US2336429A - Balancing machine attachment - Google Patents

Description

Dec. 7,1943.

E. l. WENGER 2,336,429

BALANCING MACHIN E ATTACHMENT Filed May 12, 1941 W 25 24 7 INVENTOR niga 'r ATTORNEY Patented Dec. 7, 1943 UNITED STATES PATENT OFFICE BALANCING MACHINE ATTACHMENT Edgar I. Wenger, Philadelphia, Pa.

Application May 12, 1941, Serial No. 393,025

2 Claims.

My invention relates to balancing machines and attachments andparticularly to devices used to locate and measure the amount of unbalance which can be mounted on the shaft or mandrel of the object to be balanced.

An object of my invention is to decrease the time necessary to balance an object by providing an attachment for balancing machines which have no so-called balancing head, the said attachment to be mounted on the shaft of the object to be balanced. This attachment is so arranged that an artificial unbalance of varying amount and at various angular displacements can be maintained, controlled-and adjusted while the object to be balanced is rotating. Thus by proper manipulation, the amount and angular location of the artificial unbalance may be made to exactly counter-balance the original unbalanced mass.

Another object of my invention is to provide an improved balancing mechanism of the type employing a movable element which is adjustable during the rotation of the object to be balanced in order to determine the location and/or amount of unbalance in said object while it is rotating.

In the accompanying illustrations Fig. 1 shows a side view of the attachment with certain parts shown broken away to reveal details. Fig. 2 shows a plan view of the attachment with portions thereof broken away to form substantially a longitudinal section of the attachment. Fig. 3 is a schematic layout of a conventional balancing machine supporting structure with the balancing attachment mounted on the shaft of the object to be balanced. Fig. 4 shows the schematic diagram of the electric wiring and control equipment.

In Figs. 1, 2 and 3 the clamp or attachment I is shown as mounted on the shaft 2 of the object to be balanced. A draw-in collett 3 is provided by means of which the attachment is clamped tightly to the shaft 2 thus causing the entire attachment to revolve with it. Collett 3 carries a sleeve 4 forming a journal or pivotal support for the non-magnetic block 5 which carries two permanent magnets 6 and 6 on which are nonmagnetic end pieces 1 and 8. End piece 7 is provided with a recess 9 which forms a bearing for the end of screw 10, the other end of which is held in block 5. Screw l0 carries a motor armature II on which is mounted commutator l2. Brush-holder l3 carries brushes which bear on commutator l2. Contact pieces l6 and I1 connected to said brushes are arranged to slide along contact bars 20 and 2| which are secured to magnet 6 but insulated therefrom by insulating strip I9. Conductors 22 and 23 bring electric current from slip- rings 24 and 25 to which leads 26 and 21 supply electric current through brush 23 carried on stationary support or yoke 30. Thus armature H constitutes a movable mass, which moves radially toward or away from the center line of shaft 2, the direction depending on the direction of flow of the electric current.

At the other end of the attachment and adjacent to end-piece 8 is a motor armature 32 mounted on shaft 34 which is carried in bearing 35 in end piece 8 and in bearing plate 35. Shaft 34 is mechanically coupled to a flexible shaft 31 which in turn is mechanically coupled to worm 38 engaging a worm gear on or secured to the sleeve 4 as shown. On armature 32 is mounted a commutator 33 on which bear brushes which receive electric current from leads 4| and 42 which are connected to slip rings 43 and 44 on which bear brush 45 carried on stationary yoke 3%]. Brush 45 is connected to conductors 4! and 48. Thus when electric current is supplied to the leads 4'! and 48 the armature 32 rotates in a direction dependent on the direction of flow of electric current, and the angular location of the balance indicating attachment with respect to shaft 2 can be changed while the shaft is rotating.

Figure 3 shows a diagrammatic sketch of a balancing machine with pedestals 49 and 50 flexibly mounted on springs 5| and 52 on base 55, the amount of vibration of the pedestals 49 and 50 being partially controlled by the adjustment of springs 53 and 54. Both pedestals 49 and 50 are arranged so as to be free to vibrate or to be clamped in a fixed position as desired. The removable bar H is arranged so that when bar (I is in the position as shown both pedestals vibrate in unison. When bar H is removed either of the pedestals 49 and 50 is free to vibrate or clamped in a fixed position as desired. The arm of pedestal 50 operates a dial micrometer or indicator 58 by means of the arm 59 with fulcrum support shown at 60 while BI is an adjustable electrical contact device closed by oscillation of the arm 59.

Figure 4 shows the schematic electrical diagram in which armature II is shown supplied with electric current from collector rings 24 and 25 which in turn get their current through brushes from conductors 26 and 21 leading from the reversing switch 64 which is connected to battery 10 by lead 69 and also to a manually operated switch contact 62 which when closed is connected by conductor 68 to battery Ill. By reversing switch 64 the direction of current flowing through armature II is reversed and the direction of rotation is reversed. Thus the direction of rotation and amount of rotation of armature II can be readily controlled while attachment I revolves with shaft 2. Contact 6I makes momentary contact with each vibration of the pedestal 50 to effect automatic operation of the balancing means for approximate compensation, and balancing adjustment also may be made whenever desired by momentarily closing the manually operated contact 62. Similarly armature 32 gets its electric current from conductors which are connected to collector rings 43 and 44, on which bear brushes which are connected by conductors 41 and 48 to the reversing switch 65. Switch 65 is connected, to switch blade 61 which is manually operated and makes contact with conductor 68 and thus to battery 10. The other pole of the switch 65 is connected to the conductor 69 and thus to the other pole of bat-.- tery 70.

The operation of the balancing attachment is as follows: The object to be balanced is placed on the balancing machine with the attachment I firmly secured to the shaft 2. The armature II is moved a short distance from its neutral or balanced position. The machine is then started, the belt 56 causing the object to be balanced to rotate. The bar H being in place, the two pedestals 49 and vibrate in unison and the indicator 58 shows the amount of vibration or swing. The switch 61 is now closed with the reversing switch 65 in the top position. If the indicator reading increases as the switch 6| is periodically closed by the vibration of the pedestal 50, switch 61 is opened and the reversing switch 65 thrown to the lower position and the switch 61 closed again. The indicator reading should now decrease and switch 61 is kept closed until a minimum reading is reachced when switch 61 is opened. The location of the attachment I now shows the angular position of the unbalanced mass. Now with the reversing switch 64 closed in the top position switch 62 is closed momentarily. If the indicator reading increases the reversing switch 64 is thrown to the lower position and switch 62 closed again. The reading of the indicator should now show a decreasing amount until the zero point is reached when the switch 62 is opened. The distance the armature II has moved from its neutral position multiplied by its weight in ounces gives the amount of unbalance of the original and the center line of attachment I gives the angular location of the unbalance. The above is, of course, for the correction of static unbalance and the same procedure with bar II removed and pedestal 49 secured in a fixed position will locate the dynamic unbalance taking into account the distances from the center line of pedestal 56 to center line of attachment I and also from pedestal to the vertical plane where the correction can be made.

What I claim is:

1. In a balancing machine, the combination of a supporting means for rotatively supporting an object to be balanced and a frame arranged to rotate with said object, adjustable weights mount- .ed in the frame, one of said weights comprising an electric motor having its rotor arranged to move along a path at an angle to the axis of said object when the motor is energized, the other .of said weights comprising a second electric motor arranged to move the frame angularly about the axis of said object when it is energized.

2. The combination of a balancing machine and an electrically operated balancing mechanism or attachment mounted on the shaft of the object to be balanced, said mechanism including an electric motor comprising a rotatable armature having its axis disposed radially of said shaft, said armature being so constructed and arranged as to be movable along its axis, and means for energizing the motor while the object is rotating to vary the position of said armature with respect to the shaft.

EDGAR I. WENGER.

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