U.S. patent application number 11/215936 was filed with the patent office on 2006-03-16 for oil pump supporting structure of automatic transmission.
This patent application is currently assigned to JATCO Ltd.. Invention is credited to Katsutoshi Amano, Hiroyuki Nishiyama.
Application Number | 20060054413 11/215936 |
Document ID | / |
Family ID | 35197964 |
Filed Date | 2006-03-16 |
United States Patent
Application |
20060054413 |
Kind Code |
A1 |
Nishiyama; Hiroyuki ; et
al. |
March 16, 2006 |
Oil pump supporting structure of automatic transmission
Abstract
There is provided an oil pump supporting structure which can
prevent vibration and noise of an oil pump. A pump holding member
is disposed in substantially parallel with the tensioning direction
of a chain, for connecting a partition member and the oil pump to
each other. As a result, vibration occurring in the tensioning
direction of the chain when the oil pump is driven can be
suppressed to reduce vibration noise.
Inventors: |
Nishiyama; Hiroyuki;
(Fuji-shi, JP) ; Amano; Katsutoshi; (Fuji-shi,
JP) |
Correspondence
Address: |
ROSSI, KIMMS & McDOWELL LLP.
P.O. BOX 826
ASHBURN
VA
20146-0826
US
|
Assignee: |
JATCO Ltd.
Fuji-shi
JP
|
Family ID: |
35197964 |
Appl. No.: |
11/215936 |
Filed: |
August 31, 2005 |
Current U.S.
Class: |
184/6.28 |
Current CPC
Class: |
F16H 61/0031 20130101;
F16H 57/0434 20130101 |
Class at
Publication: |
184/006.28 |
International
Class: |
F01M 11/00 20060101
F01M011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2004 |
JP |
2004-251447 |
Claims
1. An oil pump supporting structure of an automatic transmission,
comprising: a chain that connects a drive sprocket attached to a
rotary member and a driven sprocket attached to a rotary shaft of
an oil pump so that an oil pump is driven by rotation of the drive
sprocket; a partition member that supports the rotary member inside
a path of said chain; and a pump holding member that connects said
partition member and the oil pump to each other on a side on which
the driven sprocket of the oil pump is mounted, wherein a line that
connects a point of connection between said pump holding member and
the oil pump and a point of connection between said pump holding
member and said partition member is substantially parallel with a
direction of tension of said chain acting when the oil pump is
driven.
2. An oil pump supporting structure of an automatic transmission
according to claim 1, wherein the point of connection between said
pump holding member and the oil pump is away from the rotary shaft
of the oil pump.
3. An oil pump supporting structure of an automatic transmission
according to claim 1, wherein on a side that abuts on the oil pump
and said partition member, said pump holding member holds harnesses
extended from a sensor provided on the partition member inside the
path of said chain, so that the harnesses can be drawn out of the
path of said chain.
4. An oil pump supporting structure of an automatic transmission
according to claim 1, wherein: an end face of the oil pump on a
side opposite to a side on which said driven sprocket is provided
is attached to a transmission case; and a side of the oil pump to
which external force in such a direction as to pull the oil pump
from the transmission case is applied due to tension of said chain
acting when the oil pump is driven is fixed to the transmission
case by inserting a bolt from the transmission case into threads
formed at a location away from the rotary shaft of the oil
pump.
5. An oil pump supporting structure of an automatic transmission
according to claim 1, wherein the oil pump comprises a vane type
oil pump.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a supporting structure of
an oil pump that is disposed apart from an input shaft of an
automatic transmission.
[0003] 2. Description of the Prior Art
[0004] Conventionally, as an oil pump for an automatic
transmission, there has been known an oil pump that is disposed
apart from an input shaft and driven by rotation of the input shaft
via a chain that connects a drive sprocket connected to a pump
impeller of the torque converter and a driven sprocket provided in
the oil pump.
[0005] In a supporting structure of such an oil pump, an end face
of the oil pump on a side opposite to the side on which the driven
sprocket is provided is connected to a transmission case, and the
side of the oil pump on which the driven sprocket is provided is
fixed by inserting a pump shaft into a hole of a pump holder
connected to the transmission case.
[0006] Such an oil pump supporting structure is disclosed in, for
example, Japanese Laid-Open Patent Publication (Kokai) No.
2003-156127.
[0007] In the above oil pump supporting structure, however, the oil
pump is positioned and fixed by inserting the shaft of the oil pump
into the hole of the pump holder, but the process for mounting the
oil pump is complicated, and the pump holder must be larger than at
least the outer circumference of the pump shaft, making structure
large and heavy.
[0008] Further, the oil pump cannot be reliably positioned with
respect to the rotation direction of the chain, and hence the oil
pump is twisted in the same direction as the rotation direction of
the driven sprocket, causing vibration and noise.
SUMMARY OF THE INVENTION
[0009] It is therefore an object of the present invention to
provide an oil pump supporting structure that prevents vibration
and noise of an oil pump.
[0010] To attain the above object, there is provided an oil pump
supporting structure of an automatic transmission, including a
chain that connects a drive sprocket attached to a rotary member
and a driven sprocket attached to a rotary shaft of an oil pump so
that an oil pump is driven by rotation of the drive sprocket, a
partition member that supports the rotary member inside a path of
the chain, and a pump holding member that connects the partition
member and the oil pump to each other on a side on which the driven
sprocket of the oil pump is mounted, wherein a line that connects a
point of connection between the pump holding member and the oil
pump and a point of connection between the pump holding member and
the partition member is substantially parallel with a direction of
tension of the chain acting when the oil pump is driven.
[0011] According to the present invention, since the partition
member and the oil pump are fixed to each other by the pump holding
member, vibration of the oil pump in the direction of tension of
the chain acting when the oil pump is driven can be suppressed to
reduce vibration noise.
[0012] Other features and advantages of the present invention will
apparent from the following detailed description taken in
conjunction with the accompanying drawings, in which like reference
characters designate the same or similar parts throughout the
figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a sectional view showing an oil pump of a
continuously variable transmission and its vicinity according to an
embodiment of the present invention;
[0014] FIG. 2 is a front view showing the oil pump and its
vicinity;
[0015] FIG. 3 is a side view showing the way the oil pump is
supported; and
[0016] FIG. 4 is a graph showing the relationship between vibration
and noise of the oil pump.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] The present invention will now be described in detail with
reference to the drawings showing a preferred embodiment
thereof.
[0018] FIG. 1 is a sectional view showing an oil pump of a belt
type continuously variable transmission and its vicinity according
to an embodiment of the present invention. FIG. 2 is a front view
showing the oil pump and its vicinity according to the
embodiment.
[0019] A continuously variable transmission 1 to which power from
an engine is input includes an input shaft 4 to which power is
input from the engine via a torque converter 3, a forward/backward
switching mechanism 9 that changes rotation directions of the power
input to the input shaft 4, and a shift mechanism 10 that converts
and transmits revolutions to wheels of a vehicle, not shown.
[0020] A vane type oil pump 2 driven by torque from the input shaft
4 is disposed such that an oil pump rotary shaft 5 and the input
shaft 4 are in parallel with each other.
[0021] It is preferred that the vane type oil pump 2, which is
small and efficient and has high discharge pressure, is applied to
the belt type continuously variable transmission that requires high
hydraulic pressure.
[0022] A drive sprocket 6 is provided between the torque converter
3 and the forward/backward switching mechanism 9 and directly
connected to a pump impeller of the torque converter 3 as a rotary
member. A chain 8 is looped over the drive sprocket 6 and a driven
sprocket 7, which is provided on the oil pump rotary shaft 5 of the
oil pump 2, to drive the oil pump 2.
[0023] Since the oil pump 2 is not disposed coaxially with the
input shaft 4, the input shaft 4 of the continuously variable
transmission 1 can be reduced in axial length.
[0024] An end of the oil pump 2 on a side opposite to the side on
which the driven sprocket 7 is provided is connected to a
transmission case 20 of the continuously variable transmission 1,
so that the oil pump 2 is fixed.
[0025] An oil strainer 11 is connected to a lower side of the oil
pump 2 as viewed in FIG. 1. The oil pump 2 absorbs oil stored in
the lower part of the continuously variable transmission 1 through
the oil strainer 11. The oil is pressurized by a pressurizing
mechanism 12 in the oil pump 2 and supplied to an oil channel
provided on the transmission case 20 side.
[0026] The oil pump 2 is fastened on the transmission case 20 by
bolts 30, 31, and 32 that penetrate the oil pump 2 from the side on
which the driven sprocket 7 is provided up to the transmission case
20 as shown in FIG. 2. A valve unit 35 is disposed in the lower
part of the oil pump 2 at the back as viewed in FIG. 2, and hence
the bolts cannot be inserted into the oil pump 2 from the front
side as viewed in FIG. 2. Therefore, the bolts 30, 31, and 32 are
concentrated in the upper part of the oil pump 2. Further, since an
oil channel 28 connected to the oil strainer 11 is formed in the
lower part of the oil pump 2, and hence through-holes for fixing
the oil pump 2 cannot be formed in the lower part of the oil pump
2.
[0027] Therefore, in the body of the oil pump 2, threads are formed
on a side that receives external force in such a direction as to
pull the oil pump 2 away from the transmission case 20 due to
tension of the chain 8 (the lower left-hand part of FIG. 3) and at
a location set in the lower part of the oil pump 2 and as far as
possible from an oil pump rotary shaft 5. The oil pump 2 is fixed
to the transmission case 20 by inserting the bolt 33 from the
reverse side of a wall of the transmission case 20 on which the oil
pump 2 abuts.
[0028] A partition member 27, which is attached to the transmission
case 20 to support the input shaft 4, is disposed between the
torque converter 3 and the forward/backward switching mechanism
9.
[0029] Inside the path of the chain 8, a sensor 36 that detects
rotation of a drum within the forward/backward switching mechanism
9 is mounted on the partition member 27.
[0030] Harnesses 38 are extended from the sensor 36 and connected
to a transmission controller, not shown, provided in the vicinity
of the valve unit 35.
[0031] It should be noted that the harnesses 38 are bound up
halfway into a bundle having a circular cross-section surface.
[0032] On a side of the oil pump 2 opposite to the side connected
to the transmission case 20, the partition member 27 and the oil
pump 2 are connected to each other by a pump holding member 40.
[0033] The pump holding member 40 is disposed in substantially
parallel with the tensioning direction of the chain 8 as viewed
from the axial direction of the oil pump rotary shaft 5, i.e. in
FIG. 2.
[0034] FIG. 3 is a side view showing the way the oil pump 2 is
supported.
[0035] An end 44 of the pump holding member 40, which is fixed to
the partition member 27, and an end 45 of the pump holding member
40, which is fixed to the oil pump 2, are offset from each other
via a slope 41.
[0036] Inside the path of the chain 8, the end 44 of the pump
holding member 40 is fixed to the partition member 27 by a bolt 42
so that the end 44 can be prevented from interfering with the chain
8.
[0037] Here, a face of the transmission case 20, to which the oil
pump 2 is connected, and a face of the partition member 27, to
which the pump holding member 40 is connected, are offset for an
axial direction of the oil pump rotary shaft 5.
[0038] The amount of the offset is slightly lower than an axial
height of the oil pump 2.
[0039] Therefore, the driven sprocket 7 of the oil pump 2 is
disposed closer to the torque converter 3 than the partition member
27.
[0040] The chain 8, which is looped over the drive sprocket 6 and
the driven sprocket 7, is disposed closer to the pump holding
member 40.
[0041] And the chain 8 is disposed such that a path plane which is
defined by the path of the chain 8 and the face of the partition
member 27 which is connected to the pump holding member 40 are in
parallel with each other.
[0042] Consequently, the pump holding member 40 and the bolt 42 are
disposed in the path plane of the chain 8.
[0043] The end 45 of the pump holding member 40 is offset downward
from the end 44 as viewed in FIG. 3.
[0044] Thus, the end 45 is located below the driven sprocket 7
while preventing from interfering with the chain 8 and the driven
sprocket 7, and is fixed to the oil pump 2 by a bolt 43.
[0045] When the partition member 27 and the end 44 of the pump
holding member 40 are fixed to each other, the sensor 36 and a
bracket 37 that supports the harnesses 38 extended from the sensor
36 are interposed between the end 44 and the partition member 27,
and the bracket 37 as well as the pump holding member 40 is
fastened with the bolt 42.
[0046] At the outer peripheral edge of the partition member 27, the
bracket 37 is bent in a direction away from the chain 8 to form a
harness holding part 39.
[0047] The harnesses 38, which connect the sensor 36 and the
transmission controller to each other, cross the chain 8, and the
harness holding part 39 holds the harnesses 38 on the reverse side
of the pump holding member 40 (the side on which the pump holding
member 40 abuts on the oil pump 2 and the partition member 37) so
as to keep the harnesses 38 from interfering with the chain 8 and
the driven sprocket 7.
[0048] The location at which the end 45 of the pump holding member
40 is fixed to the oil pump 2 by the bolt 43 is set to be as far as
possible from the oil pump rotary shaft 5 insofar as the bolt 43
can be inserted onto the oil pump 2.
[0049] It should be noted that the bolt 33 does not penetrate
through the oil pump 2.
[0050] FIG. 4 shows the relationship in vibration frequency and
noise when the oil pump 2 is driven between the case where the oil
pump 2 is fixed by the pump holding member 40 and the bolt 33 and
the case where the oil pump 2 is not fixed by the pump holding
member 40 and the bolt 33.
[0051] As indicated by the solid line in FIG. 4, in the case where
the oil pump 2 is fixed by the pump holding member 40, noise can be
reduced as compared with the case where the oil pump 2 is not fixed
as indicated by the broken line.
[0052] In the present embodiment arranged as described above, the
pump holding member 40 is disposed in substantially parallel with
the tensioning direction of the chain 8, for connecting the
partition member 27 and the oil pump 2 to each other.
[0053] Therefore, vibration occurring in the tensioning direction
of the chain 8 when the oil pump 2 is driven can be suppressed to
reduce vibration noise.
[0054] Further, since the location at which the end 45 of the pump
holding member 40 is fixed to the oil pump 2 is set to be apart
from the oil pump rotary shaft 5, vibration of the oil pump 2
rotating about the oil pump rotary shaft 5 when the oil pump 2 is
driven can be suppressed to reduce vibration noise, because the
effect of fixing the oil pump 2 can be increased in proportion to
the distance from the oil pump 5 (moment=force distance from
shaft).
[0055] Further, since the harness holding part 39 holds the
harnesses 38 on the reverse side of the pump holding member 40, the
harnesses 38 extended from the sensor 36 can be prevented from
interfering with the chain 8 and the driven sprocket 7, so that the
harnesses 38 can be protected and prevented from being broken.
[0056] Further, since the oil pump 2 is fixed by the bolt 33 on the
side that receives external force in such a direction as to pull
the oil pump 2 away from the transmission case 20 due to tension of
the chain 8 acting when the oil pump 2 is driven, vibration
occurring in the tensioning direction of the chain 8 when the oil
pump 2 is driven and vibration occurring in the direction in which
the oil pump 2 rotates about the oil pump rotary shaft 5 can be
suppressed.
[0057] Further, since the threads are formed on the oil pump 2, and
the bolt 33 is inserted onto the oil pump 2 from the reverse side
of the wall of the transmission case 20 abutting on the oil pump 2
so as to fix the oil pump 2 and the transmission case 20 to each
other, the bolt 33 can be prevented from interfering with the oil
channel 28 formed in the oil pump 2, making it easier to design the
oil channel 28.
[0058] Further, the side of the oil pump 2 which receives external
force in such a direction as to pull the oil pump 2 away from the
transmission case 20 due to tension of the chain 8 is apart from
the partition member 27, and hence if the side of the oil pump 2
which receives external force in such a direction as to pull the
oil pump 2 away from the transmission case 20 is fixed by the pump
holding member 4 fastened on the partition member 27, the pump
holding member 40 must be long. Therefore, it is preferred that the
oil pump 2 is fastened with the bolt 33 on the side that receives
external force in such a direction as to pull the oil pump 2 away
from the transmission case 20.
[0059] Further, it is particularly effective that the present
invention is applied to a vane type oil pump that pulsates when
discharging hydraulic pressure because of its high discharge
pressure and high airtightness.
* * * * *