An experimental investigation of thermal contact conductance of multilayered electrically insulated sheets

Results are presented for an experimental investigation on thermal contact conductance of multilayered electrically insulated sheets. Electrical components made of thin sheets of electrical steels clamped together with an electrically insulating film of organic or inorganic material coating each sheet characteristically give rise to some electrical and magnetic losses resulting in heat generation. If the heat is not removed as it is generated, high temperature may result and could cause machine damage. The low effective thermal conductivity normal to the plane of laminations resulting from the thermal contact resistance of each pair of adjacent laminations makes the design for the thermal dissipation more difficult. These results, together with other published data, are intended to form a basis for a method of predicting the heat-transfer characteristics of laminated materials in general. It was considered necessary to establish reliable data before an adequate theory could be developed, as there is no other access to the assessment of the thermal behavior of elements subject to the variations incurred by regular manufacturing techniques and tolerances.