U.S. patent application number 12/255784 was filed with the patent office on 2009-12-10 for vehicular rotary electric machine.
This patent application is currently assigned to Mitsubishi Electric Corporation. Invention is credited to Masao Kikuchi, Naohide Maeda, Yuji SHIRAKATA.
Application Number | 20090302706 12/255784 |
Document ID | / |
Family ID | 41399666 |
Filed Date | 2009-12-10 |
United States Patent
Application |
20090302706 |
Kind Code |
A1 |
SHIRAKATA; Yuji ; et
al. |
December 10, 2009 |
VEHICULAR ROTARY ELECTRIC MACHINE
Abstract
A vehicular rotary electric machine has a stator and a rotor
supported by a bracket; a field winding which is provided on the
rotor and is for generating a magnetomotive force; a field circuit
section which is for supplying a current to the field winding; and
a brush holder having a brush, the field circuit section and the
brush holder being separately mounted to the bracket. In the
vehicular rotary electric machine, connecting means between the
field circuit section and the brush holder is configured by an
intermediate wiring member having a stress buffering mechanism.
Inventors: |
SHIRAKATA; Yuji;
(Chiyoda-ku, JP) ; Kikuchi; Masao; (Chiyoda-ku,
JP) ; Maeda; Naohide; (Chiyoda-ku, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W., SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
Mitsubishi Electric
Corporation
Tokyo
JP
|
Family ID: |
41399666 |
Appl. No.: |
12/255784 |
Filed: |
October 22, 2008 |
Current U.S.
Class: |
310/239 |
Current CPC
Class: |
H02K 5/24 20130101; H02K
5/141 20130101; H01R 39/385 20130101; H02K 9/28 20130101 |
Class at
Publication: |
310/239 |
International
Class: |
H01R 39/38 20060101
H01R039/38 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 10, 2008 |
JP |
2008-151730 |
Claims
1. A vehicular rotary electric machine, comprising: a bracket; a
stator supported by said bracket; a rotor supported by said
bracket; a power transmission portion provided in front; a field
winding which is provided on said rotor and is for generating a
magnetomotive force; a field circuit section which is mounted to
said bracket and is for supplying a current to said field winding;
and a brush holder having a brush, said brush holder being mounted
to said bracket separately from said field circuit section, said
vehicular rotary electric machine, comprising: connecting means
between said field circuit section and said brush holder, said
connecting means being configured by an intermediate wiring member
having a stress buffering mechanism.
2. The vehicular rotary electric machine according to claim 1,
wherein said intermediate wiring member is composed of a resin
planar face portion and a metal wiring material parallel to one
face which forms said field circuit section, said metal wiring
material protrudes toward a direction of said brush holder in a
normal direction of said planar face portion and is connected to a
terminal of said brush holder, and said intermediate wiring member
is mounted to a face on the long-side side that in on the brush
holder side of said field circuit section.
3. The vehicular rotary electric machine according to claim 2,
wherein at least either one of said field circuit section and said
brush holder is mounted to said bracket at at least two fixing
portions and above disposed parallel to said planar face portion of
said intermediate wiring member.
4. The vehicular rotary electric machine according to claim 2,
wherein said metal wiring material of said intermediate wiring
member is provided with an elastic region.
5. The vehicular rotary electric machine according to claim 2,
wherein said planar face portion of said intermediate wiring member
becomes a cover of a mounting face of said field circuit section.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a field winding type rotary
electric machine mounted with a field circuit section which
supplies a field current to a field winding of a rotor and, more
particularly, relates to a vehicular rotary electric machine to be
mounted in an automobile.
[0003] 2. Description of the Related Art
[0004] In Japanese Unexamined Patent Publication No. 2008-5676, a
hitherto known structure of a field winding type vehicular rotary
electric machine is shown. In the field winding type vehicular
rotary electric machine shown in Japanese Unexamined Patent
Publication No. 2008-5676, a magnetomotive force is produced by
supplying a current to a field winding provided on a rotor and
generation of electricity is performed; and a current adjusted by a
field circuit section is supplied from a brush incorporated in a
brush holder to the field winding through a slip ring provided in
the rotor. There is described a configuration in which the field
circuit section and the brush holder are separately mounted to a
bracket and connecting terminals integrated with the field circuit
section are connected to the brush holder.
[0005] The field circuit section is required to cool switching
elements which are for controlling the current; and therefore, the
field circuit section is mounted at a place being in contact with
ambient air on the outside of the rotary electric machine. On the
other hand, the brush is mounted in the vicinity of the center
portion of the rotary electric machine in order to bring into
contact with the rotor. For this reason, the field circuit section
and the brush holder are mounted to the rotary electric machine as
separate components.
[0006] In the meantime, in a vehicular rotary electric machine or
the like particularly to be mounted in an automobile, vibration
resistance of the rotary electric machine is required because
vibration during running is large; and generally, in the vehicular
rotary electric machine, consideration to vibration resistance is
included.
[0007] On the other hand, durability of the vehicular rotary
electric machine has been more strictly required, and vibration
durability performance has been required more than ever before.
More particularly, terminals for electrically connecting are
provided in the field circuit section and the brush holder which
are mounted to the vehicular rotary electric machine, and the field
circuit section and the brush holder separately vibrate; and
therefore, a load applied to a terminal connecting portion is
increased.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention has been made to solve the foregoing
problems, and an object of the present invention is to provide a
vehicular rotary electric machine in which a connecting portion
between a field circuit section and a brush holder is configured by
an intermediate wiring member in which connecting terminals are
separately formed from the field circuit section and a stress
buffering mechanism is provided in the intermediate wiring member,
whereby vibration applied to the connecting portion is absorbed and
vibration resistance is improved.
[0009] A vehicular rotary electric machine according to the present
invention has a bracket; a stator and a rotor which are supported
by a bracket; a power transmission portion provided in front; a
field winding which is provided on the rotor and is for generating
a magnetomotive force; a field circuit section which is for
supplying a current to the field winding; and a brush holder having
a brush, the field circuit section and the brush holder being
separately mounted to the bracket. The vehicular rotary electric
machine has connecting means between the field circuit section and
the brush holder, the connecting means being configured by an
intermediate wiring member having a stress buffering mechanism.
[0010] According to a vehicular rotary electric machine of the
present invention, an intermediate wiring member which connects a
field circuit section to a brush holder, the field circuit section
and the brush holder being separately mounted to a bracket, and
absorbs residual stress due to each positional deviation of the
field circuit section and the brush holder, whereby vibration
resistance can be improved.
[0011] The foregoing and other object, features, and advantages of
the present invention will become more apparent from the following
detailed description of the preferred embodiments and description
shown in drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0012] FIG. 1 is a top view from the rear showing a vehicular
rotary electric machine of a preferred embodiment 1 according to
the present invention;
[0013] FIG. 2 is a cross-sectional view from the side showing the
vehicular rotary electric machine of the preferred embodiment 1
according to the present invention;
[0014] FIG. 3 is a perspective view showing a field circuit section
and a brush holder portion of the vehicular rotary electric machine
in the preferred embodiment 1 according to the present
invention;
[0015] FIGS. 4A and 4B are views each showing an intermediate
wiring member of the vehicular rotary electric machine in the
preferred embodiment 1 according to the present invention;
[0016] FIG. 5 is a top view showing the field circuit section of
the vehicular rotary electric machine in the preferred embodiment 1
according to the present invention;
[0017] FIG. 6 is a top view showing a field circuit section of a
vehicular rotary electric machine in a preferred embodiment 2
according to the present invention;
[0018] FIGS. 7A and 7B are views each showing an intermediate
wiring member of a vehicular rotary electric machine in a preferred
embodiment 3 according to the present invention; and
[0019] FIG. 8 is a view showing an intermediate wiring member of
the vehicular rotary electric machine in the preferred embodiment 3
according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Preferred Embodiment 1
[0020] A preferred embodiment of a vehicular rotary electric
machine according to the present invention will be described in
detail with reference to the accompanying drawings.
[0021] FIGS. 1 to 3 are views each showing a preferred embodiment 1
of the vehicular rotary electric machine according to the present
invention; FIG. 1 is a top view from the rear of the vehicular
rotary electric machine; FIG. 2 is a cross-sectional of the side
thereof; and FIG. 3 is a perspective view showing a field circuit
section and a brush holder portion. In FIGS. 1 to 3, the vehicular
rotary electric machine of the preferred embodiment 1 has a stator
2a and a rotor 3 supported by a bracket 1; and the rotor 3 has a
field winding 4 which is for generating a magnetomotive force, a
slip ring 5, and a cooling fan 6. A power transmission portion is
provided in front of the bracket 1; on the backward side thereof, a
brush holder 8 having a brush 7 which comes in contact with the
slip ring 5, a power circuit section 20 which is for supplying an
alternating current electric power to a stator winding 2b, and a
field circuit section 30 which is for supplying a current to the
field winding 4 are separately mounted; and a case 40 is disposed
in a rotational axis direction on the backward side of the power
circuit section 20 and the field circuit section 30. In the
vehicular rotary electric machine, the field circuit section 30 and
the brush holder 8 need to be separately mounted to the bracket 1,
respectively.
[0022] The power circuit section 20 is configured by mounting
semiconductor switching elements for the power circuit 21, which is
for supplying a current to the armature winding 2b, to a heat sink
for cooling the power circuit 22.
[0023] The field circuit section 30 is configured by jointing a
metal substrate 38 to a heat sink for cooling field system 32 and a
resin case 33, the metal substrate 38 being mounted with
semiconductor switching elements for field system 31 and a control
integrated circuit (IC) (not shown in the drawings) which are for
supplying a current to the field winding 4.
[0024] Fins of the heat sink for cooling field system 32 are
extended in a reverse direction to a direction where there is a
rotational axis; and a stress buffering mechanism which is for
absorbing vibration is provided as connecting means which is for
energizing a current from the semiconductor switching elements for
field system 31 to the brush 7, as to be described later. There is
provided an intermediate wiring member 34 which is disposed on the
long-side side that is on the rotational axis side of the field
circuit section 30, and electrically connects the semiconductor
switching elements for field system 31 to the brush 7. The
intermediate wiring member 34 is protruded from one face of the
field circuit section 30 toward the rotational axis direction, and
an extending direction thereof is a normal direction of a
protruding face.
[0025] The intermediate wiring member 34 is one which connects the
field circuit section 30 to terminals of the brush holder 8, and is
composed of metal wiring materials 34a and a planar face portion
34b disposed in a right angle direction to the planar face portions
34b. The planar face portion 34b is formed using resin which is an
elastic body; and as shown in FIGS. 4A and 4B, the intermediate
wiring member 34 is configured by integrating the metal wiring
materials 34a in the planar face portion 34b by insert molding. In
addition, in FIGS. 4A and 4B, there is shown the intermediate
wiring member 34 in which two metal wiring materials 34a are
integrated with one resin planar face portion 34b; however, two
metal wiring materials 34a are not integrated with one planar face
portion 34b, but, there may be intermediate wiring members 34 in
which two metal wiring materials 34a are integrated with separate
planar face portions 34b, respectively.
[0026] As shown in FIG. 1, at least either one of the field circuit
section 30 and the brush holder 8 is mounted to the bracket 1 with
screws at two positions disposed in parallel to the planar face
portion 34b of the intermediate wiring member 34, the two positions
being fixing portions 35 mounted to the resin case 33 and being
brush holder fixing portions 9 mounted to the brush holder 8.
[0027] The stress buffering mechanism is a mechanism which absorbs
stress by the intermediate wiring member 34 which connects between
the field circuit section 30 and the brush holder 8. In the case
where vibration is applied to the vehicular rotary electric
machine, the field circuit section 30 and the brush holder 8
separately vibrate; and therefore, a large load is applied to
connecting portions 37 between the field circuit section 30 and the
brush holder 8. Consequently, in the preferred embodiment 1, in the
case where stress is applied to the metal wiring materials 34a and
the planar face portion 34b using resin that is an elastic material
for use in the intermediate wiring member 34, the planar face
portion 34b receives the stress by its face; and therefore, the
stress can be dispersed. Further, since the planar face portion 34b
is the elastic body, when the stress is applied, the planar face
portion 34b absorbs the stress by deflecting in a positive manner;
and consequently, the stress applied to the connecting portion 37
can be absorbed. Furthermore, this is not limited to the case where
the vibration is generated, but residual stress can also be
absorbed, the residual stress being generated among the field
circuit section 30, the brush holder 8, and the intermediate wiring
member 34 due to positional deviation of components when the
vehicular rotary electric machine is assembled.
[0028] The intermediate wiring member 34 is screwed to the
connecting portions 37 of the field circuit section 30 as shown in
FIG. 5; and the metal wiring materials 34a and the planar face
portion 34b are fixed to the resin case 33 by intermediate wiring
member fixing portions 36, in addition to the connecting portions
37.
[0029] In a vehicular rotary electric machine mounted in an idling
stop vehicle, a hybrid automobile, or the like, when vibration is
applied to the entire vehicular rotary electric machine at a time
of starting and due to running or the like, the field circuit
section 30 and the brush holder 8 separately mounted to the bracket
1 vibrate individually; and therefore, a large load is applied to
the connecting portions 37 between the field circuit section 30 and
the brush holder 8. However, in the vehicular rotary electric
machine of the embodiment 1, such load is absorbed by the stress
buffering mechanism provided in the intermediate wiring member 34.
That is, the planar face portion 34b disposed in a right angle
direction to the metal wiring materials 34a absorbs displacement by
deflecting in a positive manner; and therefore, stress applied to
the connecting portions 37 can be reduced and vibration resistance
can be improved.
[0030] Since the vibration applied to the field circuit section 30
is in a normal direction of the planar face portion 34b of the
intermediate wiring member 34, vibration applied in a direction
perpendicular to the fixing portion 35 to the bracket 1 is absorbed
by the stress buffering mechanism of the intermediate wiring member
34, and vibration applied in a direction parallel to the fixing
portion 35 is received by the fixing portion 35 to the bracket 1;
and accordingly, this leads to improvement in vibration resistance.
Sufficient vibration resistance is provided because the field
circuit section 30 and the brush holder 8 are provided with two
fixing positions respectively; and therefore, it becomes possible
to reduce the number of fixing components and to reduce a fixing
area.
[0031] Furthermore, as shown in FIG. 5, the field circuit section
30 and the intermediate wiring member 34 are fixed to the resin
case 33 with screws by not only the connecting portions 37 but also
by the intermediate wiring member fixing portions 36; and
accordingly, stress can be received by the intermediate wiring
member fixing portions 36, the stress applied to the connecting
portions 37 can be absorbed, and vibration resistance can be
improved.
[0032] As described above, according to the preferred embodiment 1
of the present invention, connection between the field circuit
section 30 and the brush holder 8 is performed using the
intermediate wiring member 34 and the stress buffering mechanism is
provided in the intermediate wiring member 34. Accordingly, stress
applied to the connecting portions 37 between the field circuit
section 30 and the brush holder 8 is absorbed by the stress
buffering mechanism, the stress being generated in the case where
vibration is applied to the vehicular rotary electric machine at a
time of starting and due to running or the like; and vibration
resistance of the connecting portion between the field circuit
section 30 and the brush holder 8 can be improved. Further,
mounting positions to the bracket 1 of the field circuit section 30
and the brush holder 8 are respectively fixed at two positions of
the fixing portions 35 and the brush holder fixing portions 9 to
the bracket 1, the fixing portions 35 and the brush holder fixing
portions 9 being disposed parallel to the planar face portion 34b
of the intermediate wiring member 34; and accordingly, it becomes
possible to reduce stress in a direction parallel to the mounting
positions in the case where vibration is applied, to improve
vibration resistance, to reduce the number of fixing components,
and to reduce a fixing area.
Preferred Embodiment 2
[0033] FIG. 6 is a top view showing a field circuit section of a
vehicular rotary electric machine according to a preferred
embodiment 2 of the present invention. In addition, referring to
the drawings, the same reference numerals as those shown in the
preferred embodiment 1 represent the same or corresponding
elements.
[0034] The intermediate wiring member 34 of the preferred
embodiment 1 has a shape which covers a part of the entire mounting
face with respect to the field circuit section 30; however, in the
preferred embodiment 2, the shape of a planar face portion 34b is
changed to an intermediate wiring member 34 which seems to cover
the entire field circuit section as shown in FIG. 6.
[0035] A field circuit section 30 is configured by jointing a metal
substrate 38 to a heat sink for cooling field system 32, the metal
substrate 38 being mounted with semiconductor switching elements
for field system 31 and a control IC (not shown in the drawing)
which are for supplying a current to a field winding 4, and the
semiconductor switching elements for field system 31 being
encapsulated in the intermediate wiring member 34, a resin case 33,
and the heat sink for cooling field system 32.
[0036] In the case of a vehicular rotary electric machine mounted
in an automobile, the vehicular rotary electric machine is disposed
in an engine room and dust and foreign particles are entered into
the vehicular rotary electric machine in addition to vibration
during running; and therefore, there is a possibility to enter the
dust and foreign particles into the field circuit section.
Consequently, the metal wiring material 34a for use in the
intermediate wiring member 34 is integrated with the resin planar
face portion 34b and the shape of the planar face portion 34b is
adjusted to the field circuit section 30 as shown in FIG. 6; and
accordingly, the planar face portion 34b becomes a cover of the
field circuit section 30, and it becomes possible to prevent
foreign particles from outside from entering and to prevent failure
and pattern short-circuit of the switching elements 31 and the
control IC which are disposed inside thereof.
[0037] As described above, according to the preferred embodiment 2
of the present invention, the shape of the planar face portion 34b
of the intermediate wiring member 34 is changed and the role of the
cover for the field circuit section 30 is fulfilled: and
accordingly, even in the case where dust and foreign particles are
entered into the vehicular rotary electric machine, it becomes
possible to prevent foreign particles from entering into the field
circuit section 30 and to prevent failure and pattern
short-circuit.
Preferred Embodiment 3
[0038] FIGS. 7A, 7B, and 8 are views each showing an intermediate
wiring member of a vehicular rotary electric machine according to a
preferred embodiment 3 of the present invention. In addition,
referring to the drawings, the same reference numerals as those
shown in the preferred embodiments 1 and 2 represent the same or
corresponding elements.
[0039] In the case where a width of the metal wiring material 34a
for use in the intermediate wiring member 34 of the preferred
embodiments 1 and 2 is enlarged, the percentage of the metal wiring
material 34a inserted into the planar face portion 34b increases;
and accordingly, the intermediate wiring member 34 becomes
difficult to be deflected. However, in the preferred embodiment 3,
a stress buffering mechanism is made by providing an elastic region
in the metal wiring material 34a.
[0040] That is, as shown in FIGS. 7A and 7B, the elastic region,
that is, a bent portion is provided by changing the shape in the
vicinity of a connecting portion 37 in which the metal wiring
material 34a is not covered with a planar face portion 34b.
Furthermore, a location where the elastic region is provided in the
metal wiring material 34a is a portion which is not covered with
the planar face portion 34b; however, there may be integrated with
the planar face portion 34b after the elastic region is
provided.
[0041] Furthermore, as shown in FIG. 8, an elastic region is formed
by providing a cutout at a portion where a metal wiring material
34a is not covered with a planar face portion 34b.
[0042] As shown in FIGS. 7A and 7B, the shape of the metal wiring
material 34a is changed and a spring portion of the elastic region
is provided in the metal wiring material 34a; and accordingly, a
role which absorbs vibration in a direction perpendicular to the
fixing portion 35 with respect to the field circuit section 30 and
the bracket 8 is fulfilled. Furthermore, as shown in FIG. 8, the
cutout is provided at a connecting portion between the metal wiring
material 34a and a resin case 33; and accordingly, the metal wiring
material 34b whose width is thinned becomes easy to be deflected
and a role which absorbs stress is fulfilled.
[0043] This can absorb residual stress generated to connecting
portions 37 from positional deviation due to variation in each
component in assembling. Furthermore, the stress generated also in
the case where vibration is applied can be absorbed, and stress
applied to the connecting portions 37 between the field circuit
section 30 and the brush holder 8 can be reduced.
[0044] In addition, it is possible to be a cover of the field
circuit section 30 by changing the shape of the planar face portion
34b as in the preferred embodiment 2.
[0045] As described above, according to the preferred embodiment 3
of the present invention, even in the case where the width of the
metal wiring material 34a for use in the intermediate wiring member
34 is increased and the planar face portion becomes difficult to be
deflected, the role of a stress buffering mechanism can be
fulfilled by changing the shape of the metal wiring material 34a
which is not covered with the planar face portion 34b and by
forming the elastic region.
[0046] Various modifications and alternations of this invention
will be apparent to those skilled in the art without departing from
the scope and spirit of this invention, and it should be understood
that this is not limited to the illustrative embodiments set forth
herein.
* * * * *