Description:FIELD OF INVENTION

The present invention relates to the validation of tractor’s Power Take-Off (PTO). In particular, the present invention relates to a tractor’s Mid Power Take Off (PTO) drive line validation through a hydraulic loading system by conducting the performance and endurance tests at the tractor-level. More particularly, the present invention relates to a modular test setup and hydraulic loading system for validating the tractor’s Mid PTO drive line.

BACKGROUND OF THE INVENTION

The tractor is used for pulling the construction equipment as well as agricultural implements employed for operations like tillage and sowing of various crops. A tractor is also used to power stationery and moving equipment for doing operations like threshing of crops, pumping water from tube-wells, spraying, operating rotavator and the like. Normally, the power outlet or power take-off from the tractor is located at its rear. This power outlet or power take-off is called in short as Power Take Off (PTO).

At present, this PTO is generally placed the rear side of the tractor, however it can also be placed at the front for powering front-mounted attachments or even at the middle, e.g. for export markets having Mid PTO used for lower ground applications such as snow blower, mid-mover, lawn mower and grass-cutters for gardening.

The power generated by a tractor’s engine is transferred to its Power Take-Off (PTO) shaft in the form of rotary motion after a number of reductions carried out as per the application requirements and PTO speed is varied accordingly. The power at the PTO shaft is derived from the gearbox and the countershaft of the gearbox is usually extended out at the tractor’s rear-side to function as the PTO outlet or PTO shaft.
Generally, this PTO shaft is at the rear-side of the transmission in all tractors, and usually called as rear PTO. The applicant’s tractor production units have test facilities suitable for conducting the performance and endurance tests of such rear PTOs.

The drawbacks of the current test setup for tractor’s PTO are given below:

• It cannot validate a tractor’s Mid-PTO drive gear.

• Test simulation poses extreme challenge due to simulation of different conditions in a single test setup.

• Safety is also challenging, especially while operating it at high-speed conditions.

• Optimized and realistic test conditions with respect to Real World Usage Pattern (RWUP) is one of the critical points of testing.

• Difficult to run the test cycles for given duty cycles with a combination of Rear PTO & Mid-PTO at a time.

The applicant’s production units presently have only the in-house rear PTO drive gear test facility using Eddy current dynamometer, shown in Figure 1, which is not suitable for validating the mid-PTOs. Therefore, the inventors have developed an in-house facility with available resources, which is configured as a modular test setup for validating the gear train of a tractor’s Mid Power Take-Off (PTO) at different speeds and torques with different combinations of rear and Mid-PTO.

Therefore, there is an existing need for a modular test setup for Mid-PTO gear train validation, which is based on the customer requirements, particularly for export markets in tractor models having a mid-PTO for lower ground applications.
Accordingly, a fully customized configuration of the modular test setup for mid-PTO Gear train validation is developed by the inventors, as mentioned below.

DESCRIPTION OF THE INVENTION

In accordance with the present invention, a hydraulic loading system for validating the tractor’s Mid-PTO driveline, in which a new test setup is developed in-house to enable the validation of the gear train of Mid-PTO installed in line for a proper and precise assembly of the tractors. The layout of this hydraulic loading system for validating the tractor’s Mid-PTO driveline is shown in Figure 2, wherein bearing blocks are configured to hold the torque cell in a position such that the drive shaft is in line with the Mid-PTO shaft. The hydraulic pump is connected to hydraulic power pack deployed to convert the hydraulic energy into a mechanical torque. A 3150-type hydraulic gear pump is used for this Mid-PTO hydraulic loading system, based on various parameters like the nominal displacement, maximum pressure, nominal delivery and depending on the pump performance such as typical pump delivery flow at maximum pressure and input. The materials of this test setup are rigid enough so that the measurements of the mid-PTO shaft play are accurate. A contact-type torque cell is used to ensure that the applied torque to the Mid PTO shaft is according to duty cycle. The range of this contact type torque cell is 0-100 kg-m. The propeller shaft is connected between mid-PTO shaft and the bearing coupler. The test setup developed in accordance with the present invention is capable of validating the tractor’s mid-PTO drive line as shown in Figure 3.

By using a dial gauge, the mid-PTO shaft runout is measured, which was observed to be within prescribed limits. Laser level-sensor is used for aligning the pump shaft with tractor’s Mid-PTO shaft in a straight-line. The torque-cell ensures that the requisite torque is applied to the tractor’s Mid-PTO shaft.

The main advantages of this new test cycle and simulations are as given below:

- Mid-PTO drive gear trains can be validated along with Rear-PTO gear trains in a single setup.

- Simulates the new combination of Rear-PTO and Mid-PTO field applications during testing to find premature failures in tractor’s rear-PTO and mid-PTO drive gear trains.

- Saves time by validating both Mid-PTO and Rear-PTO in a single test setup.

- Test setup is made cost effective to offer a productive testing.

- Offers flexible Test cycles and facility to simulate rear-PTO and Mid-PTO loading at different speeds and torques at single test facility.

- Provides flexible Test cycles and facility to simulate rear-PTO and Mid-PTO loading in different combinations thereof in a single test facility.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide an in-house facility with available resources to provide mid-PTO gear train validation for tractors.

Another object of the present invention is to provide a Mid-PTO driveline validation through hydraulic loading system for tractors.

A further object of the present invention is to provide a combination of rear-PTO and Mid-PTO drive gear train validation at a time through hydraulic loading system for tractors.
These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF INVENTION

In accordance with the present invention, there is provided a hydraulic loading system for validating tractor’s mid-PTO drive line, the system comprises:

• a structure for mounting the components of the hydraulic loading system thereon;

• a hydraulic pump mounted on the mounting structure;

• a mid-PTO shaft of the tractor under testing connected in an inclined manner to a propeller shaft;

• a torque cell connected between the mid-PTO shaft end and the hydraulic pump;

• the torque cell connected to a respective plumber block placed on either side thereof; the torque cell and the plumber blocks supported on support blocks supported on the mounting structure;

• a Nylon coupler connected between the torque cell and the hydraulic pump for transferring the driving force from the hydraulic pump to the mid-PTO shaft end; and

• a universal joint connected between the propeller shaft and the plumber block for an angular connection to the mid-PTO shaft end;

wherein the hydraulic pump is connected via fluid line to an oil-reservoir of a hydraulic power pack for converting the hydraulic energy into mechanical torque by the torque cell to ensure an accurate torque applied to the mid-PTO shaft end via the propeller shaft transferring the required driving force for conducting the validation of the mid-PTO drive line of the tractor under testing.

Typically, the mounting structure comprises:

(i) a base plate for supporting and mounting the components of the hydraulic loading system thereon;

(ii) an L-bracket supported on the base plate for mounting the hydraulic pump thereon; and

(iii) the pair of supporting blocks for mounting the plumber blocks thereon;

wherein the hydraulic pump, Nylon coupler, plumber blocks with the torque cell disposed therebetween, and the universal joint are aligned in a straight line by means of a laser level sensor.

Typically, the torque cell is a contact type torque cell.

Typically, the hydraulic power pack comprises:

(a) a fluid delivery line connecting the hydraulic pump to the hydraulic power pack via a suction strainer;

(b) a loading valve connected downstream the hydraulic pump via a pressure sensor;

(c) a heat exchanger downstream the loading valve connected to the oil reservoir via a fluid return line; and

(d) a safety valve disposed between the loading valve and oil reservoir;

wherein oil is sucked from the oil reservoir through the suction strainer by operating the hydraulic pump to be delivered to the loading valve via the pressure sensor measuring and maintaining the required hydraulic pressure in the hydraulic power pack.
Typically, the heat exchanger controls and maintains the oil temperature flowing through the hydraulic power pack.

Typically, the heat exchanger is an air-cooler.

Typically, the torque cell measures and maintains the torque applied at the mid-PTO shaft as per the duty cycle of the validation test conducted by the hydraulic loading system.

Typically, the safety valve relieves any sudden spike or excess pressure observed in the hydraulic loading system.

Typically, the plumber blocks support the torque cell and the hydraulic pump in-line.

Typically, the hydraulic loading system validates the tractor’s mid-PTO drive line along with the tractor’s rear-PTO gear trains in a single setup by loading thereof at different speeds and torques.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described in the following with reference to the accompanying drawings.

Figure 1 shows an existing conventional rear-PTO drive gear validation facility using an Eddy current dynamometer (dyno) attached at rear-end of the tractor.

Figure 2 shows a line diagram of the test setup for a tractor’s Mid-PTO driveline gear train validation conducted by a hydraulic loading system configured in accordance with the present invention.

Figure 3 shows a side view of the setup for a tractor’s Mid-PTO driveline gear train validation through hydraulic loading shown in Figure 2, as located under the tractor.

Figure 4 shows a comparative chart for applied hydraulic pump pressure measurement v/s the observed Mid-PTO driveline torque by the mid-PTO driveline.

Figure 5 shows an overall view of the Mid-PTO hydraulic loading system.

Figure 6 shows an overall line diagram of the tractor PTO and the hydraulic loading system shown in Figure 3.

Figure 7 shows the fluid circuit of the hydraulic loading system for validating the tractor’s mid-PTO drive line and hydraulic loading thereof.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, a modular test setup for mid-PTO gear train validation configured in accordance with the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention.

Figure 1 shows an existing conventional rear-PTO drive gear validation facility using an Eddy current dynamometer (dyno) attached at rear-end of the tractor.

Figure 2 shows a line diagram of the test setup for a tractor’s Mid-PTO driveline gear train validation conducted by a hydraulic loading system configured in accordance with the present invention. This hydraulic loading system includes a base plate 01, preferably made of mild steel (M.S.) and an L-bracket 02 as a pump mounting setup for mounting the hydraulic pump 03 thereon. A nylon coupler 04 transfers the driving force from the mid-PTO shaft 10 end to this hydraulic pump 03. The first and second plumber blocks 05, 07 support the torque cell 06 and hydraulic pump 03 in-line. The torque cell 06 measures the torque applied at the mid-PTO shaft 10. A universal joint 08 connects the propeller shaft 09 and the torque cell 06 in an angular manner to transfer the driving force from the mid-PTO shaft 10 to the hydraulic loading system. The mid-PTO shaft 10 end is connected to the propeller shaft 09 for transferring the driving force. The support blocks 11, 12 are mounted on the base plate 01 to support the plumber block 05, 07 along with the torque cell 06 assembly thereon. The hydraulic pump 03 is connected via a fluid line 13 to the hydraulic power pack 200, with an oil reservoir 120, loading valve 130 to maintain the applied torque and an oil cooling system or air-cooler 140.

Figure 3 shows a side view of the setup for a tractor’s Mid-PTO driveline validation through the hydraulic loading system as shown in Figure 2, which is marked and located under the tractor between the axles thereof.

Figure 4 shows a comparative chart for the applied hydraulic pump pressure measurement v/s the observed torque of the tractor’s mid-PTO driveline. Here, the hydraulic pressure (bar) is represented on x-axis and the tractor mid-PTO driveline torque (kg-m) is represented on y-axis. This chart shows that the ratio of the applied hydraulic pressure v/s mid-PTO torque is increasing in a straight line from 0.33 to 3.02.

Figure 5 shows an overall view of the hydraulic loading system for validating the mid-PTO drive line. Here, a tractor with mid-PTO driveline is being tested by a hydraulic loading system. An exhaust gas line is connected to the exhaust pipe 110 of the tractor 100 under testing. An oil reservoir 120 of the hydraulic power-pack 200 is connected via a loading valve 130 and through a pressure sensor 132 to this tractor 100 by a hydraulic fluid-line 122. This loading valve 130 is also connected further via another hydraulic fluid delivery line 124. A hydraulic pressure indicator 126 is placed above an air-cooler 140 provided for cooling the oil in oil reservoir 120 of the hydraulic power pack 200.

Figure 6 shows an overall line diagram of the tractor PTO and the hydraulic loading system shown in Figure 3. Here, the tractor 100 under testing is parked in a test-cell and the test setup 150 is connected between the mid-PTO shaft and the hydraulic loading circuit 200.

Figure 7 shows the fluid circuit of the hydraulic loading system for validating the tractor’s mid-PTO drive line and hydraulic loading thereof. The tractor Mid PTO shaft 10 (Fig. 7) rotates (in direction D1) the input shaft 031 of the hydraulic gear pump 03 connected to a loading valve 130 via a pressure sensor 132 further connected to a heat exchanger 134 and the cooled oil flows in the direction D2 through the hydraulic line 136 returning to the oil reservoir 120. A hydraulic system safety valve 160 is connected between the loading valve 130 and the oil reservoir 120 and a suction strainer 170 is connected between the hydraulic gear pump 03 and the oil reservoir 120.

WORKING OF THE HYDRAULIC LOADING SYSTEM

The hydraulic pump 03 is driven by the tractor’s Mid PTO shaft 10. The oil suction takes place through the suction strainer 170 from the oil reservoir 120 by operating the hydraulic pump 03, which delivers the oil-flow to the loading valve 130 through the pressure sensor 132 measuring the hydraulic pressure in the hydraulic loading system. The loading valve 130 generates the required pressure in this hydraulic loading system, which creates torque in the hydraulic pump 03 and the tractor’s mid-PTO shaft 10 connected through the torque cell 06 and the propeller shaft 09 (Figure 7). The torque cell 06 measures the torque of the mid-PTO drive shaft 10, which should be as per the test duty cycle. After passing the hydraulic loading valve 130, the hydraulic oil flow returns via the heat exchanger 134 controlling and maintaining the oil temperature. This oil-flow returns to the oil reservoir 120 via hydraulic line 136. The torque of the mid-PTO shaft 10 varies depending on this oil temperature, which is controlled and maintained by air cooler 140 (Figure 5). The safety relief valve 160 of the hydraulic loading system relieves any sudden spike or excess pressure created in this hydraulic loading system.

TEST RESULTS

This test setup has been deployed for validating the mid-PTO drive line of the tractors manufactured by the applicant and the measured values were found to be accurate, and which have also demonstrated the repeatability thereof. For example, the validation of the mid-PTO drive line of 30 HP tractor manufactured by the applicant was successfully completed as per Real World Usage Pattern (RWUP).

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The modular test setup for mid-PTO gear train validation configured in accordance with the present invention offers the following advantages:

- Validates a Mid-PTO drive gear trains along with a Rear-PTO gear trains in a single setup.

- Simulates the new combination of Rear-PTO and Mid-PTO field applications to find premature failures in drive gear trains thereof.

- Saves time by validating both Mid-PTO and Rear-PTO in a single setup.

- Offers a productive testing by making the test setup very cost effective.

- Uses flexible test cycles and facility to simulate rear-PTO and Mid-PTO loading at different speeds and torques at single test facility.
- Offers flexible test cycles and facility to simulate rear-PTO and Mid-PTO loading in different combinations thereof in a single test facility.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.

It is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

Although, the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person in the art would readily recognize that these embodiments can be applied with modifications possible within the spirit and scope of the present invention as described in this specification by making innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies, in terms of their size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to imply including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

The description of the exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are to be considered part of the entire written description.

In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top”, and “bottom” as well as derivatives thereof (e.g. “horizontally”, “inwardly”, “outwardly”; “downwardly”, “upwardly” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion.

These relative terms are for convenience of description and do not require that the corresponding apparatus or device be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected”, refer to a relationship, wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. , Claims:We claim:

1. A hydraulic loading system for validating tractor’s mid-PTO drive line, said system comprises:

• a structure for mounting the components of said hydraulic loading system thereon;

• a hydraulic pump (03) mounted on said mounting structure;

• a mid-PTO shaft (10) of the tractor under testing connected in an inclined manner to a propeller shaft (09);

• a torque cell (06) connected between said mid-PTO shaft (10) end and said hydraulic pump (03);

• said torque cell (06) connected to a respective plumber block (05; 07) placed on either side thereof; said torque cell (06) and said plumber blocks (05; 07) supported on support blocks (11; 12) supported on said mounting structure;

• a Nylon coupler (04) connected between said torque cell (06) and said hydraulic pump (03) for transferring the driving force from said hydraulic pump (03) to said mid-PTO shaft (10) end; and

• a universal joint (08) connected between said propeller shaft (09) and said plumber block (07) for an angular connection to said mid-PTO shaft (10) end;

wherein said hydraulic pump (03) is connected via fluid line (13) to an oil-reservoir (120) of a hydraulic power pack (200) for converting the hydraulic energy into mechanical torque by said torque cell (06) to ensure an accurate torque applied to said mid-PTO shaft (10) end via said propeller shaft (09) transferring the required driving force for conducting the validation of said mid-PTO drive line of the tractor (100) under testing.
2. The hydraulic loading system as claimed in claim 1, wherein said mounting structure comprises:

(i) a base plate (01) for supporting and mounting the components of said hydraulic loading system thereon;

(ii) an L-bracket (02) supported on said base plate (01) for mounting said hydraulic pump (03) thereon; and

(iii) said pair of supporting blocks (11; 12) for mounting said plumber blocks (05; 07) thereon;

wherein said hydraulic pump (03), Nylon coupler (04), plumber blocks (05; 07) with said torque cell (06) disposed therebetween, and said universal joint (08) are aligned in a straight line by means of a laser level sensor.

3. The hydraulic loading system as claimed in claim 1, wherein said torque cell (06) is a contact type torque cell.

4. The hydraulic loading system as claimed in claim 1, wherein said hydraulic power pack (200) comprises:

(a) a fluid delivery line (13) connecting said hydraulic pump (03) to said hydraulic power pack (200) via a suction strainer (170);

(b) a loading valve (130) connected downstream said hydraulic pump (03) via a pressure sensor (132);

(c) a heat exchanger (134) downstream said loading valve (130) connected to said oil reservoir (120) via a fluid return line (136); and

(d) a safety valve (160) disposed between said loading valve (130) and oil reservoir (120);

wherein oil is sucked from said oil reservoir (120) through said suction strainer (170) by operating said hydraulic pump (03) to be delivered to said loading valve (130) via said pressure sensor (132) measuring and maintaining the required hydraulic pressure in said hydraulic power pack (200).

5. The hydraulic loading system as claimed in claim 1, wherein said heat exchanger (140) controls and maintains the oil temperature flowing through the hydraulic power pack (200).

6. The hydraulic loading system as claimed in claim 5, wherein said heat exchanger (140) is an air-cooler (134).

7. The hydraulic loading system as claimed in claim 3, wherein said torque cell (06) measures and maintains the torque applied at said mid-PTO shaft (10) as per the duty cycle of said validation test conducted by said hydraulic loading system.

8. The hydraulic loading system as claimed in claim 4, wherein said safety valve (160) relieves any sudden spike or excess pressure observed in said hydraulic loading system.

9. The hydraulic loading system as claimed in claim 1, wherein said plumber blocks (05; 07) support said torque cell (06) and said hydraulic pump (03) in-line.

10. The hydraulic loading system as claimed in claim 1, wherein said hydraulic loading system validates said tractor’s mid-PTO drive line along with the tractor’s rear-PTO gear trains in a single setup by loading thereof at different speeds and torques.

Dated this 07th day of August 2023.

Digitally / e-Signed by:

SANJAY KESHARWANI
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA-2043.