate is swingable with respect to the
guide member and rotation preventing force of the guide member is
transmitted. The guide member further includes a second support
portion of which an inner peripheral surface supports the rotating
main shaft. The first support portion and the second support
portion are arranged to overlap in the axial direction of the
rotating main shaft.
Effects of the Invention
[0007] According to the wobble plate type variable displacement
compressor of the present invention, it is possible to reduce the
whirling vibration of the main shaft occurring when the compressor
is driven. Thus, it is possible to improve the contact state of
each part of the wobble plate rotation preventing mechanism and
reduce the abnormal wear of the wobble plate rotation preventing
mechanism, so that the durability of the wobble plate type variable
displacement compressor is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a sectional view illustrating a configuration
example of a wobble plate type variable displacement compressor
according to an embodiment of the present invention.
[0009] FIG. 2 is a sectional view illustrating the wobble plate
type variable displacement compressor of FIG. 1 in another
operating state.
[0010] FIG. 3 is an exploded perspective view illustrating a main
part including a wobble plate rotation preventing mechanism of the
wobble plate type variable displacement compressor of FIG. 1.
[0011] FIGS. 4A and 4B are a view illustrating an example of the
wobble plate rotation preventing mechanism of the wobble plate type
variable displacement compressor of FIG. 1, FIG. 4A being a partial
sectional view and FIG. 4B being a partial front view.
MODE FOR CARRYING OUT THE INVENTION
[0012] Hereinafter, an embodiment of the present invention is
explained with reference to the accompanying drawings.
[0013] A configuration example of an embodiment of a wobble plate
type variable displacement compressor according to the present
invention will be described with reference to FIGS. 1 to 4A and
4B.
[0014] FIG. 1 is a configuration example of a wobble plate type
variable displacement compressor according to the present
embodiment, and shows the operating state when the discharge
displacement is maximum and when the inclination angle of a swash
plate is maximum. FIG. 2 shows the operating state of the wobble
plate type variable displacement compressor of FIG. 1 when the
discharge displacement is minimum and when the inclination angle of
the swash plate is minimum. FIG. 3 is an exploded perspective view
illustrating a main part including the wobble plate rotation
preventing mechanism of the wobble plate type variable displacement
compressor of FIG. 1. FIGS. 4A and 4B show an example of a wobble
plate rotation preventing mechanism of the wobble plate type
variable displacement compressor of FIG. 1.
[0015] In the wobble plate type variable displacement compressor 1,
the inclination angle of the swash plate which synchronously
rotates with the rotating main shaft is varied with respect to the
rotational main shaft, to change the wobble width of the wobble
plate which swings along with rotation of the swash plate with
respect to the rotational main shaft, to control a stroke amount of
a piston, so that a refrigerant discharge displacement from a
cylinder bore is varied.
[0016] In the wobble plate type variable displacement compressor 1
of FIG. 1, a housing is made up of a cylinder block 2 disposed at a
middle portion, a front housing 3 disposed on a front side of the
cylinder block 2, and a rear housing 4 disposed on a rear side of
the cylinder block 2. A rotating main shaft 5 to which a rotational
driving force is input from outside is provided to penetrate from
the front housing 3 to a portion of the cylinder block 2. The front
end portion of the rotating main shaft 5 is rotatably supported on
the front housing 3 via a bearing 33 (radial bearing), and a rear
end portion of the rotating main shaft 5 is rotatably supported on
a fixed wall inside the cylinder block 2 via a bearing 22 (thrust
bearing). To the rotating main shaft 5, a rotor 6 is fixed to be
rotatable integrally therewith, and a thrust bearing 32 is
interposed between the rotor 6 and the front housing 3. To the
rotor 6, a swash plate 8 is connected via a hinge mechanism 7 so as
to be inclined with respect to the rotating main shaft 5 and
synchronously rotatable with the rotating main shaft 5. A piston 10
is inserted into each cylinder bore 9 arranged in an inner
peripheral edge portion of the cylinder block 2 so as to be
reciprocated, and the piston 10 is connected to a wobble plate 12
via a connecting rod 11. A thrust bearing 31 is interposed between
the wobble plate 12 and the swash plate 8. The wobble plate 12
swings along with rotation of the swash plate 8 to reciprocate the
piston 10 via the connecting rod 11. Along with the reciprocation
of the piston 10, a fluid (for example, refrigerant gas) to be
compressed is drawn from a suction chamber 13 formed in an inner
peripheral edge portion of the rear housing 4 into the cylinder
bore 9 through a suction hole 15 (a suction valve is not shown in
the drawing) formed in a valve plate 14, and the drawn fluid is
compressed. The compressed fluid is discharged into a discharge
chamber 17 formed in an inner central portion of the rear housing 4
through a discharge hole 16 (discharge valve not shown in the
drawing), and thereafter, the discharged fluid is sent to an
external circuit.
[0017] The wobble plate 12 swings in a state in which a wobble
plate rotation preventing mechanism 21 disposed at a middle portion
of the rotating main shaft 5, prevents the wobble plate 12 from
rotating. Hereinafter, the wobble plate rotation preventing
mechanism 21 will be explained.
[0018] The wobble plate rotation preventing mechanism 21 is movable
in an axial direction of the rotating main shaft 5, and an inner
ring rotation preventing mechanism described later prevents the
wobble plate rotation preventing mechanism 21 from rotating around
the rotating main shaft 5. The wobble plate rotation preventing
mechanism 21 includes an inner ring 27 as a guide member and a
connecting mechanism which connects the wobble plate 12 to the
inner ring 27. The inner ring 27 has a first support portion 52 of
which an outer peripheral surface is supported by an inner
peripheral surface of a guide hole 2A of the cylinder block 2 so as
to be movable in the axial direction of the rotating main shaft 5
and prevented from rotating therearound, and a second support
portion 53 of which an inner peripheral surface supports the
rotating main shaft 5 via a plain bearing 51 mounted on the inner
peripheral surface. Furthermore, the connecting mechanism is
configured as a so-called constant velocity universal joint. The
connecting mechanism includes a plurality of guide grooves 26
formed on the inner ring 27 for guiding balls provided for power
transmission, an outer ring 30 which has a plurality of guide
grooves 28 for guiding the balls at positions facing the respective
guide grooves 26 of the inner ring 27 and which functions as a
supporting member which fixedly supports the wobble plate 12 on an
outer peripheral portion of the outer ring 30 and rotatably
supports the swash plate 8 on an outer peripheral portion of the
outer ring 30 via a bearing 29 (radial bearing), a plurality of
balls 25 held by the guide grooves 26, 28 facing each other and
formed in the inner ring 27 and the outer ring 30, respectively,
and performing power transmission by being compressed between the
guide grooves 26, 28, and a sleeve 24 which supports the rotating
main shaft 5 via a bearing 23 (radial bearing) and is provided so
as to be rotatable relative to the rotating main shaft 5 and be
movable in the axial direction thereof, the sleeve 24 swingably
supporting the outer ring 30 and being engaged with the inner ring
27 to be movable in the axial direction together therewith on the
rotating main shaft 5. The outer ring 30 is swingable about the
sleeve 24 relative to the inner ring 27 through spherical surface
contact between the balls 25 and the guide grooves 26, 28 facing
each other. Furthermore, a rotation preventing force from the side
of the inner ring 27 is transmitted to the side of the outer ring
30 through the spherical surface contact between the balls 25 and
the guide grooves 26, 28.
[0019] The abovementioned inner ring rotation preventing mechanism
is configured by an abutting structure in which the guide hole 2A
of the cylinder block 2 is abutted against the outer peripheral
surface of the inner ring 27 when the rotating main shaft 5
rotates. Specifically, the outer peripheral surface of the inner
ring 27 has three peripheral surfaces formed in a substantially
triangular shape of which each angle formed by adjacent peripheral
surfaces is 60 degrees. Furthermore, the guide hole 2A of the
cylinder block 2 is also has three peripheral surfaces formed in a
substantially triangular shape of which each angle formed by
adjacent peripheral surfaces is 60 degrees so as to correspond to
the outer peripheral surface of the inner ring 27. At the time of
rotating the inner ring 27 along with rotation of a rotating main
shaft 5 with respect to the cylinder block 2, each edge portion of
peripheral surfaces of the inner ring 27 is abutted against each
peripheral surface of the guide hole 2A of the cylinder block 2 to
prevent the inner ring 27 from rotating.
[0020] The inner ring rotation preventing mechanism in the wobble
plate rotation preventing mechanism 21 of the present embodiment is
not limited to the abovementioned abutting structure, but may be a
general rotation restricting mechanism such as a key or a
spline.
[0021] FIGS. 4A and 4B show a state in which the relative angle
between the inner and outer rings 27, 30 is zero in the wobble
plate rotation preventing mechanism 21. As shown in FIG. 4A, the
guide grooves 26, 28 formed on the inner ring 27 and the outer ring
30 of the wobble plate rotation preventing mechanism 21 are
disposed to be inclined at relative angles (relative angles within
a range of 30 to 60 degrees) relative to the center axis of the
rotating main shaft 5. The guide groove 26 formed on the inner ring
27 (an axis of the guide groove 26 is indicated by symbol 42) and
the guide groove 28 formed on the outer ring 30 (an axis of the
guide groove 28 is indicated by symbol 43), which form one ball
guide 41 and face each other, are disposed so as to be
symmetrically formed relative to a plane 44 which is perpendicular
to the rotating main shaft 5 and passes through the wobble center
of the wobble plate 12, in a state in which the relative angle
between the axis of the inner ring 27 and the axis of the outer
ring 30 is zero. The ball 25 is regulated and supported on the
intersection of the axis 42 of the guide groove 26 and the axis 43
of the guide groove 28. Furthermore, as shown in FIG. 4B, a
structure can be employed in which two ball guides adjacent to each
other among a plurality of the ball guides 41 of the wobble plate
rotation preventing mechanism 21 are referred to be a pair of ball
guides, and the respective ball guides 41 in the pair of ball
guides 45, in other words, axes 46 of the guide grooves formed on
the inner and outer rings in this portion, are disposed in parallel
to each other. In such a structure, as aforementioned, since the
play in the rotational direction in the wobble plate rotation
preventing mechanism portion is schematically decided by a relation
between the distance between the bottoms of the pair of guide
grooves provided on the inner and outer rings 27, 30 and the
diameter of the balls, setting and management of a clearance are
facilitated to thereby suppress the play so that the play is small
by setting a proper clearance. The plurality of balls 25 are
supported in the compression direction between the guide grooves
26, 28 facing each other through the respective balls, and perform
power transmission. Since the ball 25 is held by the guide grooves
26, 28 facing each other so as to be embraced and comes into
contact with both guide grooves 26, 28, a sufficiently large
contact area between the ball 25 and the respective guide grooves
26, 28 may be ensured to reduce the contact surface pressure, so
that a structure is remarkably advantageous in reliability,
vibration and quiet performance. Furthermore, it is also possible
to make the diameter of the balls 25 small, so that it is possible
to reduce the size of the entire wobble plate rotation preventing
mechanism 21.
[0022] Furthermore, the load applied to the ball 25, which is
provided as a moment about the rotating main shaft 5, is generated
as a normal reaction of an actual contact surface. The smaller
inclination of a normal line of the contact surface relative to the
direction of the moment is, the smaller the contact load becomes,
and by a structure in which the pair of ball guides 45 disposed in
parallel as described above are disposed symmetrically relative to
a plane including a center axis 5a of the rotating main shaft 5, in
other words, by a structure in which the axes 46 of two sets of
guide grooves formed on the inner and outer rings 27, 30 are
disposed symmetrically relative to the plane including the center
axis 5a of the rotating main shaft 5, the mechanism is made as a
wobble plate rotation preventing mechanism which does not select
the rotational direction, and it is possible to minimize the ball
contact load.
[0023] In the abovementioned wobble plate rotation preventing
mechanism 21, the inner ring 27 including the first support portion
52 of which the outer peripheral surface is supported by the inner
peripheral surface of the guide hole 2A of the cylinder block 2,
further includes the second support portion 53 of which the inner
peripheral surface supports the rotating main shaft 5. The first
support portion 52 and the second support portion 53 of the inner
ring 27 are arranged to overlap in the axial direction of the
rotating main shaft 5, and the wobble plate rotation preventing
mechanism 21 has a function of reducing the whirling vibration of
the rotating main shaft 5. Specifically, in this embodiment,
assuming that the inclination angle of the swash plate 8
perpendicular to the rotating main shaft 5 is 0.degree., within a
range from a minimum inclination angle of the swash plate 8 shown
in FIG. 2 to a maximum inclination angle of the swash plate 8
regulated by being abutted against the rotor 6 as shown in FIG. 1,
the first support portion 52 and the second support portion 53 are
arranged to overlap in the axial direction of the rotating main
shaft 5. However, the present invention is not limited to this. The
first support portion 52 and the second support portion 53 may
overlap at least at the minimum inclination angle of the swash
plate 8 and may not overlap when the swash plate 8 has the maximum
inclination angle, for example.
[0024] In the wobble plate type variable displacement compressor 1
according to the present embodiment, since the first support
portion 52 and the second support portion 53 are arranged to
overlap in the axial direction of the rotating main shaft 5, a
supporting structure of the middle portion of the rotating main
shaft 5 is not a cantilever structure as in the prior art. Thus, it
is possible to effectively reduce the whirling vibration of the
rotating main shaft 5 occurring when the compressor is driven.
Therefore, the rotating main shaft 5 is smoothly rotated, to
improve contact state of each part of the wobble plate rotation
preventing mechanism 21 and reduce abnormal wear of the wobble
plate rotation preventing mechanism 21 and the like. As a result,
it is possible to improve durability of the wobble plate type
variable displacement compressor 1. Furthermore, in the present
embodiment, the rotating main shaft 5 is also supported by the
sleeve 24, and thus, it is possible to further effectively reduce
the whirling vibration of the rotating main shaft 5 to improve the
durability of the wobble plate type variable displacement
compressor 1.
[0025] In the present embodiment, as the connecting mechanism which
connects the wobble plate 12 to the inner ring 27, by using the
constant velocity universal joint, the rotation speed to be
transmitted does not vary even when the inclination angle changes;
however, the present invention is not limited to this. For example,
by using a universal joint, the rotation speed to be transmitted
can be varied when the inclination angle changes.
[0026] Furthermore, in the present embodiment, the bearing 23 is
interposed between the sleeve 24 and the rotating main shaft 5;
however, the bearing 23 may be omitted and the rotating main shaft
5 may be directly supported by the sleeve 24.
[0027] Moreover, in the present embodiment, the plain bearing 51 is
interposed between the inner ring 27 and the rotating main shaft 5;
however, the plain bearing 51 may be omitted and the rotating main
shaft 5 may be directly supported on the inner peripheral surface
of the inner ring 27.
[0028] There may be a case in which the inner ring 27 is formed by
assembling a plurality of divided members, for example, two divided
members. In this case, the plurality of divided members (two
divided members, for example) is arranged between the rotating main
shaft and the guide hole to support the rotating main shaft on
inner surfaces of each divided member. The inner surfaces of each
divided member, that is, a surface facing the rotating main shaft
is also included in the "inner peripheral surface".
REFERENCE SYMBOL LIST
[0029] 1 wobble plate type variable displacement compressor [0030]
2 cylinder block [0031] 2A guide hole [0032] 5 rotating main shaft
[0033] 6 rotor [0034] 8 swash plate [0035] 9 cylinder bore [0036]
10 piston [0037] 12 wobble plate [0038] 21 wobble plate rotation
preventing mechanism [0039] 22, 33 radial bearing [0040] 24 sleeve
[0041] 25 ball [0042] 26 guide groove (inner ring side) [0043] 27
inner ring [0044] 28 guide groove (outer ring side) [0045] 30 outer
ring [0046] 51 plain bearing [0047] 52 first support portion [0048]
53 second support portion
* * * * *