DESC:This application is based on and derives the benefit of Indian Provisional Application 201621011452, the contents of which are incorporated herein by reference.

TECHNICAL FIELD
[001] The embodiments herein relate to transmission systems in vehicles, and more particularly to testing of transmissions in vehicles.

BACKGROUND
[002] During field operations, the transmission in a vehicle, which is operating off-road, undergoes dynamic torque changes. These high torque variations may create localized stress/heat in transmission components. These local stresses can result in transmission failure such as tooth pitting in gears, tooth sheering and damaged bearings and so on. Also, if the transmission operates with a differential action, in which the operator can transfer the entire torque to either of the rear wheels dynamically. This dynamic torque change can cause deformations in the transmission. When the vehicle is moving downhill, the rear tyre of the vehicle acts as the prime mover and resistance is provided through engine torque (braking). This condition may result in failure of the transmission components and/or transmission.
[003] Generally, field-testing of such vehicles can be dependent on external factors such as season, crop, and so on. The field-testing team has to wait for the next season to continue with the testing in specific field operation, if testing cannot be completed in one season. Current solutions create test facilities, which can simulate field load conditions in a laboratory.
[004] The conventional transmission test facilities in the lab are based upon water pump loading mechanism, which provides steady state loading to transmission. But these setups do not provide dynamic loading. Also, the water pump loading is expensive. The solution also does not meet all test requirements, especially when the vehicle has higher power. Moreover, the conventional setups employ only a one stage step-up gearbox in between the loading device and transmission rear axle. But the one stage step-up gearbox does not cover wide range of transmissions for testing. Also, the aforementioned conventional set up cannot be run if any failure happens to the one stage step-up gearbox, and has increased down time.
OBJECTS
[005] The principal object of the embodiments herein is to provide systems for testing transmissions in vehicles, wherein the transmission can be tested across a wide range.
[006] Another object of the embodiments of this invention is to provide systems for testing transmissions in vehicles, wherein the transmission has a smaller footprint.
[007] Another object of the embodiments of this invention is to provide systems for testing transmissions in vehicles, wherein the transmission comprises a motor with a reduced size and increased torque coverage.
[008] Another object of the embodiments of this invention is to provide systems for testing transmissions in vehicles, wherein the transmission, which achieves synchronization between the motor torque curve and transmission torque curve.
[009] Another object of the embodiments of this invention is to provide systems for testing transmissions in vehicles, wherein the transmission produces higher electricity in loop.
[0010] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[0011] The embodiments of this invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0012] FIG. 1 depicts a system for testing the transmission of a vehicle, according to an embodiment as disclosed herein; and
[0013] FIG. 2 depicts and example of the system for testing the transmission of a vehicle, according to an embodiment as disclosed herein.

DETAILED DESCRIPTION
[0014] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0015] The embodiments herein achieve systems for testing transmissions in vehicles, wherein the transmission. Referring now to the drawings, and more particularly to FIGS. 1 through 2, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0016] Embodiments herein use Alternate Current (AC) regenerative motors in the system, wherein the ratios of the motor are selected in such a way to cover a high rage and to generate maximum electricity by loading motors. Embodiments herein can use a step-up gearbox with two stages, wherein gear selection can be present in one of the stages.
[0017] FIG. 1 depicts a system for testing the transmission of a vehicle. The system 100, as depicted, comprises of AC regenerative motors 101, first step-up gearboxes 102, second step-up gearboxes 103, torque sensors 104, a transmission under test 105, at least one motor driver 106, a controller 107, and a driver motor 108. The system 100 can be of a modular design. The system 100 can be a close loop control system where the driver motor 108 takes energy from the AC regenerative motors 101, while braking and rest of the required energy from mains.
[0018] The AC regenerative motor 101 can serve as a loading motor. The AC regenerative motors 101 can be connected to the first step-up gearbox 102 using a suitable means such as a coupling flange. The first step-up gearbox 102 and the second step-up gearbox 103 can be connected to each other using a suitable means such as a coupling flange. The torque sensor 104 can be coupled to the transmission under test 105, using a suitable means such a universal coupling, and so on. In an embodiment herein, the torque sensor 104 can be coupled to the axle of the transmission under test. The torque sensor 104 can couple the driver motor 108 to the transmission under test 105. In an embodiment herein, the torque sensors 104 can be torque transducers. A first torque sensor 104 can be connected just before the input of transmission, between the driver motor 108 and the transmission under test 105. Two torque sensors 104 can be connected just after the (output) axle of transmission. This position of the torque sensors 104 will ensure that the losses in the step-up gearboxes 102, 103 (such as friction losses, and so on) will not affect the torque measurement. The torque sensors 104 are installed in close loop for accuracy and precision in testing. In case of failure of torque sensing mechanism, the controller 107 can determine the torque using loading motor current and rpm. RPM sensors can be further connected to the AC regenerative motors 101. RPM sensors can be connected to the driver motor 108. An example of the system 100 is depicted in FIG. 2.
[0019] The driver motor 108 can be connected to the AC regenerative motor 101. The driver motor 108 can simulate the engine of the vehicle.
[0020] The AC regenerative motors 101, the first step-up gearboxes 102, the second step-up gearboxes 103, the torque sensors 104, the at least one motor drive 106, and a driver motor 108 can be connected to the controller 107, using a suitable means such as a canbus, profibus, and so on. In an embodiment herein, the controller 107 can be at least one of a FPGA (Field Programmable Gate Array), a CPLD (complex programmable logic devices), an ASIC (application-specific integrated circuit), and so on.
[0021] The first step-up gearbox 102 can be a 2 speed step-up gearbox. The ratios of the gearboxes 102, 103 are selected such that the entire range of power can be tested appropriately. The gearboxes 102, 103 synchronize the torque map of the transmission under test and the AC regenerative motor 101.
[0022] Consider an example where the RPM of the driver motor 108 is 2000 and torque is 200 Nm. The gear chosen by the controller 107 can have a reduction ratio of 100. Now
Torque on each rear axle = (Torque X Reduction Ratio)/2
= 20000 Nm/2
=10000 Nm
RPM on rear axle = RPM / Reduction ratio
= 2000/100
=20
[0023] Therefore to test this transmission, 10000 Nm of torque should be produced at 20 RPM. Now consider that there is a step-up gearbox with a ratio 10 between the AC regenerative motor 101 and the axle of the transmission under test. Now
Torque on AC regenerative motor = Torque on rear axle/10
=10000 Nm/10
=1000 Nm
RPM on AC regenerative motor 101 = RPM on rear axle X 10
= 20 X 10
= 200 RPM
[0024] Now the AC regenerative motor 101 should produce 1000 Nm at 200 RPM.
[0025] In an example, consider that the power can range from 58-74 horsepower (hp). Here, the step-up gearboxes 102 and 103 can have approximate ratios of 1:6, and 1:1 and 1:7.
[0026] The controller 107 can be further connected to a database 109. The database 109 can comprise of at least one memory storage location such as a memory, file server, data server, and so on. The database 109 can comprise of sample data such as expected loading conditions, and so on. Any authorized person can update the database 109. The database 109 can also comprise of data collected by the controller 107, during and after the controller 107 testing the transmission under test 105.
[0027] The controller 107 can select ratios for the AC regenerative motor, such that a high range of testing can be covered. The controller 107 can also select ratios such that the motors get loaded and maximum electricity is generated. The controller 107 can simulate the field transient conditions, using the system 100. The controller 107 can test the transmission under test 105 on designed load and torque conditions. The controller 107 can also test the transmission under test 105 on load and torque values as encountered in the field. The controller 107 can determine the simulation conditions, based on field test data (comprising of load values, torque values, and so on) present in the database 109 and/or as provided by an authorized person.
[0028] The controller 107 can collect parameters from the testing from sensors such as the torque sensors 104. The controller 107 can modify the conditions of the test, based on the collected parameters. The controller 107 can also calculate the torque from data collected from the AC regenerative motors 101. The controller 107 can also estimate an error torque, by finding the difference between the parameters collected from the torque sensors 104 and the AC regenerative motors 101. Based on the estimated error torque, the controller can determine an efficiency of the step-up gearboxes 102, 103. The controller 107 can use the estimated error to compensate for measurements, if torque is measured only from the AC regenerative motors 101.
[0029] The controller 107 can simulate downhill conditions, which occurs when the vehicle is moving in a downhill direction, wherein the axle of transmission becomes the driver or prime mover and the engine of the vehicle acts as a braking device.
[0030] The controller 107 can store the collected parameters, estimated parameters and associated data (such as test conditions/parameters, time stamps, and so on) in a suitable location such as the database 109. The controller 107 can also make the collected parameters, estimated parameters and the associated data available to a user using a suitable means such as a display, monitor, computer, console, and so on. The controller 107 can also communicate the collected parameters, estimated parameters and associated data using at least one of an email, or any other suitable means.
[0031] In an embodiment herein, if the controller 107 fails, a back-up device such as a computer can be used to control the system 100.
[0032] Use of the two speed gearboxes 102, 103 can extend the range of testing as well as helped in reducing the capacity of the AC regenerative motor 101. Though the step-up gearboxes have high strength, in case of failure of one gearbox, the system can be operational with limited test capacity. With a modular design, it is possible to remove one of the gearboxes for repair/maintenance.
[0033] Embodiments herein use a step-up gearbox with two stages, hereby reducing the size of the motor, but also increasing the torque coverage.
[0034] 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 understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
,CLAIMS:CLAIMS
We claim:
1. A system (100) for testing a transmission of a vehicle, the system comprising
a plurality of AC regenerative motors (101) are connected to a transmission under test (105), through a plurality of first step-up gearboxes (102), a plurality of second step-up gearboxes (103), and a plurality of torque sensors (104);
the torque sensors (104) are connected to each axle of the transmission under test (105);
a driver motor (108) connected to the transmission under test (105), through a torque sensor (104);
a controller (107) configured for controlling the plurality of AC regenerative motors (101), the plurality of first step-up gearboxes (102), the plurality of second step-up gearboxes (103), the plurality of torque sensors (104); and the driver motor (108) using field test data; and
the controller (108) configured for receiving parameters measured by the plurality of torque sensors (104).

2. The system, as claimed in claim 1, wherein the system (100) is a closed loop system.
3. The system, as claimed in claim 1, wherein the controller (107) is configured for communicating with the plurality of AC regenerative motors (101), the plurality of first step-up gearboxes (102), the plurality of second step-up gearboxes (103), the plurality of torque sensors (104); and the driver motor (108) using at least one of a canbus; and a profibus.

4. The system, as claimed in claim 1, wherein the controller (107) is at least one of a FPGA (Field Programmable Gate Array); a CPLD (complex programmable logic devices); and an ASIC (application-specific integrated circuit).

5. The system, as claimed in claim 1, wherein the controller (107) is configured to modify the field test data based on the received parameters.

6. The system, as claimed in claim 1, wherein the system (100) is configured to simulate downhill conditions.

7. The system, as claimed in claim 1, wherein the first step-up gearbox (102) is a two step step-up gear box.

8. The system, as claimed in claim 1, wherein the ratios of the first step-up gearboxes (102), and the plurality of second step-up gearboxes (103) are selected such that an entire range of power can be tested appropriately.

9. The system, as claimed in claim 1, wherein the first step-up gearboxes (102), and the plurality of second step-up gearboxes (103) synchronize the torque map of the transmission under test (105) and the AC regenerative motor (101).

10. The system, as claimed in claim 1, wherein the driver motor (108) draws power from
the plurality of AC regenerative motors (101); and
the mains, if power supplied by the plurality of AC regenerative motors (101) is not sufficient.