FIELD OF INVENTION
This invention relates to improved power train linkages to enhance life of
actuating lever.
BACKGROUND OF THE INVENTION
Tractors are broadly classified into engine, vehicle, transmission and
hydraulics.
As it is known, Hydraulics prime function in tractor is to use hydraulic power
(of Oil or fluid) for transmitting force in Power train linkages. Main parts which
come under Power train linkages are as follows:-
a) Hydraulic cylinder
b) Piston
c) Connecting rod
d) Actuating lever
e) Serration shaft
fj Lift Arms
In working condition, hydraulic oil is pumped by Hydraulic pump (with defined
flow rate) into the Hydraulic cylinder through control valve (set at a defined
pressure). Oil enters into the Hydraulic cylinder and generates a hydraulic
thrust on Piston. Reciprocating movement of Piston generates force on
Connecting rod mounted between Piston & Actuating lever (as shown in
Linkage mechanism fig. 1).
Actuating lever mounted over serration shaft (at center splines) generates
torque on it, which in turn makes serration shaft to rotate. With the rotation of
serration shaft, Lift arms (mounted at end splines of serration shaft) also start
rotating. Rotation of Lift arms results in lifting & lowering of Three Point
Linkages .
On the other hand, while working in the field, resistance of soil always exerts
force on draft through Top link assembly of TPL. When draft spring compresses
due to this force, it transmits the force to Spool valve through linkages.
Outward movement of spool valve results in entering of hydraulic oil into the
hydraulic cylinder. This whole process takes place instantly. So due to this,
pressure in the system becomes very high, which is controlled by a system
safety valve.
In both the above mentioned processes, a high force always acts on Power
Train Linkages as shown in fig. 5.
Further, reference may be made to fig. 5, in which serration shaft high stress
areas (S) and actuating lever high stress areas (A) are indicated.
Now, reference may be made to assembly view (fig. 2), wherein actuating lever's
spherical ball end is offset (0) (as shown in fig. 3) from center of actuating lever
hub. So when reciprocating movement of hydraulic piston exerts force on
actuating lever (through connecting rod), splines of actuating lever comes
under load on that side where offset is provided. This results in uneven loading
on the splines. With the passage of time, actuating lever splines on one side
starts wearing out. This again creates more uneven loading. This uneven
loading further generates crack on actuating lever (as shown in fig. 4) & results
in failure of actuating lever.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide improved power train
linkages to enhance life of actuating lever which overcomes disadvantage(s)
associated with the prior art.
Another object of the present invention is to provide improved power train
linkages to enhance life of actuating lever which is cost effective.
Further object of the present invention is to provide improved power train
linkages to enhance life of actuating lever which is efficient and simple in
construction.
Yet another object of the present invention is to provide improved power train
linkages to enhance life of actuating lever which enhances life of other power
train linkages.
STATEMENT OF INVENTION
According to this invention, there is provided improved power train linkages to
enhance life of actuating lever comprising of Hydraulic cylinder, Piston,
Connecting rod, Actuating lever Serration shaft and Lift Arms wherein
hydraulic oil is pumped by hydraulic pump into the Hydraulic cylinder, which
generates a hydraulic thrust on piston, reciprocating movement of which
generates force on the connecting rod provided between said piston and
actuating lever mounted over the serration shaft in which rotation of the shaft
causes rotation of lift arms, wherein length of splines of the lever is reduced
from the face with offset and length of plane diameter is increased by the same
extent in the mating part of the lever with serration shaft.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from
the ensuing description when read in conjunction with the accompanying
drawings of an exemplary embodiment and wherein:
Fig. 1 shows: Linkage mechanism
Fig.2 shows: Assembly
Fig.3 shows: Conventional layout
Fig.4 shows: Crack on actuating lever
Fig.5 shows: Serration shaft and actuating lever high stress areas
Fig.6 shows: Lever with spines on its inner surface
Fig.7 shows: Improved power train linkages of the instant invention
Fig.8 shows: Novel actuating lever of power train linkages in accordance
with the present invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS:
The present invention is directed to improved power train linkages to enhance
life of actuating lever. The invention also minimizes uneven loading on splines.
In the existing power train linkages, splines on the inner surface of the lever
are extended till the outer face of the lever as shown in fig. 6.
Referring to fig. 7, indicating improved power train linkages of the instant
invention. Said linkages comprising of Hydraulic cylinder, Piston, Connecting
rod, Actuating lever, Serration shaft and Lift Arms wherein hydraulic oil is
pumped by hydraulic pump into the Hydraulic cylinder, which generates a
hydraulic thrust on piston, reciprocating movement of which generates force on
the connecting rod provided between said piston and actuating lever mounted
over the serration shaft in which rotation of the shaft causes rotation of lift
arms.
Now, reference may be made to fig. 8 indicating novel actuating lever of power
train linkages. In the present invention, length of splines is reduced from the
face with offset. Further, in mating part of the lever with serration shaft, length
of plane diameter is increased by the same extent.
Inside diameter of actuating lever & plane diameter of serration shaft are
controlled in such a manner to make a clearance fit pair. Due to this change,
actuating lever is guided with serration shaft at the place wherein load comes
on splines.
Now when the turning force acts on the actuating lever, inspite of creating load
on the spline ends, load starts moving towards center of hub. This results in
even loading on the splines. Due to even loading, all the splines of actuating
lever come under equally distributed load, which results in less wear out of
splines & significant improvement in life of actuating lever.
Advantageous features
- Enhancement of life of Actuating lever
- Enhancement of life of other Power train linkages
- Cost Effective
- Customer satisfaction.
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. Improved power train linkages to enhance life of actuating lever
comprising of Hydraulic cylinder, Piston, Connecting rod, Actuating
lever, Serration shaft and Lift Arms wherein hydraulic oil is pumped by
hydraulic pump into the Hydraulic cylinder, which generates a hydraulic
thrust on piston, reciprocating movement of which generates force on the
connecting rod provided between said piston and actuating lever
mounted over the serration shaft in which rotation of the shaft causes
rotation of lift arms, wherein length of splines of the lever is reduced from
the face with offset and length of plane diameter is increased by the same
extent in the mating part of the lever with serration shaft.
2. Improved power train linkages as claimed in claim 1, wherein load starts
moving towards center of hub when the turning force acts on the
actuating lever, which results in even loading on the splines that leads to
less wear out of splines and significant improvement in life of actuating
lever.
3. Improved power train linkages as claimed in cIaim 1 or 2, is associated
with the advantageous features such as herein described.
4. Improved power train linkages to enhance life of actuating lever
substantially as herein described with reference to the accompanying
drawings.