A structure for fixing a permanent magnet in a rotor core. The structure includes a magnet accommodation portion into which a permanent magnet is to be inserted, an internal hole formed in an area adjacent to one end of the magnet accommodation portion, a pressing portion provided between the magnet accommodation portion and the internal hole. The pressing portion forms a convex shape toward the permanent magnet to be in contact with the permanent magnet.

A split-type laminated iron core is composed by laminating a plurality of metal plate materials having an annular shape. The metal plate material includes a first split piece and a second split piece arranged in a circumferential direction and divided by a predetermined cutting line. A shear surface formed on a first end surface of the first split piece and a shear surface formed on a second end surface of the second split piece abut on each other, and the first split piece and the second split piece are temporarily connected via the cutting line defined by a boundary between the first end surface and the second end surface so that the first end surface and the second end surface do not completely overlap.

A laminated core includes: a plurality of electrical steel sheets stacked in a thickness direction, wherein the electrical steel sheet includes an annular core back part and a plurality of tooth parts protruding from the core back part toward a radial direction and arranged at intervals in a circumferential direction of the core back part, and wherein among the plurality of electrical steel sheets, the tooth parts of the electrical steel sheets located at one side on the outside in a stacking direction are adhered to each other by an adhesion part provided between the tooth parts adjacent to each other in the stacking direction, the tooth parts of the electrical steel sheets located at the other side on the outside in the stacking direction are adhered to each other by an adhesion part provided between the tooth parts adjacent to each other in the stacking direction, and the tooth parts of the electrical steel sheets located at a center part in the stacking direction are not adhered to each other.

A laminated core includes a plurality of electrical steel sheets stacked on each other, and an adhesion part which is provided between the electrical steel sheets adjacent to each other in a stacking direction and adheres the electrical steel sheets to each other, in which the electrical steel sheet include an annular core back part, and a plurality of tooth parts which extend from the core back part in a radial direction of the core back part and are disposed at intervals in a circumferential direction of the core back part, an adhesion region in which the adhesion part is provided is formed in the core back part of the electrical steel sheet, and the adhesion region extends in a direction along a magnetic flux passing through a region of the electrical steel sheet in contact with the adhesion region.

A laminated core includes a plurality of electrical steel sheets stacked on each other and coated with an insulation coating on both surfaces thereof, and an adhesion part provided between the electrical steel sheets adjacent to each other in a stacking direction and configured to adhere the electrical steel sheets to each other, wherein an adhesion area ratio of the electrical steel sheet by the adhesion part is 1% or more and 40% or less.

The invention provides a process for preparing a methane oxidation catalyst, a methane oxidation catalyst thus prepared and a method of oxidizing methane.

A structure for fixing a permanent magnet in a rotor core. The structure includes a magnet accommodation portion into which a permanent magnet is to be inserted, an internal hole formed in an area adjacent to one end of the magnet accommodation portion, a pressing portion provided between the magnet accommodation portion and the internal hole. The pressing portion forms a convex shape toward the permanent magnet to be in contact with the permanent magnet.

A laminated core includes a plurality of electrical steel sheets that are stacked on one another. All sets of the electrical steel sheets adjacent to each other in a stacking direction are fixed to each other in the laminated core. Some sets of electrical steel sheets among all sets of the electrical steel sheets are fastened but not adhered to each other, and the remaining sets of electrical steel sheets are adhered but not fastened to each other.

An embodiment relates to a motor comprising: a shaft; a rotor connected to the shaft; and a stator disposed outside the rotor, wherein the rotor includes N rotor cores, and the number of holes formed through each of the N rotor cores is at least 2N. Accordingly, the motor allows the rotor to have a skew angle by using the multiple holes formed through the rotor cores.

A rotor structure of a synchronous motor includes: a stator; and a rotatable rotor on the inner side of the stator, in which the rotor includes: a rotor core fixed to a rotary shaft; and a permanent magnet on the outer side of the rotor core, the permanent magnet on the outer side of the rotor core includes a main magnet and an auxiliary magnet, the auxiliary magnet is provided in contact with the outer side of the rotor core, and the main magnet is provided in contact with the outer side of the auxiliary magnet.