DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULE, 2003

COMPLETE SPECIFICATION
[See section 10, Rule 13]

HYDRAULIC POWERTRAIN LUBRICATION;

MAHINDRA & MAHINDRA LIMITED, A REGISTERED COMPANY WHOSE ADDRESS IS GATEWAY BUILDING, APOLLO BUNDER, MUMBAI – 400001, MAHARASHTRA, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF THE INVENTION
The present invention relates to a hydraulic system for off-road vehicles and farm machineries including tractors. In particular, the present invention relates to a system for effectively routing hydraulic fluid to lubricate powertrain arrangement.

BACKGROUND OF THE INVENTION
Agricultural machineries such as tractors are equipped with a hydraulic system to operate hydraulic auxiliary equipment and braking system (also known as oil immersed brakes). In a typical arrangement as shown in figure 1, the hydraulic auxiliary equipment is housed in a hydraulic unit 110 which is communicably connected to an upper portion of a transmission unit 120. The hydraulic brakes – left hand brake 130a and right hand brake 130b are packaged for either inside transmission (not shown) or outside transmission (as shown in Figure 1) based on the space availability and servicing requirements. If placed inside the internal transmission, oil gets circulated within brakes, but if placed outside transmission, the brakes require external lubrication.
Auxiliary hydraulic equipments such as hydraulic powertrain consists of multiple parts such as a connecting rod, a rocker arm, a rockshaft and a lift arm, each of which is required to be lubricated.
Accordingly, tractors are provided with supply means for providing hydraulic fluid to the auxiliary equipments as well as the brakes. Figure 2 shows a supply means 200 adapted to the hydraulic unit for providing hydraulic fluid to a hydraulic powertrain 230 and brakes of the tractor (not shown). The supply means includes a distribution unit 210 and external lubrication piping 220. The distribution unit 210 comprises an inlet port 212, a left hand outlet port 214a, a right hand outlet port 214b, a bottom outlet port (now shown), and an auxiliary outlet port 216.
The inlet port receives hydraulic fluid from the return flow line of hydraulics and the fluid is distributed to the left hand outlet and right hand outlet port through which fluid is delivered to the left hand and right hand brakes respectively. Further, as shown the external lubrication pipe is coupled to the auxiliary outlet port through which fluid is delivered to the powertrain, and the remaining fluid flows through the bottom outlet port. As shown in figure 2, the external lubrication pipe extends and further divides/distributes over the hydraulic unit and is coupled to the casing of the hydraulic unit to deliver fluid to various parts of the powertrain. The external lubrication pipe is coupled to the hydraulic unit via mechanisms which require a hole to be drilled on to the hydraulic unit to allow the external lubrication pipe to direct the fluid on to various parts of the power train. Further, since the lubrication pipe is mounted externally over hydraulic unit, there is always an issue of leakage and seepage. Also, driver seat is generally mounted on tractor hydraulics and there may be a risk of driver stepping on the lubrication pipe resulting in breakage and bending of this pipe. This affects the lubrication function and overall life of components.
In view of the above, there is a need to overcome at least one of the above mentioned drawbacks.

SUMMARY OF THE INVENTION
The present invention relates to a lubrication system for lubricating a hydraulic unit and more particularly to the hydraulic power train and brakes. The lubrication system comprises a distribution unit and a lubricant splasher. The distribution unit includes an inlet port for receiving a hydraulic fluid which is distributed to a left hand outlet port, a right hand outlet port and a bottom outlet port. The lubrication spalsher has a first end and a second end such that the lubricant splasher is lockingly connected at a predetermined position to the distribution unit through the first end. The lubricant splasher receives the hydraulic fluid from the bottom outlet port and sprays it on a plurality predefined parts of the power train such as a rocker arm, a rockshaft, a lift arm and a joint between the connecting rod and the rocker arm.

BREIF DESCRIPTION OF DRAWINGS
Figure 1 is a front view of a hydraulic unit with a prior art transmission system.
Figure 2 is a perspective view of supply means for lubricating a hydraulic power train of the hydraulic unit as shown in Figure 1.
Figure 3 is a perspective view of the hydraulic unit having a lubrication system according to the present invention and the hydraulic power train.
Figure 4 is a perspective view of the lubrication system of the present invention in accordance with Figure 3.
Figure 5 is a perspective view of a distribution unit of the present invention in accordance with Figure 4.
Figure 6 is a perspective view of a lubricant splasher of the present invention in accordance with Figure 4.
Figure 7 is the hydraulic unit along with a cross sectional view showing the lubrication system of the present invention adapted to the hydraulic unit.

DESCRIPTION OF THE INVENTION
Accordingly, the present invention provides a lubrication system (400) for providing hydraulic fluid to auxiliary equipments such as hydraulic powertrain (320) as well as brakes of a tractor, wherein the lubrication system (400) obviates the use of external lubrication piping for supplying hydraulic fluid to the hydraulic powertrain (320).
In an embodiment, the lubrication system (400) is adapted to direct lubricant to be splashed on components of hydraulic powertrain (320) - rocker arm (324), connecting rod (322), rock shaft bush, etc.
The terms "a", "an", and "the" as used in the claims herein are used in conformance with long-standing claim drafting practice and not in a limiting way. Unless specifically set forth herein, the terms "a", "an", and "the" are not limited to one of such elements, but instead mean "at least one".
Figure 3 shows a hydraulic unit (300) in accordance with an embodiment of the invention. As shown, the hydraulic unit (300) has a casing (310) which houses powertrain (320) and a lubrication system (400) assembled on the hydraulic unit (300) according to the present invention. The powertrain (320) comprises a connecting rod (322), a rocker arm (324), a rockshaft (326) and a lift arm (328) each of which is lubricated by the lubrication system (400) of the present invention.
Figure 4 shows the lubrication system (400) in accordance with an embodiment of the invention. The lubrication system (400) comprises of a distribution unit (410) and a lubricant splasher (420) lockingly coupled to the distribution unit (410). As shown in the Figure 3, the distribution unit (410) is installed externally on the casing (310) of the hydraulic unit (300) and the lubricant Splasher (420) is installed internally/within the hydraulic unit (300) .
Figure 5 shows the distribution unit (410) in accordance with an embodiment of the invention. The distribution unit (410) comprises an inlet port (412), a left hand outlet port (414a), a right hand outlet port (414b), and a bottom outlet port (416). The inlet port (412) receives hydraulic fluid from a return flow line of hydraulics and the fluid is distributed to the left hand outlet (414a) port and right hand outlet port (414b) through which fluid is delivered to the left hand (730a) and right hand brakes (730b) respectively. The remainder fluid flows through the bottom outlet port (416) to the lubricant splasher (420) at a pressure. Advantageously, the distribution unit (410) does not require the auxiliary outlet port (218) as well as auxillary tubing (220) as required in the prior-art.
Figure 6 shows the lubricant splasher (420) in accordance with an embodiment of the invention. The lubricant splasher (420) is cylindrical and extends from a first end (420a) to a second end (420b). At the first end, the splasher (420) is lockingly coupled to the bottom outlet port (416) of the distribution unit (410).
At the second end (420b), the splasher (420) is provided with a plurality of holes (424). The holes (424) are provided in such a way that the lubricant is directed onto various parts of the powertrain (320) such as a connecting rod (322), a rocker arm (324), a rockshaft (326) and a lift arm (328). Also, joints between connecting rod (322) and rocker arm (324) is lubricated. As shown in the Figure 6, the holes (424) are provided at 90 degree pitch. In an embodiment of the invention location of holes, type and shape of holes, number of holes, the inclination angle of holes as well as the pitch of the holes can be modified as per requirement of the lubrication required to the powertrain (320) and the parts to be lubricated.
A locking means locks the lubricant splasher (420) to the distribution unit (410) as a predetermined position. The predetermined position is not defined in the application as a person skilled in the art can easily understand that the holes are required to be directed towards the parts to be lubricated and therefore considering the direction of the holes a predetermined position can be decided.
According to an embodiment of the present invention, the locking means comprises locking holes (422) at the first end (420a) of the splasher (420), locking holes (422) on the bottom outlet port (416) of the distribution unit (410) and a locking member for locking the lubricant splasher (420) with the distribution unit (410). Once the holes are aligned, a locking member is inserted through the holes (422) and the lubricant splasher (420) is locked with the distribution unit (410). Advantageously, the locking arrangement ensures correct position of the lubricant splasher (420) with respect to the parts that are required to be lubricated. According to the preferred embodiment of the present invention, the locking member is a split pin or a spring dowel. Alternatively, the locking means for the lubricant splasher (420) with the distribution unit (410) can be any other suitable means such as bolting arrangement, slot system arrangement, missing spline arrangement, a spring ball arrangement etc.
In an embodiment, an inner profile of the splasher (420) is circular and is substantially identical to the inner profile of the bottom outlet port (416) of the distribution unit (410). In this regard the inner profile of the splasher (420) is such that an adequate flow of fluid is supplied to the brakes through the left (414a) and right outlet ports (414b) and there is not be extra back pressure on the connector / distribution unit (410). In a relative aspect, size and diameter of holes, number of holes are also varied depending upon back pressure required to pump required flow for the brakes. Also, sometimes there may be required for additional holes to balance the back pressure.
Figure 7 shows a cross-section view of the hydraulic unit (300) with the lubrication system (400) adapted to the hydraulic unit (300). The inlet port (412) of the distribution unit (410) receives hydraulic fluid from the return flow line of hydraulics and the fluid is distributed to the left hand outlet (414a) and right hand outlet port (414b) through which fluid is delivered to the left hand brake (730a) and right hand brake (730b). As shown in figure 7 the lubricant splasher (420) sprays the fluid onto various parts of powertrain (320), and the remaining fluid falls into a transmission unit (720) through a hole provided at the bottom of the lubricant splasher (420).
Advantageously the present invention provides a cost-effective lubricant system (400) for hydraulic powertrain (320), which has a lubricant splasher (420) mounted internally within a hydraulic unit (300) obviating the need of external piping and thereby avoiding issues of leakage and seepage associated with externally installed pipings.
The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to a person skilled in the art, the invention should be construed to include everything within the scope of the disclosure:
,CLAIMS:WE CLAIM:

1. A lubrication system for lubricating a hydraulic unit, comprising:
a distribution unit having an inlet port, a left hand outlet port, a right hand outlet port and a bottom outlet port, the inlet port receiving a hydraulic fluid for distributing said hydraulic fluid through the left hand outlet port, the right hand outlet port and the bottom outlet port;
a lubricant splasher having a first end and a second end, the second end having a plurality of splashing holes, the lubricant splasher being internally positioned within the hydraulic unit, the lubricant splasher lockingly connected to the distribution unit at the first end to align the splashing holes at a predetermined position for splashing the lubricant within the hydraulic unit.

2. The lubrication system as claimed in claim 1, wherein the lubricant splasher is lockingly connected to the distribution unit with a locking means for aligning the holes at the predetermined position.

3. The lubrication system as claimed in claim 2, wherein the locking means comprises at least a first locking hole provided on the distribution unit and at least a second locking hole provided on the first end of the lubricating splasher and a locking member for inserting through the first and second locking holes for aligning the splashing holes at the predetermined position.

4. The lubrication system as claimed in claim 3, wherein the locking member is a split pin.

5. The lubrication system as claimed in claim 3, wherein the locking member is a spring dowel.

6. The lubrication system as claimed in claim 3, wherein the locking member is a bolting arrangement.

7. The lubrication system as claimed in claim 2, wherein the locking means is a missing spline arrangement or a slot system arrangement.

8. The lubrication system as claimed in claim 2, wherein the locking means is a spring ball arrangement.

9. The lubrication system as claimed in claim 1, wherein the splashing holes are configured thereon at 900 pitch for facilitating lubrication to the hydraulic unit by spraying lubricant on a connecting rod, a rocker arm, a rockshaft, a lift arm and a joint between the connecting rod and the rocker arm of the hydraulic unit.

Dated this 12th day of May, 2014.

FOR MAHINDRA & MAHINDRA LIMITED
By their Agent

(GIRISH VIJAYANAND SHETH)
Agent No. IN/PA/1022
KRISHNA & SAURASTRI ASSOCIATES