U.S. patent application number 12/104442 was filed with the patent office on 2009-10-22 for method for manufacturing a porous oil-impregnated revolving shaft assembly.
This patent application is currently assigned to Foxconn Technology Co., Ltd.. Invention is credited to CHUEN-SHU HOU.
Application Number | 20090263267 12/104442 |
Document ID | / |
Family ID | 41201254 |
Filed Date | 2009-10-22 |
United States Patent
Application |
20090263267 |
Kind Code |
A1 |
HOU; CHUEN-SHU |
October 22, 2009 |
METHOD FOR MANUFACTURING A POROUS OIL-IMPREGNATED REVOLVING SHAFT
ASSEMBLY
Abstract
A method for manufacturing a porous oil-impregnated revolving
shaft assembly includes following steps: 1) offering an amount of
metal powder, a particle diameter of the metal powder ranging from
1 .mu.m to 150 .mu.m; 2) offering a mold cavity and filling the
metal powder in the mold cavity to form a green piece, a plurality
of pores being defined between the metal powder of the green piece;
3) heating the green piece at a high temperature to sinter the
metal powder to obtain a sintered product, a volume ratio of pores
of the sintered product ranging from 12% and 20%; 4) dipping the
sintered product into oil to make the oil enter the pores of the
sintered product to thereby obtain a final desired product for
forming the porous oil-impregnated revolving shaft assembly.
Inventors: |
HOU; CHUEN-SHU; (Tu-Cheng,
TW) |
Correspondence
Address: |
PCE INDUSTRY, INC.;ATT. Steven Reiss
288 SOUTH MAYO AVENUE
CITY OF INDUSTRY
CA
91789
US
|
Assignee: |
Foxconn Technology Co.,
Ltd.
Tu-Cheng
TW
|
Family ID: |
41201254 |
Appl. No.: |
12/104442 |
Filed: |
April 17, 2008 |
Current U.S.
Class: |
419/27 |
Current CPC
Class: |
B22F 3/11 20130101; B22F
3/26 20130101; F16D 2300/06 20130101; F16D 1/101 20130101; B22F
2998/00 20130101; F16D 2250/00 20130101; B22F 2998/00 20130101;
B22F 1/0014 20130101 |
Class at
Publication: |
419/27 |
International
Class: |
B22F 3/26 20060101
B22F003/26 |
Claims
1. A method for manufacturing a porous oil-impregnated revolving
shaft assembly comprising the steps of: 1) offering a plurality of
metal powder, a particle diameter of the metal powder ranging from
1 .mu.m to 150 .mu.m; 2) offering a mold cavity and filling the
metal powder in the mold cavity to form a green piece, wherein a
plurality of pores is defined between the metal powder of the green
piece; 3) heating the green piece at a high temperature to sinter
the metal powder to obtain a sintered product, wherein a volume
ratio of pores of the sintered product ranges from 12% and 20%; 4)
dipping the sintered product in oil to make the oil enter the pores
of the sintered product to thereby obtain a final desired
product.
2. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 1, wherein the metal powder comprises an
amount of fine metal powder and an amount of super fine metal
powder, a particle diameter of the fine metal powder ranging from
10 .mu.m to 150 .mu.m.
3. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 2, wherein the particle diameter of the
fine metal powder ranges from 50 .mu.m to 80 .mu.m.
4. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 2, wherein a particle diameter of the
super fine metal powder ranges from 1 .mu.m to 10 .mu.m.
5. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 2, wherein the super fine metal powder
accounts for 1%.about.10% of a weight of the fine metal powder.
6. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 3, wherein the metal powder received in
the mold cavity is pressed to make the green piece, a volume ratio
of pores of the green piece situated between 30% and 50%.
7. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 6, wherein the volume ratio of the pores
of the green piece is situated at 35%.
8. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 1, wherein a particle diameter of the
metal powder ranges from 1 .mu.m to 20 .mu.m.
9. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 8, wherein the particle diameter of the
metal powder ranges from 5 .mu.m to 20 .mu.m.
10. The method for manufacturing a porous oil-impregnated revolving
shaft assembly as in claim 9, wherein a bonding agent mixes with
the metal powder to make a mixture and the mixture is injected into
the mold cavity to obtain the green piece.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for manufacturing
a porous oil-impregnated revolving shaft assembly, and more
particularly to a method for manufacturing a porous oil-impregnated
revolving shaft assembly with multiple communicated pores receiving
lubricating oil therein.
[0003] 2. Description of related art
[0004] Generally, a revolving shaft assembly is used as a hinge in
electronic devices, such as notebook, mobile phone, media player
and so on. The revolving shaft assembly includes a driving member
and a driven member interfereferingly and pivotally engaging with
the driving member. Each of the driving member and the driven
member has an inner surface intimately engages with each other. A
plurality of holes is defined between the driving member and driven
member to storage oil to lubricate the inner surfaces of the
driving member and the driven member. A part of the inner surfaces
of the driving member and the driven member where the oil can not
reach is not lubricated. As a result, a serious friction occurs
between the part of the inner surfaces of the driving member and
the driven member and noise is unavoidable to occur after a period
of use of the shaft assembly. The function and the lifespan of the
revolving shaft assembly are accordingly affected and
shortened.
[0005] It is therefore desirable to provide a method for
manufacturing an improved revolving shaft assembly with a driving
member and a driven member which can rotate smoothly relative to
each other.
SUMMARY OF THE INVENTION
[0006] A method for manufacturing a porous oil-impregnated
revolving shaft assembly includes following steps: 1) offering an
amount of metal powder, a particle diameter of the metal powder
ranging from 1 .mu.m to 150 .mu.m; 2) offering a mold having a
cavity and filling the metal powder in the cavity of the mold to
make a green piece, a plurality of pores being defined between the
metal powder of the green piece; 3) heating the green piece at a
high temperature to sinter the metal powder to obtain a sintered
product, a volume ratio of pores of the sintered product ranging
from 12% and 20%; 4) dipping the sintered product into oil to make
the oil enter the pores of the sintered product thereby to obtain
the desired final product.
[0007] Other advantages and novel features will become more
apparent from the following detailed description of preferred
embodiments when taken in conjunction with the accompanying
drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Many aspects of the present embodiments can be better
understood with reference to the following drawings. The components
in the drawings are not necessarily drawn to scale, the emphasis
instead being placed upon clearly illustrating the principles of
the present embodiments. Moreover, in the drawings, like reference
numerals designate corresponding parts throughout the several
views.
[0009] FIG. 1 is an assembled view of a porous oil-impregnated
revolving shaft assembly in accordance with a first embodiment of
the present invention;
[0010] FIG. 2 is an exploded view of FIG. 1;
[0011] FIG. 3 is an inverted view of FIG. 2; and
[0012] FIG. 4 is a scanning electron micrograph of a section of a
green piece for forming the porous oil-impregnated revolving shaft
assembly of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to FIGS. 1-3, a porous oil-impregnated revolving
shaft assembly comprises a driving member 10 and a driven member 20
pivotally engaging with the driving member 10. The driving and
driven members 10, 20 are provided to a shaft (not shown) passing
therethrough in series. The driving member 10 rotates with the
shaft synchronously. The driven member 20 is fixed to a main
bracket (not shown). Each of the driving member 10 and the driven
member 20 has an inner surfaces (not labeled) oriented towards each
other. The inner surfaces of the driving member 10 and the driven
member 20 intimately engage with each other. The driving member 10
and the driven member 20 can be rotated relative to each other.
[0014] Referring to FIG. 4 also, a method for manufacturing the
porous oil-impregnated revolving shaft assembly in accordance with
a first embodiment of the present invention comprises the steps of:
1) offering a quantity of fine metal powder (not labeled), each
fine metal powder having a particle diameter ranging from 10 .mu.m
to 150 .mu.m, wherein a particle diameter ranging from 50 .mu.m to
80 .mu.m is preferable; 2) offering a quantity of super fine metal
powder (not labeled), each super fine metal powder having a
particle diameter ranging from 1 .mu.m to 10 .mu.m; 3) mixing the
fine metal powder and the super fine metal powder to have mixed
powder; 4) offering a mold (not shown) having a cavity and filling
the mixed powder into the cavity of the mold and pressing the mixed
powder to make a green piece, wherein pores 30 are defined between
the pressed mixed powder and a volume ratio of the pores 30 of the
green piece is situated between 30% and 50%, and a volume ratio 35%
of the pores 30 in the green piece is preferable; 5) heating the
green piece at a high temperature, whereby the mixed powder of the
green piece is sintered and diffusion bonded together to obtained a
sintered product, wherein particles of the mixed powder after the
sintering have approximately the same diameter to enhance the
performance of the porous oil-impregnated revolving shaft assembly;
and wherein a volume ratio of pores of the sintered product is
situated between 5% and 30%, and a volume ratio of pores of the
sintered product situated between 12% and 20% is preferable; 6)
dipping the sintered product into oil to fill the oil in the pores
30 of the sintered product thereby to obtain a final desired
product for forming the porous oil-impregnated revolving shaft
assembly.
[0015] In this embodiment, the metal powder is manufactured by
mechanical method, such as cutting, crushing, chipping, etc. Super
fine metal powder acting as an additive is added to the fine metal
powder to improve the sintering strength of the fine metal powder.
The super fine metal powder accounts for 1%.about.10% of the fine
metal powder by weight. When the driving member 10 and the driven
member are assembled together, inner surfaces of the driving member
10 and the driven member 20 are intimately engaged with each other.
An oil film is formed between the inner surfaces of the driving
member 10 and the driven member 20 to lubricate the whole of inner
surfaces of the driving member 10 and the driven member 20. Thus,
the driving member 10 and the driven member 20 can rotate smoothly
relative to each other and the noise generated by the conventional
revolving shaft assembly after a period of use thereof can be
avoided by the present invention.
[0016] A method for manufacturing the porous oil-impregnated
revolving shaft assembly in accordance with a second embodiment of
the present invention comprises the steps of: 1) offering an amount
of super fine metal powder (not shown), a particle diameter of each
super fine metal powder ranging from 1 .mu.m to 20 .mu.m, wherein a
particle diameter ranging from 5 .mu.m to 20 .mu.m is preferable;
2) offering a bonding agent (not shown) to mix with the super fine
metal powder together to thereby obtain a mixture and injecting the
mixture into a mold cavity (not shown) to obtain a green piece; 3)
heating the green piece at a selected temperature to obtain a
sintered product, wherein the super fine metal powder is sintered;
4) dipping the sintered product into oil to fill pores in the
sintered product with the oil thereby to obtain a desired final
product for forming the revolving shaft assembly.
[0017] In the second embodiment, the temperature of sintering is
lower than that of the first embodiment, and the volume ratio of
the porous of the desired final product is the same as that of the
first embodiment.
[0018] It is believed that the present embodiments and their
advantages will be understood from the foregoing description, and
it will be apparent that various changes may be made thereto
without departing from the spirit and scope of the invention or
sacrificing all of its material advantages, the examples
hereinbefore described merely being preferred or exemplary
embodiments of the invention.
* * * * *