U.S. patent application number 13/427104 was filed with the patent office on 2012-10-04 for compressor with transmission.
This patent application is currently assigned to KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. Invention is credited to Nobuaki HOSHINO, Koji KAWAMURA, Yoshio KIMOTO, Masaki OTA, Noriyuki SHINTOKU, Yusuke YAMAZAKI.
Application Number | 20120251347 13/427104 |
Document ID | / |
Family ID | 46845264 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120251347 |
Kind Code |
A1 |
KIMOTO; Yoshio ; et
al. |
October 4, 2012 |
COMPRESSOR WITH TRANSMISSION
Abstract
A compressor with a transmission includes a clutch that varies
the rotational speed of an output shaft between two different
speeds. The clutch includes a friction layer, which secures a ring
roller by movement of the ring roller in a first direction
(securing direction), a first control chamber, a first control
piston accommodated in the first control chamber and movable in the
direction of an input shaft axis, a first thrust bearing between
the first control piston and the ring roller, a second control
chamber facing the first control chamber, a second control piston
accommodated in the second control chamber and movable in the
direction of the axis), a second thrust bearing between the second
control piston and the ring roller, and a pressure control
mechanism, which controls a first control pressure supplied to the
first control chamber and a second control pressure supplied to the
second control chamber.
Inventors: |
KIMOTO; Yoshio; (Kariya-shi,
JP) ; SHINTOKU; Noriyuki; (Kariya-shi, JP) ;
OTA; Masaki; (Kariya-shi, JP) ; HOSHINO; Nobuaki;
(Kariya-shi, JP) ; KAWAMURA; Koji; (Kariya-shi,
JP) ; YAMAZAKI; Yusuke; (Kariya-shi, JP) |
Assignee: |
KABUSHIKI KAISHA TOYOTA
JIDOSHOKKI
Aichi-ken
JP
|
Family ID: |
46845264 |
Appl. No.: |
13/427104 |
Filed: |
March 22, 2012 |
Current U.S.
Class: |
417/319 |
Current CPC
Class: |
F04C 29/005 20130101;
F04C 18/0215 20130101; F04C 23/02 20130101; F04C 29/04 20130101;
F04C 28/08 20130101; F16H 3/62 20130101; F04C 29/0071 20130101 |
Class at
Publication: |
417/319 |
International
Class: |
F04C 18/00 20060101
F04C018/00; F25B 1/00 20060101 F25B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 28, 2011 |
JP |
2011-069103 |
Claims
1. A compressor with a transmission, comprising: a housing; a
compression mechanism formed in the housing and being capable of
compressing refrigerant; an input shaft extending into the housing
from the outside of the housing, the input shaft being supported to
be rotational about an axis; an output shaft extending in the
housing, the output shaft being supported to be rotational about
the axis and being capable of driving the compression mechanism; a
transmission mechanism located between the input shaft and the
output shaft in the housing, the transmission mechanism being
capable of driving the compression mechanism at two different
speeds by transmitting torque of the input shaft to the output
shaft and also transmitting the rotational speed of the input shaft
to the output shaft at an equal speed or an increased speed; and a
control mechanism for controlling the transmission mechanism,
wherein the transmission mechanism includes a planet roller
mechanism having a sun roller, a plurality of planet rollers, a
carrier, and a ring roller, the carrier rotationally retains the
planet rollers and is rotational integrally with the input shaft,
the sun roller engages with the planet rollers and is rotational
integrally with the input shaft, and the ring roller engages with
the planet rollers and is secured to the housing by moving relative
to the housing in a first direction parallel to the axis, and the
ring roller is rotational with respect to the housing by moving
relative to the housing in a second direction, which is opposite to
the first direction, wherein the control mechanism includes: a
one-way clutch arranged between the carrier and the ring roller,
wherein the one-way clutch permits relative rotation of the carrier
and the ring roller in one direction and restricts relative
rotation in the other direction; and a clutch arranged between the
housing and the ring roller, the clutch selectively restricting and
permitting rotation of the ring roller by engagement between the
housing and the ring roller, wherein the clutch includes: a
friction layer arranged between the housing and the ring roller,
the friction layer securing the ring roller to the housing by
movement of the ring roller in the first direction; a first control
chamber formed in the housing and open toward the ring roller; a
first control piston accommodated in the first control chamber and
movable in the direction of the axis; a first thrust bearing
arranged between the first control piston and the ring roller; a
second control chamber formed in the housing, the second control
chamber facing the first control chamber and open toward the ring
roller; a second control piston accommodated in the second control
chamber and movable in the direction of the axis; a second thrust
bearing arranged between the second control piston and the ring
roller; and a pressure control mechanism for controlling a first
control pressure supplied to the first control chamber and a second
control pressure supplied to the second control chamber.
2. The compressor with a transmission according to claim 1, wherein
the housing includes a transmission chamber for accommodating the
transmission mechanism, and a space in the transmission chamber is
isolated from the refrigerant.
3. The compressor with a transmission according to claim 2, wherein
the first control piston has a first control pressure receiving
area and the second control piston has a second control pressure
receiving area, the second control pressure receiving area being
set to be greater than the first control pressure receiving area,
the first control pressure is one of a suction pressure of the
refrigerant drawn into the compression mechanism and a discharge
pressure generated by the compression mechanism, and the second
control pressure is the suction pressure.
4. The compressor with a transmission according to claim 1, wherein
the first control piston and the second control piston each have an
annular shape coaxial with the axis, the first control piston
having an O-ring arranged between the first control piston and the
first control chamber, and the second control piston having an
O-ring arranged between the second control piston and the second
control chamber.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a compressor with a
transmission.
[0002] Japanese Laid-Open Patent Publication No. 2007-107412
discloses a conventional compressor with a transmission. The
compressor with a transmission includes a housing, a compression
mechanism, an input shaft, an output shaft, a transmission
mechanism, and a control mechanism. The compression mechanism is
provided in the housing and compresses refrigerant. The input shaft
extends into the housing from the outside of the housing and is
supported to be rotational about the axis. The output shaft extends
in the housing and is supported to be rotational about the axis to
drive the compression mechanism. The transmission mechanism is
provided inside the housing between the input shaft and the output
shaft. Also, the transmission mechanism drives the compression
mechanism at different speeds by transmitting torque of the input
shaft to the output shaft and also by selectively increasing and
decreasing the rotational speed of the input shaft before
transmitting to the output shaft. The control mechanism controls
the transmission mechanism.
[0003] The transmission mechanism includes a first planet gear
mechanism, which is located relatively frontward in the axial
direction, that is, relatively close to the input shaft, and a
second planet gear mechanism, which is located relatively rearward
in the axial direction, that is, relatively close to the output
shaft. Each of the first and second planet gear mechanisms includes
a sun gear, planet gears, a carrier, which rotationally retains the
planet gears, and ring gears, which respectively engage with the
planet gears. A thrust bearing and a radial bearing are arranged
between each ring gear and the housing. The ring gears can be fixed
to or rotational with respect to the housing.
[0004] The control mechanism includes a first one-way clutch, which
is located between the ring gear of the first planet gear mechanism
and the housing, a first clutch, which is located between the ring
gear of the first planet gear mechanism and the carrier, a second
one-way clutch, which is located between the ring gear of the
second planet gear mechanism and the carrier, and a second clutch,
which is located between the ring gear of the second planet gear
mechanism and the housing. The first and second clutches each
secure the corresponding ring gear to the carrier or the housing by
being displaced in the forward or rearward direction.
[0005] According to the conventional compressor configured as
described above, the first and second clutches independently or
simultaneously secure or release the ring gears. Then, the first
and second one-way clutches permit or restrict relative rotation of
the ring gears with respect to the housing or the carrier. Thus,
transmission means is capable of driving the compression mechanism
while varying the speed in a stepwise manner.
[0006] Since the structure of the conventional compressor with a
transmission is complicated, the manufacturing costs are increased,
and vibration noise is significant.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an objective of the present invention to
provide a compressor with a transmission that has reduced
manufacturing costs and noise.
[0008] To achieve the foregoing objective and in accordance with
one aspect of the present invention, a compressor with a
transmission is provided that includes a housing, a compression
mechanism formed in the housing and being capable of compressing
refrigerant, an input shaft extending into the housing from the
outside of the housing, an output shaft extending in the housing, a
transmission mechanism located between the input shaft and the
output shaft in the housing, and a control mechanism for
controlling the transmission mechanism. The input shaft is
supported to be rotational about an axis. The output shaft is
supported to be rotational about the axis and is capable of driving
the compression mechanism. The transmission mechanism is capable of
driving the compression mechanism at two different speeds by
transmitting torque of the input shaft to the output shaft and also
transmitting the rotational speed of the input shaft to the output
shaft at an equal speed or an increased speed. The transmission
mechanism includes a planet roller mechanism having a sun roller, a
plurality of planet rollers, a carrier, and a ring roller. The
carrier rotationally retains the planet rollers and is rotational
integrally with the input shaft. The sun roller engages with the
planet rollers and is rotational integrally with the input
shaft.
[0009] The ring roller engages with the planet rollers and is
secured to the housing by moving relative to the housing in a first
direction parallel to the axis. The ring roller is rotational with
respect to the housing by moving relative to the housing in a
second direction, which is opposite to the first direction. The
control mechanism includes a one-way clutch arranged between the
carrier and the ring roller and a clutch arranged between the
housing and the ring roller. The one-way clutch permits relative
rotation of the carrier and the ring roller in one direction and
restricts relative rotation in the other direction. The clutch
selectively restricts and permits rotation of the ring roller by
engagement between the housing and the ring roller. The clutch
includes a friction layer arranged between the housing and the ring
roller, a first control chamber formed in the housing and open
toward the ring roller, a first control piston accommodated in the
first control chamber and movable in the direction of the axis, a
first thrust bearing arranged between the first control piston and
the ring roller, a second control chamber formed in the housing, a
second control piston accommodated in the second control chamber
and movable in the direction of the axis, a second thrust bearing
arranged between the second control piston and the ring roller, and
a pressure control mechanism for controlling a first control
pressure supplied to the first control chamber and a second control
pressure supplied to the second control chamber. The friction layer
secures the ring roller to the housing by movement of the ring
roller in the first direction. The second control chamber faces the
first control chamber and opens toward the ring roller.
[0010] Other aspects and advantages of the present invention will
become apparent from the following description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
the presently preferred embodiments together with the accompanying
drawings in which:
[0012] FIG. 1 is a longitudinal cross-sectional view illustrating a
compressor with a transmission according to one embodiment of the
present invention;
[0013] FIG. 2 is an enlarged longitudinal cross-sectional view
illustrating part of the compressor with a transmission of FIG. 1
in a state where the clutch permits rotation of the ring roller;
and
[0014] FIG. 3 is an enlarged longitudinal cross-sectional view
illustrating part of the compressor with a transmission of FIG. 1
in a state where the clutch restricts rotation of the ring
roller.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] A compressor with a transmission according to one embodiment
of the present invention will now be described with reference to
the drawings.
Embodiment
[0016] As shown in FIG. 1, a compressor with a transmission
(hereinafter, simply referred to as a compressor) includes a scroll
type compression mechanism 20 to which a transmission mechanism 30
and a control mechanism 40 are integrally combined. The compressor
is mounted on, for example, a vehicle and forms a part of an air
conditioning system. In FIGS. 1 to 3, the left side, that is, the
position at which an input shaft 1 is located is defined as the
front side, and the right side, that is, the position at which an
output shaft 2 is located is defined as the rear side.
[0017] The compressor includes a housing 10, which is formed by
integrally fastening a first housing member 3, a second housing
member 4, a third housing member 5, and a fourth housing member 6
in that order. The rear end face of the first housing member 3 and
the front end face of the second housing member 4 engage with and
are fastened to each other to form a transmission chamber 10a. The
transmission chamber 10a is filled with traction oil. A passage 3a
is formed in the first housing member 3. The passage 3a introduces
the traction oil provided in an outer circumferential area of the
transmission chamber 10a to an inner circumferential area of the
transmission chamber 10a.
[0018] A fixed scroll 21 described below is integrally formed with
the third housing member 5. Components such as a movable scroll 22
described below are accommodated between the second housing member
4 and the third housing member 5. The third housing member 5 and
the fourth housing member 6 are fastened to each other so that a
suction chamber 28 and a discharge chamber 29 are formed
inside.
[0019] The input shaft 1 is supported by a boss of the first
housing member 3 via a sealing member 7 and a bearing system 8 to
be rotational about an axis O1. An assembly S includes the input
shaft 1, a carrier 9, a radial bearing 31, planet rollers 32, a sun
roller 14, a ring roller 33, a friction layer 35, a retaining ring
34a, and a one-way clutch 34. The bearing system 8 is press-fitted
in the first housing member 3, but a gap is formed between the
bearing system 8 and the input shaft 1. The gap and a key 15 permit
the assembly S to move with respect to the first housing member 3
in a direction parallel to the axis O1, that is, left or right in
FIGS. 1 to 3. The forward or frontward direction corresponds to the
first direction (fixing direction) of the present invention, and
the rear direction corresponds to the second direction (releasing
direction) of the present invention.
[0020] The rear end of the input shaft 1 protrudes in the rearward
direction in the transmission chamber 10a. A carrier main body 9a
is formed integrally with the input shaft 1 at the rear end of the
input shaft 1. The carrier main body 9a faces the first housing
member 3 with a gap in between, and extends radially outward into a
disk-like shape. The carrier main body 9a forms a part of the
transmission mechanism 30, which will be described below.
[0021] The output shaft 2 is supported in a boss of the second
housing member 4 to be rotational about the axis O1 via a sealing
member 11 and a radial bearing 12. The front end of the output
shaft 2 is located in the carrier main body 9a of the input shaft
1. A radial bearing 13 is also provided between the carrier main
body 9a and the output shaft 2. A passage 1a is formed in the input
shaft 1. The passage 1a communicates with the passage 3a formed in
the first housing member 3 and extends to the radial bearing 13.
The sun roller 14 located to the rear of the carrier main body 9a
is provided on the output shaft 2. The key 15 is provided between
the output shaft 2 and the sun roller 14. The key 15 permits the
sun roller 14 to rotate integrally with the output shaft 2 and to
move with respect to the output shaft 2 in a direction parallel to
the axis O1. The sun roller 14 also forms a part of the
transmission mechanism 30 described below. The rear end of the
output shaft 2 extends in the rearward direction toward the movable
scroll 22.
[0022] The compression mechanism 20 will now be described. A drive
bushing 23 integrated with a balancer and the movable scroll 22 are
accommodated between the second housing member 4 and the third
housing member 5.
[0023] The drive bushing 23 is secured to the rear end of the
output shaft 2 in an eccentric state, and rotates integrally with
the output shaft 2. A radial bearing 24 is arranged on the outer
circumferential surface of the drive bushing 23.
[0024] The movable scroll 22 includes a boss 22a, which is
supported to be rotational with respect to the drive bushing 23 via
the radial bearing 24, a disk-like movable plate 22b, which is
integrally formed with the boss 22a and extends in the radial
direction, and a movable volute portion 22c, which protrudes in the
rearward direction from the movable plate 22b in parallel to the
axis O1.
[0025] Three or more securing pins 25a are secured to the rear
surface of the second housing member 4 in parallel to the axis O1.
Also, movable pins 25b the number of which is equal to the number
of the securing pins 25a are secured to the movable plate 22b of
the movable scroll 22 in parallel to the axis O1. Furthermore,
movable rings 25c the number of which is equal to the number of the
securing pins 25a and the movable pins 25b are arranged between the
second housing member 4 and the movable plate 22b. Each movable
ring 25c has a through hole 25d. A pair of the securing pin 25a and
the movable pin 25b are accommodated in the through hole 25d in a
state where the distance between the axes corresponds to the orbit
distance of the movable scroll 22. The securing pins 25a, the
movable pins 25b, and the movable rings 25c form an anti-rotation
mechanism 25, which prevents rotation of the movable scroll 22.
[0026] The fixed scroll 21 is formed integrally with the third
housing member 5. The fixed scroll 21 includes a disk-like fixed
plate 21b, which extends in a radial direction, and a fixed volute
portion 21c, which protrudes in the forward direction from the
fixed plate 21b in parallel to the axis O1.
[0027] The protruding length of the fixed volute portion 21c of the
fixed scroll 21 and the protruding length of the movable volute
portion 22c of the movable scroll 22 in the direction of the axis
O1 are set equal to each other. The fixed volute portion 21c of the
fixed scroll 21 slides with respect to the movable plate 22b of the
movable scroll 22, and the movable volute portion 22c of the
movable scroll 22 slides with respect to the fixed plate 21b of the
fixed scroll 21.
[0028] A discharge port 29a extends through the central portion of
the fixed plate 21b to communicate with the discharge chamber 29. A
discharge valve 26 and a retainer 27 are secured to the fixed plate
21b in the discharge chamber 29 to close the discharge port 29a.
Furthermore, an intake port 28a extends through the outer
circumferential portion of the fixed plate 21b. The intake port 28a
communicates with the suction chamber 28.
[0029] The second to fourth housing members 4, 5, 6, the output
shaft 2, the drive bushing 23, the movable scroll 22, the
anti-rotation mechanism 25, and the fixed scroll 21 form the
scroll-type compression mechanism 20.
[0030] The discharge chamber 29 is connected to a condenser 42 via
a pipe 41. The condenser 42 is connected to an evaporator 45 via an
expansion valve 44 through a pipe 43. The evaporator 45 is
connected to the suction chamber 28 via a pipe 46. A discharge
pressure supply channel (the path Pd-Pd shown in FIG. 1), which
supplies discharge pressure Pd in the discharge chamber 29 to a
passage switching electromagnetic valve 63 described below, is
provided in the discharge chamber 29. Also, a suction pressure
supply channel (the path Ps-Ps in FIG. 1), which supplies suction
pressure Ps in the suction chamber 28 to the passage switching
electromagnetic valve 63, is provided in the suction chamber
28.
[0031] The transmission chamber 10a communicates with the
atmosphere via the passage 3a and a filter 3d. Also, the
transmission chamber 10a is partitioned from the compression
mechanism 20, the suction chamber 28, and the discharge chamber 29
by the sealing member 11. Thus, the transmission chamber 10a is
filled with atmospheric pressure isolated from refrigerant.
[0032] The transmission mechanism 30 will now be described. As
shown in FIGS. 2 and 3 in the enlarged state, four first support
shafts 9b and four second support shafts 9c are provided in the
transmission chamber 10a. The first support shafts 9b and the
second support shafts 9c protrude in the rearward direction and are
alternately arranged along an imaginary circle defined about the
axis O1 on the periphery of the rear surface of the carrier main
body 9a. One of the first support shafts 9b and one of the second
support shafts 9c are shown in FIGS. 2 and 3. The first support
shafts 9b are columnar shafts, and the second support shafts 9c are
stepped columnar shafts having a large diameter portion at the
middle. Each of the first support shafts 9b rotationally supports
the corresponding planet roller 32 via the associated radial
bearing 31. The outer circumferential surfaces of the four planet
rollers 32 engage the outer circumferential surface of the sun
roller 14. The outer circumferential surfaces of the planet rollers
32 and the outer circumferential surface of the sun roller 14 have
small surface roughness to prevent relative slipping.
[0033] One rear carrier 9d is secured to the rear ends of the first
support shafts 9b and the second support shafts 9c. The rear
carrier 9d has a substantially cylindrical shape extending in the
rearward direction. An inner flange 9e, which selectively contacts
the rear end of the sun roller 14, is formed on the inner side of
the rear carrier 9d. The carrier main body 9a, the first support
shafts 9b, the second support shafts 9c, and the rear carrier 9d
form the carrier 9, which rotationally supports the four planet
rollers 32 and rotates integrally with the input shaft 1.
[0034] The ring roller 33 is arranged between the planet rollers 32
and the first and second housing members 3, 4. The ring roller 33
includes a cylindrical first ring portion 331 and a cylindrical
second ring portion 332. The first ring portion 331 and the second
ring portion 332 are coupled to each other by pins 333.
[0035] The first ring portion 331 is formed of material having a
relatively low rigidity, and can be displaced in the radial
direction. The inner circumferential surface of the first ring
portion 331 engages the outer circumferential surfaces of the
planet rollers 32. Thus, the first ring portion 331 can be
displaced in the radial direction using the interferences between
the sun roller 14 and the planet rollers 32 and between the planet
rollers 32 and the ring roller 33. The inner circumferential
surface of the first ring portion 331 also has a small surface
roughness to prevent relative slipping.
[0036] The second ring portion 332 is formed of material having a
relatively high rigidity. The outer circumferential surface of the
one-way clutch 34 contacts the inner circumferential surface of the
second ring portion 332.
[0037] An inner flange 33a, which selectively engages with the
front ends of the planet rollers 32, is formed on the inner side of
the first ring portion 331. An inner flange 33b, which selectively
engages with the rear ends of the planet rollers 32, is formed at
the front end of the second ring portion 332. That is, the position
of the planet rollers 32 and the ring roller 33 in the front and
rear direction is determined by sandwiching the planet rollers 32
from the front and rear sides by the inner flanges 33a, 33b.
[0038] In the case where the first ring portion 331 and the second
ring portion 332 are both rotational and move in the direction
parallel to the axis O1, the second ring portion 332 supports the
one-way clutch 34 maintaining high accuracy of, for example, the
dimension and the cylindricity without being influenced by radial
displacement of the first ring portion 331. Therefore, function of
the one-way clutch 34 is not impaired.
[0039] The sun roller 14, the planet rollers 32, the ring roller
33, and the carrier 9 form a planet roller mechanism, which is the
transmission mechanism 30 in this embodiment.
[0040] The one-way clutch 34 is secured to the outer
circumferential surface of the rear carrier 9d by the retaining
ring 34a. The outer circumferential surface of the one-way clutch
34 contacts the inner circumferential surface of the second ring
portion 332 of the ring roller 33. The one-way clutch 34 is a known
general-purpose component, and permits the ring roller 33 to rotate
relative to the carrier 9 in one direction and restricts relative
rotation in the other direction. In the present embodiment, the
direction in which the input shaft 1 and the carrier 9 rotate about
the axis O1 is set to the clockwise direction as viewed from the
front of the compressor. While the one-way clutch 34 permits the
ring roller 33 to rotate relative to the carrier 9 in the
counterclockwise direction, the one-way clutch 34 restricts the
ring roller 33 to rotate relative to the carrier 9 in the clockwise
direction.
[0041] The friction layer 35, which faces the rear surface of the
first housing member 3, is provided on the front surface of the
first ring portion 331 of the ring roller 33. The friction layer 35
is an annular flat plate formed of material having a relatively
high coefficient of friction. As will be described below with
reference to FIG. 3, when the ring roller 33 moves in the forward
direction, the friction layer 35 contacts the rear surface of the
first housing member 3.
[0042] A first control chamber 136 is formed in the second housing
member 4 at a position facing the rear surface of the ring roller
33 in such a manner as to form a recess. The first control chamber
136 is an annular groove coaxial with the axis O1, and is open
toward the rear surface of the ring roller 33.
[0043] An annular first control piston 137 coaxial with the axis O1
is accommodated in the first control chamber 136. The first control
piston 137 can move in the forward direction from the first control
chamber 136. Ring grooves are respectively formed in the inner
circumferential surface and the outer circumferential surface of
the first control piston 137. Rubber O-rings 138a, 138b are fitted
to the ring grooves.
[0044] That is, the first control piston 137 has the O-rings 138a,
138b arranged between the first control piston 137 and the first
control chamber 136. The O-rings 138a, 138b seal the boundary
between the first control piston 137 and the first control chamber
136.
[0045] A first thrust bearing 139 is mounted on the front portion
of the first control piston 137. The first thrust bearing 139 faces
the rear surface of the ring roller 33.
[0046] A second control chamber 236 is formed in the first housing
member 3 in such a manner as to form a recess at the position
facing the area outward of the friction layer 35 on the front
surface of the ring roller 33. The second control chamber 236 is an
annular groove that is coaxial with the axis O1, and is open toward
the front surface of the ring roller 33. The first control chamber
136 and the second control chamber 236 face each other in the front
and rear direction.
[0047] An annular second control piston 237, which is coaxial with
the axis O1, is accommodated in the second control chamber 236. The
second control piston 237 can move in the rearward direction from
the second control chamber 236. Ring grooves are respectively
formed in the inner circumferential surface and the outer
circumferential surface of the second control piston 237. Rubber
O-rings 238a, 238b are fitted in the ring grooves. That is, the
second control piston 237 has the O-rings 238a, 238b arranged
between the second control piston 237 and the second control
chamber 236. The O-rings 238a, 238b seal the boundary between the
second control piston 237 and the second control chamber 236.
[0048] A second thrust bearing 239 is mounted on the rear portion
of the second control piston 237. The second thrust bearing 239
faces the front surface of the ring roller 33.
[0049] The outer diameter of the second control piston 237 is set
to be greater than the outer diameter of the first control piston
137. Also, the distance between the inner circumferential surface
and the outer circumferential surface of the second control piston
237 is set to be greater than the distance between the inner
circumferential surface and the outer circumferential surface of
the first control piston 137. Accordingly, a second control
pressure receiving area of the second control piston 237 is set to
be greater than a first control pressure receiving area of the
first control piston 137.
[0050] A first control pressure supply passage 61, which connects
the first control chamber 136 to the passage switching
electromagnetic valve 63, is formed in the second housing member 4.
The passage switching electromagnetic valve 63 selectively connects
the first control chamber 136 to the discharge pressure supply
channel (the path Pd-Pd shown in FIG. 1) and the suction pressure
supply channel (the path Ps-Ps shown in FIG. 1). Thus, the first
control pressure supplied to the first control chamber 136 is
either the discharge pressure Pd or the suction pressure Ps.
[0051] A second control pressure supply passage 62, which connects
the second control chamber 236 to the suction chamber 28, is formed
in the first housing member 3 and the second housing member 4.
Thus, the second control pressure supplied to the second control
chamber 236 is always the suction pressure Ps.
[0052] As described above, the pressure in the transmission chamber
10a against which the first control piston 137 and the second
control piston 237 face is maintained at the atmospheric pressure.
When the compressor is operated, the relationship between the
discharge pressure Pd, the suction pressure Ps, and the atmospheric
pressure is as follows.
Discharge Pressure Pd>Suction Pressure Ps>Atmospheric
Pressure
[0053] A force F2, which presses the second control piston 237 in
the rearward direction, is always applied to the second control
piston 237 by the difference between the second control pressure in
the second control chamber 236, which is the suction pressure Ps
(>atmospheric pressure) in this embodiment, and the atmospheric
pressure in the transmission chamber 10a.
[0054] Force that presses the first control piston 137 in the
forward direction applied to the first control piston 137 is
changed as follows by switching the passage switching
electromagnetic valve 63.
[0055] As shown in FIG. 2, when the passage switching
electromagnetic valve 63 switches the first control pressure in the
first control chamber 136 to the suction pressure Ps, a force Fs1,
which presses the first control piston 137 in the forward
direction, acts on the first control piston 137 by the difference
between the suction pressure Ps in the first control chamber 136
(>atmospheric pressure) and the atmospheric pressure in the
transmission chamber 10a. In this case, the second control pressure
receiving area of the second control piston 237 is set greater than
the first control pressure receiving area of the first control
piston 137. Thus, even if the first control pressure and the second
control pressure are both the suction pressure Ps, the force F2,
which presses the second control piston 237 in the rearward
direction, is greater than the force Fs1, which presses the first
control piston 137 in the forward direction.
[0056] In contrast, as shown in FIG. 3, when the passage switching
electromagnetic valve 63 switches the first control pressure in the
first control chamber 136 to the discharge pressure Pd, a force Fd1
(>Fs1), which presses the first control piston 137 in the
forward direction, is applied to the first control piston 137 due
to the pressure difference between the discharge pressure Pd in the
first control chamber 136 (>suction pressure Ps>atmospheric
pressure) and the atmospheric pressure in the transmission chamber
10a. In this case, since the discharge pressure Pd is significantly
higher than the suction pressure Ps, the force Fd1, which presses
the first control piston 137 in the forward direction, is
significantly greater than the force F2, which presses the second
control piston 237 in the rearward direction.
[0057] The first control pressure supply passage 61, the second
control pressure supply passage 62, and the passage switching
electromagnetic valve 63 form a pressure control mechanism.
[0058] The friction layer 35, the first control chamber 136, the
first control piston 137, the first thrust bearing 139, the second
control chamber 236, the second control piston 237, the second
thrust bearing 239, the first control pressure supply passage 61,
the second control pressure supply passage 62, and the passage
switching electromagnetic valve 63 form a clutch 60, which secure
or rotate the ring roller 33 with respect to the first housing
member 3. The one-way clutch 34 and the clutch 60 form the control
mechanism 40.
[0059] An electromagnetic clutch 50 is coupled to the front end of
the input shaft 1. The electromagnetic clutch 50 includes a
disk-like hub 51, which is secured to the front end of the input
shaft 1 to rotate integrally with the input shaft 1, an armature
53, which is connected to the hub 51 by a plate spring 52, and a
coil 54, which is secured to the front surface of the first housing
member 3. A pulley 56 is rotationally supported by the boss of the
first housing member 3 via a radial bearing 55. A non-illustrated
belt connected to an external driving source, which is an engine in
this embodiment, is wound about the pulley 56. The coil 54 is
arranged in the pulley 56.
[0060] In the compressor of the present embodiment formed as
described above, when power is supplied to the coil 54 of the
electromagnetic clutch 50, the armature 53 adheres to the pulley 56
by magnetic force against elasticity of the plate spring 52, as
shown in FIG. 1. Accordingly, the input shaft 1 rotates integrally
with the pulley 56, and torque is applied to the input shaft 1.
When the input shaft 1 rotates about the axis O1, rotation of the
input shaft 1 is transmitted to the output shaft 2 by the
transmission mechanism 30 at an equal speed or an increased
speed.
[0061] In contrast, when power supply to the coil 54 is stopped,
although not shown, the armature 53 separates from the pulley 56 by
elasticity of the plate spring 52, and torque applied to the input
shaft 1 is disconnected. Thus, drive power applied to the input
shaft 1 from the outside is disconnected by the electromagnetic
clutch 50.
[0062] As shown in FIG. 1, in the compression mechanism 20, when
the output shaft 2 is rotated, the drive bushing 23 rotates
decentered from its axis, and the movable scroll 22 orbits in a
state where rotation is restricted by the anti-rotation mechanism
25. Thus, the capacity of the compression chamber formed between
the fixed scroll 21 and the movable scroll 22 decreases from the
periphery toward the central portion. Thus, the refrigerant in the
suction chamber 28 is compressed in the compression chamber, and
discharged to the discharge chamber 29. The refrigerant in the
discharge chamber 29 is supplied to the condenser 42, and vehicle
is cooled by the evaporator 45.
[0063] Meanwhile, as shown in FIG. 3, when the passage switching
electromagnetic valve 63 switches the first control pressure in the
first control chamber 136 to the discharge pressure Pd, the force
Fd1, which presses the first control piston 137 in the forward
direction, becomes significantly greater than the force F2, which
presses the second control piston 237 in the rearward direction as
described above. Thus, the first control piston 137 moves in the
forward direction against the force F2, which presses the second
control piston 237 in the rearward direction. The first control
piston 137 then moves the second ring portion 332 in the forward
direction, the second ring portion 332 moves the first ring portion
331 in the forward direction, and the first ring portion 331 is
pressed against the first housing member 3. Thus, the first control
piston 137 presses the assembly S in the forward direction via the
ring roller 33. Since the frictional force acts between the
friction layer 35 and the first housing member 3, the ring roller
33 is secured to the first housing member 3.
[0064] Then, the one-way clutch 34 permits the ring roller 33 to
rotate relative to the carrier 9 in one direction, or permits the
ring roller 33 to rotate relative to the carrier 9 in the
counterclockwise direction as viewed from the front of the
compressor. Thus, the planet rollers 32, which orbit about the axis
O1 in the clockwise direction in accordance with the rotation of
the input shaft 1 and the carrier 9, rotate about the support
shafts 9b in the counterclockwise direction by the interference
between the planet rollers 32 and the first ring portion 331. As a
result, the sun roller 14, which contacts the planet rollers 32,
and the output shaft 2, which rotates integrally with the sun
roller 14, are rotated at the increased speed since rotation of the
input shaft 1 is increased and transmitted.
[0065] In contrast, as shown in FIG. 2, when the passage switching
electromagnetic valve 63 switches the first control pressure in the
first control chamber 136 to the suction pressure Ps, the force F2,
which presses the second control piston 237 in the rearward
direction, becomes greater than the force Fs1, which presses the
first control piston 137 in the forward direction as described
above. Accordingly, the second control piston 237 presses the ring
roller 33 in the rearward direction against the force Fs1, which
presses the first control piston 137 in the forward direction.
Thus, the friction layer 35 and the first housing member 3 are
separated so that frictional force does not act between the
friction layer 35 and the first housing member 3. This permits the
ring roller 33 to rotate relative to the first housing member
3.
[0066] At this time, the entire assembly S moves in the rearward
direction together with the ring roller 33. The first control
piston 137 also moves in the rearward direction into the first
control chamber 136 by being pressed by the ring roller 33 moving
in the rearward direction.
[0067] Thus, the ring roller 33 starts to rotate clockwise about
the axis O1 following the rotation of the input shaft 1. As the
planet rollers 32, which engage with the sun roller 14, rotate
clockwise, the ring roller 33 tends to relatively pass the input
shaft 1 in the clockwise direction. The one-way clutch 34 restricts
the ring roller 33 from rotating relative to the carrier 9 in the
clockwise direction, that is, as viewed from the front of the
compressor. In this state, the first thrust bearing 139 arranged
between the ring roller 33 and the first control piston 137 rolls
to prevent the ring roller 33 from dragging against the first
control piston 137. The second thrust bearing 239 arranged between
the ring roller 33 and the second control piston 237 also rolls to
prevent the ring roller 33 from dragging against the second control
piston 237. As a result, the input shaft 1, the carrier 9, the
planet rollers 32, the sun roller 14, the ring roller 33, and the
output shaft 2 rotate integrally. The output shaft 2 is rotated at
the equal speed since the rotation of the input shaft 1 is
transmitted at the equal speed.
[0068] Since the compressor employs the transmission mechanism 30
including the planet roller mechanism, vibration is not easily
generated and noise is reduced. Also, the manufacturing costs are
reduced since the compressor has a simple structure while the
compression mechanism 20 can be operated at two different
speeds.
[0069] Thus, the compressor of the present embodiment has less
manufacturing costs and less noise. Also, the transmission chamber
10a of this compressor is filled with the atmospheric pressure.
Thus, when the first control pressure in the first control chamber
136 is switched to the suction pressure Ps, the first control
piston 137 might not be retracted into the first control chamber
136 depending on the difference between the first control pressure
in the first control chamber 136 and the atmospheric pressure in
the transmission chamber 10a. However, according to this
compressor, the clutch 60 has the second control chamber 236 and
the second control piston 237. Since the second control piston 237
moves in the rearward direction from the second control chamber
236, the ring roller 33 and the first control piston 137 is
reliably moved in the rearward direction. Thus, the friction layer
35 and the first housing member 3 are reliably separated from each
other, and friction between the friction layer 35 and the first
housing member 3 is reliably eliminated. Thus, the ring roller 33
is reliably prevented from dragging. As a result, the compressor is
not likely to cause power loss, and excellent compression
efficiency is exerted.
[0070] Furthermore, according to the compressor, since the interior
of the transmission chamber 10a is isolated from the refrigerant,
the transmission mechanism is further reliably operated by
providing the interference between the sun roller and the planet
rollers and between the planet rollers and the ring roller, and
providing traction oil with high viscosity between them. Also,
since the traction oil is reliably prevented from being mixed with
the refrigerant, deterioration of the traction oil is
prevented.
[0071] According to the compressor, the pressure control mechanism,
which is the first control pressure supply passage 61, the second
control pressure supply passage 62, and the passage switching
electromagnetic valve 63 in this embodiment, reliably moves the
first control piston 137 and the second control piston 237 in
forward or rearward directions using the atmospheric pressure, the
suction pressure Ps, and the discharge pressure Pd without
separately providing a pressure supply source. Thus, the
manufacturing costs are reliably reduced in to this compressor.
[0072] Furthermore, since the first control piston 137 and the
second control piston 237 formed as described above press the ring
roller 33 in forward or rearward directions uniformly about the
axis O1, the transmission mechanism 30 is further reliably
operated.
[0073] The present invention is described according to the
embodiment but is not restricted to the illustrated embodiment. The
invention may be embodied in the following forms without departing
from the spirit or scope of the invention.
[0074] For example, in the present embodiment, the bearing system 8
is press-fitted in the first housing member 3, and a gap is formed
between the bearing system 8 and the input shaft 1. However, a gap
may be provided between the first housing member 3 and the bearing
system 8, and the bearing system 8 may be press-fitted to the input
shaft 1.
[0075] Also, in the present embodiment, the front direction is
referred to as the first direction (fixing direction), and the rear
direction is referred to as the second direction (releasing
direction), but the front direction may be referred to as the
second direction (releasing direction), and the rear direction may
be referred to as the first direction (fixing direction). More
specifically, the friction layer 35 may be provided at the rear end
of the ring roller 33 instead of the front end of the ring roller
33. In this case, when the ring roller 33 moves in the rearward
direction, the friction layer 35 is pressed against the second
housing member 4.
[0076] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive and the invention is
not to be limited to the details given herein, but may be modified
within the scope and equivalence of the appended claims.
* * * * *