U.S. patent application number 09/808292 was filed with the patent office on 2002-03-14 for swash plate for compresser.
Invention is credited to Isomura, Naohiki, Iwama, Kazuaki, Kawachi, Shigeki, Kayukawa, Hiroaki, Sugiura, Manabu.
Application Number | 20020031434 09/808292 |
Document ID | / |
Family ID | 18593417 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020031434 |
Kind Code |
A1 |
Sugiura, Manabu ; et
al. |
March 14, 2002 |
Swash plate for compresser
Abstract
A swash plate used in a compressor. A side of the swash plate
that contacts head side shoes is coated with two layers. The first
layer is formed of aluminum material and the second layer is formed
with solid lubricant. A side of the swash plate that contacts skirt
side shoes is coated with a single layer of solid lubricant.
Accordingly, the swash plate has a sufficiently wear resistance on
both sides for the minimized cost.
Inventors: |
Sugiura, Manabu;
(Kariya-shi, JP) ; Iwama, Kazuaki; (Kariya-shi,
JP) ; Isomura, Naohiki; (Kariya-shi, JP) ;
Kawachi, Shigeki; (Kariya-shi, JP) ; Kayukawa,
Hiroaki; (Kariya-shi, JP) |
Correspondence
Address: |
MORGAN & FINNEGAN, L.L.P.
345 Park Avenue
New York
NY
10154
US
|
Family ID: |
18593417 |
Appl. No.: |
09/808292 |
Filed: |
March 14, 2001 |
Current U.S.
Class: |
417/269 ;
417/222.1; 417/222.2 |
Current CPC
Class: |
F05C 2203/086 20130101;
F05C 2251/14 20130101; F05C 2201/903 20130101; F04B 27/1054
20130101; F05C 2253/12 20130101; F05C 2225/04 20130101; F05C
2203/0882 20130101 |
Class at
Publication: |
417/269 ;
417/222.2; 417/222.1 |
International
Class: |
F04B 001/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 17, 2000 |
JP |
2000-075537 |
Claims
What is claimed is:
1. A swash plate used in a compressor, the swash plate is mounted
on a drive shaft and coupled to a single-head piston to convert a
rotational movement of the drive shaft to a linearly reciprocal
movement of the piston, the piston having a head portion
compressing gas and receiving reaction force from the gas and a
skirt portion accommodating a first shoe and a second shoe opposed
to each other, the first shoe being disposed closer to the piston
head than the second shoe, the first shoe and the second shoe being
respectively kept in a slidable contact with a first contact
surface and a second contact surface opposed to each other in the
swash plate, the swash plate comprising: a first coating formed on
the first contact surface, the first coating being made of an
aluminum based material; and a second coating formed on the second
contact surface, the second coating material being made of a
material simpler for production than the aluminum based
material.
2. The swash plate as set forth in claim 1, wherein the second
coating is made of one of a rigid lubrication layer, a plating
layer and a sinter.
3. The swash plate as set forth in claim 1, wherein the first
coating is formed on the first contact surface by one selected from
a group consisting of a pressure welding, a welding and a flame
spraying.
4. The swash plate as set forth in claim 1, wherein the first
contact surface is finished by roughening.
5. The swash plate as set forth in claim 1, wherein the first
coating is coated by a rigid lubrication layer.
6. The swash plate as set forth in claim 5, wherein the first
coating has a roughened surface.
7. A swash plate used in a compressor, the swash plate is mounted
on a drive shaft and coupled to a single-head piston to convert a
rotational movement of the drive shaft to a linearly reciprocal
movement of the piston, the piston having a head portion
compressing gas and receiving reaction force from the gas and a
skirt portion accommodating a first shoe and a second shoe opposed
to each other, the first shoe being disposed closer to the piston
head than the second shoe, the first shoe and the second shoe being
respectively kept in a slidable contact with a first contact
surface and a second contact surface opposed to each other in the
swash plate, the swash plate comprising: a first coating formed on
the first contact surface, the first coating being made of an
aluminum based material; and a second coating formed on the second
contact surface, the second coating material being made of one of a
rigid lubrication layer and a plating layer.
8. The swash plate as set forth in claim 7, wherein the first
coating is made of an aluminum alloy containing silicon.
9. The swash plate as set forth in claim 7, wherein the first
coating includes a first layer made of an aluminum alloy containing
silicon and a second layer formed on the first layer and made of a
rigid lubrication agent.
10. The swash plate as set forth in claim 9, wherein the first
layer is formed of the aluminum alloy containing 10 to 20 weight
percent of the silicon.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a swash plate that is used
in a compressor, for example, in a refrigerant circuit of an air
conditioner, and is coupled to single headed pistons by pairs of
shoes. Each pair of the shoes has a head side shoes and a skirt
side shoes. The head side shoes contacts a head side face of the
swash plate, or the face that is closer to the piston heads. The
skirt side shoes contacts the other side of the swash plate, or the
skirt side face, which is closer to the end of the piston
skirts.
[0002] The shoes and the swash plate in a swash plate type
compressor are lubricated by lubricant oil retained in the
compressor. Specifically, the lubricant oil is converted into mist
by gas circulating in the compressor. The oil mist is then supplied
to the joint between the shoes and the swash plate.
[0003] However, if the compressor is de-activated for a relatively
long time, the lubricant oil that has been applied to the joint
between the shoes and the swash plate is removed by refrigerant gas
when the compressor is re-started. Thus, when the compressor is
re-started, the lubrication between the shoes and the swash plate
is insufficient until refrigerant returns to the compressor and
convert the lubricant oil into mist.
[0004] Accordingly, to ensure minimum lubrication even when the
lubricant supply is insufficient, various procedures for coating
part of a swash plate that contacts shoes have been proposed.
[0005] Load applied to the head side face of a swash plate by the
head side shoes is different from load applied to the skirt side
face of the swash plate by the skirt side shoes. That is, when gas
is drawn into the associated cylinder bore, the piston is pulled
outward by the swash plate and the reaction force of the suction
mainly acts on the skirt side face of the swash plate. When the gas
is compressed in each cylinder bore, the associated piston is
pressed into the cylinder bore and the reaction force of the
compression mainly acts on the head side face of the swash plate.
The load based on the compression reaction force is generally
greater than the load based on the suction reaction force.
[0006] Therefore, the head side face, which contacts the head side
shoess, need to have relatively high wear resistance. On the other
hand, even if the wear resistance of the skirt side face, which
contacts the skirt side shoess, is not as high as the level
required for the head side face, the lubrication between the skirt
side face and the skirt side shoess is maintained for an extended
period.
[0007] Since the difference of the load acting on both sides of a
swash plates has never been considered in prior art, the skirt side
face is treated to have the same coating as that of the head side
face. In other words, the skirt side face has been given an
excessive wear resistance, which increases the cost for coating the
swash plate.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is an objective of the present invention to
provide a swash plate the head and skirt side faces of which are
appropriately coated for reduced cost such that necessary
reliability is obtained.
[0009] To achieve the foregoing and other objectives and in
accordance with the purpose of the present invention, a swash plate
used in a compressor is provided. The swash plate is mounted on a
drive shaft and coupled to a single-headed piston to convert a
rotational movement of the drive shaft to a linearly reciprocal
movement of the piston. The piston has a head portion compressing
gas and receiving reaction force from the gas and a skirt portion
accommodating a first shoe and a second shoe opposed to each other.
The first shoe is disposed closer to the piston head than the
second shoe. The first shoe and the second shoe are respectively
kept in a slidable contact with a first contact surface and a
second contact surface opposed to each other in the swash plate.
The swash plate includes a first coating formed on the first
contact surface. The first coating is made of an aluminum based
material. The swash plate also includes a second coating formed on
the second contact surface. The second coating material is made of
a material simpler for production than the aluminum based
material.
[0010] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
the presently preferred embodiments together with the accompanying
drawings in which:
[0012] FIG. 1 is a cross-sectional view illustrating a swash plate
type variable displacement compressor according to a first
embodiment of the present invention;
[0013] FIG. 2 is a partial cross-sectional view illustrating the
swash plate and a pair of the shoes of the compressor shown in FIG.
1;
[0014] FIG. 3 is a rear view showing the swash plate of the
compressor shown in FIG. 1, with a metal supplier shown in
perspective;
[0015] FIG. 4 is a view schematically showing a coating apparatus
of the first embodiment; and
[0016] FIG. 5 is a view schematically showing a coating apparatus
of a second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] First and second embodiments of the present invention will
now be described with reference to the attached drawings. In
describing the second embodiment, only the differences from the
first embodiment will be discussed. Same or like reference numerals
are given to parts in the second embodiment that are the same as or
like corresponding parts of the first embodiment.
[0018] First, the compressor will be described.
[0019] As shown in FIG. 1, the compressor includes a cylinder block
1, a front housing member 2, a valve plate 3, and a rear housing
member 4. The front housing member 2 is coupled to a front end of
the cylinder block 1. The front end is to the left in FIG. 1. The
rear housing member 4 is connected to the rear end of the cylinder
block 1 through the valve plate 3. The cylinder block 1, the front
housing member 2, the valve plate 3, and the rear housing member 4
are fastened together with through bolts (not shown) to define a
compressor housing.
[0020] A crank chamber 5, a suction chamber 6 and a discharge
chamber 7 are defined in the housing. Cylinder bores 1a (only one
is shown in FIG. 1) are defined in the cylinder block 1. A
single-headed piston 8 is reciprocally accommodated in each
cylinder bore 1a. To reduce the weight, each piston 8 is made of
aluminum based material. Valve flaps are provided in the valve
plate 3 for selectively connecting the suction chamber 6 and the
discharge chamber 7 with each cylinder bore 1a.
[0021] A drive shaft 9 is rotationally supported in the crank
chamber 5. A swash plate 10 is fitted around the drive shaft 9. A
through hole 10a extends in the middle of the swash plate 10. The
drive shaft 9 extends through the through hole 10a. The swash plate
10 is connected with the drive shaft 9 through a hinge mechanism 13
and a lug plate 11 to rotate integrally with the drive shaft 9. The
swash plate 10 inclines with respect to the drive shaft 9 while
axially sliding along the surface of the drive shaft 9. The skirt
of each piston 8 is connected with the swash plate 10 by a skirt
side shoe 20A and a head side shoe 20B. The shoes 20A, 20B slide
along the periphery of the swash plate 10.
[0022] When the swash plate 10 rotates integrally with the drive
shaft 9 while inclined with respect to the drive shaft 9, each
piston 8 moves in the associated cylinder bore 1a by a stroke
corresponding to the inclination angle. Refrigerant gas is drawn
from the suction chamber 6 (the zone in which suction pressure Ps
acts) to the cylinder bore 1a. The gas is then compressed in the
cylinder bore 1a and is discharged to the discharge chamber 7 (the
zone in which discharge pressure Pd acts). This series of steps is
repeated.
[0023] A spring 14 urges the swash plate 10 toward the cylinder
block 1 (to decrease the inclination of the swash plate 10). A snap
ring 15 is secured to the drive shaft 9 for determining the minimum
angle of inclination .theta.min (for example, three to five
degrees) of the swash plate 10. A counterweight 10b is provided on
the swash plate 10. The counterweight 10b abuts against a
restricting portion 11a of the lug plate 11. This determines the
maximum inclined angle .theta.max of the swash plate 10.
[0024] The inclination angle of the swash plate 10 is determined
according to various moments acting on the swash plate 10. The
moments include a rotational moment, which is based on the
centrifugal force of the rotating swash plate 10, a spring force
moment, which is based on the force of the spring 14, a moment of
inertia of the piston reciprocation, and a gas pressure moment.
[0025] The gas pressure moment is generated by the force of the
pressure in the cylinder bores 1a and the pressure in the crank
chamber 5 (crank pressure Pc). Depending on the crank pressure Pc,
the gas pressure moment acts either to increase or decrease the
inclination angle of the swash plate 10. The swash plate type
compressor of FIG. 1 has a control valve 16 that adjusts the crank
pressure Pc to alter the moment of the gas pressure as necessary.
The control valve 16 thus selects the inclination angle of the
swash plate 10 within a range between the minimum angle of
inclination .theta.min and the maximum angle of inclination
.theta.max.
[0026] The swash plate 10 will now be described.
[0027] As shown in FIGS. 1 to 3, an annular skirt side contact
surface 30A is formed on a side of the swash plate 10 that is
closer to the ends of the piston skirts, and an annular head side
contact surface 30B is formed on a side of the swash plate that is
closer to the piston head. The skirt side shoes 20A slide on the
skirt side contact surface 30A, and the head side shoes 20B slide
the head side contact surface 30B.
[0028] The swash plate 10 is formed of relatively heavy, iron-based
material (for example, cast iron FCD700) to optimize the moment of
rotation due to centrifugal force caused by rotation of the swash
plate 10. The shoes 20A, 20B are also formed of iron-based material
(bearing steel) to increase their mechanical strength. If two
different components formed of the same material (in this case, the
swash plate 10 and the shoes 20A, 20B) slide against each other
under severe conditions, seizure may occur. Accordingly, in the
first embodiment, skirt side coating 31A and had side coating 31B
are formed at least on the associated contact surfaces 30A, 30B.
The coatings 31A, 31B allow the shoes 20A, 20B to slide smoothly
along the contact surfaces 30A, 30B. That is, the procedure of the
present invention is performed on the contact surfaces 30A, 30B of
the swash plate 10.
[0029] The skirt side coating 31A, which is formed on the skirt
side contact surface 30A, is made of solid lubricant. The thickness
of the skirt side coating 31A is for example 0.5 to 10 82 m. The
solid lubricant includes at least one of molybdenum disulfide,
tungsten disulfide, graphite, boron nitride, antimony oxide, lead
oxide, indium, tin and fluorocarbon resin. When forming the skirt
side coating 31A, a liquid paint that includes the solid lubricant
is applied to the skirt side contact surface 30A through spray
coating, roll coating or screen printing.
[0030] The head side coating 31B, which is formed on the head side
contact surface 30B, has a two-layer structure. A first layer 31B-1
of the head side coating 31B is formed of metal different from that
forming the body of the swash plate 10 and the bodies of the shoes
20A, 20B. The material of the first layer 31B-1 may be Al--Si based
material including, for example, silicon containing aluminum alloys
and intermetallic compounds consisting of aluminum and silicon. The
physical properties such as hardness and melting point of the
Al--Si based material, or aluminum based material, vary in
accordance with the silicon content of the material. In the first
embodiment, the Al--Si based material contains 10 to 20 weight
percent (preferably, from 15 to 18 percent) silicon.
[0031] A second layer 31B-2 of the head side coating 31B covers the
first layer 31B-1. Like the skirt side coating 31A, the second
layer 31B-2 is formed of solid lubricant and the thickness is
between 0.5 and 10.mu.m.
[0032] The coatings 31A, 31B prevent seizure from occurring between
the shoes 20A, 20B and the contact surfaces 30A, 30B. The coatings
31A, 31B also allow the shoes 20A, 20B to slide smoothly along the
contact surfaces 30A, 30B of the swash plate 10. In other words,
even when the lubricant oil supply to the compressor is
insufficient, the coatings 31A, 31B ensure a certain level of
lubrication between the swash plate 10 and the shoes 20A, 20B.
[0033] A procedure for forming the coatings 31A, 31B will hereafter
be described. The head side contact surface 30B is roughened
through, for example, shot blasting.
[0034] As shown in FIG. 3, the procedure is performed with a
cylindrical metal supplier 40. The supplier 40 is formed of Al--Si
based material. The supplier 40 has a planer end 41 having a
diameter substantially equal to a radial dimension of the head side
contact surface 30B of the swash plate 10 (the difference between
the outer radius and the inner radius of the head side contact
surface 30B).
[0035] As shown in FIG. 4, the swash plate 10 is mounted to a first
drive mechanism 51, and the supplier 40 is connected to a second
drive mechanism 52.
[0036] The first drive mechanism 51 is driven by a first motor M1.
When the first motor Ml drives the first drive mechanism 51, the
swash plate 10 is rotated about an axis L. Specifically, with the
swash plate 10 mounted to the first drive mechanism 51, the head
side contact surface 30B is centered on the axis L and is
perpendicular to axis L. In this state, a portion of the head side
contact surface 30B faces and is spaced from the end 41 of the
supplier 40.
[0037] The second drive mechanism 52 is operably connected to a
linear mover 53 and a second motor M2. The linear mover 53 operates
to move the supplier 40 axially. Specifically, the linear mover 53
enables the supplier 40 to contact the swash plate 10. The supplier
40 is then pressed against the head side contact surface 30B of the
swash plate 10 by the linear mover 53. Afterwards, the linear mover
53 separates the supplier 40 from the swash plate 10. When the
linear mover 53 moves the supplier 40, the second motor M2 rotates
the supplier 40 about the axis L', which is the axis of the
supplier 40.
[0038] The end 41 of the supplier 40 is perpendicular to the axis
L'. When the supplier 40 is mounted to the second drive mechanism
52, the end 41 is parallel to the head side contact surface 30B,
and the rotation axis L' of the supplier 40 is offset from axis L.
That is, when the supplier 40 is pressed against the head side
contact surface 30B of the swash plate 10, one point on the
circumference of the end 41 touches the outer circumference of the
head side contact surface 30B, and a diametrically opposite point
on the end 41 touches the inner circumference of the head side
contact surface 30B (as indicated by broken lines in FIG. 3).
[0039] After the swash plate 10 and the supplier 40 are mounted on
the associated drive mechanisms 51, 52, the second motor M2 rotates
the supplier 40 at a predetermined speed (for example, 1,500 rpm)
about the axis L'. The linear mover 53 causes the supplier 40 and
the second drive mechanism 52 to approach the swash plate 10. After
the supplier 40 contacts the head side contact surface 30B of the
swash plate 10, the supplier 40 is pressed against the head side
contact surface 30B until the pressure reaches a predetermined
level (for example, 18 MPa).
[0040] When the supplier 40 is pressed against the head side
contact surface 30B, the first motor Ml rotates the swash plate 10
by a predetermined rotation speed (for example, 1 rpm). That is,
the supplier 40 and the head side contact surface 30B move relative
to each other along the circumferential direction of the head side
contact surface 30B.
[0041] Heat, which is caused by friction, is generated between the
end 41 of the supplier 40 and the head side contact surface 30B.
The heat is mainly caused by the relatively rapid rotation of the
supplier 40. The heat softens a portion of the supplier 40 near its
end 41. Molten metal is then supplied from the soft portion of the
supplier 40 to a corresponding portion of the head side contact
surface 30B. Accordingly, while the supplier 40 is moving relative
to the head side contact surface 30B, molten metal is continuously
supplied from the supplier 40 to the head side contact surface 30B
along the annular path of the surface 30B.
[0042] When at least one rotation cycle is completed by the swash
plate 10, molten metal is supplied to the entire head side contact
surface 30B. This forms the first layer 31B-1 of Al--Si based
material. The thickness of the head side coating 31B is, for
example, 70 to 100 micrometers. The thickness is determined by
adding a finishing allowance (which is, for example, 20 to 50
micrometers) to the desired coating thickness (which is, for
example, 50 micrometers).
[0043] Afterwards, the surface of the first layer 31B-1 is machined
through cutting or grinding to adjust the thickness of the first
layer 31B-1 as desired.
[0044] The surface of the first layer 31B-1 is roughened through,
for example, shot blasting. Liquid paint containing solid lubricant
is applied to the roughened surface of the first layer 31B-1 in the
same manner as the procedure for forming the skirt side coating
31A. Thereafter, the applied liquid paint is baked for forming the
second layer 31B-2. Afterwards, the surface of the second layer
31B-2 is machined through cutting or grinding to adjust the
thickness of the first layer 31B-1, or the thickness of the head
side coating 31B, as desired.
[0045] The first embodiment has the following advantages.
[0046] (1) The first layer 31B-1 is formed only on the head side
contact surface 30B, which need to have high wear resistance. The
skirt side contact surface 30A, which need to have relatively low
wear resistance, is coated with the solid lubricant skirt side
coating 31A. Solid liquid is inexpensive. Therefore, the swash
plate 10 has sufficient level of lubrication for a minimized
cost.
[0047] (2) The first layer 31B-1 is hard and therefore is easy to
crack if the first layer 31B-1 directly contacts the head side
shoes 20B. However, in the first embodiment, the relatively soft
second layer 31B-2 is formed on the first layer 31B-1, which
prevents the first layer 31B-1 from directly contacting the head
side shoes 20B. Cracking of the first layer 31B-1 is thus
prevented.
[0048] (3) The head side contact surface 30B is roughened before
applying the first layer 31B-1. This increases the contact area
between the head side contact surface 30B and the first layer 31B-1
and thus improves the adherence.
[0049] (4) The surface of the first layer 31B-1 is roughed before
applying the second layer 31B-2. This increases the contact area
between the first layer 31B-1 and the second layer 31B-2 and thus
improves the adherence.
[0050] (5) The first layer 31B-1 is formed on the head side contact
surface 30B by pressing the metal supplier 40 against the head side
contact surface 30B. Therefore, unlike thermal spraying, no
spraying noise is produced. Also, metal powder is not spread, which
improves yield and working conditions.
[0051] (6) Molten metal is reliably separated from the supplier 40
and is supplied to the head side contact surface 30B. That is, a
predetermined amount of metal is reliably supplied from the
supplier 40 to the head side contact surface 30B. The first layer
31B-1 thus has a desired uniform thickness along the entire head
side contact surface 30B.
[0052] (7) The supplier 40, which is a solid metal cylinder, is
pressed against the head side contact surface 30B for forming the
first layer 31B-1. Therefore, unlike thermal spraying, costly metal
powder is not needed. Further, metal cylinders are easier to handle
than metal powder, which improves the efficiency and the working
conditions.
[0053] A second embodiment will now be described with reference to
FIG. 5. In the second embodiment, the first layer 31B-1 is formed
through build up welding by using a coated electrode 54.
[0054] FIG. 5 schematically shows an arc welding apparatus 60. A
first drive mechanism 51 of the second embodiment is installed such
that the axis L is perpendicular to the axis L in the embodiment of
FIGS. 1 to 4. The arc welding apparatus 60 includes an electrode 54
and a welding source 55, which applies voltage to the electrode 54
and the swash plate 10. The electrode 54 is formed by applying flux
54b on a core 54a, which is made of Al--Si based material. The
electrode 54 is supported by a support 56, which is connected to a
lift 57.
[0055] The axis of the electrode 54 is offset from the axis L of
the swash plate 10, which is placed on the first drive mechanism 51
and is located above the head side contact surface 30B. The support
56, together with the electrode 54, is moved vertically as viewed
in the drawing by the lift 57, which permits the electrode 54 to
approach and separate from a part of the head side contact surface
30B.
[0056] When the lift 57 lowers the electrode 54 toward a part of
the head side contact surface 30B and the welding source 55 is
activated, arc is generated between the electrode 54 and the swash
plate 10. The heat of the arc melts part of the electrode core 54a.
Molten metal is dropped onto the contact surface. The molten part
of the electrode 54 is fused with part of the head side contact
surface 30B, which is also molten by the arc heat. The motor M1
rotates the first drive mechanism 51 with the swash plate 10, which
continuously changes part of the head side contact surface 30B that
is located below the electrode 54.
[0057] When at least one rotation cycle is completed by the swash
plate 10, molten metal is supplied to the entire head side contact
surface 30B. This forms the first layer 31B-1 of Al--Si based
material.
[0058] The second embodiment has the advantages (1)-(5) and (7) of
the first embodiment.
[0059] It should be apparent to those skilled in the art that the
present invention may be embodied in many other specific forms
without departing from the spirit or scope of the invention.
Particularly, it should be understood that the invention may be
embodied in the following forms.
[0060] The first layer 31B-1 may be formed through thermal
spraying. In thermal spraying, metal powder is molten and sprayed
on to the head side contact surface 30B with flame.
[0061] The first layer 31B-1 may be formed through sintering. In
sintering, metal powder is sintered on to the head side contact
surface 30B with flame.
[0062] The skirt side coating 31A may be formed of tin through
electroplating or through electroless plating.
[0063] In the second embodiment, the first layer 31B-1 is formed
through arc welding by using the coated electrode 54. However, the
first layer 31B-1 may be formed through gas-shielded arc welding or
submerged-arc welding. Gas-shielded arc welding includes metal
inert gas (MIG) welding, metal active gas (MAG) welding and TIG
welding.
[0064] The procedures of the present invention may be applied to
swash plates 10 formed of aluminum based material instead of iron
based material.
[0065] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive and the invention is
not to be limited to the details given herein, but may be modified
within the scope and equivalence of the appended claims.
* * * * *