Title of Invention

"A MACHINE USEFUL FOR CONDITION MONITORING OF BEARINGS"

Abstract

Title A machine useful for condition monitoring of bearings. A machine useful for condition monitoring of bearings, which comprises a vertical main column (1) having its bottom end fixed to a base plate (15), characterized in that the top end of the said column having a hinged joint (2) connected to one end of a horizontal loading lever (3), the other end of the said loading lever being provided with a slidable vertical loading pan (5,6), the said loading lever also being provided with a loading contact unit (4) so as to make direct contact with the top most point of a bearing bolder (8) for holding a test bearing (13) inside it, the said bearing holder being rigidly mounted onto mountings (14) fixed to the said base plate (15), the said bearing holder being provided with connection to attach oil flow line (7), transducer (9) of a shock pulse meter and strain gauge (10,11), the said bearing holder being also provided with a concentric drive shaft (12) for mounting the test bearing (13), the said drive shaft being mounted on support bearings (18) and coupled by test bearing (17) to a variable speed prime mover (16) mounted onto the said base plate (15).

Full Text

This invention relates to a machine useful for condition monitoring of bearings. The present invention particularly relates to an improved bearing test stand which is a machine set up to study the performance of a very important machine element, the bearing; journal or rolling element type. Different standards, such as, IS 3832 :1998 and IS 3824 (Part 1) : 1983, stipulate the technical requirements for different types of rolling element bearings, but not the kind of machines to be used to know such data. Keeping such requirements in mind, a machine has been invented that can be used for both types of bearings; journal as well as rolling element types. The main usage of this machine is for the condition monitoring of the bearings, both journal type as well as rolling element type. The condition monitoring consists of status of mechanical condition, including the surface condition of the bearings, temperature rise, comparative contact area between the journal and the bearing, friction coefficient, wear, fatigue life, reliability factor, lubricant compatibility. The machine of the present invention offers the flexibility to evaluate all the above survival factors for most of the types of bearings in use in the industrial platform. Reference is drawn to the(US patent no. 476352 dated 16.8.88 with the title, Roller Bearing Testing Device. This is a device for testing axle-mounted roller bearings of a rail car. Here, the condition of bearing is sensed Foreign should be seplaced by indian equivalens by recording "acoustic emission" from the bearing. The mounting system of the test bearing is biased to the existence of axle and variation of test speed is not possible to the extent of requirement (say, in the range 600 to 1200 rpm or more) of various standards, say, ISO 281 (1990), variation of load (say, from 0 to 5000 Newton, or more) is not possible, tapping of lubricant for condition monitoring through Ferrography is not possible. The advantage of monitoring through "shock pulse" gives extended vibration-signature, in comparison to the acoustic emission method. The six station journal bearing testing machine developed by Plint & Partner Ltd., England and U.S patent no. 48541597 dated 8.8.89, with the title, journal Bearing Simulator, cannot test roller bearings. This machine is Clerical error 'basically used to measure the load bearing capacity of engine oils under the conditions of test. The actual area of contact between the bearing and the journal under different stress conditions cannot be tackled. Ashok Brothers Impex Pvt. Ltd., New Delhi, is making bearing testing machine; but this machine measures the running noise of the bearing. This read out is related only to the noise emission of the machine elements and does not give any information on the load bearing capacity/states of the bearing under test. The main object of the present invention is to provide a machine useful for condition monitoring of bearings which obviates the drawbacks as detailed above. Another object is to provide a machine for condition monitoring and evaluation of journal and rolling element bearings. Yet another object of the present invention is to evaluate, from the same set up, the friction force between the journal and the bearing at various loading and at various rpm. Still another object of the present invention is to provide the facility to examine the status of the lubricant through Ferrography, making the machine more versatile. Yet another object of the present inventions to provide the facility to study the temperature-signature of the bearings; journal or roller. Another object of the present invention is to provide the facility, from the same set up to vary the load as well the speed to the test bearings, journal or roller, the maximum load and maximum speed is only limited by the strength of the respective components of the structure, when the geometry of the machine remains the same. Yet another object of the present invention is to provide, in the same set up, the facility to evaluate the comparative contact area between the journal and the bearing to estimate the bearing ratio graph. In the drawings accompanying this specification an embodiment of the machine of the present invention has been depicted. In Figure 1 of the drawings the side view of the machine is shown wherein : 1) is the main column 2) hinge 3) loading lever 4) loading contact unit 5) sliding means 6) laoding pan 7) oil flow line 8) bearing holder 9) stud for the transducer (for sensing shock pulse) 10) strain gauge lever 11) auxiliary column 12) drive shaft 13) the test bearing 14) bearing holder mounting 15) is the base plate Figure 2 of the drawings is the representative view of machine of the present invention to show the relative positions of the different machine elements, where (16) is a drive motor, (12) is a drive shaft, (13) is the test bearing (17) is shaft coupling (18) are support bearings for the drive shaft (4) loading contact unit, (8) bearing holder alongwith the test bearing inside, (15) is base plate. Accordingly the present invention provides a machine useful for condition monitoring of bearings, which comprises a vertical main column (1) having its bottom end fixed to a base plate (15), characterized in that the top end of the said column having a hinged joint (2) connected to one end of a horizontal loading lever (3), the other end of the said loading lever being provided with a slidable vertical loading pan (5,6), the said loading lever also being provided with a loading contact unit (4) so as to make direct contact with the top most point of a bearing bolder (8) for holding a test bearing (13) inside it, the said bearing holder being rigidly mounted onto mountings (14) fixed to the said base plate (15), the said bearing holder being provided with connection to attach oil flow line (7), transducer (9) of a shock pulse meter and strain gauge (10,11), the said bearing holder being also provided with a concentric drive shaft (12) for mounting the test bearing (13), the said drive shaft being mounted on support bearings (18) and coupled by test bearing (17) to a variable speed prime mover (16) mounted onto the said base plate (15). The description of the Test Stand follows with reference to figure 2 and 1, wherein the drive motro (16), either variable speed or constant speed according to the test requirement, drives the drive shaft (12) to rotate the test bearing (13) housed inside the bearing holder (8). The shock pulse meter (9) picks up the vibration signature for analysis, the thermocouple (when required for surface temperature measurement of the test bearing), is positioned on the surface of the test bearing to measure the temperature. To measure the friction force between the journal and the bearing, the strain gauge lever (10) is used. To load the test bearing, force is applied through the loading contact unit (4) via the load lever (3) and loading pan (6). The bearing condition is monitored, varying the speed of the drive motor. The status of the lubricant oil is examined through Ferrography, when the oil input is done through the oil flow line (7). The rig configuration remain same for the journal bearing and roller bearing, only the test bearing is positioned inside the bearing holder accordingly to the test programme. The following example is given by way of illustration of the present invention and should not be construed to limit the scope of the present invention. Example 1 One of the well known type of ball bearings was fatigue life tested. The bearing having the dimention 40x62x15 mm. The said bearing was assembled on the drive shaft of the Test Stand as described above, in the bearing holder and a load upto 75 kg was put on the loading pan to get an effective radial load of 500 kg on the bearing (as required for this specific test). The shaft was rotated at 1000 rpm (as required for this specific test) for 24 million revolutions; the prescribed life of the above bearing. At regular intervals the shock pulse was noted, to know the mechanical condition of the bearing. Test Results: (Table Removed) Note : Code No. XO - X7 - Surface condition good X8 - X9 - Surface condition bad X - Type of bearing. Cond. No. 30 - 40 - damage in progress > 45 - Severe damage The novelty and inventive steps in the present example is that the high frqeuency vibration shock pulses coming out of the bearing can be sensed while in operation under desired load and speed, which can be varied as per the requirements. A complete test can be made to evaluate the fatigue life of rolling bearings as per IS : 3824 (Part 1), 1983 of ISO - 281 (1990) - Dynamic load ratings of Rolling Bearings; which are missing in the prior arts. Also use lubricant has been tapped from time to time for Ferrographic analysis to ascertain the condition of bearing elements under test. There is no such provisions in other prior arts. The main advantages of the present invention are :- 1. It can test the performance of both journal as well as rolling element bearings. 2. The friction force/coefficient of friction between the journal and the bearing in a journal bearing test situation can be measured. 3. The frictional losses in the rolling element bearings can be evaluated under varying loads and speeds. 4. The performance of lubricants can be evaluated. 5. There is hardly any size limitation of the test bearing, when the test stand made to the required dimension, keeping the geometry and the number of components same. 6. Comparative contact area between the journal and the bearing can be evaluated, to estimate the bearing ratio graph. 7. Surface temperature of the test bearing can be surveyed. Claim: 1. A machine useful for condition monitoring of bearings, which comprises a vertical main column (1) having its bottom end fixed to a base plate (15), characterized in that the top end of the said column having a hinged joint (2) connected to one end of a horizontal loading lever (3), the other end of the said loading lever being provided with a slidable vertical loading pan (5,6), the said loading lever also being provided with a loading contact unit (4) so as to make direct contact with the top most point of a bearing bolder (8) for holding a test bearing (13) inside it, the said bearing holder being rigidly mounted onto mountings (14) fixed to the said base plate (15), the said bearing holder being provided with connection to attach oil flow line (7), transducer (9) of a shock pulse meter and strain gauge (10,11), the said bearing holder being also provided with a concentric drive shaft (12) for mounting the test bearing (13), the said drive shaft being mounted on support bearings (18) and coupled by test bearing (17) to a variable speed prime mover (16) mounted onto the said base plate (15). 2. A machine useful for condition monitoring of bearings substantially as herein described with reference to figures 1 & 2 of the drawings accompanying this specification and the examples.

Documents:

1088-del-1999-abstract.pdf

1088-del-1999-claims.pdf

1088-del-1999-correspondence-others.pdf

1088-del-1999-correspondence-po.pdf

1088-del-1999-description (complete).pdf

1088-del-1999-drawings.pdf

1088-del-1999-form-1.pdf

1088-del-1999-form-19.pdf

1088-del-1999-form-2.pdf