Patent GB-461387-A (GB)
Title: Improvements in machines for testing the balance of rotary apparatus
IPC: G01M1/04
Filed: 1936-02-15
Abstract: 461,387. Testing balance of rotary bodies. LEWIN, F. (Schenck Eisengiesserie und Maschinenfabrik Darmstadt, C.) Feb. 15, 1936, No. 4691. [Class 106 (ii)] A balancing machine in which the out-ofbalance forces of a body 6 (or 32) under test are compensated by rotating counter forces of which the magnitude and phase are adjustable during running of the machine, is characterized in that the said magnitude is adjustable by means of a single compensating mass 21 (or 51), which rotates with constant eccentricity relative to its own axis of rotation 19 and which is variable as to its distance a from the point about which the said axis pivots. Bearings 4, 5 are pivotally mounted by springs 2 and 3 on base 1, and carry the shaft 61 of the body 6 to be balanced. This shaft is rotated by coupling 9, 10 and shafts 8 and 7 driven by means not shown. Pins 11 and 12 on the bearings 4 and 5 may be connected in a known manner with the base 1. It is thus possible to cause either pin 11 or pin 12 to be the pivoting axis of the whole system. Ring bearings 13 and 14 on the shaft 6<1> are articulated by rods 15, 16 to similar bearings 17 and 18 which carry a shaft 19. Along the whole of this shaft is a feather-way coacting with a disc 20 carrying an eccentric mass 21. The shaft 19 is driven synchronously with, and preferably in the opposite direction to the shaft 61 from shaft 7 through wheels 22-26 and shaft 26. A shaft 28 with a knob 31 has a splined connection with the sleeve 27 carrying wheels 23 and has a threaded connection with the sleeve 30 carrying wheel 24 so that by depressing the knob 31 during running, the wheel 24 may be adjusted up to 360‹ relatively to the wheel 23 to give any desired phase displacement. A scale (not shown) connected to part 28 or 31 gives, the amount. For adjusting the magnitude (distance a) of the compensating force during running the disc 20 may be moved along shaft 19 by a fork which has balls or rollers engaging the disc 20 and which is shifted by means of a spindle parallel to shaft 19. First one pin, say 12, is held against bodily movement and the apparatus used as above described to find the phase and magnitude (the latter being read off a scale, (not shown), and then the operations repeated with pin 12 free and pin 11 held. In a modification, Figs. 3 and 4 the shaft 33 of the body 32 to be balanced is laid at each end between two rollers 34, 35 on aT-piece 36 pivoted at 39 to a pillar 38 on a saddle 37 which latter is displaceable, perpendicular to the plane of the drawing, along a foundation 40. Also at each end on the saddle is an upright 46 to which 'is pivoted at 47 an internally threaded sleeve 45 for a rod 44 attached to a spring 41, the other end of which is attached to a block 42 slidable in a groove 43 of the T-piece 36. Slidable on a rod 54 are two blocks 55, 56 between which and the T-pieces 36 are two thrust rods 52, 53. Rod 54 is supported in a bearing 57 which is rotatable about a vertical pivot 58 and is slidable along the foundation 40. Each T- piece 36 carries a bearing 49 for the shaft 50 along which is slidable a disc 51 having an eccentric mass. Shafts 50 and 33 are driven in synchronism. Shaft 50 is so mounted that, as well as rotating, it can make small pivoting movements in all directions, for instance like the shaft 6<1> in Fig. 1. The springs 41 are tensioned by the nuts 48 so that rods 52, 53 are under pressure and the T-pieces 36 and shaft 54 move together. The axis 58 is adjusted into first one and then, if desired, a second plane in which the compensating weights are to be applied and the magnitudes of the compensating forces determined by adjusting the disc 51 carrying the eccentric mass. The eccentric mass 21, Fig. 1, or 51, Fig. 3, remains constant during one running but may be varied between tests to suit various cases.