Patent GB-944193-A (GB)
Title: Laminated core structure for electric machine
Inventor: HAIFLEY WILLIAM ELI
IPC: H02K15/02
Filed: 1962-07-12
Abstract: 944,193. Assembling laminated cores; shearing. FRANKLIN ELECTRIC CO. Inc. Aug. 12, 1962, No. 26819/62. Headings B3A and B3W. [Also in Division H2] A method of assembling a laminated core comprises stacking a number of core laminations which have slots across their peripheral edges in aligned face-to-face relation with the slots forming one or more banding strip receiving grooves, axially compressing the stack, and rolling a strip banding material into each of the grooves. An apparatus for carrying out the method comprises a movable base 11 on which is stacked a number of laminations 12, a head member 13, a number of banding strip-applying devices 14 and strip-forming devices 17. The base member 11 comprises a cylindrical table 32 having an upper annular surface 33 on which the laminations are stacked. The diameter of the table is less than the outer diameter of the laminations. The laminations are held in position on the table by an arbor assembly 34 comprising an axially movable tapered member 36 and an outer segmental sleeve 37 having a tapered bore and lugs 41 which anchor the segments by hooking under a flange 42 of the table 32. The tapered member 36 is actuated by an hydraulic cylinder mechanism 38. The laminations 12 have a number of shallow slots around their periphery which are aligned on the table 32 by a fixed guide 44 to form band receiving grooves 26. After sufficient laminations have been stacked the arbor assembly is operated to grip the stack and the base member lifted vertically to an intermediate position by an hydraulic mechanism 18 mounted on a bed 43 to engage four band-applying devices 14 spaced around the stack in alignment with the grooves 26. Each of the devices 14 comprise an elongated arm 48, having a spring-loaded guide member 45 and a deforming serrated roller 50. The arm 48 is mounted on a frame 52 by a fixed pivot 49 and is rotationally adjusted by screw arrangements 53, 57. The upper end of the guide 45 is located below the roller 50, and has a bevelled carbide insert 61 which acts as a groove positioning member. Each device is adapted to support a prebent end 69 of band material 16, the end engaging a corner 72 at the upper end of a guide passage 71 in the guide 45. The strip 16 is fed into the passage 71 via a set of forming rolls 102, 103 and an idler roll 74 mounted in a slot 89. Immediately after the stack reaches the intermediate position the prebent end is hooked over the top of the stack and the hydraulically-operated head member 13 is lowered to compress the stack against the base member 11. The member 13 comprises a circular inverted cup 76 having four recessed inserts 78 which clamp the ends 69 when the cup engages the stack. Each insert has a toothed bottom face 79 to facilitate gripping of the end 69. Continued upward movement of the stack 12 is maintained against the member 13 which keeps the stack in compression and each strip 16 is progressively laid in its groove 26 and deformed laterally by the rollers 50 until the bottom of the stack passes above the top of the rollers. The strips then overlay recessed cut-off blocks 94 mounted, in alignment with the grooves, below the surface of the body 32 and having flat top end faces 96 parallel to the bottom end of the stack and located in spaced relation thereto and front faces 97 shaped to the shape of the strip prior to deforming by the roller. The operation is completed by hydraulically operated cut-off devices 21, each comprising a horizontal blade 98, bevelled on both the top and bottom sides 101, which enters the spaces between the surfaces 96 and the bottom of the stack to sever the strip 16 and form one end over the end of the stack and prebend the other end of the strip against the face 96. After cutting the arbor mechanism 34 is contracted to release the stack and the base member 11 returned to the loading position leaving the completed stack supported on the blades 98 from which it is lifted. The strip is initially formed with two longitudinally extending corrugations and is slightly narrower than the grooves 26. The corrugations are formed on a flat strip by sets of forming rolls 17, each comprising rolls 102, 103 mounted on a carriage 107 which is slidably mounted on a fixed member 108 between a fixed stop 112 and an adjustable stop 113. The carriage is urged away from the stop 112 by a spring 114. In operation, the pulling force exerted on the strip 16 by the upward movement of the member 11 causes the carriage 107 to engage the stop 112, after the severing of the strip by the blades 98 the weight of the roll set 17 together with the force of the spring 114 returns the carriage into engagement with the stop 113 and hence draws the prebent end 69 into engagement with the corner 72 of the guide rib 61, i.e. the re-set position. The roller 50 is serrated to provide teeth 82 having side bevelling 83, the crown of the teeth between the bevels is flat or arcuate depending on whether the bottom of the groove 26 is flat or arcuate.