FIELD OF INVENTION
This invention relates to a method of manufacturing hollow crankshaft for
tractor/construction equipment and a hollow crankshaft thereof.
PRIOR ART
Currently the crankshaft is manufactured by forging and casting. Both are
solid, wherein oil holes are provided by machining.
The solid crankshafts are heavy by weight and therefore expensive. Hence, a
crankshaft is required to be developed so as- to address the aforesaid
drawbacks.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide a method of
manufacturing hollow crankshaft for tractor/construction equipment and a
hollow crankshaft thereof which is having reduced weight.
Another object of the present invention is to provide a method of
manufacturing hollow crankshaft for tractor/construction equipment and a
hollow crankshaft thereof which is cost effective.
Further object of the present invention is to provide a method of manufacturing
hollow crankshaft for tractor/construction equipment and a hollow crankshaft
thereof which avoids machining for boring oil holes.
Yet another object of the present invention is to provide a method of
manufacturing hollow crankshaft for tractor/construction equipment and a
hollow crankshaft thereof which is efficient.
Yet another object of the present invention is to provide a method of
manufacturing hollow crankshaft for tractor/construction equipment and a
hollow crankshaft thereof which is better than prior art in terms of
serviceability by considering weight factor.
STATEMENT OF INVENTION
According to this invention, there is provided hollow crankshaft for
tractor/construction equipment comprising of a hollow crankshaft, wherein a
journal part and/or a pin part is provided with hollow section together with the
oil holes.
Further, according to this invention there is provided a method of
manufacturing hollow crankshaft for tractor/construction equipment
comprising steps of : casting hole in the crankshaft, forming of oil holes in the
journal part and pin part by casting with the core and forming of hollow section
of an arm part.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Further objects and advantages of this invention will be more apparent from
the ensuing description when read in conjunction with the accompanying
drawing and wherein:
Fig. 1 shows: exemplary embodiment of hollow crankshaft of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWING:
The present invention is directed to a method of manufacturing hollow
crankshaft for tractor/construction equipment and a hollow crankshaft
thereof. This method gives rise to a hollow crankshaft with reduced weight due
to hole casting. The hollow crankshaft is accurately manufactured with high
productivity by eliminating the deflection of core during manufacturing and
also rise of the core while pouring molten metal. Further, this method
eliminates the need of boring oil holes.
Now, reference may be made to fig. 1 indicating the following:
1. COPE pattern
2. DRAG pattern
3. CORE
4. Oil hole core
5. Parting line.
The hollow section of a journal part and/or pin part is formed in an for ex.
elliptic shape, and oil holes in the journal part and pin part are formed by
casting with the core. The hollow sectiofi of an arm part is also formed in an for
ex. elliptic shape. The core of elliptic shape is bent in the horizontal direction
and has a vertical major axis in its cross section at the journal part and/or the
pin part. The core bent in the horizontal direction having a plurality of core
print parts extending toward a mold or a plurality of core print parts extending
toward the mold in the vertical direction at the journal part and/or the pin part
is hole-cast to integrally form the hollow part and the oil holes with each other.
Example :
a. Casting:-
Material for casting is nodular cast iron. Considering ferrite content of
6-8 percent, heating of this material is upto 1400-1450 "c. Cores are
of mushroom type for better holding and smooth flow of oil through
holes with less friction.
b. Cooling
As surface area to weight is increasing so cooling time is less upto 1-2
min thereby increasing the productivity.
Advantageous features
- Reduction in weight and cost effective.
- Avoids machining for boring oil holes.
- High productivity by eliminating deflection of core during manufacturing
and rise of the core while pouring molten metal.
- Eliminating the requirement of boring oil holes.
It is to be noted that the present invention is susceptible to modifications,
adaptations and changes by those skilled in the art. Such variant embodiments
employing the concepts and features of this invention are intended to be within
the scope of the present invention, which is further set forth under the
following claims:

WE CLAIM
1. Hollow crankshaft for tractor/construction equipment comprising of a
hollow crankshaft, wherein a journal part and/or a pin part is provided
with hollow section together with the oil holes.
2. Hollow crankshaft as claimed in claim 1, wherein the hollow section is
provided in an for example elliptic shape.
3. Hollow crankshaft as claimed in claim 1 or 2, wherein an arm part is
provided with hollow section in an for ex. elliptic shape.
4. Hollow crankshaft as claimed in any of the preceding claims, wherein
core of elliptic shape is provided with a bend in the horizontal direction
and a vertical major axis in its cross section at the journal part and/or
pin part.
5. Hollow crankshaft as claimed in any of the preceding claims, wherein the
core bent in the horizontal direction having a plurality of core print parts
extending toward a mold or a plurality of core print parts extending
toward the mold in the vertical direction at the journal part and/or the
pin part.
6. A method of manufacturing hollow crankshaft for tractor/construction
equipment comprising steps of : casting hole in the crankshaft, forming
of oil holes in the journal part and pin part by casting with the core and
forming of hollow section of an arm part.
7. A method as claimed in claim 6, wherein the hollow section of the journal
part and/or pin part and arm part is formed in an for ex. elliptic shape.
8. A method as claimed in claim 6 or 7, wherein the oil holes in the journal
part and pin part are formed by casting with the core.
9. A method as claimed in any of the preceding claims, comprising bending
of core of elliptic shape in the horizontal direction with a vertical major
axis in the cross section of the core at the journal part and/or the pin
part.
10. A method as claimed in any of the preceding claims, wherein the
core bent in the horizontal direction having a plurality of core print parts
extending toward a mold or a plurality of core print parts extending
toward the mold in the vertical direction at the journal part and/or the
pin part is hole-cast so as to integrally form the hollow part and oil holes.
11. A method of manufacturing hollow crankshaft for
tractor/construction equipment and a hollow crankshaft thereof as
claimed in any of the preceding claims, is associated with the
advantageous features such as herein described.