U.S. patent application number 16/300931 was filed with the patent office on 2020-10-08 for variable speed gearbox.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES COMPRESSOR CORPORATION. The applicant listed for this patent is MITSUBISHI HEAVY INDUSTRIES COMPRESSOR CORPORATION. Invention is credited to Masahiro Kobayashi, Hiroyuki Miyata, Yasushi Mori, Yoshiyuki Okamoto.
Application Number | 20200318714 16/300931 |
Document ID | / |
Family ID | 1000004928415 |
Filed Date | 2020-10-08 |
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United States Patent
Application |
20200318714 |
Kind Code |
A1 |
Miyata; Hiroyuki ; et
al. |
October 8, 2020 |
VARIABLE SPEED GEARBOX
Abstract
A variable speed gearbox includes: an electric driving device
which generates a rotational driving force; and a transmission
device which changes the speed of the rotational driving force and
transmits the changed rotation driving force to a driving target.
The transmission device includes: a sun gear; a sun gear shaft; a
planetary gear which meshes with the sun gear; an internal gear
which meshes with the planetary gear; a planetary gear carrier
which has a planetary gear carrier shaft; and an internal gear
carrier which has an internal gear carrier shaft. The electric
driving device includes: a constant-speed motor having a
constant-speed rotor; and a variable-speed motor having a
variable-speed rotor. The internal gear carrier includes a clutch
mechanism including: a moving portion; a drive portion; a fixed
portion; and an engaging portion which engages the moving portion
and the fixed portion.
Inventors: |
Miyata; Hiroyuki;
(Hiroshima-shi, JP) ; Kobayashi; Masahiro;
(Hiroshima-shi, JP) ; Mori; Yasushi;
(Hiroshima-shi, JP) ; Okamoto; Yoshiyuki;
(Hiroshima-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI HEAVY INDUSTRIES COMPRESSOR CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES
COMPRESSOR CORPORATION
Tokyo
JP
|
Family ID: |
1000004928415 |
Appl. No.: |
16/300931 |
Filed: |
July 20, 2016 |
PCT Filed: |
July 20, 2016 |
PCT NO: |
PCT/JP2016/071248 |
371 Date: |
November 12, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H 57/043 20130101;
F16H 57/0484 20130101; F16D 11/14 20130101; H02K 7/108 20130101;
F16H 3/724 20130101; H02K 7/116 20130101; H02K 9/06 20130101 |
International
Class: |
F16H 3/72 20060101
F16H003/72; F16H 57/04 20060101 F16H057/04; H02K 7/108 20060101
H02K007/108; H02K 7/116 20060101 H02K007/116; H02K 9/06 20060101
H02K009/06 |
Claims
1. A variable speed gearbox comprising: an electric driving device
which generates a rotational driving force; and a transmission
device which changes the speed of the rotational driving force
generated by the electric driving device and transmits the changed
rotation driving force to a driving target, wherein the
transmission device comprises a sun gear which rotates about an
axis, a sun gear shaft which is fixed to the sun gear and extends
in an axial direction around the axis, a planetary gear which
meshes with the sun gear, revolves around the axis and rotates
about its own center line, an internal gear which has a plurality
of teeth aligned annularly around the axis and meshes with the
planetary gear, a planetary gear carrier which has a planetary gear
carrier shaft extending in the axial direction around the axis and
supports the planetary gear to revolve around the axis and to be
rotatable around a center line of the planetary gear itself, and an
internal gear carrier which has an internal gear carrier shaft
extending in the axial direction around the axis and supports the
internal gear to be rotatable about the axis, the sun gear shaft
forms an output shaft connected to the driving target, the internal
gear carrier shaft forms a constant-speed input shaft, and the
planetary gear carrier shaft forms a variable-speed input shaft,
the electric driving device comprises a constant-speed motor having
a constant-speed rotor which rotates the constant speed input shaft
of the transmission device, and a variable-speed motor having a
variable-speed rotor connected to the variable-speed input shaft of
the transmission device, the internal gear carrier includes a
clutch mechanism which connects a cylindrical portion connected to
the internal gear with the internal gear carrier shaft, and the
clutch mechanism comprises a moving portion which is connected to
one of the cylindrical portion and the internal gear carrier shaft
to be movable in the axial direction, a drive portion which drives
the moving portion in the axial direction, a fixed portion which is
fixed to the other one of the cylindrical portion and the internal
gear carrier shaft, and an engaging portion which engages the
moving portion and the fixed portion by moving the moving portion
in the axial direction.
2. The variable speed gearbox according to claim 1, wherein the
drive portion comprises a disk which is fixed to the other one of
the cylindrical portion and the internal gear carrier shaft to face
the moving portion in the axial direction and forms an oil supply
space between the disk and the moving portion, an oil supply
portion which supplies oil into the oil supply space, and an oil
discharge portion which discharges the oil from the oil supply
space.
3. The variable speed gearbox according to claim 2, wherein the oil
supply portion includes an oil supply path which is formed in at
least one of the fixed portion and the disk, and a nozzle which
supplies the oil supplied to the oil supply path into the oil
supply space.
4. The variable speed gearbox according to claim 2, wherein the oil
supply space includes a first oil supply space which is formed
between the moving portion and the disk, and a second oil supply
space which communicates with the first oil supply space and is
formed inside the constant-speed rotor, and the oil supply portion
supplies the oil into the second oil supply space.
5. The variable speed gearbox according to claim 1, wherein the
variable-speed rotor is formed in a cylindrical shape centered on
the axis, and the constant-speed input shaft is inserted through a
shaft insertion hole which passes therethrough in the axial
direction.
6. The variable speed gearbox according to any one of claim 2,
wherein the variable-speed rotor is formed in a cylindrical shape
centered on the axis, and the constant-speed input shaft is
inserted through a shaft insertion hole which passes therethrough
in the axial direction.
7. The variable speed gearbox according to any one of claim 3,
wherein the variable-speed rotor is formed in a cylindrical shape
centered on the axis, and the constant-speed input shaft is
inserted through a shaft insertion hole which passes therethrough
in the axial direction.
8. The variable speed gearbox according to any one of claim 4,
wherein the variable-speed rotor is formed in a cylindrical shape
centered on the axis, and the constant-speed input shaft is
inserted through a shaft insertion hole which passes therethrough
in the axial direction.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a variable speed gearbox
which includes an electric driving device including a
constant-speed motor and a variable-speed motor, and a planetary
gear transmission device for changing the speed of a rotational
driving force generated by the electric driving device and then
transmitting the speed-changed rotational driving force to a
driving target.
BACKGROUND ART
[0002] As an apparatus for driving a rotary machine such as a
compressor, there is an apparatus including an electric driving
device for generating a rotational driving force and a transmission
device for changing the speed of a rotational driving force
generated by the electric driving device and then transmitting the
speed-changed rotational driving force to the rotary machine.
[0003] Patent Document 1 discloses that a constant-speed motor and
a variable-speed motor for speed change are used as the electric
driving device and a planetary gear transmission device is used as
the transmission device to accurately control a gear ratio. In this
apparatus, it is possible to change a rotation rate of an output
shaft of the planetary gear transmission device connected to the
rotary machine by changing a rotation rate of the variable-speed
motor.
CITATION LIST
Patent Literature
[0004] [Patent Document 1]
[0005] Japanese Patent Publication No. 4472350
SUMMARY OF INVENTION
Technical Problem
[0006] In the above-described variable speed gearbox, for example,
electric power supply to the electric motor may be cut off due to
overvoltage, overcurrent, or the like. In such a case, both the
constant-speed motor and the variable-speed motor are stopped. At
this time, the variable-speed motor connected to the constant-speed
motor via the transmission device or the compressor to be driven
may over-rotate due to the rotation rate of the constant-speed
motor or the inertia of the compressor.
[0007] The present invention relates to a variable speed gearbox
which includes an electric driving device including a
constant-speed motor and a variable-speed motor, and a planetary
gear transmission device for changing the speed of a rotational
driving force generated by the electric driving device and then
transmitting the speed-changed rotational driving force to a
driving target, and it is an object of the present invention to
provide a variable speed gearbox capable of preventing
over-rotation of the variable-speed motor or the driving
target.
Solution to Problem
[0008] According to a first aspect of the present invention, there
is provided a variable speed gearbox including an electric driving
device which generates a rotational driving force, and a
transmission device which changes the speed of the rotational
driving force generated by the electric driving device and
transmits the changed rotation driving force to a driving target,
wherein the transmission device includes a sun gear which rotates
about an axis, a sun gear shaft which is fixed to the sun gear and
extends in an axial direction around the axis, a planetary gear
which meshes with the sun gear, revolves around the axis and
rotates about its own center line, an internal gear which has a
plurality of teeth aligned annularly around the axis and meshes
with the planetary gear, a planetary gear carrier which has a
planetary gear carrier shaft extending in the axial direction
around the axis and supports the planetary gear to revolve around
the axis and to be rotatable around a center line of the planetary
gear itself, and an internal gear carrier which has an internal
gear carrier shaft extending in the axial direction around the axis
and supports the internal gear to be rotatable about the axis, the
sun gear shaft forms an output shaft connected to the driving
target, the internal gear carrier shaft forms a constant-speed
input shaft, and the planetary gear carrier shaft forms a
variable-speed input shaft, the electric driving device includes a
constant-speed motor having a constant-speed rotor which rotates
the constant-speed input shaft of the transmission device, and a
variable-speed motor having a variable-speed rotor connected to the
variable-speed input shaft of the transmission device, the internal
gear carrier includes a clutch mechanism which connects a
cylindrical portion connected to the internal gear with the
internal gear carrier shaft, and the clutch mechanism includes a
moving portion which is connected to one of the cylindrical portion
and the internal gear carrier shaft to be movable in the axial
direction, a drive portion which drives the moving portion in the
axial direction, a fixed portion which is fixed to the other one of
the cylindrical portion and the internal gear carrier shaft, and an
engaging portion which engages the moving portion and the fixed
portion by moving the moving portion in the axial direction.
[0009] According to such a constitution, in the variable speed
gearbox, for example, when power supply to the electric motor is
cut off due to an overvoltage, overcurrent, or the like, a driving
force of the constant-speed motor transmitted to the transmission
device can be disconnected. Therefore, over-rotation of the
variable-speed motor or the driving target can be prevented due to
transmitting the rotation of the constant-speed rotor.
[0010] In the variable speed gearbox, the drive portion may include
a disk which is fixed to the other one of the cylindrical portion
and the internal gear carrier shaft to face the moving portion in
the axial direction and forms an oil supply space between the disk
and the moving portion, an oil supply portion which supplies oil
into the oil supply space, and an oil discharge portion which
discharges the oil from the oil supply space.
[0011] According to such a constitution, it is possible to move the
moving portion using the oil supplied to the bearing due to a
constitution in which the moving portion is moved due to the oil
pressure. Also, the engagement due to the engagement portion can be
released by discharging the oil from the oil supply space.
[0012] In the variable speed gearbox, the oil supply portion may
include an oil supply path which is formed in at least one of the
fixed portion and the disk, and a nozzle which supplies the oil
supplied to the oil supply path into the oil supply space.
[0013] In the variable speed gearbox, the oil supply space may
include a first oil supply space which is formed between the moving
portion and the disk, and a second oil supply space which
communicates with the first oil supply space and is formed inside
the constant-speed rotor, and the oil supply portion may supply the
oil into the second oil supply space.
[0014] According to such a constitution, due to the centrifugal
force applied to the oil, the oil is supplied not to the first oil
supply space in which the pressure becomes higher but to the second
oil supply space in which the pressure is lower. Thus, it is
possible to easily supply the oil to the oil supply space.
[0015] In the variable speed gearbox, the variable-speed rotor may
be formed in a cylindrical shape centered on the axis, and the
constant-speed input shaft may be inserted through a shaft
insertion hole which passes therethrough in the axial
direction.
Advantageous Effects of Invention
[0016] According to the present invention, in the variable speed
gearbox, for example, when the electric power supply to the
electric motor is cut off due to overvoltage, overcurrent, or the
like, a driving force of the constant-speed motor transmitted to
the transmission device can be disconnected. Thus, it is possible
to prevent the variable-speed motor or the driving target from
over-rotating by transmitting the rotation of the constant-speed
rotor.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a cross-sectional view of a variable speed gearbox
according to a first embodiment of the present invention.
[0018] FIG. 2 is a cross-sectional view of a transmission device
according to the first embodiment of the present invention.
[0019] FIG. 3 is a cross-sectional view of an electric driving
device according to the first embodiment of the present
invention.
[0020] FIG. 4 is a cross-sectional view of an internal gear carrier
according to the first embodiment of the present invention.
[0021] FIG. 5 is a cross-sectional view of a clutch mechanism
according to the first embodiment of the present invention.
[0022] FIG. 6 is a plan view of a Hirth coupling of the first
embodiment according to the present invention.
[0023] FIG. 7 is a cross-sectional view of the Hirth coupling of
the first embodiment according to the present invention.
[0024] FIG. 8 is a schematic diagram showing a constitution of a
transmission device according to the first embodiment of the
present invention.
[0025] FIG. 9 is a cross-sectional view of the clutch mechanism
according to the first embodiment of the present invention which
shows a state in which engagement of the Hirth coupling is
released.
[0026] FIG. 10 is a cross-sectional view of a clutch mechanism
according to a second embodiment of the present invention.
[0027] FIG. 11 is a cross-sectional view of a clutch mechanism
according to a third embodiment of the present invention.
[0028] FIG. 12 is a cross-sectional view of an internal gear
carrier according to a fourth embodiment of the present
invention.
[0029] FIG. 13 is a cross-sectional view of a clutch mechanism
according to the fourth embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0030] Hereinafter, a variable speed gearbox according to a first
embodiment of the present invention will be described in detail
with reference to the drawings.
[0031] As shown in FIG. 1, the variable speed gearbox 1 of the
embodiment includes an electric driving device 50 which generates a
rotational driving force, and a transmission device 10 which
changes the speed of a rotational driving force generated by the
electric driving device 50 and then transmits the speed-changed
rotational driving force to a driving target. The variable speed
gearbox 1 can be applied to, for example, a fluid mechanical system
such as a compressor system.
[0032] The driving target of the variable speed gearbox 1 of the
embodiment is a compressor C.
[0033] The transmission device 10 is a planetary gear transmission
device.
[0034] The electric driving device 50 includes a constant-speed
motor 51 having a constant-speed rotor 52 which rotates at a
constant speed, and a variable-speed motor 71 having a
variable-speed rotor 72 which rotates at an arbitrary rotation
rate. Each of the constant-speed rotor 52 and the variable-speed
rotor 72 is connected to the transmission device 10.
[0035] The electric driving device 50 is supported on a frame 90 by
an electric driving device support portion 50S. The transmission
device 10 is supported on the frame 90 by a transmission device
support portion 10S. The electric driving device 50 and the
transmission device 10 which are heavy objects can be securely
fixed by these support portions.
[0036] As shown in FIG. 2, the transmission device 10 includes a
sun gear 11 which rotates about an axis Ar extending in a
horizontal direction, a sun gear shaft 12 fixed to the sun gear 11,
a plurality of planetary gears 15 which mesh with the sun gear 11,
revolve around the axis Ar and rotate about their own center lines
Ap, an internal gear 17 in which a plurality of teeth are arranged
in an annular shape around the axis Ar and which meshes with the
plurality of planetary gears 15, a planetary gear carrier 21 which
supports the plurality of planetary gears 15 to allow the plurality
of planetary gears 15 to revolve around the axis Ar and to rotate
about their own center lines Ap, an internal gear carrier 31 which
supports the internal gear 17 to allow the internal gear 17 to
rotate about the axis Ar, and a transmission casing 41 which covers
these elements.
[0037] Hereinafter, a direction in which the axis Ar extends is
defined as an axial direction, one side in the axial direction is
defined as an output side, and a side opposite to the output side
is defined as an input side. Also, a radial direction around the
axis Ar is simply referred to as a radial direction. In the
variable speed gearbox 1 of the embodiment, the electric driving
device 50 is disposed on the input side in the axial direction, and
the transmission device 10 is disposed on the output side of the
electric driving device 50. The compressor C is disposed on the
output side of the variable speed gearbox 1.
[0038] The sun gear shaft 12 has a circular column shape centered
on the axis Ar and extends from the sun gear 11 toward the output
side in the axial direction. A flange 13 is formed at an
output-side end of the sun gear shaft 12. For example, a rotor of
the compressor C which serves as a driving target is connected to
the flange 13. The sun gear shaft 12 is supported to be rotatable
about the axis Ar by a sun gear bearing 42 disposed on the output
side of the sun gear 11. The sun gear bearing 42 is installed at
the transmission casing 41.
[0039] The planetary gear carrier 21 includes a planetary gear
shaft 22 provided for each of the plurality of planetary gears 15,
a carrier main body 23 which fixes the relative positions of the
plurality of planetary gear shafts 22, and an output-side planetary
gear carrier shaft 27o which extends in the axial direction
centered on the axis Ar. The output-side planetary gear carrier
shaft 27o is fixed to an inner side of the carrier main body 23 in
the radial direction.
[0040] The planetary gear shaft 22 passes through the center lines
Ap of the planetary gears 15 in the axial direction and supports
the planetary gears 15 to allow the planetary gears 15 to rotate
about a center line thereof. The carrier main body 23 extends
outward in the radial direction from the plurality of planetary
gear shafts 22.
[0041] The output-side planetary gear carrier shaft 27o extends
from the carrier main body 23 toward the output side. The
output-side planetary gear carrier shaft 27o is formed in a
cylindrical shape centered on the axis Ar.
[0042] The output-side planetary gear carrier shaft 27o is
supported to be rotatable about the axis Ar by a planetary gear
carrier bearing 43. The planetary gear carrier bearing 43 is
installed at the transmission casing 41. The sun gear shaft 12 is
inserted through the inner circumferential side of the output-side
planetary gear carrier shaft 27o.
[0043] The transmission device 10 includes an input-side planetary
gear carrier shaft 27i which is connected to the variable-speed
rotor 72 of the variable-speed motor 71, and a transmitting shaft
25 which transmits rotation of the input-side planetary gear
carrier shaft 27i to the planetary gear carrier 21.
[0044] The input-side planetary gear carrier shaft 27i is formed in
a cylindrical shape centered on the axis Ar. The input-side
planetary gear carrier shaft 27i is disposed on the input side of
the transmission device 10 and is supported by the planetary gear
carrier bearing 44 to be rotatable about the axis Ar. The planetary
gear carrier bearing 44 is installed at the transmission casing 41.
An internal gear carrier shaft 37 for driving the internal gear
carrier 31 of the transmission device 10 is inserted through the
inner circumferential side of the input-side planetary gear carrier
shaft 27i.
[0045] An annular flange 28 which expands outward in the radial
direction is formed at the input-side end of the input-side
planetary gear carrier shaft 27i. An input-side arm portion 26
which extends outward in the radial direction is formed on the
output-side end of the input-side planetary gear carrier shaft
27i.
[0046] The transmitting shaft 25 is supported to be rotatable about
the axis At. The transmitting shaft 25 is installed at the
transmission casing 41 via a bearing (not shown). An input-side
transmitting gear 29i and an output-side transmitting gear 290 are
fixed to both ends of the transmitting shaft 25.
[0047] The input-side transmitting gear 29i meshes with a gear
formed on the outer circumference of the input-side arm portion 26.
The output-side transmitting gear 290 meshes with a gear formed on
the outer circumference of the carrier main body 23. Accordingly,
the rotation of the input-side planetary gear carrier shaft 27i is
transmitted to the planetary gear carrier 21 via the transmitting
shaft 25.
[0048] The internal gear carrier 31 includes a carrier main body 33
to which the internal gear 17 is fixed, and the internal gear
carrier shaft 37 which is fixed to the carrier main body 33 and
extends in the axial direction centered on the axis Ar.
[0049] The carrier main body 33 includes a cylindrical portion 35
which has a cylindrical shape centered on the axis Ar and has the
internal gear 17 fixed to the inner circumferential side thereof,
and a clutch mechanism 2 which connects the input-side end of the
cylindrical portion 35 with the output-side end of the internal
gear carrier shaft 37.
[0050] The clutch mechanism 2 is a mechanism which transmits or
blocks the rotation of the internal gear carrier shaft 37
(constant-speed rotor 52) to the cylindrical portion 35.
[0051] The internal gear carrier shaft 37 having a column shape
around the axis Ar is disposed on the input side of the sun gear
shaft 12 (refer to FIG. 2) having a column shape around the axis
Ar. The internal gear carrier shaft 37 is inserted through the
inner circumferential side of the cylindrical input-side planetary
gear carrier shaft 27i (refer to FIG. 2).
[0052] The output side of the internal gear carrier shaft 37 is
supported by an internal gear carrier bearing 77. The internal gear
carrier bearing 77 is a composite bearing in which a radial bearing
for receiving a radial load and a thrust bearing for receiving a
thrust load are integrated.
[0053] The internal gear carrier shaft 37 includes a thrust collar
37a which supports the internal gear carrier bearing 77 in the
axial direction. The thrust collar 37a protrudes radially outward
from the outer circumferential surface of the internal gear carrier
shaft 37.
[0054] The clutch mechanism 2 includes a moving portion 36 which is
connected to the cylindrical portion 35 to be movable in the axial
direction, a drive portion 38 which drives the moving portion 36 in
the axial direction, a fixed portion 39 which is fixed to the
internal gear carrier shaft 37 (constant-speed rotor 52), and a
Hirth coupling 40 (engaging portion) which engages the moving
portion 36 with the fixed portion 39 by moving the moving portion
36 in the axial direction.
[0055] The drive portion 38 includes a first disk portion 45 (disk)
which is disposed on the input side of the moving portion 36 to
face the moving portion 36 in the axial direction and forms a first
oil supply space S1 between the first disk portion 45 and the
moving portion 36, a fixed seal portion 49 which forms the first
oil supply space S1 in cooperation with the first disk portion 45
and the moving portion 36, an oil supply portion 57 which supplies
a working oil to the first oil supply space S1. The fixed seal
portion 49 has a cylindrical shape and is fixed to the transmission
casing 41 (refer to FIG. 2).
[0056] An oil supply path 78 extending in the radial direction is
formed inside the fixed seal portion 49 and the first disk portion
45. An end of the oil supply path 78 on the outer side in the
radial direction is opened in the fixed seal portion 49. An end of
the oil supply path 78 on the inner side in the radial direction is
connected to a nozzle 79 for introducing oil into the first oil
supply space S1.
[0057] The oil supply portion 57 is provided inside or outside the
transmission casing 41 and supplies the working oil to the first
oil supply space S1 via a pipe 57a and the oil supply path 78. As
the working oil is supplied to the first oil supply space S1, a
second disk portion 46 of the moving portion 36 is pressed from the
input side by an oil pressure of the working oil. As the second
disk portion 46 is pressed from the input side, the moving portion
36 moves to the output side.
[0058] The oil supply portion 57 may be an oil supply device which
supplies oil to bearings supporting the internal gear carrier shaft
37.
[0059] As shown in FIG. 5, the Hirth coupling 40 includes a first
Hirth coupling 40a fixed to the moving portion 36, and a second
Hirth coupling 40b fixed to the fixed portion 39.
[0060] As the moving portion 36 moves to the output side, the first
Hirth coupling 40a and the second Hirth coupling 40b are engaged
with each other. The rotation of the internal gear carrier shaft 37
is transmitted to the cylindrical portion 35 via the fixed portion
39 and the moving portion 36 by engaging the first Hirth coupling
40a and the second Hirth coupling 40b.
[0061] In a state in which the first Hirth coupling 40a and the
second Hirth coupling 40b are not engaged with each other, the
rotation of the internal gear carrier shaft 37 is not transmitted
to the cylindrical portion 35. That is, in a state in which the
moving portion 36 is disposed on the input side and the Hirth
coupling 40 is not engaged, the driving force of the constant-speed
rotor 52 is not transmitted to the transmission device 10.
[0062] As shown in FIGS. 6 and 7, the first Hirth coupling 40a and
the second Hirth coupling 40b are disk-shaped members which are
perforated. A claw 40c having a square (trapezoidal, rectangular
wave-like) cross-sectional shape is formed on one surface of each
of the first Hirth coupling 40a and the second Hirth coupling 40b.
Each claw 40c extends radially. The plurality of claws 40c are
formed at regular intervals in the circumferential direction.
[0063] As the first Hirth coupling 40a and the second Hirth
coupling 40b have such a shape, for example, it is possible to
transmit a stronger driving force as compared with a claw having a
triangular cross section.
[0064] The fixed portion 39 has a disk-shaped third disk portion 47
in which a through-hole is formed at the center thereof and a
cylindrical boss portion 58 provided on the inner side of the third
disk portion 47 in the radial direction. The second Hirth coupling
40b is fixed to the surface of the third disk portion 47 which
faces the input side.
[0065] The inner circumferential surface of the boss portion 58 is
fixed to the outer circumferential surface of the internal gear
carrier shaft 37. The fixed portion 39 is fixed to the output-side
end of the internal gear carrier shaft 37 so that the main surface
of the third disk portion 47 is orthogonal to the axis Ar.
[0066] The moving portion 36 includes the disk-shaped second disk
portion 46 having a through-hole formed in the center thereof, a
fourth disk portion 48 disposed on the outer side of the second
disk portion 46 in the radial direction, and a connecting portion
59 which connects the end of the second disk portion 46 on the
outer side in the radial direction with the end of the fourth disk
portion 48 on the inner side in the radial direction.
[0067] The second disk portion 46 is disposed on the input side of
the third disk portion 47 of the fixed portion 39 so that the main
surface of the second disk portion 46 and the main surface of the
third disk portion 47 are parallel to each other.
[0068] A seal member 60a is provided between the inner
circumferential surface of the second disk portion 46 and the outer
circumferential surface of the boss portion 58. The seal member 60a
is, for example, a gland packing having a function of restricting
the working oil from flowing out of the first oil supply space
S1.
[0069] The first Hirth coupling 40a is fixed to a surface of the
second disk portion 46 which faces the output side. A seal member
60b is provided between the outer circumferential surface of the
second disk portion 46 and the inner circumferential surface of the
fixed seal portion 49.
[0070] The connecting portion 59 protrudes to the output side from
the end of the second disk portion 46 on the outer side in the
radial direction. The outer circumferential surface of the fourth
disk portion 48 is connected to the inner circumferential surface
of the cylindrical portion 35 to be movable in the axial
direction.
[0071] The fourth disk portion 48 and the cylindrical portion 35
are connected to each other not to move relative to each other in
the circumferential direction. Specifically, a first spur gear 48a
which has linear teeth parallel to the axis Ar is formed on the
outer circumferential surface of the fourth disk portion 48, and a
second spur gear 35a which meshes with the first spur gear 48a of
the fourth disk portion 48 is formed on the inner circumferential
surface of the cylindrical portion 35. The fourth disk portion 48
(moving portion 36) moves in the axial direction as the first spur
gear 48a moves on the second spur gear 35a.
[0072] The moving portion 36 is biased toward the input side by a
biasing mechanism 67. The biasing mechanism 67 includes a plurality
of spring fixing members 68 fixed to the input-side end of the
cylindrical portion 35, and a plurality of tension coil springs 69.
The plurality of spring fixing members 68 are fixed at intervals in
the circumferential direction.
[0073] The spring fixing members 68 protrude radially inward from
the inner circumferential surface of the cylindrical portion 35.
The spring fixing members 68 are disposed on the input side of the
fourth disk portion 48. The tension coil spring 69 connects the
spring fixing member 68 with the fourth disk portion 48. The moving
portion 36 is biased toward the input side by the tension coil
springs 69.
[0074] The first disk portion 45 is disposed on the input side of
the second disk portion 46 of the moving portion 36 so that the
main surface of the first disk portion 45 and the main surface of
the second disk portion 46 are parallel to each other. The outer
circumferential surface of the first disk portion 45 is fixed to
the inner circumferential surface of the fixed seal portion 49.
[0075] A seal member 60c is provided between the inner
circumferential surface of the first disk portion 45 and the outer
circumferential surface of the internal gear carrier shaft 37.
[0076] The first oil supply space S1 is an enclosed space formed by
the first disk portion 45, the second disk portion 46, and the
fixed seal portion 49. As the moving portion 36 moves in the axial
direction, a volume of the first oil supply space S1 increases or
decreases. That is, as the moving portion 36 moves to the input
side, the volume of the first oil supply space S1 increases, and as
the moving portion 36 moves to the output side, the volume of the
first oil supply space S1 decreases.
[0077] As shown in FIG. 4, an oil discharge mechanism 70 (oil
discharge portion) for discharging the working oil in the first oil
supply space S1 is provided at the lower end of the fixed seal
portion 49. The oil discharge mechanism 70 includes a valve which
can be controlled by a control device 3.
[0078] As shown in FIG. 3, the constant-speed motor 51 rotationally
drives the internal gear carrier shaft 37 of the transmission
device 10. The variable-speed motor 71 rotationally drives the
input-side planetary gear carrier shaft 27i of the transmission
device 10. The electric driving device 50 has a cooling fan 91
which cools the constant-speed motor 51 and a fan cover 92 which
covers the cooling fan 91.
[0079] The internal gear carrier shaft 37 is a constant-speed input
shaft Ac which rotates at a constant speed under a driving force of
the constant-speed motor 51. The input-side planetary gear carrier
shaft 27i is a variable speed input shaft Av which rotates at an
arbitrary rotation rate under a driving force of the variable-speed
motor 71.
[0080] The variable speed gearbox 1 can change the rotation rate of
an output shaft Ao of the transmission device 10 connected to the
driving target by changing the rotation rate of the variable-speed
motor 71.
[0081] In the embodiment, the constant-speed motor 51 is, for
example, a four-pole three-phase induction motor. Further, the
variable-speed motor 71 is an eight-pole three-phase induction
motor having more poles than the constant-speed motor 51. The
specifications of the constant-speed motor 51 and the
variable-speed motor 71 are not limited to these and can be
appropriately changed.
[0082] The constant-speed motor 51 includes a constant-speed rotor
52 which rotates about the axis Ar and is connected to the internal
gear carrier shaft 37 which is the constant-speed input shaft Ac of
the transmission device 10, a constant-speed stator 66 disposed on
the outer circumferential side of the constant-speed rotor 52, and
a constant-speed motor casing 61 in which the constant-speed stator
66 is fixed to the inner circumferential side thereof.
[0083] The constant-speed rotor 52 includes a constant-speed rotor
shaft 53 which has a column shape around the axis Ar, and a
conductive body 56 fixed to the outer circumference of the
constant-speed rotor shaft 53. The cooling fan 91 is fixed to the
input side end of the constant-speed rotor shaft 53.
[0084] The constant-speed stator 66 is disposed radially outward
from the conductive body 56 of the constant-speed rotor 52. This
constant-speed stator 66 is formed of a plurality of coils.
[0085] The constant-speed motor casing 61 includes a casing main
body 62 having a cylindrical shape centered on the axis Ar and in
which the constant-speed stator 66 is fixed to the inner
circumferential side thereof, and covers 63i and 63o which close
both axial ends of the cylindrical casing main body 62.
Constant-speed rotor bearings 65i and 65o are installed at the
respective covers 63i and 63o to rotatably support the
constant-speed rotor shaft 53 about the axis Ar. A plurality of
openings 64 axially passing through the respective covers 63i and
63o at positions radially outward from the constant-speed rotor
bearing 65i are formed in the respective covers 63i and 63o.
[0086] The input-side end of the constant-speed rotor shaft 53
protrudes toward the input side from the input-side cover 63i of
the constant-speed motor casing 61. The cooling fan 91 is fixed to
the input-side end of the constant-speed rotor shaft 53.
[0087] When the constant-speed rotor 52 rotates, the cooling fan 91
also rotates integrally with the constant-speed rotor 52. The fan
cover 92 includes a cylindrical cover main body 93 disposed on the
outer circumferential side of the cooling fan 91, and an air
circulating plate 94 installed at an opening of the cover main body
93 on the inlet side and having a plurality of air holes formed
therein. The fan cover 92 is fixed to the cover 63i of the
constant-speed motor casing 61 on the input side.
[0088] The variable-speed motor 71 includes a variable-speed rotor
72 which rotates about the axis Ar and is connected to the
input-side planetary gear carrier shaft 27i which is the
variable-speed input shaft Av, a variable-speed stator 86 disposed
on the outer circumferential side of the variable-speed rotor 72,
and a variable-speed motor casing 81 in which the variable-speed
stator 86 is fixed to the inner circumferential side thereof.
[0089] The variable-speed rotor 72 has a variable-speed rotor shaft
73 and a conductive body 76 fixed to the outer circumference of the
variable-speed rotor shaft 73. The variable-speed rotor shaft 73
has a cylindrical shape around the axis Ar and has a shaft
insertion hole 74 passing through the variable-speed rotor shaft 73
in the axial direction. The internal gear carrier shaft 37 as the
constant-speed input shaft Ac is inserted through the shaft
insertion hole 74 of the variable-speed rotor shaft 73. An annular
flange 73o expanding radially outward is formed at the output-side
end of the variable-speed rotor shaft 73.
[0090] The variable-speed stator 86 is disposed radially outward
from the conductive body 76 of the variable-speed rotor 72. The
variable-speed stator 86 is formed of a plurality of coils.
[0091] The variable-speed motor casing 81 includes a casing main
body 82 having a cylindrical shape around the axis Ar and to the
inner circumferential side of which the variable-speed stator 86 is
fixed, an output-side cover 83o which closes the output-side end of
the cylindrical casing main body 82, and an inlet-side cover 83i
disposed on the input side of the variable-speed stator 86 and
fixed to the inner circumferential side of the cylindrical casing
main body 82. Variable-speed rotor bearings 85i and 85o which
rotatably support the variable-speed rotor shaft 73 about the axis
Ar are installed at the respective covers 83i and 83o. In the
respective covers 83i and 83o, a plurality of openings 84 passing
through the respective covers 83i and 83o in the axial direction
are formed at positions radially outward from the variable-speed
rotor bearings 85i and 85o.
[0092] A space in the variable-speed motor casing 81 and a space in
the constant-speed motor casing 61 communicate with each other
through the plurality of openings 84 formed in the respective
covers 83i and 83o of the variable-speed motor casing 81 and the
plurality of openings 64 formed in the respective covers 63i and
63o of the constant-speed motor casing 61.
[0093] The variable speed gearbox 1 of the embodiment includes a
variable-speed flexible coupling 95 which is disposed between the
input-side planetary gear carrier shaft 27i which is the
variable-speed input shaft Av and the variable-speed rotor 72 and
connects them.
[0094] Further, in the variable speed gearboxl of the embodiment,
the constant-speed rotor 52, the variable-speed rotor 72 and the
sun gear shaft 12 are arranged on the same axis.
[0095] As shown in FIG. 8, the constant-speed motor 51 is set to
rotate the constant-speed rotor 52 (internal gear 17) in the second
direction R2 in the circumferential direction of the axis Ar by
supplying the electric power to the constant-speed motor 51. As the
constant-speed rotor 52 rotates in the second direction R2, the
internal gear carrier shaft 37 and the internal gear carrier 31
rotate in the second direction R2.
[0096] The output shaft Ao of the transmission device 10 is set to
rotate in the first direction R1 opposite to the second direction
R2 by the constant speed rotor 52 of the constant-speed motor 51
rotating at the maximum rotation rate in the second direction R2.
That is, the forward rotation of the constant-speed motor 51 is the
second direction R2, and the forward rotation of the output shaft
Ao of the transmission device 10 is the first direction R1. The
compressor C operates normally as the output shaft Ao rotates
forward.
[0097] In the following description, the rotation direction of the
first direction R1 is referred to as a positive rotation direction,
and the rotation direction of the second direction R2 is referred
to as a negative rotation direction. For example, the maximum
rotation rate of the constant-speed motor 51 is -1800 rpm.
[0098] The variable-speed motor 71 rotationally drives the
variable-speed rotor 72 (planetary gear carrier 21) in the first
direction R1 and the second direction R2 which are the
circumferential directions of the axis Ar. That is, the
variable-speed motor 71 can rotate forward and in reverse.
[0099] The variable-speed motor 71 serves as a generator by
rotating the variable-speed rotor 72 by an external force. A state
in which the variable-speed motor 71 serves as a generator is
referred to as a generator mode.
[0100] The variable-speed motor 71 serves as an electric motor by
supplying the electric power. A state in which the variable-speed
motor 71 serves as an electric motor is referred to as an electric
motor mode.
[0101] As the variable-speed rotor 72 rotates in the first
direction R1, the planetary gear carrier 21 rotates in the first
direction R1.
[0102] The variable speed gearbox 1 of the embodiment includes a
rotation rate controller 100 which controls the rotation rate of
the variable-speed motor 71, a variable-speed motor switch 111
which sets the variable-speed motor 71 to be in a power supply
state and a power cutoff state, a constant-speed motor switch 112
which sets the constant-speed motor 51 to be in the power supply
state and the power cutoff state, and a controller 120 which
controls operations of the rotation rate controller 100, the
variable-speed motor switch 111 and the constant-speed motor switch
112.
[0103] The controller 120 is constituted of a computer. The
controller 120 includes a receiving portion 121 which directly
receives an instruction from an operator or receives an instruction
from a host control device, an interface 122 which provides
instructions to the variable-speed motor switch 111, the rotation
rate controller 100 and the constant-speed motor switch 112, and a
calculating portion 123 which creates an instruction for the
variable-speed motor switch 111, the constant-speed motor switch
112, and the rotation rate controller 100 according to the
instructions received by the receiving portion 121 or the like.
[0104] The variable-speed motor switch 111 is electrically
connected to a power source line 110 and the rotation rate
controller 100. The rotation rate controller 100 is electrically
connected to the variable-speed motor 71. The constant-speed motor
switch 112 is electrically connected to the power source line 110
and the constant-speed motor 51.
[0105] The variable-speed motor switch 111 is turned on by an ON
instruction from the controller 120 and turned off by an OFF
instruction from the controller 120. When the variable-speed motor
switch 111 is turned on, electric power from the power source line
110 is supplied to the variable-speed motor 71 through the rotation
rate controller 100, and the variable-speed motor 71 is in the
power supply state. When the variable-speed motor switch 111 is
turned off, the power supply from the power source line 110 to the
rotation rate controller 100 and the variable-speed motor 71 is cut
off, and the variable-speed motor 71 is in the power cutoff
state.
[0106] The constant-speed motor switch 112 is turned on by an ON
instruction from the controller 120 and turned off by an OFF
instruction from the controller 120. When the constant-speed motor
switch 112 is turned on, the electric power from the power source
line 110 is supplied to the constant-speed motor 51, and the
constant-speed motor 51 is in the power supply state. When the
constant-speed motor switch 112 is turned off, the power supply
from the power source line 110 to the constant-speed motor 51 is
cut off, and the constant-speed motor 51 is in the power cutoff
state.
[0107] The rotation rate controller 100 includes a frequency
conversion portion 101 which changes a frequency of the electric
power supplied from the power source line 110, and a rotation
direction switching portion 102 which changes a rotation direction
of the variable-speed motor 71.
[0108] The frequency conversion portion 101 supplies the electric
power instructed by the controller 120 to the variable-speed motor
71. The variable-speed rotor 72 of the variable-speed motor 71
rotates at a rotation rate corresponding to this frequency. Since
the rotation rate of the variable-speed rotor 72 changes in this
manner, the rotation rate of the planetary gear carrier 21 of the
transmission device 10 connected to the variable-speed rotor 72
also changes. As a result, the rotation rate of the sun gear shaft
12 which is the output shaft Ao of the transmission device 10 also
changes.
[0109] The rotation direction switching portion 102 is a device
which changes the rotation direction of the variable-speed motor 71
by using a circuit for switching a plurality of (three in the case
of the embodiment) power source lines connected to the
variable-speed motor 71. That is, the rotation direction switching
portion 102 can rotate the variable-speed rotor 72 forward and in
reverse.
[0110] Here, the relationship between the number of teeth of each
gear of the transmission device 10 and the rotation rate of each
shaft of the transmission device 10 will be described with
reference to FIG. 8.
[0111] The rotation rate of the sun gear shaft 12 as the output
shaft Ao is indicated by .omega.s, the rotation rate of the
internal gear carrier shaft 37 (constant-speed motor 51) that is
the constant-speed input shaft Ac is indicated by .omega.i, and the
rotation rate of the input-side planetary gear carrier shaft 27i
(variable-speed motor 71) that is the variable-speed input shaft Av
is indicated by .omega.h. Further, the number of teeth of the sun
gear 11 is indicated by Zs, and the number of teeth of the internal
gear 17 is indicated by Zi.
[0112] Also, a ratio .omega.s/.omega.i of the rotation rate
.omega.s of the output shaft Ao to the rotation rate .omega.i of
the constant-speed motor 51 is indicated by U. The ratio U of the
rotation rate .omega.s of the output shaft Ao to the rotation rate
.omega.i of the constant-speed motor 51 is the same as a ratio
Zi/Zs of the number of teeth Zi of the internal gear 17 to the
number of teeth Zs of the sun gear 11.
[0113] Also, a ratio .omega.c/.omega.h of the rotation rate
.omega.c of the planetary gear carrier 21 to the rotation rate
.omega.h of the variable-speed motor 71 is indicated by P.
[0114] The relationship between the number of teeth of each gear
and the rotation rate of each shaft in the transmission device 10
can be expressed by the following Formula (1):
.OMEGA.s/.omega.i=P.times..omega.h/.omega.i-(1-P.times..omega.h/.omega.i-
).times.U (1)
[0115] When the constant-speed motor 51 is a four-pole induction
motor and the power source frequency is 60 Hz, the rotation rate
.omega.i (rated rotation rate) of the constant-speed rotor 52
(constant-speed input shaft Ac) is -1,800 rpm. Further, when the
variable-speed motor 71 is an eight-pole induction motor and the
power source frequency is 60 Hz, the maximum rotation rate .omega.h
(rated rotation rate) of the variable-speed rotor 72
(variable-speed input shaft Av) is 900 rpm.
[0116] Further, the ratio U of the rotation rate .omega.s of the
output shaft Ao to the rotation rate .omega.i of the constant-speed
motor 51 (ratio Zi/Zs of the number of teeth Zs of the sun gear 11
to the number of teeth Zi of the internal gear 17) is set to 4.
[0117] Furthermore, the ratio P of the rotation rate .omega.c of
the planetary gear carrier 21 to the rotation rate .omega.h of the
variable-speed motor 71 is set to 0.3.
[0118] In this case, when the rotation direction of the
constant-speed rotor 52 (internal gear 17) is the rotation (-1,800
rpm) in the second direction R2 and the rotation direction of the
variable-speed rotor 72 (planetary gear carrier 21) has the maximum
rotation rate (900 rpm) in a direction opposite to the rotation of
the constant-speed rotor 52 (rotation in the first direction R1),
the rotation rate .omega.s of the sun gear shaft 12 which is the
output shaft Ao is 11,700 rpm. This rotation rate (11,700 rpm) is
the maximum rotation rate of the sun gear shaft 12.
[0119] That is, in the transmission device 10 of the embodiment,
the rotation rate .omega.s of the output shaft Ao becomes the
maximum rotation rate when the internal gear 17 corresponding to
the constant-speed input shaft Ac rotates at -1,800 rpm and the
planetary gear carrier 21 corresponding to the variable-speed input
shaft Av rotates at 900 rpm.
[0120] Assuming that a variable speed range of the variable-speed
input shaft Av is from -900 rpm to +900 rpm, the rotation rate
.omega.s of the output shaft Ao lowers as the rotation rate of the
variable-speed input shaft Av approaches -900 rpm.
[0121] Next, the operation of the variable speed gearbox 1 of the
embodiment will be described.
[0122] The variable speed gearbox 1 of the embodiment can prevent
the driving force of the constant-speed motor 51 from being
transmitted to the transmission device 10 using the clutch
mechanism 2.
[0123] As shown in FIG. 5, during a normal operation, the driving
force of the constant-speed motor 51 (refer to FIG. 1) is
transmitted to the transmission device 10 by the clutch mechanism
2. During the normal operation, the working oil is supplied from
the oil supply portion 57 (refer to FIG. 4) to the first oil supply
space S1, and the moving portion 36 is moved to the output side. As
the moving portion 36 moves to the output side, the first Hirth
coupling 40a and the second Hirth coupling 40b constituting the
Hirth coupling 40 are engaged. Accordingly, the driving force of
the constant-speed motor 51 is transmitted to the cylindrical
portion 35 via the constant-speed rotor 52 (refer to FIG. 1), the
internal gear carrier shaft 37, the fixed portion 39 and the moving
portion 36.
[0124] As shown in FIG. 9, when the clutch mechanism 2 is used to
prevent the driving force of the constant-speed motor 51 from being
transmitted to the transmission device 10, the control device 3
controls the oil discharge mechanism 70 (refer to FIG. 4) to
discharge the working oil in the first oil supply space S1.
Therefore, the moving portion 36 moves to the input side. As the
moving portion 36 moves to the input side, the first Hirth coupling
40a and the second Hirth coupling 40b are separated from each
other, and the driving force on the side of the constant-speed
rotor 52 is not transmitted to the cylindrical portion 35.
[0125] According to the embodiment, in the variable speed gearbox
1, for example, when the power supply to the electric motor is cut
off due to overvoltage, overcurrent, or the like, the driving force
of the constant-speed motor 51 transmitted to the transmission
device 10 can be disconnected.
[0126] Accordingly, over-rotation of the variable-speed motor 71 or
the compressor C which is the driving target can be prevented by
the rotation of the constant-speed rotor 52 being transmitted.
[0127] Further, it is possible to move the moving portion 36 using
oil supplied to the bearings by adopting a configuration in which
the moving portion 36 is moved by the oil pressure. Furthermore, it
is possible to release the engagement by the Hirth coupling 40 by
discharging the oil from the first oil supply space S1.
[0128] In addition, in the embodiment, the internal gear carrier
shaft 37 which is a rod-shaped shaft is inserted through the
variable-speed rotor shaft 73 which is a cylindrical shaft in which
the shaft insertion hole 74 is formed. That is, the constant-speed
input shaft Ac having a large output is inserted through the
variable-speed rotor shaft 73 of the variable-speed motor 71 having
a smaller output than the constant-speed motor 51. Accordingly, as
the constant-speed motor 51, one having a larger output
(horsepower) can be adopted.
[0129] Further, in the embodiment, the whole apparatus can be made
more compact by arranging the constant-speed motor 51, the
variable-speed motor 71, the transmission device and the compressor
C linearly in this order.
Second Embodiment
[0130] Hereinafter, a variable speed gearbox according to a second
embodiment of the present invention will be described in detail
with reference to the drawings. In this embodiment, differences
from the above-described first embodiment will be mainly described,
and description of similar portions will be omitted.
[0131] The first disk portion 45 of the variable speed gearbox
according to the embodiment is movable in the axial direction like
the moving portion 36.
[0132] The first disk portion 45 is connected to the transmission
casing 41 (refer to FIG. 2) via a rail (not shown). The first disk
portion moves along the rail in the axial direction.
[0133] A thrust collar 37b is formed on the internal gear carrier
shaft 37, and a surface 45a facing the input side of the first disk
portion 45 is supported by the thrust collar 37b via a thrust
bearing 87.
[0134] An opening (nozzle) of the oil supply path 78 on the inner
side in the radial direction is provided in the inner
circumferential surface of the first disk portion 45. A seal member
60d is provided between the outer circumferential surface of the
first disk portion 45 and the inner circumferential surface of the
fixed seal portion 49.
[0135] According to the embodiment, the thrust bearing 87 and the
thrust collar 37b can receive the oil pressure applied to the first
oil supply space S1 by allowing the first disk portion 45 to be
movable in the axial direction. Accordingly, the force applied to
the internal gear carrier shaft 37 can be canceled out as the force
received by the fixed portion 39 is offset against the force
received by the thrust collar 37b.
Third Embodiment
[0136] Hereinafter, a variable speed gearbox according to a third
embodiment of the present invention will be described in detail
with reference to the drawings. In this embodiment, differences
from the above-described first embodiment will be mainly described,
and a description of similar portions will be omitted.
[0137] As shown in FIG. 11, the inner circumferential surface of
the first disk portion 45 of the embodiment is fixed to the outer
circumferential surface of the internal gear carrier shaft 37. That
is, the first disk portion 45 of the embodiment rotates together
with the internal gear carrier shaft 37.
[0138] A seal member 60e is provided between the outer
circumferential surface of the first disk portion 45 and the inner
circumferential surface of the fixed seal portion 49.
[0139] An oil supply path 78C of the embodiment is formed only in
the fixed seal portion 49.
[0140] An oil supply nozzle 88 is provided inside the first oil
supply space S1. Like the fixed seal portion 49, the oil supply
nozzle 88 is a fixed member.
[0141] The oil supply nozzle 88 has a cylindrical shape and extends
in the radial direction. An end of the oil supply nozzle 88 on the
outer side in the radial direction is connected to an opening of
the oil supply path 78C formed in the inner circumferential surface
of the fixed seal portion 49. The oil supply nozzle 88 extends to
the vicinity of the outer circumferential surface of the internal
gear carrier shaft 37.
[0142] According to the embodiment, it is possible to supply oil
using the oil supply nozzle 88 from the inner side in the radial
direction in which the pressure is lowered rather than the outer
side in the radial direction in which the pressure is increased by
the centrifugal force applied to the oil.
Fourth Embodiment
[0143] Hereinafter, a variable speed gearbox according to a fourth
embodiment of the present invention will be described in detail
with reference to the drawings. In this embodiment, differences
from the above-described third embodiment will be mainly described,
and description of similar portions will be omitted.
[0144] As shown in FIG. 12, a second oil supply space S2 is formed
inside the internal gear carrier shaft 37 of the embodiment. The
second oil supply space S2 is an enclosed space formed at the
output-side end of the internal gear carrier shaft 37. The first
oil supply space S1 and the second oil supply space S2 communicate
with each other through a communication path S3.
[0145] The oil supply portion 57 is provided inside or outside the
transmission casing 41 and supplies the working oil to the second
oil supply space S2 via a pipe 57a. As the working oil is supplied
from the oil supply portion 57 to the second oil supply space S2,
the working oil is supplied from the radially inner side to the
first oil supply space S1 via the communication path S3. As the
working fluid is supplied to the first oil supply space S1, the
second disk portion 46 of the moving portion 36 is pressed from the
input side due to the oil pressure of the working oil. The moving
portion 36 moves to the output side by the second disk portion 46
being pressed from the input side.
[0146] The oil supply portion 57 may be an oil supply device which
supplies oil to the bearings supporting the internal gear carrier
shaft 37.
[0147] As shown in FIG. 13, during normal operation, the driving
force of the constant-speed motor 51 (refer to FIG. 1) is
transmitted to the transmission device 10 by the clutch mechanism
2. During normal operation, the working oil is supplied from the
oil supply portion 57 (refer to FIG. 4) to the first oil supply
space S1 via the second oil supply space S2 and the communication
path S3, and the moving portion 36 moves to the output side.
[0148] According to the above-described embodiment, due to the
constitution in which the oil is supplied from the second oil
supply space S2 having a lower pressure rather than the first oil
supply space S1 in which the pressure is increased by the
centrifugal force applied to the oil, it is possible to easily
supply the oil to the oil supply spaces S1 and S2.
[0149] Further, according to the above-described embodiment, the
moving portion 36 is connected to the cylindrical portion 35 to be
movable in the axial direction. However, the present invention is
not limited thereto. The moving portion 36 may be connected to the
internal gear carrier shaft 37 to be movable in the axial
direction. In this case, the fixed portion 39 is fixed to the
cylindrical portion 35.
[0150] Further, in the above-described embodiment, a four-pole
three-phase induction motor is an exemplary example of a
constant-speed motor 51 suitable for rotating the compressor C at
high speed, and an eight-pole three-phase induction motor is an
exemplary example of a variable-speed motor 71 suitable for varying
the rotation rate of the compressor C within a certain range.
However, when it is unnecessary to rotate the driving target at
high speed, other types of electric motors may be used as the
constant-speed motor 51 and the variable-speed motor 71.
REFERENCE SIGNS LIST
[0151] 1 Variable speed gearbox [0152] 2 Clutch mechanism [0153] 10
Transmission device [0154] 10S Transmission device support portion
[0155] 11 Sun gear [0156] 12 Sun gear shaft [0157] 15 Planetary
gear [0158] 17 Internal gear [0159] 21 Planetary gear carrier
[0160] 22 Planetary gear shaft [0161] 25 Transmitting shaft [0162]
27 Planetary gear carrier shaft [0163] 27i Input-side planetary
gear carrier shaft [0164] 27o Output-side planetary gear carrier
shaft [0165] 28 Flange [0166] 31 Internal gear carrier [0167] 33
Carrier main body [0168] 35 Cylindrical portion [0169] 35a Second
spur gear [0170] 36 Moving portion [0171] 37 Internal gear carrier
shaft [0172] 38 Drive portion [0173] 39 Fixed portion [0174] 40
Hirth coupling (engaging portion) [0175] 40a First Hirth coupling
[0176] 40b Second Hirth coupling [0177] 40c Claw (Hirth coupling)
[0178] 41 Transmission casing [0179] 42 Sun gear bearing [0180] 45
First disk portion [0181] 46 Second disk portion [0182] 47 Third
disk portion [0183] 48 Fourth disk portion [0184] 48a First spur
gear [0185] 49 Fixed seal portion [0186] 50 Electric driving device
[0187] 50S Electric driving device support portion [0188] 51
Constant-speed motor [0189] 52 Constant-speed rotor [0190] 53
Constant-speed rotor shaft [0191] 56 Conductive body [0192] 57 Oil
supply portion [0193] 57a Pipe [0194] 58 Boss portion [0195] 59
Connecting portion [0196] 60a Seal member [0197] 60b Seal member
(second disk portion) [0198] 60c Seal member (first disk portion)
[0199] 60d Seal member (first disk portion) [0200] 60e Seal member
(first disk portion) [0201] 61 Constant-speed motor casing [0202]
64 Opening (constant-speed motor casing) [0203] 66 Constant-speed
stator [0204] 67 Biasing mechanism [0205] 68 Spring fixing member
[0206] 69 Tension coil spring [0207] 70 Oil discharge mechanism
(oil discharge portion) [0208] 71 Variable-speed motor [0209] 72
Variable-speed rotor [0210] 73 Variable-speed rotor shaft [0211] 74
Shaft insertion hole [0212] 76 Conductive body [0213] 77 Internal
gear carrier bearing [0214] 78, 78C Oil supply path [0215] 79
Nozzle [0216] 81 Variable-speed motor casing [0217] 84 Opening
(variable-speed motor casing) [0218] 86 Variable-speed stator
[0219] 87 Thrust bearing [0220] 88 Oil supply nozzle [0221] 90
Frame [0222] 91 Cooling fan [0223] 100 Rotation rate controller
[0224] 101 Frequency conversion portion [0225] 102 Rotation
direction switching portion [0226] 110 Power source line [0227] 111
Variable-speed motor switch [0228] 112 Constant-speed motor switch
[0229] 120 Controller (control device) [0230] 121 Receiving portion
[0231] 122 Interface [0232] 123 Calculating portion [0233] Ac
Constant-speed input shaft [0234] Ao Output shaft [0235] Ap Center
line (planetary gear shaft) [0236] Ar Axis [0237] Av Variable-speed
input shaft [0238] C Compressor [0239] R1 First direction [0240] R2
Second direction [0241] S1 First oil supply space [0242] S2 Second
oil supply space [0243] S3 Communication path
* * * * *