FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
SYNCHRONIZER TEST BENCH
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001, Maharashtra, India
INVENTOR
HIRAL PATEL
Indian national
of TATA MOTORS LIMITED,
An Indian company having its registered office
At Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention

Field of invention:
This invention relates to durability and performance measurement test bench for synchronizer of manual transmission for passenger car and commercial vehicle application.
Background of invention:
The present disclosure generally relates to durability and performance measurement test bench for synchronizer of manual transmission.
Gear changing in manual gearboxes is a complicated process. Synchromesh mechanisms insure these functions and from a global point of view, they satisfied automotive engineers in the last 30 years, so little attention was paid to its study. Today, increasing power of engines, more sophisticated user comfort requirements, and robotization of manual gear changing, need more detailed studies of gear changing. High changing forces are needed both during synchronization and during indexing phase. Synchronization force / shift force largely depends on the synchronizer design and its co-efficient of friction.
Present invention discloses test bench to accurately measure co-efficient of friction and perform durability of synchronizer and study compatibility of synchronizer lining with oil at different load / pressure. P-V diagram can be generated through series of test on this test bench.
Objects of the invention:
The main objective of the present invention is to obviate above mentioned drawbacks. Another object of the invention is to provide simple and cost effective test bench to evaluate friction lining performance and durability of synchronizer (single, double or even triple cone) and relatively small period of time.
Brief description
The drawings described herein are for illustration purpose only and are not intended to limit the scope of the present disclosure in anyway.

Figure - 1 is a schematic layout of test bench.
Figure - 2 is a test gear and gear adaptor assembly.
Figure - 3 is a test synchronizer and synchronizer adaptor assembly.
Figure - 4 is a flywheel assembly.
Figure - 5 is a schematic electric circuit.
Summary
The instant invention provides a simplified and cost effective test bench to evaluate friction lining performance and durability of synchronizer (single, double or even triple cone) and relatively small period of time. The Test bench disclosed here provides a self-contained platform needed to conduct comprehensive range of validation tests on a synchronizer ring & cone assembly used in automotive gear transmissions. This assembly has to be tested under specified operating conditions, for High speed and Low speed performance.
According to present invention, Synchronizer test bench comprises; small capacity motor (2) and main motor (5) mounted on test bed (1) at ergonomic height for easy access to test engineer to load / unload test synchronizer (28) and gear (13). Several flywheel (8) mounted on bearing assembly (9) to simulate reflected inertia on the gear (13). Flywheel flange is provided with magnetic clutch (7) through which it gets connected to magnetic clutch (6) mounted on main motor (5). Small motor (2) and main motor (5) can be connected through magnetic clutch (3,4). Other flange of flywheel assembly is connected to gear adaptor (30) which holds test gear (13). Test synchronizer (28) is held in synchronizer adaptor (14) which is mounted on shaft (16). Load cell (21) is mounted at other end of Shaft (16) and further connects to torque sensor (22) to measure synchronization torque. Torque sensor is connected to linear actuator (23) which provides translational motion to synchronizer (28) during test. Gear and synchronizer adaptor (30, 14) are in test chamber (12). Oil level in test chamber is adjusted automatically during test through oil sump (19) and oil channel (18). Heater is provided in oil sump to maintain the temperature of oil during test. To prevent oil cooling insulation (17) is provided around oil sump.
Detailed Description of the Invention:

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application or uses. It should be understood that throughout the drawings, corresponding reference numericals indicate similar or corresponding parts and features.
According to present invention, Synchronizer test bench comprises; small capacity motor (2) and main motor (5) mounted on test bed (1) at ergonomic height for easy access to test engineer to load / unload test synchronizer (28) and gear (13). Several flywheel (8) mounted on bearing assembly (9) to simulate reflected inertia on the gear (13). Flywheel flange is provided with magnetic clutch (7) through which it connect main motor (5). Small motor (2) and main motor (5) can be connected through magnetic clutch (3). Other flange of flywheel assembly is connected to gear adaptor (30) which holds test gear (13). Test synchronizer (28) is held in synchronizer adaptor (14) which is mounted on shaft (16). Load cell (21) is mounted at other end of Shaft (16) and further connects to torque sensor (22) to measure synchronization torque. Torque sensor is connected to linear actuator (23) which provides translational motion to synchronizer (28) during test. Gear and synchronizer adaptor (30, 14) are in test chamber (12). Oil level in test chamber is adjusted automatically during test through oil sump (19) and oil channel (18). Heater is provided in oil sump to maintain the temperature of oil during test. To prevent oil cooling insulation (17) is provided around oil sump.
Small motor (2) is mounted on test bed (1). This motor is used to provide drive to the test gear (13) during co-efficient of friction evaluation. High speed motor (5) provides drive to test gear (13) only during durability test. Large amout of heat gets generated if gear (13) is rotated at high speed with force applied through synchronizer (28) over it. Hence, small motor is provided to evaluate co-efficient of friction at constant load. Small motor (2) gets connected as and when required to main motor (5) through magnetic clutch (3) and main motor flange (4).
Main motor (5) can be connected to the flywheel assembly through magnetic clutch (6) and flywheel assembly flange (26). Required interia flywheel (8) can be connected to flywheel bearing assembly / plumber block (9) to simulate reflected inertia onto the gear (13) during durability test. Flywheel bearing assembly / plumber block is mounted on test bed (1). Flywheel not used can be connected to test bed (1) as shown in Figure - 1. Another end of flywheel

bearing assembly / plumber block (9) is connected to test gear adaptor (30) through shaft as shown in Figure - 1.
Test gear (13) can be mounted onto the gear adaptor (30), Axial motion of test gear (13) is restricted by nut (31). Rotation of test gear restricted by applying appropriate flange sealant onto the gear bore or gear adaptor (30) surface. Rotation of gear (13) can also be restricted by other means such as keyway or dowel.
Test synchronizer (28), single, double or triple cone can be held in synchronizer adaptor (14). Provision should be made in synchronizer adaptor (14) to rest synchronizer lug and hence restrict relative motion between of outer cone or single cone (28) and synchronizer adaptor (14). Inner and intermediate cone remains free as per transmission mounting to simulate actual working condition of synchronizer like in transmission. Synchronizer adaptor (14) is mounted onto the load cell (21) shaft through spline or other means, hence restricting rotational motion of synchronizer adaptor (14). Axial motion of synchronizer adaptor (14) is restricted by flanged nut (15) as shown in figure - 3. Thermocouple (29) is provided onto the synchronizer adaptor (14) to measure synchronizer lug / synchronizer lining temperature during test.
Load cell (21) is provided to measure actual load applied during test through linear actuator (23). Load cell (21) is connected to torque sensor (22) which senses synchronization torque during test. Torque sensor is connected to linear actuator (23) which applies required force during test.
Proximity sensor (20) is mounted on shaft connected to Synchronizer adaptor (14). Proximity sensor measures synchronizer lining wear. Load cell (21) face provides reflecting surface to the proximity sensor (20). String pot, linear pot or any other means can be used to sense the synchronizer wear instead of proximity sensor (20).
Test chamber (12) is transparent to assist inspection of synchronizer (28) and gear (31) functioning during test. Gear adaptor (30) assembly and synchronizer adaptor (14) assembly as shown in Figure - 2 and 3, respectively will be in test chamber (12). Oil level in test chamber

can be adjusted during test through oil sump (19) and oil channel (18). Heater is provided in oil sump to maintain set temperature of oil during test.
Indicator lamp (24) is provided to help operator to view state of test bench such as running, emergency operated or warring during test.
During durability test, magnetic clutch (3) remains disconnected. Magnetic clutch (7) gets connected and main motor (5) increase its speed to set values. Once set speed is achieved magnetic clutch (7) gets disconnected and linear actuator (23) will push torque sensor (22) which in turn push load cell (21) which further push synchronizer adaptor (14) and finally, synchronizer adaptor (14) push test synchronizer (28) onto the conical surface of gear (14). Load cell (21) provides continuous input to linear actuator (23) to maintain set force during contact of gear (13) and synchronizer (28). Once free rotating gear (13) with inertia wheel assembly with come to halt, synchronizer (28) along with synchronizer adaptor (14) will move back by set value through linear actuator (23). This complete once cycle. Test bench can perform required number of cycles as specified in program.
During drag test, magnetic clutch (3) get connects main motor (5) through flange (4). Magnetic clutch (7) engages main motor (5) and inertia wheel assembly flange (26). During this test drive will be provide by small motor (2). which will get transmitted through main motor (5) to the gear adaptor (30) and gear (13). During test, small motor (2) will rotate test gear at set speed (less than 25 rpm). Once set speed is achieved magnetic clutch (7) gets disconnected and linear actuator (23) will push torque sensor (22) which in turn push load cell (21) which further push synchronizer adaptor (14) and finally, synchronizer adaptor (14) push test synchronizer (28) onto the conical surface of gear (14). Load cell (21) provides continuous input to linear actuator (23) to maintain set force during contact of gear (13) and synchronizer (28). Linear actuator (23) will apply set force for set duration of time. After set time, synchronizer (28) along with synchronizer adaptor (14) will move back by set value through linear actuator (23). Small motor (2) reduce speed to zero and both magnetic clutch (3, 7) gets disconnected. If there are further cycles to be completed as per set number of cycles In test program then magnetic clutch (3, 7) will not get disconnected and next cycle will start with raving up speed on gear (13) through small motor (2).

Further sequence will be same as explained above. This test is specifically to determine co-efficient of friction of friction lining.
During test, signal from load cell (21), torque sensor (22), proximity sensor (20) goes to controller software (102). Motor (2, 5) speed signal from drive unit (103) of motor goes to controller (102). Signal gets filtered through filer circuit get recorded through data acquisition system (101). Especially, to reduce delay in speed signal, speed data is taken through drive unit (103) and not through encoder circuit provided in motor (3, 5).
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.