Laminated core, rotor, and manufacturing method of laminated core
This laminated core is formed integrally by laminating a plurality of steel sheets including a first steel sheet and a second steel sheet. The first steel sheet is disposed as an outermost layer on one end side along the central axis and including a first exposed surface. The second steel sheet is disposed as an outermost layer on the other end side along the central axis and including a second exposed surface. In this laminated core, a difference between a maximum value and a minimum value in a distribution of a thickness that is a distance between the first exposed surface and the second exposed surface is 0.25 mm or less.
1 . A laminated core being integrally formed by laminating a plurality of steel sheets including a first steel sheet and a second steel sheet, the first steel sheet being disposed as an outermost layer on one end side along a central axis and including a first exposed surface, the second steel sheet being disposed as an outermost layer on the other end side along the central axis and including a second exposed surface,
wherein a difference between a maximum value and a minimum value in a distribution of a thickness, calculated at a plurality of positions, on a same circumference at an easily deformable portion of the laminated core, that is a distance between the first exposed surface and the second exposed surface is 0.25 mm or less.
2 . The laminated core according to claim 1 , wherein each of the plurality of steel sheets is a non-oriented electrical steel sheet having a yield point of 320 MPa or more.
3 . The laminated core according to claim 1 , wherein
the laminated core has a structure in which a steel sheet among the plurality of steel sheets and an adhesive resin are alternately laminated, and
each of the plurality of steel sheets has a diameter of 80 mm or more and a sheet thickness of 0.35 mm or less.
4 . The laminated core according to claim 3 , wherein the adhesive resin is an acrylic resin or an epoxy resin.
5 . The laminated core according to claim 1 , further comprising a slot,
wherein the thickness includes a measurement value at a first measurement position between the slots adjacent to each other in a circumferential direction.
6 . The laminated core according to claim 1 , further comprising a slot,
wherein the thickness includes a measurement value at a second measurement position between the central axis and the slot.
7 . The laminated core according to claim 1 , further comprising a slot,
wherein the thickness includes a measurement value at a third measurement position between the slots adjacent to each other in a radial direction perpendicular to the central axis.
8 . The laminated core according to claim 1 , further comprising a slot,
wherein the thickness includes a measurement value at a fourth measurement position between an outer circumferential edge and the slot.
9 . The laminated core according to claim 1 , wherein
the steel sheets adjacent to each other among the plurality of steel sheets are joined to each other via a crimping portion formed in each of the steel sheets adjacent to each other, and
the thickness includes a measurement value at a fifth measurement position between the crimping portions adjacent to each other in a circumferential direction.
10 . A rotor comprising the laminated core according to claim 1 , wherein an amplitude amount in a radial direction perpendicular to the central axis when the rotor is rotated at 16000 rpm is 250 μm or less.