U.S. patent application number 12/662999 was filed with the patent office on 2010-11-18 for electric pump.
This patent application is currently assigned to MIKUNI CORPORATION. Invention is credited to Hideki Endo, Naohisa Koike, Haruo Kotera, Yoshihiro Sakaguchi, Minoru Suzuki, Shingo Tabata, Kenta Tanaka, Michihiro Yokoyama.
Application Number | 20100290933 12/662999 |
Document ID | / |
Family ID | 42536356 |
Filed Date | 2010-11-18 |
United States Patent
Application |
20100290933 |
Kind Code |
A1 |
Tabata; Shingo ; et
al. |
November 18, 2010 |
Electric pump
Abstract
An electric pump includes a pump; a motor having a motor shaft,
the motor shaft being connected to the pump to drive the pump; a
support member which is arranged between the pump and a front end
portion of the motor, the front end portion of the motor being a
motor shaft side, the support member supporting the pump and the
motor when the motor shaft penetrates the pump; a motor cover which
covers the motor, the motor cover having a closed-end cylindrical
shape, and an opened end side of the motor cover being fixed to the
support member; and an elastic member which is in a state of being
compressed positioned between a rear end portion of the motor and a
bottom portion of the motor cover. The motor is supported by the
support member as being urged thereto by the elastic member.
Inventors: |
Tabata; Shingo;
(Odawara-shi, JP) ; Yokoyama; Michihiro;
(Odawara-shi, JP) ; Suzuki; Minoru; (Odawara-shi,
JP) ; Sakaguchi; Yoshihiro; (Okazaki-shi, JP)
; Endo; Hideki; (Okazaki-shi, JP) ; Kotera;
Haruo; (Okazaki-shi, JP) ; Koike; Naohisa;
(Okazaki, JP) ; Tanaka; Kenta; (Nagoya-shi,
JP) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700, 1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
MIKUNI CORPORATION
Tokyo
JP
MITSUBUSHI JIDOSHA KOGYO KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
42536356 |
Appl. No.: |
12/662999 |
Filed: |
May 14, 2010 |
Current U.S.
Class: |
417/410.3 |
Current CPC
Class: |
F01C 21/10 20130101;
F04B 53/003 20130101; F04C 2270/12 20130101; F04C 15/0042
20130101 |
Class at
Publication: |
417/410.3 |
International
Class: |
F04B 17/03 20060101
F04B017/03; F04B 53/00 20060101 F04B053/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 15, 2009 |
JP |
2009-118768 |
Claims
1. An electric pump comprising: a pump; a motor having a motor
shaft, the motor shaft being connected to the pump to drive the
pump; a support member which is arranged between the pump and a
front end portion of the motor, the front end portion of the motor
being a motor shaft side, the support member supporting the pump
and the motor when the motor shaft penetrates the pump; a motor
cover which covers the motor, the motor cover having a closed-end
cylindrical shape, and an opened end side of the motor cover being
fixed to the support member; and an elastic member which is in a
state of being compressed positioned between a rear end portion of
the motor and a bottom portion of the motor cover, wherein the
motor is supported by the support member as being urged thereto by
the elastic member.
2. The electric pump according to claim 1, wherein the elastic
member comprises a first elastic member provided in a state of
being compressed along an axial direction of the motor shaft, and
the motor is urged to the support member side along the axial
direction of the motor shaft by the first elastic member.
3. The electric pump according to claim 1, wherein the elastic
member comprises a second elastic member provided in a state of
being compressed along a radial direction having the motor shaft as
an approximate center, and the motor is urged to the motor shaft
side along the radial direction by the second elastic member.
4. The electric pump according to claim 1, wherein the elastic
member comprises: a first elastic member provided in a state of
being compressed along an axial direction of the motor shaft, the
motor being urged to the support member side along the axial
direction of the motor shaft by the first elastic member; and a
second elastic member provided in a state of being compressed along
a radial direction having the motor shaft as an approximate center,
the motor being urged to the motor shaft side along the radial
direction by the second elastic member.
5. The electric pump according to claim 1, wherein the elastic
member comprises a compressed spring.
6. The electric pump according to claim 1, wherein the elastic
member comprises a plate spring.
7. The electric pump according to claim 1, wherein the elastic
member comprises a disk spring.
8. The electric pump according to claim 1, wherein the motor and
the motor cover are not in contact with each other.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Japanese Patent
Application No. 2009-118768, filed on May 15, 2009 in the Japanese
Patent Office, the disclosure of which is incorporated herein by
reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates to an electric pump having a
pump connected to a motor shaft of an electric motor.
[0004] 2. Description of the Related Art
[0005] In a case where a brake servomechanism is operated in an
electric vehicle similar to a gasoline engine vehicle, a vacuum
pump is separately required since negative pressure is not
generated in the electric vehicle not like in an intake manifold of
the gasoline engine (see Japanese Patent Publication No. 10-329701,
for example).
[0006] Such a vacuum pump is provided with a pump (for example, a
vane type vacuum pump) connected to a motor shaft at a side from
which the motor shaft of an electric motor is protruded.
[0007] Further, to substitute for a vacuum pump, an electric pump
has been proposed to directly connect a pump to a motor shaft of an
electric motor to simplify assembly.
[0008] For example, in Japanese Patent Publication No. 63-21786, a
single cylindrical housing accommodates a pump assembly constituted
with a motor and a pump connected to the motor shaft of the
motor.
[0009] Within the housing, a rubber cushion formed to be
disk-shaped to cover an end portion of the pump side is arranged
between an outer face of the end portion of the pump side and an
inner face of the housing at the end portion of the pump side of
the pump assembly.
[0010] Further, within the housing, a rubber cushion formed to be
disk-shaped to cover an end portion of the motor side is arranged
between an outer face of the end portion of the motor side and the
inner face of the housing at the end portion of the motor side of
the pump assembly. This configuration aims to suppress vibration
and noise at the pump assembly.
[0011] In Japanese Patent Publication No. 63-21786, the pump
assembly constituted with the pump and the motor is supported to
the housing via the rubber cushion. Accordingly, vibration and
noise can be reduced by suppressing vibration transmission from the
pump and the motor to the housing. However, absorbing vibration
with the rubber cushion is limited. In addition, since a
rubber-like vibration absorbing member to absorb vibration is
necessary, there is a problem of deterioration with usage
environment and durability.
SUMMARY
[0012] Therefore, it is one aspect to provide an electric pump
constituted with a motor and a pump connected to a motor shaft of
the motor being capable of sufficiently suppressing vibration and
noise of the motor.
[0013] It is another aspect to provide an electric pump having a
highly durable mechanism for suppressing noise caused by
vibration.
[0014] Additional aspects will be set forth in part in the
description which follows and, in part, will be apparent from the
description, or may be learned by practice of the invention.
[0015] In accordance with one aspect, an electric pump includes a
pump, a motor having a motor shaft, the motor shaft being connected
to the pump to drive the pump, a support member which is arranged
between the pump and a front end portion of the motor being the
motor shaft side and which supports the pump and the motor in a
state of having the motor shaft inserted, a motor cover which
covers the motor having a closed-end cylindrical shape as the
opened end side thereof is fixed to the support member, and an
elastic member which is in a state of being compressed between a
rear end portion of the motor and a bottom portion of the motor
cover, and the motor is supported by the support member as being
urged thereto with the elastic member.
[0016] In the electric pump, the motor may be supported in a
cantilevered state by the support member arranged between the pump
and the motor. Further, the motor may be arranged in the closed-end
cylindrical motor cover fixed to the support member and the elastic
member in the compressed state may be arranged between the bottom
portion of the motor cover and the rear end portion of the motor,
so that the motor is urged to the support member side by the
elastic member. At that time, the elastic member may be in the
state of being compressed in the axial direction of the motor.
[0017] In this state, the elastic member may urge the motor to the
support member and reaction force generated at the elastic member
incident thereto may be exerted in the direction toward the bottom
portion of the motor cover. Further, the elastic member may be
compressed in the radial direction of the motor depending on the
compression condition of the elastic member. Accordingly, the
urging force from the elastic member may be exerted along the
radial direction of the motor toward the axial center of the motor.
In this case, due to the elastic force of the elastic member, the
urging force may be exerted from the motor cover to the axial
center side of the motor and the reaction force may be exerted from
the motor side toward the outer circumference side.
[0018] In accordance with an aspect, when the motor vibrates due to
rotational imbalance of the motor and transmission of pump
vibration with operation of the motor, the urging force and the
reaction force become large by the force of the motor vibration. In
this case, since both of the urging force and the reaction force of
the elastic member are exerted on the support member being the same
member, the urging force and the reaction force are balanced out.
Accordingly, the vibration can be damped and noise caused by the
motor vibration can be reduced.
[0019] Compared to a case that the motor is supported to the
housing with the rubber cushion, that is, compared to a case that
vibration transmission is discontinued between the motor and the
housing, the noise caused by the motor vibration can be reduced
more reliably. Further, since it is not required to utilize a
vibration absorbing member to absorb vibration, the durability can
be improved without being affected by usage environment.
[0020] In accordance with another aspect, the electric pump may
include a first elastic member provided as the elastic member in a
state of being compressed along the axial direction of the motor
shaft, and the motor may urged to the support member side along the
axial direction of the motor shaft by the first elastic member.
[0021] The first elastic member as the elastic member may be
compressed along the axial direction of the motor shaft.
Accordingly, as described above, the urging force and the reaction
force of the elastic member incident thereto may be exerted along
the axial direction of the motor shaft. By arranging the elastic
member in the axial direction, the area for placing the elastic
member is preferably ensured at the motor and the motor cover.
Accordingly, the urging force and the reaction force generated at
the elastic member may be reliably received and balanced out by the
support member, so that the vibration displacement is damped and
the vibration and noise are suppressed.
[0022] In accordance with yet another aspect the electric pump may
include a second elastic member provided as the elastic member in a
state of being compressed along the radial direction having the
motor shaft as an approximate center, and the motor may be urged to
the motor shaft side along the radial direction by the second
elastic member.
[0023] The second elastic member as the elastic member may be
compressed along the radial direction having the motor shaft as an
approximate center. Accordingly, as described above, the urging
force and the reaction force may be exerted along the radial
direction of the motor shaft. When the motor vibrates in this
state, the urging force and the reaction force in the radial
direction of the elastic member generated by the vibration force
may be balanced out at the support member, so that the vibration
displacement is damped and the vibration and noise are
suppressed.
[0024] Since the motor is in a cantilevered state as being
supported by the support member at the front end portion side
thereof, there is a risk that the motor vibrates so that the rear
end portion side is displaced having the front end portion as the
center. By urging the rear end portion side of the motor to the
radial direction by the second elastic member, the noise caused by
such vibration can be effectively suppressed. In addition, compared
to arranging in the axial direction, the elastic member can be
compactly arranged.
[0025] According to the foregoing aspects, since vibration and
noise can be reduced more reliably, a quiet atmosphere can be
provided for a user of an electric vehicle, for example, in the
case that the electric pump is mounted on the electric vehicle.
[0026] In addition, since the structure of noise reduction measures
at the motor cover can be eliminated, cost reduction can be
achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] These and/or other aspects will become apparent and more
readily appreciated from the following description of the
embodiments, taken in conjunction with the accompanying drawings of
which:
[0028] FIG. 1 is a side view which illustrates an electric pump of
the first embodiment;
[0029] FIG. 2 is a sectional view of the electric pump;
[0030] FIG. 3 is a disassembled perspective view of the electric
pump;
[0031] FIG. 4 is a perspective view which illustrates a first
elastic member of the electric pump;
[0032] FIG. 5 is a sectional view which illustrates an electric
pump of the second embodiment;
[0033] FIG. 6 is a disassembled perspective view of the electric
pump of the second embodiment; and
[0034] FIG. 7 is a perspective view which illustrates a second
elastic member of the electric pump.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0035] Reference will now be made in detail to the embodiments,
examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to like elements
throughout.
[0036] In the following, the first embodiment will be described
with reference to the attached drawings. FIG. 1 is a side view
illustrating an electric pump of the first embodiment. FIG. 2 is a
sectional view of the electric pump. FIG. 3 is a disassembled
perspective view of the electric pump. FIG. 4 is a perspective view
illustrating a first elastic member of the electric pump.
[0037] A vacuum pump mounted on an electric vehicle is an example
of the electric pump. The vacuum pump is driven by direct current
of a battery mounted on the electric vehicle.
[0038] As illustrated in FIGS. 1 to 3, the electric pump includes a
motor 1 and a pump 31. A motor shaft 2 of the motor 1 is connected
to a rotor 32 of the pump 31.
[0039] Further, the electric pump includes an attachment mount
(i.e., a support member) 51 to fix the electric pump at a
predetermined position of a vehicle.
[0040] The attachment mount 51 includes a base 52 fixed to a
vehicle side and an approximately plate-shaped connecting plate 53
which is vertically arranged to the base 52 and to which the motor
1 and the pump 31 are attached. The motor 1 is fixed to one side
face of the connecting plate 53 and the pump 31 is fixed to the
other side face thereof.
[0041] The motor 1 is a direct current motor provided with a rotor
and a stator (not illustrated) in an approximately cylindrical case
3. The motor shaft 2 rotating integrally with the rotor is
protruded from the top end portion of the case 3.
[0042] A protrusion is formed as protruding from the center of the
top end portion of the motor 1 where the motor shaft 2 is
protruded. An attaching plate 4 having an engaging hole engaged
with the protrusion is fixed to the top end portion of the motor 1
with screws 5.
[0043] Further, the attaching plate 4 is fixed to one side face of
the connecting plate 53 of the attachment mount 51 with screws
6.
[0044] A through hole through which the motor shaft 2 of the motor
1 penetrates is formed at the center of the connecting plate 53.
The top end portion of the motor shaft 2 penetrating through the
connecting plate 53 arrives at the rotor 32 in the pump 31.
[0045] The motor 1 is connected to the connecting plate 53 via the
attaching plate 4, so that the periphery of the protrusion at the
center of the motor 1 is in a state of being covered with the
connecting plate 53
[0046] In addition, the motor 1 is covered with a closed-end
cylindrical motor cover 8 at an outer circumference face and a rear
end face except for the top end face thereof. An open end portion
of the motor cover 8 is fixed to the connecting plate 53 with
screws 11 at the periphery of the top end portion of the motor 1.
Here, the top end portion of the motor cover 8 is flange-shaped and
a seal ring 12 is arranged between the connecting plate 53 and the
top end face of the motor cover 8.
[0047] Further, the motor cover 8 includes a cylinder portion 9
being approximately cylindrical and a bottom portion 10 being
approximately disk-shaped which is attached to a rear end portion
so as to close an opening of the rear end portion thereof. The
bottom portion 10 is fixed to the rear end portion of the cylinder
portion 9 with screws 13.
[0048] A seal ring 14 is arranged between the bottom portion 10 and
the cylinder portion 9.
[0049] Although the motor 1 and the motor cover 8 are to be
connected via the connecting plate 53, a clearance is left between
the outer circumferential face of the motor 1 and the inner
circumferential face of the cylinder portion 9 of the motor cover
8. In addition, a clearance is left between the rear end face of
the motor 1 and the bottom face 10 of the motor cover 8. Therefore,
the motor 1 and the motor cover 8 are not in contact.
[0050] The pump 31 is connected to the other side face of the
connecting plate 53. The pump 31 includes a pump unit 33
accommodating the rotor 32 to which the motor shaft 2 is connected
and a pump cover 34 covering the pump unit 33.
[0051] For example, the pump unit 33 includes the rotor 32 having a
vane and a housing of the pump unit 33 includes a suction port and
a discharge port.
[0052] The suction port is arranged at a side of a face of the pump
unit 33 being connected to the connecting plate 53. Then, the pump
unit 33 is connected to the connecting plate 53 with screws.
[0053] A concave portion communicated with the suction port of the
pump unit 33 is formed within the connecting plate 53. A suction
path is connected to the concave portion and is opened at the outer
circumferential face of the connecting plate 53. A suction pipe 54
is connected to the suction path.
[0054] The pump cover 34 to cover the pump unit 33 has a closed-top
cylindrical shape and the end portion of the opened side (i.e., the
bottom portion) is connected to the other side face of the
connecting plate 53 at the outer side from the pump unit 33 with
screws 56. A seal ring 55 is arranged between the pump cover 34 and
the connecting plate 53.
[0055] A clearance is left between the pump cover 34 and the pump
unit 33. Accordingly, although the pump cover 34 and the pump unit
33 are connected via the connecting plate 53, the pump cover 34 and
the pump unit 33 are not directly contacted.
[0056] At the rear end portion of the motor 1, a protrusion 7 is
formed cylindrical at the center thereof. The protrusion 7 and the
motor shaft 2 are coaxially arranged.
[0057] At the bottom portion 10 of the motor cover 8, a cylindrical
protrusion 16 protruding toward the periphery of the protrusion 7
is formed at a position to be opposed to the protrusion 7.
[0058] The cylindrical protrusion 16 covers the outer
circumferential face of the protrusion 7 at the rear end face of
the motor 1 and the top end thereof is closed to a part of the rear
end face of the motor 1 being at the periphery of the protrusion
7.
[0059] The outer circumferential face of the protrusion 7 at the
rear end portion of the motor 1 and the inner circumferential face
of the cylindrical protrusion 16 at the bottom portion 10 of the
motor cover 8 are opposed to each other while having clearance
therebetween. Here, the protrusion 7 of the motor 1 and the
cylindrical protrusion 16 of the bottom portion 10 are coaxially
arranged.
[0060] The cylindrical protrusion 16 has a stepped portion 19
between an inner circumferential portion 17 and an outer
circumferential portion 18. As described above, the inner
circumferential portion 17 is protruded being elongated to be close
to the rear end face of the motor 1. Meanwhile, the outer
circumferential portion 18 is lowered in one step. That is, the
protruding amount of the inner circumferential portion 17 from the
inner face of the bottom portion 10 is larger than that of the
outer circumferential portion 18. Accordingly, the inner
circumferential portion 17 is closed to the rear end face of the
motor 1 and the outer circumferential portion 18 is distanced from
the rear end face of the motor 1.
[0061] Then, a first elastic member 21 as a plate spring of an
approximate diaphragm shape (i.e., a disk spring shape) is arranged
between the top end face of the outer circumferential portion 18
and the rear end face of the motor 1.
[0062] As illustrated in FIG. 4, the first elastic member 21 is
formed into an approximate truncated cone shape and a tube shape
(i.e., a disk shape, a diaphragm shape and the like) and a circular
opening portion 22 to which the inner circumferential portion 17 of
the cylindrical protrusion 16 is inserted is formed at the center
thereof.
[0063] Further, a ring portion 23 constituted with a short
cylindrical part and a part of a circular ring shape expanding
outward from an end portion of the top end side (i.e., an end
portion of the bottom portion 10 side) is formed at the periphery
of the circular opening portion 22 of the first elastic member
21.
[0064] Then, a plate spring portion 24 is arranged at the periphery
of the ring portion 23. The plate spring portion 24 is formed to be
inclined closer to the rear end face side of the motor 1 from the
inner face side of the bottom portion 10 as approaching outwardly
in the radial direction (i.e., to be a truncated cone shape). A
first cutout portion 25 is arranged respectively at two positions
being opposed to each other of the plate spring portion 24. The
first cutout portion 25 is formed wide along the circumferential
direction lying from the outer circumferential edge of the plate
spring portion 24 to the outer circumferential edge of the ring
portion 23.
[0065] Due to two of the first cutout portions 25, the plate spring
portion 24 is separated into two pieces. A second cutout portion 26
being narrower and shallower than the first cutout portion 25 is
formed respectively at the center of the two separated pieces of
the plate spring portion 24.
[0066] The first elastic member 21 is arranged so that the inner
circumferential portion 17 of the cylindrical protrusion 16 of the
bottom portion 10 of the motor cover 8 is inserted into the
circular opening portion 22 at the inside of the ring portion 23
while the side face of the top end side of the ring portion 23 is
contacted to the end face of the outer circumferential portion 18
of the cylindrical protrusion 16.
[0067] Further, the plate spring portion 24 is in a state of being
compressed in the axial direction as being curved while the top end
portion of the plate spring portion 24 is contacted to the rear end
face of the motor 1. With this configuration, the first elastic
member 21 exerts urging force in the direction so that the rear end
face of the motor 1 and the bottom face 10 are being distanced.
[0068] Accordingly, the plate spring as the first elastic member 21
urges the motor 1 toward the connecting plate 53 and the reaction
force of the plate spring acts toward the bottom portion 10 side.
The bottom portion 10 is fixed to the cylinder portion 9 and the
cylinder portion 9 is fixed to the connecting plate 53. In
addition, the top end face of the motor 1 is fixed to the
connecting plate 53 as well. Accordingly, the urging force and the
reaction force of the plate spring as the first elastic member 21
are received by the connecting plate 53, so that a balanced state
is maintained. Therefore, the motor 1 is maintained in a stable
state. When vibration force occurs at the motor 1 caused by force
due to the own rotation of the motor 1 and the rotation of the pump
31, the urging force and the reaction force of the plate spring
become large since the force (i.e., the load) acting on the plate
spring becomes large. Even in this case, since the urging force and
the reaction force generated at the plate spring are to be received
by the connecting plate 53, the urging force and the reaction force
are balanced out at the connecting plate 53. Accordingly, the motor
1 can be maintained in a stable state even when the force becomes
large.
[0069] As described above, when the motor 1 vibrates, the force
(i.e., the load) is exerted on the plate spring due to the
vibration, so that the urging force and the reaction force
generated at the plate spring are increased. However, since the
urging force and the reaction force of the plate spring are
balanced out to each other, displacement of the vibration can be
suppressed to be small. In addition, noise can be prevented by
suppressing the vibration.
[0070] In this manner, being different from the related art having
a main function to suppress vibration of a cover as disconnecting
vibration transmission from a motor to the cover by arranging a
member such as vibration absorbing rubber between the motor and the
cover, for example, the above embodiment mainly damps vibration by
converting motor vibration into urging force and reaction force of
a spring which are to be balanced out as arranging a compressed
spring as an elastic member therebetween to apply urging force
(i.e., spring load).
[0071] With this configuration, vibration and noise can be surely
suppressed compared to the related art.
[0072] FIGS. 5 to 7 illustrate an electric pump of the second
embodiment. FIG. 5 is a sectional view of the electric pump of the
second embodiment. FIG. 6 is a disassembled perspective view of the
electric pump of the second embodiment. FIG. 7 is a perspective
view illustrating a second elastic member of the electric pump.
[0073] In the electric pump of the second embodiment, a
later-described second elastic member 41 is arranged instead of the
first elastic member 21 as the elastic member. The rest of the
configuration is similar to the electric pump of the first
embodiment. The same reference numerals are given to structural
elements similar to that of the first embodiment illustrated in
FIGS. 1 to 4 and description thereof will not be repeated.
[0074] The second elastic member 41 is cylindrical and is arranged
to be compressed in the radial direction between the outer
circumferential face of the protrusion 7 at the rear end face of
the motor 1 and the inner circumferential face of the cylindrical
protrusion 16 (i.e., the inner circumferential portion 17) of the
bottom portion 10 of the motor cover 8. The second elastic member
41 includes a cylindrical portion 42 formed in a short cylindrical
shape and a plurality of rectangular convex portions 43 protruding
to the outer circumferential side from the cylindrical portion
42.
[0075] The convex portion 43 is formed by bending the cylindrical
portion 42 from the inner side to the outer side so as to function
as a plate spring that is elastically deformable in the radial
direction. Specifically, the plurality of convex portions 43
functioning as plate springs to generate urging force in the radial
direction when being compressed in the radial direction are
arranged in parallel. Here, the rectangular concave portion 43 is
formed with a rectangular top board being along the circumferential
direction of the cylindrical portion 42 and four faces
approximately being along the radial direction of the cylindrical
portion 42 corresponding to respective four sides of the top board.
In a case that a wall-shaped member is formed respectively at the
four faces, the adjacent wall-shaped members may be configured to
be separated at the corner part therebetween. Instead, the convex
portion 43 may be formed that only two opposed faces among the four
faces are respectively with a wall-shaped member and the remaining
two opposed faces are opened without any member.
[0076] As described above, the second elastic member 41 is arranged
to be sandwiched by the outer circumferential face of the
protrusion 7 of the motor 1 and the inner circumferential face of
the cylindrical protrusion 16 of the motor cover 8 in the state
that the convex portions 43 are compressed and deformed.
Accordingly, the protrusion 7 of the motor 1 is urged toward the
center axis in the radial direction and the reaction force
generated at the second elastic member 41 is exerted on the
cylindrical protrusion 16 of the motor cover 8 outward in the
radial direction. Similar to the first embodiment, the top end side
of the motor 1 is fixed to the connecting plate 53 of the
attachment mount 51. Further, the bottom portion 10 is fixed to the
cylinder portion 9 and the cylinder portion 9 is fixed to the
connecting plate 53. Accordingly, the urging force and the reaction
force of the plate spring as the second elastic member 41 are
received by the connecting plate 53, so that a balanced state is
maintained. Therefore, the motor 1 is maintained in a stable state.
When vibration force occurs at the motor 1 in the radial direction
caused by force due to the own rotation of the motor 1 and the
rotation of the pump 31, the urging force and the reaction force of
the plate spring become large since the force (i.e., the load)
acting on the plate spring becomes large. Since the urging force
and the reaction force generated at the plate spring are to be
received by the connecting plate 53, the urging force and the
reaction force are balanced out. Accordingly, the motor 1 can be
maintained in a stable state. In short, although the urging force
and the reaction force generated at the plate spring become large
due to the force in the radial direction to generate vibration, the
forces are balanced out each other and the vibration is
suppressed.
[0077] Further, as described above, since the rear end portion of
the motor 1 is to be urged in the direction toward the axial center
of the motor shaft 2 in a state that the top end side of the motor
1 is attached to the attachment mount 51, it is also possible to
suppress vibration such as swinging of the rear end of the motor 1
having the top end of the motor 1 as the center by arranging the
second elastic member 41.
[0078] As another embodiment, it is also possible to arrange both
the first elastic member 21 and the second elastic member 41. With
this configuration, the vibration and noise of the motor 1 can be
suppressed as well. In this case, the first elastic member 21 can
suppress vibration by being arranged between the motor 1 and the
motor cover 8 in the axial direction and the second elastic member
41 can suppress vibration by being arranged between the motor 1 and
the motor cover 8 in the radial direction. However, not limited to
the above configuration, another configuration can be adopted as
long as vibration is damped by converting force due to vibration
into urging force and reaction force of a spring and balancing out
the respective forces.
[0079] Here, as described above, it is preferable that the elastic
member is a compressed spring, particularly, a plate spring
including a disk spring, capable of generating urging force even
with slight deformation not to be a rubber-like member. Adopting a
plate spring enables arrangement thereof into a slight gap. In this
manner, being different from a member in the related art aiming to
discontinue vibration by absorbing or letting out vibration like a
variety of insulators such as vibration absorbing rubber, for
example, the elastic member of the present invention aims to
generate the abovementioned reaction force with the elastic force
generated by being compressed so as to balance out the force
causing vibration.
[0080] Although a few embodiments have been shown and described, it
would be appreciated by those skilled in the art that changes may
be made in these embodiments without departing from the principles
and spirit of the invention, the scope of which is defined in the
claims and their equivalents.
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