Title of Invention | METHOD AND APPARATUS FOR TESTING STATIC STRENGTH OF TRANSMISSION HOUSING |
---|---|
Abstract | A method and apparatus for testing static strength of transmission housing under various load conditions are disclosed. The method involves mounting a gear box on a mounting bracket, and fitting a loading wheel on an input shaft of the gear box. A wire rope can be wound on the loading wheel, and an output shaft of the gear box can be locked by means of a locking lever supported on a locking bracket. Load is gradually applied to an input side of said loading wheel through a crane hook, depending on a test mode until a desired torque. Then, the readings of the applied load are recorded through a load indicator, and torque from a load obtained value can be calculated using a torque formula, which achieves effective testing of the transmission housing at aggregate level and in a simple manner. |
Full Text | FORM 2 THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE OF THE INVENTION Method And Apparatus For Testing Static Strength Of Transmission Housing 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 INVENTORS Mr. Bhaskar B Godbole, Mr. Yuvaraj M Jadhav and Mr. Sudhir M Sutar all are Indian Nationals 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 complete specification particularly describes the invention and the manner in which it is to be performed. FIELD OF INVENTION The present invention relates to the fields of manual transmission of a vehicle. The present invention specifically relates to a method and apparatus for testing static strength of vehicle transmission housing or casing under various load conditions. BACKGROUND OF INVENTION In motor vehicles, transmissions are used for transmitting engine torque to wheels via a propeller shaft and axle.. Such transmissions may be called as gearbox, which includes casing/ housing, an input shaft, main shaft, counter shaft and output shaft. Torque is transmitted through the engagement of particular gear pair from the said main shaft and the said counter shaft. Vehicle transmission undergoes various duty cycles in the field during its life. Where vehicle transmissions are required to transmit large output torques, the continued operational reliability of the vehicle transmissions is extremely important. Therefore, the vehicle transmissions are often required to be tested prior to installation, at full operational loads. Numerous bench tests as well as vehicle tests are carried out in order to validate the suitability of vehicle transmissions for various duty cycles. Such tests can help to ensure that the transmissions are capable of producing the required output without malfunctioning and failure. Moreover, these transmission bench tests are classified as performance tests, endurance tests and structural tests. In performance tests, performance of the vehicle transmissions is determined in terms of torque losses, lubrication losses, churning losses, heat losses, efficiency at various torque levels, noise and vibration levels. The endurance tests are conducted under different load conditions observed by the transmissions in its entire life span. All the transmission components are tested during the endurance tests, which provide the confidence on the life of transmission. The transmission structural test is generally conducted at vehicle level. It is necessary to test the structural strength of the vehicle transmissions, since it observes high level torque shocks during starting the vehicle, driving on a gradient and braking. There are numerous apparatus and methods employed in industry for testing the structural strength of the vehicle transmissions. Especially, in the case of structural strength test of a device, under normal ambient conditions, the device is operated under predetermined load conditions until it fails. With respect to the conventional arts, the testing of structural strength of the transmissions is quite expensive and very difficult for pure torsion. Therefore, it is desirable to provide a method and apparatus for testing static strength of the transmission housing, which achieves effective testing of the transmission housing at low cost and in a simple manner. OBJECTS OF INVENTION An object of the present invention is to provide a method of testing static strength of a transmission housing under various load conditions, which achieves effective testing of the transmission housing at aggregate level. Another object of the present invention is to provide an apparatus for testing static strength of a transmission housing under various load conditions, which achieves effective testing of the transmission housing at low cost. SUMMARY OF THE INVENTION According to one aspect, the present invention, which achieves the objectives, relates to a method of testing static strength of a transmission housing under various load conditions comprising: mounting a gear box on a mounting bracket, and fitting a loading wheel on an input shaft of the gear box. A wire rope can be wound on the loading wheel, and an output shaft of the gear box can be locked by means of a locking lever supported on a locking bracket. Load is gradually applied to an input side of said loading wheel through a crane hook, depending on a test mode, until the desired torque. Then, the readings of the applied load are recorded through a load indicator, and torque from a load obtained value can be calculated using a torque formula, which achieves effective testing of the transmission housing at aggregate level and in a simple manner. Furthermore, the test mode includes a forward driving test mode, forward coasting test mode, reverse driving test mode and reverse coasting test mode. In forward driving, the input shaft of the gear box can be rotated in a clockwise direction, with forward gear engaged and locking the output shaft of the gear box. In forward coasting, the input shaft of the gear box is rotated in an anticlockwise direction, with forward gear engaged and locking the output shaft. In reverse driving, the reverse gear of the transmission is engaged, input shaft of the gear box is rotated in a clockwise direction, and locking the output shaft. In reverse coasting, the input shaft of the gear box is rotated in an anticlockwise direction, with reverse gear engaged and locking the output shaft. According to another aspect, the present invention, which achieves the objectives, relates to an apparatus for testing static strength of transmission housing under various load conditions comprising a gear box with an adaptor mounted on a transmission mounting bracket, where an input shaft of the gear box can be guided in a bearing assembly. The adaptor is mounted on the bearing assembly whereas a loading wheel is mounted on the adaptor. A wire rope can be wound in a clockwise or anticlockwise manner depending on a test mode. A load cell is attached to the wire rope using eye bolts, where the load cell is connected between wire rope eye bolt and crane hook. Load on the load cell is displayed on the load indicator. A locking lever is connected to a locking bracket support for locking an output shaft of the gear box. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a schematic view of an apparatus for testing static strength of a transmission housing, in accordance with an exemplary embodiment of the present invention; FIG. 2 illustrates a detailed view of a transmission mounting bracket, in accordance with an exemplary embodiment of the present invention; FIG. 3 illustrates a detailed view of a loading wheel, in accordance with an exemplary embodiment of the present invention; FIG. 4 illustrates a diagrammatic representation of a forward driving test mode, in accordance with an exemplary embodiment of the present invention; FIG. 5 illustrates a diagrammatic representation of a forward coasting test mode, in accordance with an exemplary embodiment of the present invention; FIG. 6 illustrates a diagrammatic representation of a reverse driving test mode, in accordance with an exemplary embodiment of the present invention; and FIG. 7 illustrates a diagrammatic representation of a reverse coasting test mode, in accordance with an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION The invention will be discussed in greater detail with reference to the accompanying Figures. FIG. 1 shows a schematic view of an apparatus for testing static strength of a transmission housing, in accordance with an exemplary embodiment of the present invention. The apparatus comprises a gear box (1) with an adaptor (4) that can be mounted on a transmission mounting bracket (2), where the detailed view of the transmission mounting bracket (2) is shown in FIG. 2. An input shaft of the gear box (1) can be guided in a bearing assembly (3). The adaptor (4) can be mounted on the bearing assembly (3) whereas a loading wheel (5) can be mounted on the adaptor (4). A wire rope (6) is wrapped and wound in a clockwise or anticlockwise manner depending on a test mode. A load cell (9) of appropriate capacity can be attached to the wire rope (6) using standard eye bolts. One end of the load cell (9) is connected to a load indicator (10) whereas other end of the load cell (9) is connected to a crane hook (11). Furthermore, the transmission is set into a desired gear in the gear box (1) and the output of the transmission is locked with the help of locking arrangement. The locking arrangement consists of a locking lever (7) that is connected to an output flange of the transmission. The locking lever (7) can be locked with help of locking bracket support (8). Referring to FIG. 3, a detailed view of the loading wheel (5) is illustrated, in accordance with an exemplary embodiment of the present invention. The wire rope (6) can be wound on the loading wheel (5), through which load from the load cell (9) is applied to the input shaft of the gear box (1). Moreover, the static strength of the gear box (1) can be tested in four different modes, i.e. forward driving test mode, forward coasting test mode, reverse driving test mode and reverse coasting test mode. After setting up the apparatus according to one of the test modes, the load is applied to the input shaft of the gear box (1) through a loading arrangement such as crane, gradually in upward direction. Simultaneously, the output shaft of the gear box is locked using the locking lever (7), hence the applied load is observed by the housing or casing of the subject gearbox (1). Then, the reading of the applied load can be recorded through the load indicator (10). Finally, the torque from load obtained value is calculated by torque formula (torque = load x distance). The transmission is loaded up to "x" times of estimated input torque of the transmission. In this test, the acceptance criterion is that the transmission housing or casing should not fail or crack for lesser torque than the stated specification. Similar test is conducted in case of failures on gear teeth of the gear box (1). Referring to FIG. 4, a diagrammatic representation of the forward driving test mode is illustrated, in accordance with an exemplary embodiment of the present invention. In this forward driving test mode, the forward gear of the transmission is engaged in the gear box (1). The input shaft of the gear box (1) can be rotated in a clockwise direction with the help of loading wheel (5), while the output shaft of the gear box (1) is kept locked with the locking bracket (8). Referring to FIG. 5, a diagrammatic representation of the forward coasting test mode is illustrated, in accordance with an exemplary embodiment of the present invention. In this forward coasting test mode, the forward gear of the transmission is engaged in the gear box (1), as similar to the forward driving test mode. Then, the input shaft of the gear box (1) is rotated in an anticlockwise direction with the help of loading wheel (5), while the output shaft is kept locked with the locking bracket (8). Referring to FIG. 6, a diagrammatic representation of the reverse driving test mode is illustrated, in accordance with an exemplary embodiment of the present invention. In the reverse driving test mode, the reverse gear of the transmission is engaged in the gear box (1). The input shaft of the gear box (1) is rotated in a clockwise direction with the help of loading wheel (5), while the output shaft is kept locked with the locking bracket (8). Referring to FIG. 7, a diagrammatic representation of the reverse coasting test mode is illustrated, in accordance with an exemplary embodiment of the present invention. In this reverse coasting test mode, the reverse gear of the transmission is engaged in the gear box (1), as similar to the reverse driving test mode. Thereafter, the input shaft of the gear box (1) is rotated in an anticlockwise direction with the help of loading wheel (5), while the output shaft is kept locked with the locking bracket (8). 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. A method of testing static strength of a transmission housing under multiple load conditions, comprising: mounting a gear box on a transmission mounting bracket and fitting a loading wheel on an input shaft of said gear box; winding a wire rope on said loading wheel and locking an output shaft of said gear box by means of a locking lever supported on a locking bracket; gradually applying load to an input side of said loading wheel through a crane depending on a test mode until a desired torque; and recording reading of the applied load through a load indicator, and calculating torque from a load obtained value using a standard torque formula. 2. The method as claimed in claim 1, wherein said test mode is selected from a group consisting of forward driving test mode, forward coasting test mode, reverse driving test mode and reverse coasting test mode. 3. The method as claimed in claim 2, wherein said forward driving test mode further comprising: engaging a forward gear of transmission in said gear box; and rotating said input shaft of said gear box in clockwise direction using said loading wheel, while said output shaft of said gear box is kept locked with a locking bracket. 4. The method as claimed in claim 2, wherein said forward coasting test mode further comprising: engaging the forward gear of transmission in said gear box; and rotating said input shaft of said gear box in anticlockwise direction using said loading wheel, while said output shaft of said gear box is kept locked with a locking bracket. 5. The method as claimed in claim 2, wherein said reverse driving test mode further comprising: engaging a reverse gear of transmission in said gear box; and rotating said input shaft of said gear box in clockwise direction using said loading wheel, while said output shaft of said gear box is kept locked with a locking bracket. 6. The method as claimed in claim 2, wherein said reverse coasting test mode further comprising: engaging the reverse gear of transmission in said gear box; and rotating said input shaft of said gear box in anticlockwise direction using said loading wheel, while said output shaft of said gear box is kept locked with a locking bracket. 7. An apparatus for testing static strength of a transmission housing under multiple load conditions, comprising: a gear box mounted on a transmission mounting bracket; a bearing assembly connected to said gear box, so that an input shaft of said gear box is guided in said bearing assembly; an adaptor mounted on said bearing assembly, and a loading wheel mounted on said adaptor; a wire rope wound on said loading wheel in clockwise or anticlockwise direction depending on a test mode; and a load cell attached between said wire rope using eye bolts and crane hook, and signal is given to said load indicator a locking lever connected to a locking bracket support for locking an output shaft of said gear box, wherein said input shaft of said gear box is gradually loaded through said crane hook in upward direction, while locking said output shaft of said gear box. %. The.apparatus as claimed in claim 7, wherein said test mode. is. selected from a group consisting of forward driving test mode, forward coasting test mode reverse driving test mode and reverse coasting test inode. 9. The apparatus as claimed in claim 1, wherein said load cell configured to indicate reading of the load applied to said input shaft of said gear box, so that torque from load obtained value is calculated by a standard torque formula. 10. The method and apparatus for testing the static strength of said transmission housing under multiple load conditions as claimed in claims 1 - 9 wherein largely as described in specifications and as illustrated in accompanying figures. Dated this 27th day of January 2009 TATA Motors Limited By their Agent & Attorney |
---|
Patent Number | 279801 | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Indian Patent Application Number | 164/MUM/2009 | ||||||||||||
PG Journal Number | 05/2017 | ||||||||||||
Publication Date | 03-Feb-2017 | ||||||||||||
Grant Date | 31-Jan-2017 | ||||||||||||
Date of Filing | 27-Jan-2009 | ||||||||||||
Name of Patentee | TATA MOTORS LIMITED | ||||||||||||
Applicant Address | BOMBAY HOUSE, 24 HOMI MODY STREET, HUTATMA CHOWK, MUMBAI. | ||||||||||||
Inventors:
|
|||||||||||||
PCT International Classification Number | G01M19/00; G01N3/00 | ||||||||||||
PCT International Application Number | N/A | ||||||||||||
PCT International Filing date | |||||||||||||
PCT Conventions:
|