Magnetic dampening unit for an exercise gym apparatus

Abstract

A magnetic dampening unit for an exercise gym apparatus includes a plate and an axle secured on the plate. A flywheel is rotatably mounted on the axle and has a hub. A stub is formed at a central portion of the hub and opposed to the plate. A non-magnetic metal member is provided in the flywheel and faces the plate. A disk is rotatably mounted on the axle and between the flywheel and the plate. A resilient member is mounted on the axle and between the disk and the plate. Multiple permanent magnets are provided on the disk with an alternate arrangement of N-polarities and S-polarities and facing the non-magnetic metal member. Two cables are provided on the disk and extend out from the plate. When drilling the flywheel for a dynamic balance, material waste will not be drawn to the magnets and the flywheel can be easily cleaned.

1 . A magnetic dampening unit for an exercise gym apparatus, the magnetic dampening unit comprising: 
 a plate ( 20 );    an axle ( 17 ) secured on the plate ( 20 );    a flywheel ( 10 ) rotatably mounted on the axle ( 17 ), the flywheel ( 10 ) having a hub ( 11 ), a stub ( 12 ) formed at a central portion of the hub ( 11 ) and opposed to the plate ( 20 ), a non-magnetic metal member ( 14 ) provided in the flywheel ( 10 ) and facing the plate ( 20 );    a disk ( 15 ) movably mounted on the axle ( 17 ) and between the flywheel ( 10 ) and the plate ( 20 );    a resilient member ( 18 ) mounted on the axle ( 17 ) and between the disk ( 15 ) and the plate ( 20 );    a plurality of permanent magnets ( 16 ) provided on the disk ( 15 ) with an alternate arrangement of N-polarities and S-polarities and facing the non-magnetic metal member ( 14 );    two first cables ( 19 ) provided on the disk ( 15 ) and extending out from the plate ( 20 ); and    a belt ( 30 ) provided on the stub ( 12 ).    
   
   
       2 . The magnetic dampening unit as claimed in  claim 1 , wherein the flywheel ( 10 ) has two bearings ( 121 ) provided in the stub ( 12 ) for rotatably installing the flywheel ( 10 ) on the axle ( 17 ).  
   
   
       3 . The magnetic dampening unit as claimed in  claim 1 , wherein the flywheel ( 10 ) has a recess ( 13 ) defined at a side facing the plate ( 20 ), the non-magnetic metal member ( 14 ) is formed in the recess ( 13 ) and the disk ( 15 ) is located in the recess ( 13 ).  
   
   
       4 . The magnetic dampening unit as claimed in  claim 3 , wherein the balance ( 10 ) is made of plastic material by means of injection molding and provided with an iron ring ( 101 ) embedded in the flywheel ( 10 ).  
   
   
       5 . The magnetic dampening unit as claimed in  claim 1 , further comprising a pulley ( 21 ) provided on the plate ( 20 ), the first cables ( 19 ) having distal ends fastened on the pulley ( 21 ).  
   
   
       6 . The magnetic dampening unit as claimed in  claim 5 , further comprising a second cable ( 22 ) fastened on the pulley ( 21 ).