U.S. patent application number 11/983485 was filed with the patent office on 2008-10-02 for gear case assembly.
This patent application is currently assigned to Samsung Techwin Co., Ltd.. Invention is credited to Yeong-soo Hwang, Bea-seog In.
Application Number | 20080240918 11/983485 |
Document ID | / |
Family ID | 39794687 |
Filed Date | 2008-10-02 |
United States Patent
Application |
20080240918 |
Kind Code |
A1 |
In; Bea-seog ; et
al. |
October 2, 2008 |
Gear case assembly
Abstract
A gear case assembly includes an upper gear case and a lower
gear case accommodating a drive axle, at least one rotation axle
receiving power from the drive axle, and a power transmission unit
for transmitting the power to the at least one rotation axis. The
upper and lower gear cases are horizontally divided, and upper and
a lower shrouds are integrally formed on the upper and lower gear
cases proximate to ends of the rotation axis. The upper and lower
shrouds form a surface for guiding a fluid that flows from an
impeller connected to the rotation axle, and are horizontally
divided. Scroll cases mounted on the upper and lower gear cases,
together with the upper and lower shrouds, define a path for
guiding the fluid that flows from the impeller. A common plane
divides the upper and lower gear cases, and also divides the upper
and lower shrouds.
Inventors: |
In; Bea-seog; (Seongnam-si,
KR) ; Hwang; Yeong-soo; (Seongnam-si, KR) |
Correspondence
Address: |
DRINKER BIDDLE & REATH LLP;ATTN: PATENT DOCKET DEPT.
191 N. WACKER DRIVE, SUITE 3700
CHICAGO
IL
60606
US
|
Assignee: |
Samsung Techwin Co., Ltd.
Changwon-city
KR
|
Family ID: |
39794687 |
Appl. No.: |
11/983485 |
Filed: |
November 9, 2007 |
Current U.S.
Class: |
415/214.1 ;
415/182.1; 415/230 |
Current CPC
Class: |
F04D 29/083 20130101;
F04D 29/4206 20130101; F04D 25/163 20130101 |
Class at
Publication: |
415/214.1 ;
415/182.1; 415/230 |
International
Class: |
F04D 29/40 20060101
F04D029/40; F04D 29/08 20060101 F04D029/08; F04D 29/10 20060101
F04D029/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2007 |
KR |
10-2007-0031965 |
Claims
1. A gear case assembly comprising: a first gear case and a second
gear case accommodating a drive axle adapted to be rotatably driven
by a driving unit, a first rotation axle receiving power from and
being rotated by the drive axle, a power transmission unit for
transmitting the power from the drive axle to the first rotation
axle, and a plane dividing the first and second gear cases; a first
shroud and a second shroud being respectively integrally formed on
the first and second gear cases and proximate a first end of the
first rotation axle, the first and second shrouds forming a first
surface for guiding a fluid that flows from a first impeller
disposed on the first rotation axle, and the plane dividing the
first and second shrouds; and a first scroll case mounted on the
first and second gear cases and proximate to the first and second
shrouds, the first scroll case and the first surface defining a
path for guiding the fluid that flows from the first impeller,
wherein mating surfaces of the first and second gear cases coincide
with the plane, and mating surfaces of the first and second shrouds
coincide with the plane.
2. The gear case assembly of claim 1, wherein of the first gear
case that is integrally formed with the first shroud and the second
gear case that is integrally formed with the second shroud are
fastened together with a threaded fastener.
3. The gear case assembly of claim 2, further comprising a seal
disposed between the mating surfaces of the first and second gear
cases.
4. The gear case assembly of claim 3, wherein the seal comprises an
O-ring.
5. The gear case assembly of claim 1, further comprising a second
rotation axle being disposed parallel to the drive axle, and the
drive axle being disposed between the first rotation axle and the
second rotation axle.
6. The gear case assembly of claim 5, wherein the first impeller is
disposed at one end of the first rotation axle, a second impeller
is disposed at another end of the first rotation axle, a third
impeller is disposed at one end of the second rotation axle,
wherein the fluid compressed by the first impeller then flows into
the second impeller and is compressed by the second impeller, and
the fluid compressed by the second impeller then flows into the
third impeller and is compressed by the third impeller, and wherein
sets of the first and second shrouds are formed on the first and
second cases, respectively, and each set of the first and second
shrouds is disposed proximate to a corresponding end of the first
and second rotation axles.
7. The gear case assembly of claim 6, further comprising a bull
gear disposed on the driving axle, a first pinion gear disposed on
the first rotation axle, and a second pinion gear disposed on the
second rotation axle, wherein the first pinion gear and the second
pinion gear mesh with the bull gear.
8. The gear case assembly of claim 1, wherein the driving unit is
one selected from the group consisting of a turbine, a motor, and
an engine.
9. The gear case assembly of claim 1, further comprising a carbon
seal disposed between the first rotation axle and the first and
second gear cases.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 10-2007-0031965, filed on Mar. 30, 2007, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a gear case assembly, and
more particularly, to a gear case assembly that accommodates a
rotation body used for a turbo compressor, a centrifugal
compressor, or another mechanical device that increases the
pressure of a gas by reducing its volume.
[0004] 2. Description of the Related Art
[0005] A rotation body, such as an impeller on an axle, may be
installed in a compressor, a blower, a turbo charger, or a marine
engine. In order to drive the rotation body, a power transmission
unit is accommodated in a gear case assembly to transmit power from
a drive source to the impeller. Alternatively, a rotation body such
as a turbine on an axle may be installed in an expander or another
mechanical device that extracts energy from a fluid flow, and may
provide a drive source from which power may be transmitted via a
gear case assembly.
[0006] A known gear case assembly includes a gear case divided
into, for example, an upper gear case and a lower gear case for
supporting the rotation body and the power transmission unit
therein. A shroud may be integrally formed on the gear case. The
shroud defines a surface for guiding a fluid that flows from an
impeller, and includes a roughly circular shape around a central
bore. For example, a circular shroud is formed on a front portion
of the lower gear case and protrudes toward the upper gear
case.
[0007] According to the known gear case assembly, the rotation body
includes an impeller disposed on an axle and driven by a drive
source via the power transmission unit. The impeller is mounted at
an end of the axle and has a diameter greater than that of the
axle. The axle is accommodated in the gear case assembly, and the
impeller is disposed outside the shroud of the gear case assembly.
In order to accommodate the axle in the gear case assembly, a bore
is formed in the gear case through the shroud.
[0008] However, when the impeller is preassembled to the axle, such
a rotation body assembly cannot be mounted on the lower gear case
as a whole since the diameter of the bore of the shroud is
frequently less than the diameter of the impeller. Thus, the
impeller must be disassembled from the axle in order to insert the
rotation body assembly through the bore in the shroud of the lower
gear case of the gear case assembly. Thereafter, a seal must be
interposed between the gear case assembly and the rotation body
assembly to prevent a leak from occurring therebetween.
[0009] However, before installing the rotation body assembly, a
balancing operation is performed on the rotation body assembly
before being disassembled. After installing the axle, the impeller
is reassembled on the axle. As a result, the rotation body assembly
may be out of balance due to the disassembling and reassembling of
the rotation body assembly after the balancing operation is
performed.
[0010] Also, in order to insert the rotation body assembly in the
bore of a known gear case assembly, the bore must be of sufficient
size in order to prevent interference between the elongated
rotation body assembly and the gear case. Therefore, a seal holder
needs to be additionally interposed between the rotation body
assembly and the bore of the gear case and, as a result, the number
of components increases, the assembly process becomes more
complicated, and production costs also increase. Additionally, it
is difficult to cast the gear case having the protruding shroud at
the front portion of the lower gear case and it is also hard to
perform a milling process, such as a cutting process or a finishing
process, on the lower gear case because of limited working
space.
[0011] Furthermore, because a groove that is required for a sealing
O-ring is difficult to form in the lower gear case, the groove that
is required for the sealing O-ring must be formed in the upper gear
case. However, it is disadvantageous to turn the upper gear case
upside down to form the groove required for the sealing O-ring.
SUMMARY OF THE INVENTION
[0012] The present invention provides a gear case assembly that
simplifies the assembly process, has improved efficiency in terms
of repair and maintenance, and has a reduced number of
components.
[0013] In accordance with an aspect of the present invention, there
is provided a gear case assembly including an upper gear case and a
lower gear case accommodating a driving axis rotatably driven by a
driving unit, at least one rotation axis receiving power from the
driving axis and rotating, a power transmit unit for transmitting
the power to the rotation axis, the upper gear case is horizontally
divided from the lower gear case; an upper shroud and a lower
shroud are integrally formed in end regions of the rotation axis of
the upper and lower gear cases, respectively, to form a surface for
guiding a fluid that flows from an impeller connected to the
rotation axis, the upper shroud is horizontally divided from the
lower shroud; and scroll cases are mounted in the end regions of
the upper and lower gear cases opposite the upper and lower
shrouds, respectively, to form a path for guiding the fluid that
flows from the impeller together with the upper and lower shrouds.
A bottom surface of the upper gear case is on the same level with a
bottom surface of the upper shroud, and a top surface of the lower
gear case is on the same level with a top surface of the lower
shroud.
[0014] The upper gear case that is integrally formed with the upper
shroud and the lower gear case that is integrally formed with the
lower shroud using, for example, a bolt, and the bottom surface of
the upper gear case may be on the same level with the top surface
of the lower gear case.
[0015] Therefore, since a rotation axis assembly can be assembled
to the gear case assembly without disjointing the impeller from the
rotation axis assembly, an assembling process and repair and
maintenance work can be facilitated, and the rotation axis assembly
can be well balanced. Also, a milling process can be easily
performed on the upper and lower gear cases at low cost since the
bottom surface of the upper gear case and the top surface of the
lower gear case are both plane. Furthermore, the upper and lower
gear cases can be easily manufactures using a casting process.
[0016] A seal, for example, an O-ring, may be disposed between the
top surface of the lower gear case, and the bottom surface of the
upper gear case.
[0017] Since the top surface of the lower shroud is on the same
level with the top surface of the lower gear case, a groove used
for disposing the O-ring can be formed in the lower gear case. In
this case, a surface of the lower gear case to be processed (i.e.,
the top surface of the lower gear surface) faces upward, so that it
is unnecessary to turn the lower gear case upside down. Therefore,
the groove used for disposing the O-ring can be easily processed in
the top surface of the lower gear case that is combined with the
bottom surface of the upper gear case.
[0018] A carbon seal may be interposed between the rotation axis
and the upper and lower gear cases in a rear end region of the
third impeller. In this case, it is unnecessary to enlarge a bore
formed in the upper and lower gear cases to assemble the elongated
rotation axis assembly unlike in the conventional case. Therefore,
an additional component is not required to mount the carbon seal
between the rotation axis and the upper and lower gear cases.
[0019] In accordance with another aspect of the present invention,
there is provided a gear case assembly that includes a first gear
case and a second gear case that accommodate a drive axle that is
adapted to be rotatably driven by a driving unit, a first rotation
axle that receives power from and is rotated by the drive axle, a
power transmission unit that transmits the power from the drive
axle to the first rotation axle, and a plane that divides the first
and second gear cases. A first shroud and a second shroud are
respectively integrally formed on the first and second gear cases
and proximate a first end of the first rotation axle, the first and
second shrouds form a first surface for guiding a fluid that flows
from a first impeller disposed on the first rotation axle, the
plane divides the first and second shrouds, and a first scroll case
mounted on the first and second gear cases and proximate to the
first and second shrouds, the first scroll case and the first
surface define a path for guiding the fluid that flows from the
first impeller. Wherein mating surfaces of the first and second
gear cases coincide with the plane, and mating surfaces of the
first and second shrouds coincide with the plane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The above and other features and advantages of the present
invention will become more apparent by describing in detail
exemplary embodiments thereof with reference to the attached
drawings in which:
[0021] FIG. 1 is a front view of a gear case assembly used for a
turbo compressor according to an embodiment of the present
invention;
[0022] FIG. 2 is a plan view of a lower gear case assembly of the
gear case assembly shown in FIG. 1, according to an embodiment of
the present invention; and
[0023] FIG. 3 is a magnified view of region "A" of FIG. 2,
according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, which show
exemplary embodiments according to aspects of the invention.
[0025] FIG. 1 is a front view of a gear case assembly used for a
turbo compressor according to an exemplary embodiment of the
present invention, FIG. 2 is a plan view of a lower gear case
assembly of the gear case assembly shown in FIG. 1, according to an
exemplary embodiment of the present invention, and FIG. 3 is an
enlarged view of region "A" of FIG. 2, according to an exemplary
embodiment of the present invention.
[0026] Referring to FIGS. 1 through 3, the gear case assembly used
for the turbo compressor according to an exemplary embodiment of
the present invention includes an upper gear case 20, a lower gear
case 10, first through third upper shrouds (only first and third
upper shrouds 21 and 23 are shown in FIG. 1), first through third
lower shrouds 11, 12, and 13, and first through third impellers 41,
42, and 43. The upper gear case 20 is horizontally divided from the
lower gear case 10. The upper gear case 20 is combined with the
lower gear case 10 such that a bottom surface of the upper gear
case 20 is in contact with a top surface of the lower gear case 10,
and the bottom surface of the upper gear case 20 forms a planar
surface with the top surface of the lower gear case 10. A drive
axle 30 and first and second rotation axles 31 and 32, are
accommodated between the upper and lower gear cases 20 and 10.
[0027] The drive axle 30 is connected to a driving source, for
example, a turbine (not shown), and rotatably driven thereby. For
example, if the turbo compressor is driven by a gas turbine engine,
the turbine rotates due to air heated by a combustor of the gas
turbine engine and, in turn, the turbine drives the drive axle 30
of the turbo compressor.
[0028] The first rotation axle 31 and the second rotation axle 32
are disposed on the left and right sides of the drive axle 30,
respectively. A power transmission unit, which transmits power from
the drive axle 30 to the first and second rotation axles 31 and 32
includes a bull gear 33, a first pinion gear 34, and a second
pinion gear 35. The bull gear 33 is mounted on the drive axle 30,
the first pinion gear 34 is mounted on the first rotation axle 31,
and the second pinion gear 35 is mounted on the second rotation
axle 32. The bull gear 33 meshes with each of the first and second
pinion gears 34 and 35.
[0029] The first impeller 41 is disposed at a front end of the
first rotation axle 31, the second impeller 42 is disposed at a
rear end of the first rotation axle 31, and the third impeller 43
is disposed at a front end of the second rotation axle 32. The
first and second rotation axles 31 and 32 receive power from the
drive axle 30 and rotate the first, second, and third impellers 41,
42, and 43.
[0030] Since the number of teeth and diameter of the first pinion
gear 34 are smaller than those of the bull gear 33, the first
rotation axle 31 rotates at a higher rate than the drive axle 30.
Also, since the number of teeth and diameter of the second pinion
gear 35 are smaller than those of the first pinion gear 34, the
second rotation axle 32 rotates at a higher rate than the drive
axle 30. Thus, air is compressed by the first impeller 41 in a
first compression stage, the compressed air is further compressed
by the second impeller 42 in a second compression stage, and the
compressed air is further compressed by the third impeller 43 in a
third compression stage. Hence, the turbo compressor according to
the illustrated exemplary embodiment is a three-stage compressor.
Although the gear case assembly used for the three-stage turbo
compressor is exemplarily illustrated and described in the present
embodiment, the present invention is not limited thereto. The
present invention may be applied to any gear case assembly
including a rotation body, such as the third impeller 43 disposed
on the second rotation axle 32, the lower and upper gear cases 10
and 20 accommodating the rotation body, and the third lower and
third upper shrouds 13 and 23, which are respectively formed on the
gear cases 10 and 20.
[0031] The first lower shroud 11 is formed in the lower gear case
10 proximate the front end of the first rotation axle 31. The first
lower shroud 11 is horizontally divided from the first upper shroud
21 such that a top surface of the first lower shroud 11 forms a
planar surface with the top surface of the lower gear case 10, and
a bottom surface of the first upper shroud 21 forms a planar
surface with the bottom surface of the upper gear case 20.
[0032] Similarly, the second lower shroud 12 is formed in the lower
gear case 10 proximate the rear end of the first rotation axle 31.
The second lower shroud 12 is horizontally divided from the second
upper shroud (not shown). Also, the third lower shroud 13 is formed
in the lower gear case 10 proximate the front end of the second
rotation axle 32. The third lower shroud 13 is horizontally divided
from the third upper shroud 23.
[0033] When the first upper shroud 21 is combined with the first
lower shroud 11, a circular shroud surface having a central bore is
formed. Fluid flow provided by the first impeller 41 due to
rotation of the first rotation axle 31 is guided by the circular
shroud surface 11 and 21.
[0034] The first through third upper shrouds 21, (not shown), and
23 and the upper gear case 20 are integrally formed by, for
example, a casting process. Also, the first through third lower
shrouds 11, 12, and 13 and the lower gear case 10 are integrally
manufactured by, for example, a casting process. The upper gear
case 20 including the first through third upper shrouds 21, (not
shown), and 23 and the lower gear case 10 including the first
through third lower shrouds 11, 12, and 13 may be secured together
with a threaded faster such as a bolt, a bolt and nut, or another
type of releasable fastener. For example, one or more bolts may
pass through the upper gear case 20 and be fastened to a threaded
portion of the lower gear case 10 in order to secure together the
upper and lower gear cases 20 and 10.
[0035] Since the upper gear case 20 that is integrally formed with
the first through third upper shrouds 21, (not shown), and 23 is
horizontally divided from the lower gear case 10 that is integrally
formed with the first through third lower shrouds 11, 12, and 13,
it is not necessary to disassemble the impellers 41, 42, and 43
from the first and second rotation axles 31 and 32 in order to
install the first and second rotation axles 31 and 32 in the gear
case assembly. Thus, the gear case assembly can be easily assembled
and, in terms of repair and maintenance, achieve improved
efficiency. Additionally, preassembly and balancing of the first
and second rotation axles 31 and 32 is provided such that
disassembly is not required.
[0036] Also, a milling process can be easily performed on the lower
and upper gear cases 10 and 20 at low cost since both the bottom
surface of the upper gear case 20 and the lower gear case 10 are
planar. Furthermore, the upper and lower gear cases 20 and 10 can
be easily manufactured by a casting process.
[0037] In addition, since the upper gear case 20, which is
integrally formed with the first through third upper shrouds 21,
(not shown), and 23, is horizontally divided from the lower gear
case 10, which is integrally formed with the first through third
lower shrouds 11, 12, and 13, it is unnecessary to increase the
size of bore portions 10a and 20a, which are respectively formed in
the upper and lower gear cases 10 and 20, to install the rotation
axles 31 and 32, as is the case in a known gear case assembly.
Thus, referring to FIG. 3, it is only necessary to insert a carbon
seal 51 between the first and second rotation axles 31 and 32 and
the lower and upper gear cases 10 and 20 in a rear region of the
third impeller 43. Unlike the known gear case assembly, a separate
carbon seal holder is not required to mount the carbon seal 51.
Therefore, the number of components can be reduced, the assembly
costs can be reduced, and failures caused by additional steps of
the assembling process can be eliminated. Hence, the carbon seal 51
functions to prevent the leakage of air compressed by the third
impeller 43.
[0038] A seal (not shown) is disposed between the top surface of
the lower gear case 10 and the bottom surface of the upper gear
case 20. The seal may be an O-ring. To install the O-ring, a groove
10b is formed in the top surface of the lower gear case 10, which
mates with the bottom surface of the upper gear case 20.
[0039] In the known gear case assembly, since the entire shroud is
integrally formed with the lower gear case 1 and protrudes upward
from the lower gear case 1, a groove, such as the groove 10b
required for an O-ring, cannot be formed in the lower gear case 1.
Thus, with the known gear case assembly, it becomes necessary to
disadvantageously turn the upper gear case 20 upside down and
handle the upper gear case 20 to form the groove required for the
O-ring in the upper gear case 20. However, according to aspects of
exemplary embodiments of the present embodiment, since top surfaces
of the first through third lower shrouds 11, 12, and 13 are on the
same plane with the top surface of the lower gear case 10, it is
possible to form the groove 10b in the lower gear case 10. In this
case, since a surface of the lower gear case 10 that is to be
processed (i.e., the top surface of the lower gear surface 10)
faces upward, it is unnecessary to additionally handle, e.g., turn
over, the lower gear case 10. In conclusion, the groove 10b
required for the O-ring can be easily processed.
[0040] Referring particularly to FIG. 2, a first scroll case 36 is
mounted to the lower and upper gear cases 10 and 20 proximate to
the front end of the first rotation axle 31, a second scroll case
37 is mounted to the lower and upper gear cases 10 and 20 proximate
to the rear end of the first rotation axle 31, and a third scroll
case 38 is mounted to the lower and upper gear cases 10 and 20
proximate to the front end region of the second rotation axle 32.
As illustrated in FIG. 3, along with the third lower and upper
shrouds 13 and 23, the third scroll case 38 defines a path that
guides air compressed by the third impeller 43. Although not shown
in the drawings, the third scroll case 38 may be mounted on the
lower and upper gear cases 10 and 20 using, for example, bolts or
other releasable fasteners.
[0041] Although a gear case assembly used for a turbo compressor
according to the exemplary embodiments of the present invention has
been explained, the present invention is not limited thereto. For
example, a gear case assembly according to exemplary embodiments of
the present invention can be applied to a blower, a turbo charger,
an engine, and an expander. That is, any gear case assembly
including a rotation body, such as the third impeller 43 disposed
on the second rotation axle 32, the lower and upper gear cases 10
and 20 accommodating the rotation body, and any of the first
through third lower shrouds 11, 12, and 13, and first through third
upper shrouds 21, (not shown), and 23 formed in the lower and upper
gear cases 10 and 20, may be within the scope of the present
invention. In this case, a driving gear for driving the rotation
body, such as the third impeller 43 disposed on the second rotation
axle 32, may be a turbine, a motor, or an engine.
[0042] While the present invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will
be understood by one of ordinary skill in the art that various
changes in form and details may be made therein without departing
from the spirit and scope of the present invention as defined by
the following claims.
* * * * *