| 摘要 |
Four-ball extreme pressure tester to measure tribological properties of lubricant which contains a test friction node composed of four balls, where one upper ball rotates and the remaining three balls are immobile and pressed against the upper ball from the bottom up, and which also contains a motor powering a spindle terminated with the upper ball holder, and a control and measurement circuit composed of parallel circuits. The motor (1) powered by a controller (33) drives the spindle (10), via a coupling with a damping insert (11); in the bottom part of the spindle (10), there is mounted a holder (2), which fixes the upper ball in the spindle (10); the holder (4) with bottom balls is pressed against the upper ball by a lever (14) with a weight (16), via a pusher (8), a sleeve (12) and a support (3), on which a loading force transducer (18) is placed. The lever (14), on its left side, has a counterweight (17); a motor (9) is fixed to the flange of the counterweight (17), and the motor pin is connected with a power screw (6) supported on a bearing (15) inside the lever (14) and mated with a nut (7) fixed to the counterweight (16) moving on the external surface of the lever (14); the bottom balls holder (4) is also connected with a converter of the resistances to motion (5), and it has a thermocouple (19) positioned centrally in its bottom cylindrical section; a control and measurement circuit (U1) composed of four parallel circuits (O1-O4), whose outputs are connected in series with an interface (35) and a computer (37) via a port (36), contains the first circuit (O1), whose input is connected with a transducer of the friction node load (18), composed of a series connection of an amplifier (20), an a/d converter (21) and an impulse counter (22); the second circuit (O2), whose input is connected with the motion resistance converter (5), composed of a series connection of an amplifier (23), an a/d converter (24) and an impulse counter (25); the third circuit (O3), whose input is connected with the rotations detector (13), composed of a series connection of a receiver (26) and an impulse counter (27); the fourth circuit (O4), whose input is connected with a thermocouple (19), composed of a series connection of an amplifier (28), an a/d converter (29) and an impulse counter (30),... |
