Structure with thermoplastic elastomer enveloping layer, bearing, and drive module

A bearing comprising:

• an outer ring, and
• an enveloping layer formed on an outer circumferential surface of the outer ring,
• wherein the enveloping layer comprises
• a first material layer formed on the outer circumferential surface of the outer ring, and
• a second material layer which is a thermoplastic elastomer layer thermally bonded to an outer surface of the first material layer and is an outer circumferential surface layer forming an outer circumferential surface of the enveloping layer,
• the second material layer is made of a material which is softer than the first material layer, and
• the first material layer comprises an outer circumferential surface layer configured to cover the outer circumferential surface of the outer ring, and a pair of side surface layers connected to both axial sides of the outer circumferential surface layer and configured to cover both axial side surfaces of the outer ring, and
• wherein
• the first material layer is formed from an amorphous plastic, and
• the second material layer is formed from a thermoplastic elastomer selected from the group consisting of styrenes, olefins, polyvinyl chlorides, urethanes and polyesters.

A bearing comprising:

• an outer ring, and
• an enveloping layer formed on an outer circumferential surface of the outer ring,
• wherein the enveloping layer comprises
• a first material layer formed on the outer circumferential surface of the outer ring, and
• a second material layer which is a thermoplastic elastomer layer thermally bonded to an outer surface of the first material layer and is an outer circumferential surface layer forming an outer circumferential surface of the enveloping layer,
• the second material layer is made of a material which is softer than the first material layer, and
• the first material layer comprises an outer circumferential surface layer configured to cover the outer circumferential surface of the outer ring, and a pair of side surface layers connected to both axial sides of the outer circumferential surface layer and configured to cover both axial side surfaces of the outer ring,
• wherein
• the second material layer comprises an outer circumferential surface layer configured to cover an outer circumferential surface of the first material layer, and
• a pair of side surface layers connected to both axial sides of the outer circumferential surface layer and configured to cover both axial side surfaces of the pair of side surface layers of the first material layer, and
• wherein
• an axial dimension between an outer surface of one side surface layer and an outer surface of the other side surface layer of the pair of side surface layers of the first material layer is formed to increase from a radially inner side toward a radially outer side, and
• an axial dimension between an inner surface and an inner surface of the pair of the other side surface layer of side surface layers of the second material layer is formed to increase from the radially inner side toward the radially outer side in correspondence with the pair of side surface layers of the first material layer.