Patent ID: 7728705

Claim:
An electromagnetic transmission device, comprising: a fixed base; at least one guide bar connected to the fixed base and comprising magnetic-permeable material and a first central height plane; a coil connected to the fixed base; a support base movably fit on the guide bar; an annular magnetic member connected to the support base and surrounded by the coil, wherein a magnetization direction of the annular magnetic member is perpendicular to a moving direction of the support base and annular magnetic member, the annular magnetic member comprises a second central height plane, the first and second central height planes parallel the magnetization direction of the annular magnetic member, the coil interacts with the annular magnetic member to generate a first force, driving the support base and annular magnetic member to move along a direction perpendicular to the magnetization direction of the annular magnetic member, when moving to separate the second central height plane from the first central height plane, the annular magnetic member interacts with the guide bar to generate a second force, the direction of the second force is the same as that of the first force, and the second force drives the support base and annular magnetic member to move along the direction perpendicular to the magnetization direction of the annular magnetic member; and a resilient member connecting the coil to the annular magnetic member, providing the support base and annular magnetic member with restoring resilience.