FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
TITLE OF THE INVENTION
"OIL PUMP DRIVING ARRANGEMENT OF FORCED LUBRICATED AXLE FOR VEHICLE"
APPLICANT
TATA MOTORS LIMITED of BOMBAY HOUSE, 24 HOMI MODY STREET, Mumbai-400001-MAHARASHTRA.India; AN INDIAN COMPANY
The following specification particularly describes the invention and the manner in which it is to be performed

Field of invention:
The present invention relates to rear tandem drive axle and more particularly it relates to a driving arrangement of oil pump for forced oil lubrication in rear tandem drive axle.
Background of the invention:
Generally the rear tandem axle with two driving for off-road and high way application, has an oil pump for lubricating the inner components of the drive assembly which is disposed at higher level away from oil sump. Typically the driving pin having is an external thread which is screwed to the pinion shaft having the internal threads. The oil pump shaft is in engagement with said driving pin. The pinion shaft end drives driving pin. The driving pin drives the oil pump shaft which is connected pump driving pin. The oil pump shaft in turn drives the oil pump. In the conventional arrangement, due to variations in assembly and machining of oil pump shaft and pump driving pin, the assembly the said oil pump shaft and said driving pin is non- coaxial assembly and the assembly is an eccentric engagement between the oil pump shaft and pump driving pin.
While vehicle running in forward direction, the driving pin which is having external threads keep tightening against pinion shaft end. This results, driving pin fails to sustain driving torque of pump as well as eccentricity induced pushes the oil pump shaft side ways and thus resulting in shearing off at neck of said pin, thus resulting in no drive transfer to oil pump and oil pump stops functioning. Further the oil is contaminated due to failed parts causing failure of other components of driveline.
While running the vehicle in reverse direction, the threads provided on a driving pin keep loosening and thus pushing against the oil pump shaft leading to breakage of oil pump driving pin due to no space available to accommodate the

unscrewed pin hence resulting in to unsafe operating condition to oil pump and other driveline components.
The present invention is developed in order to provide fail safe oil pump driving arrangement to eliminate the above said disadvantages of the conventional system.
Object of invention:
The main object of the present invention is to provide a oil pump driving arrangement of forced lubricated axle for vehicle.
Another object of the present invention is to provide a oil pump driving arrangement of forced lubricated axle for vehicle which eliminates the damage of drive components.
Yet another object of the present invention is to provide a oil pump driving arrangement of forced lubricated axle for vehicle which ensures oil pump operation for uninterrupted oil supply for lubricating the assembly components.
Still another object of the present invention is to provide a oil pump driving arrangement of forced lubricated axle for vehicle which is easy to assemble and dismantle
Statement of invention
An oil pump driving arrangement of forced lubricated axle for vehicle comprises; oil pump (1) for supplying lubricant; oil pump shaft (2) connected to said oil pump (1); a driving tennon (3); a retainer pin (6); pinion shaft end (7); wherein said oil pump shaft (2), said driving tennon (3) and said pinion shaft end

(7) are co-axially aligned in such a way that said driving tennon (3) is operably coupled to said pinion shaft end(7) and transmit the torque from said pinion shaft (7) to said oil pump shaft (2), said driving tennon (3) is free to move in all directions to accommodate any eccentricity between oil pump shaft (2) and pinion shaft end (7) facilitating the drive to pass through said driving tennon (3) to oil pump shaft (2) thereby resulting in to no load on said retainer pin (6) ensuring fail safe operation of said oil pump (1).
The oil pump driving arrangement, in accordance with this invention, wherein said pinion shaft end (7) is having an axial hole (9).
The oil pump driving arrangement, in accordance with this invention, wherein said driving tennon (3) is coupled to said pinion shaft end (7) with the help of said retainer pin (6) disposed through said hole (9).
The oil pump driving arrangement, in accordance with this invention wherein said driving tennon (3) is having a first slot (4) provided towards oil pump shaft (2).
The oil pump driving arrangement, in accordance with this invention, wherein said driving tennon (3) is having at least two parallel flat surface (5) provided on outer diameter of said driving tennon (3).
The oil pump driving arrangement, in accordance with this invention, wherein said first slot (4) and parallel surface (5) of said driving tennon (3) are perpendicular to each other.

The oil pump driving arrangement, in accordance with this invention, wherein said first slot (4) and second slot (8)) are perpendicular to each other.
The oil pump driving arrangement, in accordance with this invention, wherein said pinion shaft end (7) is having a second slot (8) which is conjugate profile to accommodate said flat surface (5) of said driving tennon (3).
The oil pump driving arrangement, in accordance with this invention, wherein mating end of said oil pump shaft (2) is having conjugate profile receivable by-said first slot (4) provided on said driving tennon (3).
Brief description of the invention:
In accordance with the present invention, Oil pump driving arrangement of forced lubricated axle for vehicle comprises; oil pump (1) for supplying lubricant; oil pump shaft (2) connected to said oil pump (1); a driving tennon (3); a retainer pin (6); pinion shaft end (7); wherein said oil pump shaft (2), said driving tennon (3) and said pinion shaft end (7) are co-axially aligned in such a way that said driving tennon (3) is operably coupled to transmit the torque from said pinion shaft (7) to said oil pump shaft (2); said driving tennon (3) is coupled to said pinion shaft end (7) with the help of said retainer pin (6) disposed through the hole provided on said driving tennon (3). The said pinion shaft end (7) is having a second slot (8). The said driving tennon (3) is having a first slot (4) provided towards oil pump shaft (2) and across flat surface (5) to be coupled with said oil pump shaft (2) and said second slot (8) of pinion shaft end (7) respectively. The mating end of said oil pump shaft (2) is having conjugate profile of first slot (4) provided on said driving tennon (3).

Detail description of invention:
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.
Figure-01 shows the oil pump driving arrangement in accordance with the
present invention,
Figure-02 shows the assembly of driving arrangement in accordance with the
present invention.
Figure-03 shows the isometric and split view of the driving arrangement in
accordance with the present invention.
In accordance with the present invention, Oil pump driving arrangement of forced lubricated axle for vehicle comprises; oil pump (1) for supplying lubricant; oil pump shaft (2) connected to said oil pump (1); a driving tennon (3); a retainer pin (6); pinion shaft end (7); wherein said oil pump shaft (2), said driving tennon (3) and said pinion shaft end (7) are co-axially aligned in such a way that said driving tennon (3) is operably coupled to transmit the torque from said pinion shaft (7) to said oil pupm shaft (2);
Said driving tennon (3) is coupled to said pinion shaft end (7) with the help of said retainer pin (6) disposed through the hole provided on said driving tennon (3). The said pinion shaft end (7) is having a second slot (8). The said driving tennon (3) is having a first slot (4) provided towards oil pump shaft (2) and across flat surface (5) to be coupled with said oil pump shaft (2) and said second slot (8) of pinion shaft end (7) respectively. The mating end of said oil pump shaft (2) is having conjugate profile of first slot (4) provided on said driving tennon (3).

Said pinion shaft end (7) is provided with said second slot (8) by machining. The said second slot (8) is provided for mating with the across flat surface (5) of said driving tennon (3). The said second slot (8) provided on said pinion shaft (7) is perpendicular to axis of said pinion shaft (7). The pinion shaft end (7) is provided with a pin hole (9) through which the said retainer pin (6) is disposed to couple said driving tennon (3) with said pinion shaft (7).
Said driving tennon (3) is provided with at least two across flat surface (5) opposite to each other on outer diameter by machining. Said driving tennon (3) is located freely in said second slot (8) provided on said pinion shaft end (7) with the help of said retainer pin (6) which is press fitted in a pin hole (9) provided on said pinion shaft.
Said driving tennon (3) is provided with said first slot (4) which is perpendicular to said across flat surface (5) so that said second slot (8) provided on said pinion shaft end (7) and said first slot (4) provided on tennon (3) are perpendicular to each other after assembly.
The said oil pump (1) is assembled to the location on axle. The said oil pump shaft (2) is connected to said oil pump (1). Said oil pump shaft (2) engages with said first slot (4) provided on said driving tennon (3).
The said oil pump shaft (2), said first slot (4) and across flat surface (5) of said driving tennon (3) and said second slot (8) provided on pinion shaft end (7) are configured in such a manner to get assembly stack which allows movement of said driving tennon (3) along said second slot (8) provided on pinion shaft end (7) and oil pump shaft (2) along said first slot (4) provided on said driving tennon (3).

The movement of said driving tennon (3) along said first slot (4) provided therein and said second slot (8) provided on pinion shaft end (7) facilitates to accommodate the eccentricity, caused due to assembly and manufacturing variation, of said oil pump shaft (2) and pinion shaft end (7) which eliminates the damage of the drive components .
The torque is transmitted from said pinion shaft end (7) to said oil pump shaft (2) through said second slot (8) provided on said pinion shaft end (7) to said across flat surface (5) provided on said driving tennon (3) and from said first slot (4) on said driving tennon (3) to said oil pump shaft (2) without imparting the load on said retainer pin (6) which results in no failure of arrangement.
Also since no threads are used the mechanism works identical vehicle movement in forward and reverse direction. The present invention facilitates uninterrupted forced lubrication to the axle assembly parts in all driving condition and the cost of damages to the axle assembly parts due to loss of lubrication and oil contamination due to failed parts is avoided. The driving arrangement of present invention is easy to assemble and dismantle and the downtime of vehicle is reduced.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

We claim:
1. An oil pump driving arrangement of forced lubricated axle for vehicle comprises; oil pump (1) for supplying lubricant; oil pump shaft (2) connected to said oil pump (1); a driving tennon (3); a retainer pin (6); pinion shaft end (7); wherein said oil pump shaft (2), said driving tennon (3) and said pinion shaft end (7) are co-axially aligned in such a way that said driving tennon (3) is operably coupled to said pinion shaft end(7) and transmit the torque from said pinion shaft (7) to said oil pump shaft (2), said driving tennon (3) is free to move in all directions to accommodate any eccentricity between oil pump shaft (2) and pinion shaft end (7) facilitating the drive to pass through said driving tennon (3) to oil pump shaft (2) thereby resulting in to no load on said retainer pin (6) ensuring fail safe operation of said oil pump (1).
2. The oil pump driving arrangement as claimed in claim 1, wherein said pinion shaft end (7) is having an axial hole (9).
3. The oil pump driving arrangement as claimed in claim 1, wherein said driving tennon (3) is coupled to said pinion shaft end (7) with the help of said retainer pin (6) disposed through said hole (9).
4. The oil pump driving arrangement as claimed in claim 1, wherein said driving tennon (3) is having a first slot (4) provided towards oil pump shaft
(2).
5. The oil pump driving arrangement as claimed in claim 1, wherein said
driving tennon (3) is having at least two parallel flat surface (5) provided on
outer diameter of said driving tennon (3).

6. The oil pump driving arrangement as claimed in claim 1, wherein said first slot (4) and parallel surface (5) of said driving tennon (3) are perpendicular to each other.
7. The oil pump driving arrangement as claimed in claim 1, wherein said first slot (4) and second slot (8)) are perpendicular to each other.
8. The oil pump driving arrangement as claimed in claim 1, wherein said pinion shaft end (7) is having a second slot (8) which is conjugate profile to accommodate said flat surface (5) of said driving tennon (3).
9. The oil pump driving arrangement as claimed in claim 1, wherein mating end of said oil pump shaft (2) is having conjugate profile receivable by said first slot (4) provided on said driving tennon (3).
10. An oil pump driving arrangement of forced lubricated axle for vehicle as herein described with reference to accompanying drawings.