Patent ID: 7101320

Claim:
A damping device for an exercise bicycle, the device comprising: a support base; a housing secured on a side of the support base and having an inside formed with a receiving chamber, the housing including a first shell secured on the support base, a middle shell combined with the first shell and having a center formed with a mounting ring, and a second shell combined with the middle shell; a pivot shaft rotatably mounted on the support base; a resistance wheel coaxially secured on the pivot shaft to be rotatable therewith by a rear wheel of an exercise bicycle; a magnetic disk mounted in the receiving chamber of the housing and secured on an end of the pivot shaft to rotate therewith; a fixing disk movably mounted on the mounting ring of the middle shell at a distance from the magnetic disk and having a periphery provided with a plurality of magnetic members aligned with the magnetic disk, the fixing disk having a center formed with a receiving recess having a wall formed with two positioning holes; an action block rotatably mounted in the receiving recess of the fixing disk and having a periphery formed with two symmetrical guide slots; two urging balls each mounted in a respective one of the two positioning holes of the fixing disk and each slidably mounted in a respective one of the two guide slots of the action block; and a motor secured on an outer wall of the middle shell of the housing and having a first end provided with a rotatable spindle extended through the fixing disk and fixed in the action block for rotating the action block wherein rotation of the action block causes the urging balls to move within the guide slots which displaces the fixing disk relative to the magnetic disk.