U.S. patent application number 13/418820 was filed with the patent office on 2012-09-27 for pump mounting structure.
This patent application is currently assigned to KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. Invention is credited to Tatsuyuki HOSHINO, Ryo UMEYAMA, Kazuho YAMADA.
Application Number | 20120244021 13/418820 |
Document ID | / |
Family ID | 45936821 |
Filed Date | 2012-09-27 |
United States Patent
Application |
20120244021 |
Kind Code |
A1 |
UMEYAMA; Ryo ; et
al. |
September 27, 2012 |
PUMP MOUNTING STRUCTURE
Abstract
A pump mounting structure is disclosed. The structure includes a
mounting surface on a body having an insertion recess, and at least
one mounting member having a mounting portion inserted into the
insertion recess. The mounting portion has an outer surface and an
insertion hole through which a bolt is inserted. A first gap is
formed between the insertion hole and the bolt. A second gap is
formed between the outer surface of the mounting portion and an
inner surface of the insertion recess. A seal member is disposed on
an open side of the insertion recess.
Inventors: |
UMEYAMA; Ryo; (Kariya-shi,
JP) ; YAMADA; Kazuho; (Kariya-shi, JP) ;
HOSHINO; Tatsuyuki; (Kariya-shi, JP) |
Assignee: |
KABUSHIKI KAISHA TOYOTA
JIDOSHOKKI
Kariya-shi
JP
|
Family ID: |
45936821 |
Appl. No.: |
13/418820 |
Filed: |
March 13, 2012 |
Current U.S.
Class: |
417/360 |
Current CPC
Class: |
F16B 39/284 20130101;
F04C 2240/805 20130101; F16B 5/0241 20130101; F04C 15/0034
20130101; F04C 2/12 20130101; F04C 2270/12 20130101; F04C 2230/604
20130101; F01C 21/10 20130101; F01C 21/007 20130101; F04C 11/008
20130101 |
Class at
Publication: |
417/360 |
International
Class: |
F04C 15/00 20060101
F04C015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 25, 2011 |
JP |
2011-067924 |
Claims
1. A pump mounting structure, wherein the pump includes a housing,
a rotation shaft and a pump portion being housed in the housing,
the rotation shaft being rotated by driving force of a driving
source, the pump portion being driven along with rotation of the
rotation shaft, the rotation shaft being rotatably supported on the
housing via a bearing, a plurality of mounting members being
provided for the housing, a bolt being inserted into each of the
plurality of mounting members and being fastened to a body to be
mounted to thereby mount the pump to the body, the structure
comprising a mounting surface on the body, wherein an insertion
recess is formed in the mounting surface, wherein the insertion
recess includes an inner surface; at least one mounting member
having a mounting portion inserted into the insertion recess,
wherein the mounting portion has an outer surface and an insertion
hole through which the bolt is inserted, wherein a first gap is
formed between the insertion hole and the bolt, and wherein a
second gap is formed between the outer surface of the mounting
portion and the inner surface of the insertion recess; and a seal
member disposed on an open side of the insertion recess relative to
an area between the mounting portion and the insertion recess into
which lubricant is filled.
2. The pump mounting structure according to claim 1, wherein the
bolt and the mounting portion move relative to each other in
accordance with a difference between deformation amount of the
housing and deformation amount of the body.
3. The pump mounting structure according to claim 1, wherein a
groove is formed in the mounting portion and the seal member is
mounted to the groove.
4. The pump mounting structure according to claim 1, wherein the
pump is an electric roots-type pump.
5. The pump mounting structure according to claim 1, wherein the
pump is mounted to a body forming a fuel cell system mounted in a
fuel cell powered vehicle.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a pump mounting
structure.
BACKGROUND
[0002] In general, a rotation shaft rotated by a driving force from
a driving source and a pump portion driven in accordance with the
rotation of the rotation shaft are housed in a housing of a pump
such as a compressor. The rotation shaft is rotatably supported on
the housing via bearings. The housing of the pump is provided with
at least three mounting members for mounting the pump to a surface
of a body to be mounted that forms an engine compartment, so as to
ensure resistance to vibration of the pump, for example. Each
mounting member is fastened to the mounting surface with a bolt,
thereby mounting the pump to the body. For example, see Japanese
Laid-open Patent Publication No. 2009-150236.
[0003] The temperature within the engine compartment increases, for
example, due to heat generated from the engine of a vehicle while
driving. The temperature of each of the housing and the body rises
due to the heat generated from the engine, and the housing and body
thermally expand with the rise of temperature. Since there occurs a
difference in temperature and also a difference in thermal
expansion coefficients between the housing and the body, there is a
relative difference between the thermal expansion of the housing
and the thermal expansion of the body. Thus, the amount of
deformation of the housing due to the thermal expansion is
different from that of the body. Due to the difference in the
amount of deformation between the housing and the body, a load is
applied to the bolt for fastening a mounting member and the
corresponding mounting surface, so that the housing is deformed
with the displacement of the bolt caused by the load applied to the
bolt. Then, the position of each bearing provided in the housing is
displaced, and the center axis of each of the bearings for
supporting the rotation shaft is displaced. When the rotation shaft
is rotated in a state where this axial displacement takes place, it
is possible that noise is generated and the durability of each
bearing is decreased. Particularly, in a mesh-type pump including
two or more rotation shafts, it is a great issue if an interference
occurs in a pump portion because the shafts are not parallel with
each other.
[0004] Further, friction is generated between each mounting member
and the corresponding mounting surface due to the thermal expansion
of the housing and the body, which results in abrasion between the
mounting member and the mounting surface. This leads to a reduction
in fastening power of the bolt between the mounting member and the
mounting surface. As a result, there is a possibility that the pump
itself largely vibrates due to vibration of the vehicle during
driving.
[0005] It is an object of the present invention to provide a pump
mounting structure capable of suppressing the axial displacement of
a bearing supporting the rotation shaft as much as possible, and
capable of suppressing a large vibration of the pump itself.
SUMMARY OF THE INVENTION
[0006] One aspect of the present invention is a pump mounting
structure. The pump includes a housing, a rotation shaft and a pump
portion being housed in the housing. The rotation shaft is rotated
by driving force of a driving source. The pump portion is driven
along with rotation of the rotation shaft. The rotation shaft is
rotatably supported on the housing via a bearing. A plurality of
mounting members are provided for the housing. A bolt is inserted
into each of the plurality of mounting members and is fastened to a
body to be mounted to thereby mount the pump to the body. The
structure includes a mounting surface on the body, at least one
mounting member and a seal member. An insertion recess is formed in
the mounting surface. The insertion recess includes an inner
surface. At least one mounting member has a mounting portion
inserted into the insertion recess. The mounting portion has an
outer surface and an insertion hole through which the bolt is
inserted. A first gap is formed between the insertion hole and the
bolt. A second gap is formed between the outer surface of the
mounting portion and the inner surface of the insertion recess. The
seal member is disposed on an open side of the insertion recess
relative to an area between the mounting portion and the insertion
recess into which the lubricant is filled.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a sectional view of an electric roots-type pump
according to one embodiment;
[0008] FIG. 2A is an enlarged sectional view illustrating a state
where a mounting member is mounted on a mounting surface;
[0009] FIG. 2B is a sectional view taken along the line 2B-2B of
FIG. 2A;
[0010] FIG. 3A is a sectional view illustrating a state where a
housing and a body to be mounted have thermally expanded;
[0011] FIG. 3B is a sectional view taken along the line 3B-3B of
FIG. 3A;
[0012] FIG. 4A is a sectional view illustrating a state where a
housing and a body to be mounted according to another embodiment
are thermally expanded; and
[0013] FIG. 4B is a sectional view taken along the line 4B-4B of
FIG. 4A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] One embodiment of an electric roots-type pump mounting
structure will be described with reference to FIGS. 1 to 4B. An
electric roots-type pump is mounted in a fuel cell powered vehicle,
and is used to supply hydrogen to a fuel cell system that generates
electric power by supplying oxygen and hydrogen to fuel cells. In
the following description, "front" and "rear" of the electric
roots-type pump correspond to the front and rear directions
indicated by an arrow Y1 illustrated in FIG. 1, and "left" and
"right" of the electric roots-type pump correspond to the right and
left directions indicated by an arrow Y2 illustrated in FIG. 1.
[0015] As illustrated in FIG. 1, an electric roots-type pump 10
includes a pump portion 11 and a driving portion 12. A housing H of
the electric roots-type pump 10 is configured so that a gear
housing 14 made of aluminum is joined and fixed to the front side
of a rotor housing 13 made of iron and a motor housing 17 made of
aluminum is joined and fixed to the front side of the gear housing
14. The rotor housing 13 includes a first housing 13a for forming
the rotor housing 13 and a second housing 13b for forming the rotor
housing 13. The pump portion 11 is formed so that the second
housing 13b is fixed to the rear side of the first housing 13a with
a fixing bolt 13c. A pump chamber 15 is formed between the first
housing 13a and the second housing 13b. The gear housing 14 is
joined and fixed to the front side of the first housing 13a, and a
gear chamber 16 is formed between the first housing 13a and the
gear housing 14.
[0016] The driving portion 12 is formed by joining and fixing the
motor housing 17 to the front side of the gear housing 14. A motor
chamber 18 is formed between the motor housing 17 and the gear
housing 14. The motor chamber 18 houses an electric motor 19
serving as a driving source.
[0017] A stator 19a is fixed to an inner peripheral surface of the
motor housing 17. The stator 19a is configured so that a coil 192a
is wound around teeth (not illustrated) of a stator core 191a fixed
to the inner peripheral surface of the motor housing 17. A motor
rotor 19b is provided within the stator 19a. The motor rotor 19b
includes a rotor core 191b fixed to a driving shaft 21 serving as a
rotation shaft, and a plurality of permanent magnets 192b provided
on a peripheral surface of the rotor core 191b.
[0018] The driving shaft 21 is rotatably supported on the first
housing 13a and the motor housing 17 via bearings 23a and 23c. A
driven shaft 22 provided in parallel with the driving shaft 21 is
rotatably supported on the first housing 13a via a bearing 23b. The
bearings 23a and 23b are respectively fit into fitting holes 24a
and 24b formed in the first housing 13a, thereby being supported on
the first housing 13a. The gear chamber 16 houses a driving gear
25, which is fixed to the driving shaft 21, and a driven gear 26,
which is fixed to the driven shaft 22, in a state where the driving
gear 25 and the driven gear 26 are engaged with each other. The
driving shaft 21 and the driven shaft 22 are coupled via the
driving gear 25 and the driven gear 26.
[0019] A drive rotor 27, which is made of iron and housed in the
pump chamber 15, is fixed to the driving shaft 21. A driven rotor
28, which is made of iron and housed in the pump chamber 15, is
fixed to the driven shaft 22. The shapes of the driving rotor 27
and the driven rotor 28 bifoliate or gourd in a cross-sectional
view orthogonal to the direction along an axis line M (axial
direction) of the driving shaft 21. That is, the driving rotor 27
and the driving rotor 28 each have two lobes. The driving rotor 27
and the driven rotor 28 are housed in the pump chamber 15 so that
convex teeth 27a of the driving rotor 27 and concave teeth 28a of
the driven rotor 28 can be engaged with each other and concave
teeth (not illustrated) of the driving rotor 27 and convex teeth
(not illustrated) of the driven rotor 28 can be engaged with each
other. The rotor housing 13 (second housing 13b) has an suction
port 31 for drawing a fluid into the pump chamber 15, and a
discharge port 32 for discharging the fluid transferred in the pump
chamber 15 to a position opposite to the intake port 31.
[0020] In the electric roots-type pump 10 having a structure as
described above, the driving of the electric motor 19 causes the
driving shaft 21 to rotate, so that the driven shaft 22 is rotated
in a direction different from that of the driving shaft 21 through
engagement between the driving gear 25 and the driven gear 26.
Then, in the pump chamber 15, the driving rotor 27 and the driven
rotor 28 synchronously rotate with a phase difference (90 degrees)
of the driving shaft 21 and the driven shaft 22. Then, the fluid is
drawn into the pump chamber 15 from the suction port 31 in
accordance with the synchronous rotation of the driving rotor 27
and the driven rotor 28. The outer surfaces of the rotors 27 and 28
cooperate with an inner peripheral surface 15a of the pump chamber
15 to transfer the fluid drawn into the pump chamber 15. The
transferred fluid is discharged to the exterior of the pump chamber
15 from the discharge port 32.
[0021] The housing H of the electric roots-type pump 10 configured
as described above is provided with first to fourth mounting
members 41a, 41b, 41c, and 41d each serving as a mounting member.
Each of the mounting members 41a, 41b, 41c, and 41d is used to
mount the electric roots-type pump 10 to a body Bd serving as a
body to be mounted that forms a fuel cell system mounted in a fuel
cell powered vehicle.
[0022] The first mounting member 41a is provided so as to extend in
the leftward direction from an outer peripheral surface 17a of the
motor housing 17. The second mounting member 41b is provided so as
to extend rightward from the outer peripheral surface 17a of the
motor housing 17. The third mounting member 41c is provided so as
to extend leftward from an outer peripheral surface 131b of the
second housing 13b. The fourth mounting member 41d is provided so
as to extend rightward from the outer peripheral surface 131b of
the second housing 13b. In the motor housing 17, the first mounting
member 41a and the second mounting member 41b are disposed at
positions opposing to each other in the right-left direction. In
the second housing 13b, the third mounting member 41c and the
fourth mounting member 41d are disposed at positions opposing each
other in the right-left direction.
[0023] The first mounting member 41a has an insertion hole 411a
having a circular shape through which a bolt B (see FIGS. 2A and
2B) is inserted. The bolt B is inserted into the insertion hole
411a and fastened to the body Bd, thereby fastening the first
mounting member 41a with respect to the body Bd rigidly.
[0024] Next, a structure for mounting the second mounting member
41b will be described in detail. It should be noted that structures
for mounting the third and fourth mounting members 41c and 41d are
substantially the same as the structure for mounting the second
mounting member 41b, so detailed description thereof is
omitted.
[0025] As illustrated in FIGS. 2A and 2B, the second mounting
member 41b has a cylindrical mounting portion 43. A lower portion
of the mounting portion 43 is inserted into an insertion recess 51.
The insertion recess 51 is defined by a surface Bd1 of the body Bd
and has a circular cross-sectional area. An insertion hole 42
having a circular shape is formed within the mounting portion 43
and the bolt B is inserted through the insertion hole 42. A
diameter L1 of the insertion hole 42 is larger than a diameter L2
of a shaft portion B1 of the bolt B. Accordingly, in a state where
the shaft portion B1 of the bolt B is inserted into the insertion
hole 42, a first gap S1 is formed over the circumference in the
circumferential direction between an inner peripheral surface 42a
defining the insertion hole 42 and an outer peripheral surface B1a
of the shaft portion B1 of the bolt B.
[0026] On an outer peripheral surface 43a, which is an outer
surface of the mounting portion 43, a groove 45 extending over the
circumference is formed. A seal member 48 is disposed in the groove
45. A part of the seal member 48 projects toward the outside from
the outer peripheral surface 43a of the mounting portion 43.
[0027] A diameter L3 of the insertion recess 51 is larger than an
outer diameter L4 of the mounting portion 43. Accordingly, a second
gap S2 is formed over the circumference in the circumferential
direction between the outer peripheral surface 43a of the mounting
portion 43 and an inner peripheral surface 51a of the insertion
recess 51. Lubricant oil 60 is filled into the insertion recess 51.
The lubricant oil 60 fills the insertion recess 51 to below a
location where the seal member 48 is disposed to provide
lubrication between the bottom surface 43b of the mounting portion
43 and the bottom surface 51b of the insertion recess 51. The seal
member 48 seals the opening side of the insertion recess 51
relative to the area between the outer peripheral surface 43a of
the mounting portion 43 and the inner peripheral surface 51a of the
insertion recess 51 into which the lubricant is filled, thereby
preventing the lubricant oil 60 from leaking out of the insertion
recess 51.
[0028] The bolt B is inserted into each insertion hole 42 and
fastened to the body Bd, thereby fastening the second to fourth
mounting members 41b, 41c, and 41d to the body Bd. Fastening of the
mounting members 41a, 41b, 41c, and 41d to the body Bd allows the
electric roots-type pump 10 to be mounted to the body Bd.
[0029] Next, the operation of this embodiment will be
described.
[0030] In a fuel cell system, for example, electric power is
generated by supplying oxygen and hydrogen to fuel cells, so that
the temperature of each of the housing H and the body Bd rises due
to heat generated by electric power generation. Along with the
temperature rise, the housing H and the body Bd are thermally
expanded. Here, there occur a difference in temperature and also a
difference in thermal expansion coefficients between the housing H
and the body Bd, there is a relative difference between the thermal
expansion of the housing H and the thermal expansion of the body
Bd. Thus, the amount of deformation of the housing H due to the
thermal expansion is different from that of the body Bd.
[0031] FIGS. 3A and 3B illustrate an example where the temperature
of the housing H is higher than that of the body Bd and the amount
of deformation of the housing H in a direction spaced apart from
the first mounting member 41a, i.e., the direction indicated by the
arrow X1 in FIG. 3A, is larger than the amount of deformation of
the body Bd in a direction spaced apart from the first mounting
member 41a, i.e., the direction indicated by the arrow X2 in FIG.
3A. In this case, the bolt B is allowed to move along a direction
orthogonal to the axial direction of the driving shaft 21 along
with the thermal expansion of the body Bd within the insertion hole
42 by the amount corresponding to the first gap S1. Specifically,
since the amount of deformation of the housing H is larger than the
amount of deformation of the body Bd, the bolt B is disposed within
the insertion hole 42 at the position closer to the first mounting
member 41a than a central portion of the insertion hole 42.
[0032] The mounting portion 43 of the second mounting member 41b is
allowed to move along the direction orthogonal to the axial
direction of the driving shaft 21 from the first mounting member
41a within the insertion recess 51 by the amount corresponding to
the first gap S1 and the second gap S2. Specifically, since the
amount of deformation of the housing H is larger than the amount of
deformation of the body Bd, the mounting portion 43 is arranged
within the insertion recess 51 at the position closer to the
opposite side of the first mounting member 41a than a central
portion of the insertion recess 51. That is, the bolt B and the
mounting portion 43 move relative to each other in accordance with
the difference between the amount of deformation of the housing H
and the amount of deformation of the body Bd to suppress the load
on the bolt B.
[0033] Here, even when the mounting portion 43 moves within the
insertion recess 51, the seal member 48 is elastically deformed,
thereby maintaining a seal between the outer peripheral surface 43a
of the mounting portion 43 and the inner peripheral surface 51a of
the insertion recess 51 and preventing the lubricant oil 60 from
leaking out of the insertion recess 51.
[0034] Similarly, the mounting portion 43 of the third mounting
member 41c is allowed to deform so as to be spaced apart in the
axial direction of the driving shaft 21 from the first mounting
member 41a within the insertion recess 51 by the amount
corresponding to the first gap S1 and the second gap S2. Further,
the bolt B is allowed to move along the axial direction of the
driving shaft 21 along with the deformation of the body Bd within
the insertion hole 42 by the amount corresponding to the first gap
S1.
[0035] Similarly, the mounting portion 43 of the fourth mounting
member 41d is allowed to deform so as to intersect the axial
direction of the driving shaft 21 from the first mounting member
41a within the insertion recess 51 and to be spaced apart from the
third mounting member 41c, by an amount corresponding to the first
gap S1 and the second gap S2. Further, the bolt B is allowed to
intersect the axial direction of the driving shaft 21 and move
apart from the third mounting member 41c along with the deformation
of the body Bd within the insertion hole 42, by an amount
corresponding to the first gap S1. Accordingly, even when there
occurs a difference between the amount of deformation of the
housing H and that of the body Bd, a load applied to the bolt B is
suppressed.
[0036] Additionally, since the lubricant oil 60 is filled into the
insertion recess 51, the lubricant oil 60 can provide excellent
lubrication between the bottom surface 43b of the mounting portion
43 and the bottom surface 51b of the insertion recess 51.
Therefore, abrasion between the bottom surface 43b of the mounting
portion 43 and the bottom surface 51b of the insertion recess 51 is
suppressed.
[0037] The embodiment described above can provide the following
advantageous effects.
[0038] (1) Each of the second to fourth mounting members 41b, 41c,
and 41d includes the mounting portion 43 having the insertion hole
42, and the mounting portion 43 is inserted into the insertion
recess 51 of the surface Bd1 to be mounted. The first gap S1 is
formed between the insertion hole 42 and the bolt B, and the second
gap S2 is formed between the mounting portion 43 and the insertion
recess 51. The lubricant oil 60 is filled into the insertion recess
51. Accordingly, when there occurs a difference between the amount
of deformation due to thermal expansion of the housing H and that
of the body Bd, the bolt B is allowed to move within the insertion
hole 42 along with the thermal expansion of the body Bd by the
amount corresponding to the first gap S1, and the mounting portion
43 is allowed to move within the insertion recess 51 by the amount
corresponding to the first gap S1 and the second gap S2. Therefore,
even when there occurs a difference between the amount of
deformation of the housing H and that of the body Bd, a load
applied to the bolt B can be suppressed. Consequently, deformation
of the housing H can be suppressed, and an axial displacement of
each of the bearings 23a and 23b, and 23c for supporting the
driving shaft 21 and the driven shaft 22 can be suppressed as much
as possible.
[0039] The lubricant oil 60 is filled into the insertion recess 51.
Accordingly, even when there occurs a difference between the amount
of deformation of the housing H and that of the body Bd and the
mounting portion 43 moves within the insertion recess 51 so that
the bottom surface 43b of the mounting portion 43 and the bottom
surface 51b defining the insertion recess 51 come into sliding
contact with each other, the lubricant oil 60 can provide excellent
lubrication between the bottom surface 43b of the mounting portion
43 and the bottom surface 51b of the insertion recess 51.
Therefore, abrasion between the bottom surface 43b of the mounting
portion 43 and the bottom surface 51b of the insertion recess 51
can be suppressed, and a decrease in fastening power of the bolt B
with the second to fourth mounting members 41b, 41c, and 41d can be
suppressed. Consequently, large vibration of the electric
roots-type pump 10 itself can be suppressed even when the vehicle
vibrates during driving.
[0040] Furthermore, the seal member 48 is disposed on the opening
side of the insertion recess 51 relative to the area between the
mounting portion 43 and the insertion recess 51 in which the
lubricant oil 60 is filled. Accordingly, the seal member 48 seals a
section on the opening side of the insertion recess 51 relative to
the area between the mounting portion 43 and the insertion recess
51 in which the lubricant oil 60 is filled, so that the seal member
48 can prevent the lubricant oil 60, which is filled into the
insertion recess 51, from leaking out of the insertion recess
51.
[0041] (2) Even when the mounting portion 43 moves within the
insertion recess 51 due to thermal expansion of the housing H and
the body Bd, the seal member 48 is elastically deformed, thereby
J_J maintaining a seal between the outer peripheral surface 43a of
the mounting portion 43 and the inner peripheral surface 51a of the
insertion recess 51 and preventing the lubricant oil 60 from
leaking out of the insertion recess 51.
[0042] (3) When the mounting portion 43 moves within the insertion
recess 51 due to thermal expansion of the housing H and the body
Bd, the seal member 48 can prevent collision of the outer
peripheral surface 43a of the mounting portion 43 against the inner
peripheral surface 51a of the insertion recess 51.
[0043] (4) According to the electric roots-type pump 10 configured
as described above, axial displacement of each of the bearings 23a
and 23b, and 23c for supporting the driving shaft 21 and the driven
shaft 22 can be suppressed as much as possible, and interference
between both rotors 27 and 28 can be suppressed.
[0044] The above embodiment may be modified as follows.
[0045] In the above embodiment, the temperature of the housing H is
higher than that of the body Bd, and the amount of deformation of
the housing H in the direction spaced apart from the first mounting
member 41a is larger than the amount of deformation of the body Bd
in the direction spaced apart from the first mounting member 41a.
However, the present invention is not limited thereto. For example,
FIGS. 4A and 4B illustrate an example where the temperature of the
housing H is lower than that of the body Bd, and the amount of
deformation of the housing H in a direction spaced apart from the
first mounting member 41a, i.e., the direction indicated by the
arrow X3 in FIG. 4A, is smaller than the amount of deformation of
the body Bd in the direction spaced apart from the first mounting
member 41a, i.e., the direction indicated by the arrow X4 in FIG.
4A.
[0046] In this case, for example, the mounting portion 43 of the
second mounting member 41b is allowed to deform so as to be spaced
apart in a direction orthogonal to the axial direction of the
driving shaft 21 from the first mounting member 41a within the
insertion recess 51 by the amount corresponding to the first gap S1
and the second gap S2. Specifically, since the amount of
deformation of the housing H is smaller than the amount of
deformation of the body Bd, the mounting portion 43 is disposed
closer to the first mounting member 41a than a central portion of
the insertion recess 51 within the insertion recess 51.
[0047] Further, the bolt B is allowed to move along a direction
orthogonal to the axial direction of the driving shaft 21 along
with the deformation of the body Bd within the insertion hole 42,
by the amount corresponding to the first gap S1. Specifically,
since the amount of deformation of the housing H is smaller than
the amount of deformation of the body Bd, the bolt B is arranged
apart from the first mounting member 41a than a central portion of
the insertion hole 42 within the insertion hole 42.
[0048] Instead of forming the groove 45 extending over the
circumference in the outer peripheral surface 43a of the mounting
portion 43 and disposing the seal member 48 in the groove 45, a
groove extending over the circumference may be formed in the inner
peripheral surface 51a of the insertion recess 51, and a seal
member may be disposed in this groove.
[0049] The first mounting member 41a does not necessarily have to
be rigidly fastened with respect to the body Bd. That is, the
structure for mounting the first mounting member 41a may be the
same as that of the second mounting member 41b.
[0050] Two, three, or five or more mounting members may be provided
for the housing H.
[0051] The present invention is embodied as an electric roots-type
pump 10, but the present invention is not limited thereto. The
present invention may also be embodied as other pump or compressor
types such as a scroll-type compressor, a screw-type compressor, or
a piston-type compressor.
[0052] The present invention is embodied as an electric roots-type
pump 10 using the electric motor 19, but the present invention is
not limited thereto. For example, the present invention may also be
embodied as a pump using an engine as a drive source. In this case,
the pump can be mounted in a hybrid vehicle, or a vehicle that is
driven only by the engine, and is mounted to the engine of the
vehicle, with the body forming an engine compartment, or the
like.
* * * * *