U.S. patent application number 11/157740 was filed with the patent office on 2006-12-21 for swash ring compressor with spherical bearing.
This patent application is currently assigned to Visteon Global Technologies, Inc.. Invention is credited to Michael Gregory JR. Theodore.
Application Number | 20060285981 11/157740 |
Document ID | / |
Family ID | 37563644 |
Filed Date | 2006-12-21 |
United States Patent
Application |
20060285981 |
Kind Code |
A1 |
Theodore; Michael Gregory
JR. |
December 21, 2006 |
Swash ring compressor with spherical bearing
Abstract
A variable displacement compressor includes a housing and a
rotatable shaft supported within the housing. A pin extends
generally outward from the shaft and includes a generally
cylindrical distal end. A sleeve is slidably mounted about the
shaft and rotates with the shaft. A swash ring is pivotally
supported on the sleeve by a pair of bearing pins that extend
radially outward from opposite sides of the sleeve and pivotally
engage the swash ring. The swash ring is rotatable with the shaft
and includes a radially inwardly open spherical pocket. A spherical
bearing insert is positioned within the pocket and the cylindrical
distal end of the pin slidably engages the spherical bearing
insert. The swash ring defines an adjustable angle with respect to
the longitudinal axis of the shaft. A biasing member engages the
sleeve and biases the sleeve along the shaft.
Inventors: |
Theodore; Michael Gregory JR.;
(Plymouth, MI) |
Correspondence
Address: |
VISTEON
C/O BRINKS HOFER GILSON & LIONE
PO BOX 10395
CHICAGO
IL
60610
US
|
Assignee: |
Visteon Global Technologies,
Inc.
|
Family ID: |
37563644 |
Appl. No.: |
11/157740 |
Filed: |
June 21, 2005 |
Current U.S.
Class: |
417/269 |
Current CPC
Class: |
F04B 27/1072
20130101 |
Class at
Publication: |
417/269 |
International
Class: |
F04B 27/08 20060101
F04B027/08 |
Claims
1. A variable displacement compressor comprising; a housing; a
shaft supported within the housing for rotational movement about an
axis running longitudinally therethrough; a pin extending generally
outward from the shaft and including a generally cylindrical distal
end; a sleeve mounted about the shaft, being slidable along the
shaft and rotatable with the shaft; a swash ring pivotally
supported on the sleeve by a pair of bearing pins, the bearing pins
being axially aligned with one another and extending radially
outward from diametrically opposed sides of the sleeve and
pivotally engaging the swash ring wherein the swash ring is
pivotable about an axis running longitudinally through the bearing
pins and perpendicularly through the axis of the shaft, the swash
ring being rotatable with the shaft and further including a
radially inwardly open spherical pocket; a spherical bearing insert
being positioned within the pocket, the cylindrical distal end of
the pin slidably engaging the spherical bearing insert thereby
pivotally coupling the swash ring to the distal end of the pin, the
swash ring further defining an angle with respect to the
longitudinal axis of the shaft, the angle being adjustable with
respect to the axis; a piston supported within the housing, the
piston coupled to the swash ring whereby rotation of the swash ring
causes reciprocating axial movement of the piston; and a biasing
member engaging the sleeve and biasing the sleeve along the
shaft.
2. The variable displacement compressor of claim 1 wherein the
biasing member is positioned between the sleeve and a structural
portion of the compressor.
3. The variable displacement compressor of claim 1 wherein the
shaft includes a snap ring groove having a snap ring positioned
therein and the biasing member is positioned between the sleeve and
the snap ring.
4. The variable displacement compressor of claim 1 wherein the
biasing member is a spring.
5. The variable displacement compressor of claim 1 wherein the
spherical bearing insert includes a cylindrical orifice extending
therethrough, the cylindrical distal end of the pin being received
within the cylindrical orifice of the spherical bearing insert.
6. The variable displacement compressor of claim 1 wherein the
spherical bearing insert is formed of a copper alloy.
7. The variable displacement compressor of claim 1 wherein the
swash ring is made from a non-ferrous alloy and the spherical
bearing is made from a ferrous alloy.
8. A variable displacement compressor comprising; a housing; a
shaft supported within the housing for rotational movement about an
axis running longitudinally therethorugh; a pin extending generally
outward from the shaft and including a generally cylindrical distal
end; a sleeve mounted about the shaft, being slidable along the
shaft and rotatable with the shaft; a swash ring pivotally
supported on said sleeve by a pair of bearing pins, the bearing
pins being axially aligned with one another and extending radially
outward from diametrically opposed sides of the sleeve and
pivotally engaging the swash ring wherein the swash ring is
pivotable about an axis running longitudinally through the bearing
pins and perpendicularly through the axis of the shaft, the swash
ring being rotatable with the shaft and further including a
radially inwardly open spherical pocket; a copper alloy spherical
bearing insert being positioned within the pocket, the spherical
bearing insert including a cylindrical orifice extending
therethrough, the cylindrical distal end of the pin being slidably
received within the cylindrical orifice, thereby pivotally coupling
the swash ring to the distal end of the pin, the swash ring further
defining an angle with respect to the longitudinal axis of the
shaft, the angle being adjustable with respect to the axis; a
piston supported within the housing, the piston coupled to the
swash ring whereby rotation of the swash ring causes reciprocating
axial movement of the piston; and a biasing member engaging the
sleeve and biasing the sleeve along the shaft.
9. The variable displacement compressor of claim 8 wherein the
biasing member is positioned between the sleeve and a structural
portion of the compressor.
10. The variable displacement compressor of claim 8 wherein the
shaft includes a snap ring groove having a snap ring positioned
therein and the biasing member is positioned between the sleeve and
the snap ring.
11. The variable displacement compressor of claim 8 wherein the
biasing member is a spring.
Description
BACKGROUND OF INVENTION
[0001] 1. Technical Field of the Invention
[0002] The present invention generally relates to a variable
displacement compressor having a swash ring construction. More
specifically, the present invention relates to a variable
displacement swash-ring compressor having spherical bearing.
[0003] 2. Description of the Prior Art
[0004] In an automotive vehicle equipped with air conditioning, a
compressor is used to pump coolant through the air conditioning
system to cool the vehicle. Most often, the compressor is driven by
a serpentine belt of the vehicle and, hence, the speed of the
compressor is controlled by the speed of the vehicle. In order to
provide consistent operation of the air conditioning system,
variable displacement compressors have been developed to allow the
compressor to provide constant performance at all vehicle speeds.
In a variable displacement compressor, higher displacement is
necessary when the vehicle is idling or running at low speeds. When
the vehicle is running at high speeds, the compressor is cycling
much more rapidly, and therefore can provide equivalent performance
at a lower displacement.
[0005] The typical automotive air conditioning compressor uses
multiple pistons to pump the coolant through the system. The
pistons are driven back and forth within the compressor by a plate
or ring that is attached to a rotating shaft. The plate or ring is
mounted at an angle relative to the shaft and engages each of the
pistons. Due to the angle of the ring, radial positions around a
periphery of the ring have varying axial positions within the
compressor. The pistons are fixed radially within the compressor
housing, so that as the shaft and ring rotate the pistons slide
along the periphery of the ring and are thereby moved axially back
and forth with rotations of the shaft and ring. Variable
displacement is achieved by limiting the stroke of the pistons.
Variable displacement compressors are available in three basic
types: 1) wobble plate compressors, 2) swash-plate compressors, or
3) swash ring compressors. The present invention is related to a
swash ring compressor.
[0006] In a swash ring compressor, the pistons within the
compressor are driven by a swash ring. Variable displacement, by
limiting the stroke of the pistons, is achieved by varying the
angle of the swash ring relative to the rotating shaft. U.S. Pat.
No. 6,164,252 describes the construction of a variable displacement
swash ring compressor and is hereby incorporated by reference into
the present application.
[0007] In the '252 patent, a sleeve is slidably mounted for limited
axial movement along the compressor's shaft and a swash ring is
pivotally mounted onto the sleeve. A pin, rigidly mounted within
and extending from the shaft, engages the swash ring at an axial
distance from the pivotal connection between the swash ring and the
sleeve. As the sleeve slides along the shaft, the swash ring moves
axially with the sleeve at the pivotal connection, but cannot move
axially at the point where the pin engages the swashring. This
causes the swash ring to pivot about the point where the pin
engages the swash ring, thereby changing the angle of the swash
ring relative to the shaft.
[0008] As a result of the pin transferring rotation to the swash
ring, the pin undergoes very high stresses and is therefore made
from very hard materials. The contact between the pin and a pocket
formed within the swash ring is generally a point contact, causing
very high stress at that point, leading to accelerated wear.
[0009] As seen from the above, there is a need to improve the
design of the pin/swash ring interface for a compressor so that the
compressor can be made more robust.
SUMMARY OF THE INVENTION
[0010] The disadvantages of the prior art are overcome by providing
a variable displacement swash ring compressor with a spherical
bearing insert that couples the pin to the swash ring. Use of the
spherical bearing insert spreads the loads out over a larger area
of the pocket within the swash ring, thereby reducing the point
loads and stresses.
[0011] In one aspect, the present invention is a compressor that
includes a shaft rotatably mounted within the compressor. A sleeve
is slidably supported on the shaft. A swash ring is pivotally
mounted onto the sleeve such that the swash ring is angularly
adjustable with respect to the shaft. A pin is fixedly mounted to
and extends from the shaft and has a cylindrical distal end. The
swash ring includes a radially inwardly open spherical pocket. A
spherical bearing insert is positioned within the pocket and the
cylindrical distal end of the pin slidably engages the spherical
bearing insert such that the distal end of the pin is pivotally
coupled to the swash ring. The connection between the swash ring
and the pin forces the swash ring to rotate with the shaft, while
allowing the swash ring to be angularly adjusted relative to the
shaft. The sleeve is further biased along the shaft by a spring
whose position may be varied.
[0012] In another aspect of the present invention, the spherical
bearing insert includes a cylindrical orifice extending
therethrough, the cylindrical distal end of the pin being received
within the cylindrical orifice of the spherical bearing insert.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above, as well as other advantages of the present
invention, will become readily apparent to those skilled in the art
from the following detailed description of a preferred embodiment
when considered in the light of the accompanying drawings in
which:
[0014] FIG. 1 is a sectional view of a swash-ring compressor of the
present invention;
[0015] FIG. 2 is a perspective view of the shaft, swash-ring and
sleeve of the compressor of FIG. 1;
[0016] FIG. 3 is a sectional view taken along lines 3-3 of FIG.
2;
[0017] FIG. 4 is an enlarged portion of FIG. 3 as indicated by the
circle labeled "FIG. 4" in FIG. 3;
[0018] FIG. 5 is a side view of the swash ring and sleeve showing
the engagement of the pin with the spherical bearing insert and
swash ring; and
[0019] FIG. 6 is a sectional view taken along line 6-6 of FIG.
2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] A complete description of a variable displacement swash-ring
compressor is found in U.S. Pat. No. 6,164,252 which has been
incorporated by reference into the present application.
[0021] Referring now to FIG. 1, a variable displacement piston
compressor of the present invention is shown generally at 10. The
compressor 10 includes a driven shaft 12 having a first end 14 and
a second end 16. The first and second ends 14, 16 of the shaft 12
are supported within a compressor housing 18 by bearing elements
20. The shaft 12 is adapted for rotational movement within the
compressor housing 18. Typically, the shaft 12 will have a pulley
(not shown) mounted to one of the ends 14, 16. The pulley engages a
serpentine belt of an automotive vehicle, although, the concepts of
the present invention would work on a compressor where the shaft 12
is driven by other means.
[0022] Referring now also to FIGS. 2 and 3, a sleeve 22 is slidably
supported on the shaft 12 and includes a first collar portion 24
and a second collar portion 26 at opposing ends thereof. The first
and second collar portions 24, 26 slidably support the sleeve 22 on
the shaft 12. A spring 28 is mounted on the shaft 12 to bias the
sleeve 22 along the shaft 12 for adjustment purposes of a swash
ring 30 further discussed below.
[0023] The spring 28 can be positioned between one of the collar
portions 24, 26 of the sleeve 22 and a structural portion of the
compressor 10. As shown in FIG. 3, the shaft 12 includes a snap
ring groove formed therein. A snap ring 52 is positioned within the
snap ring groove 50 to provide a stop to support the spring 28.
[0024] Referring to FIG. 6, the swash ring 30 is pivotally mounted
onto the sleeve 22. The sleeve 22 includes a pair of axially
aligned bearing pins 32. The bearing pins 32 extend radially
outward from diametrically opposite sides of the sleeve 22. The
swash ring 30 is pivotally supported on distal ends 34 of the
bearing pins 32 such that the swash ring 30 is pivotal about an
axis 36 running longitudinally through the bearing pins 32 and
perpendicular to and through a central axis 38 of the shaft 12. The
pivotal connection between the swash ring 30 and the sleeve 22
allows the angle of the swash ring 30 relative to the shaft 12 to
be adjusted.
[0025] Referring again to FIGS. 2 and 3, a pin 40 is mounted within
and extends from the shaft 12. A distal end 42 of the pin 40 is
generally cylindrical. The swash ring 30 includes a radially
inwardly open pocket 44. Referring to FIGS. 4 and 5, the pocket 44
is generally spherical in shape and is sized to receive and retain
a spherical bearing insert 46 therein. The spherical bearing insert
46 includes a cylindrical orifice 48 extending therethrough.
[0026] The distal end 40 of the pin 42 slidingly engages the
orifice 48 within the spherical bearing insert 46. The spherical
bearing insert 46 allows pivotal movement of the pin relative to
the swash ring such that the swash ring 30 is allowed to pivot
about the distal end 42 of the pin 40. However, the connection
between the distal end 42 of the pin 40 and the swash ring 30
forces the swash ring 30 to rotate with the shaft 12.
[0027] Because the shape of the pocket 44 and the spherical bearing
insert 46 are both generally spherical, the engagement between the
pocket 44 and the spherical bearing insert 46 is over a large
portion of the surface area of the pocket. This larger area of
engagement spreads the loads transferred between the pin 40 and the
swash ring 30 over the contact area, thereby reducing the point
loads that are experienced by the pin 40, the bearing insert 46,
and the swash ring 30. Because the loads experienced are low, the
spherical bearing insert 46 can be formed of a softer alloy, such
as copper alloys. The use of the spherical bearing insert 46 will
reduce the overall wear and tear experienced by the swash ring 30
and the pin 40, thereby increasing the life of the compressor
10.
[0028] The foregoing discussion discloses and describes the
preferred embodiment, and variations thereof, of the present
invention. One skilled in the art will readily recognize from such
discussion, and from the accompanying drawings and claims, that
changes and modifications can be made to the invention without
departing from the true spirit and fair scope of the invention as
defined in the following claims. The invention has been described
in an illustrative manner, and it is to be understood that the
terminology which has been used is intended to be in the nature of
words of description rather than of limitation.
* * * * *