Split gear for avoiding backlash when engaging a mating gear

Abstract

Split gear ( 1 ) for avoiding backlash when engaging a mating gear ( 4 ), comprising a first ( 2 ) and second ( 3 ) toothed gear wheel, rotating means ( 5 ) for coaxially interconnecting the first ( 2 ) and second ( 3 ) gear at least partially rotatable with respect to each other around a mutual rotational axis ( 15 ) and a spring ( 10 ) resiliency interconnecting the first ( 2 ) and second ( 3 ) gear for creating a negative moment between the first ( 2 ) and second ( 3 ) gear upon alignment of the teeth ( 12, 13 ) of the first ( 2 ) and second ( 3 ) gear by rotation of the first ( 2 ) gear with respect to the second ( 3 ) gear so that the mating gear ( 4 ) can be engaged, characterised in that the spring ( 10 ) is integrally formed with the second ( 3 ) gear wheel.

1 . Split gear ( 1 ) for avoiding backlash when engaging a mating gear ( 4 ), comprising a first ( 2 ) and second ( 3 ) toothed gear wheel, rotating means ( 5 ) for coaxially interconnecting the first ( 2 ) and second ( 3 ) gear at least partially rotatable with respect to each other around a mutual rotational axis ( 15 ) and a spring ( 10 ) resiliently interconnecting the first ( 2 ) and second ( 3 ) gear for creating a negative moment between the first ( 2 ) and second ( 3 ) gear upon alignment of the teeth ( 12 ,  13 ) of the first ( 2 ) and second ( 3 ) gear by rotation of the first ( 2 ) gear with respect to the second ( 3 ) gear so that the mating gear ( 4 ) can be engaged, the negative moment being between 1 Nm-200 Nm, characterised in that the spring ( 10 ) is integrally formed with the second ( 3 ) gear wheel. 
   
   
       2 . Split gear as claimed in  claim 1 , characterised in that the spring ( 10 ) is separate from the rotating means ( 5 ). 
   
   
       3 . Split gear as claimed in  claim 1 ; characterised in that the spring ( 10 ) is a torsion spring. 
   
   
       4 . Split gear as claimed in  claim 3 , characterised in that the spring ( 10 ) is an annular spring. 
   
   
       5 . Split gear as claimed in  claim 1 , characterised in that the spring ( 10 ) is substantially coplanar with the second gear ( 3 ). 
   
   
       6 . Split gear as claimed in  claim 1 , characterised in that the split gear ( 1 ) comprises fastening means ( 6 ) for fixing the axial position of the first gear ( 2 ) with respect to the second gear ( 3 ) along the rotational axis ( 15 ). 
   
   
       7 . Split gear as claimed in  claim 6 , characterised in that the fastening means ( 6 ) comprise a bayonet mount ( 22 ) for fixing the axial position of the first gear ( 2 ) with respect to the second gear ( 3 ) upon alignment of the teeth ( 12 ,  13 ) of the first ( 2 ) and second ( 3 ) gear wheel. 
   
   
       8 . Split gear as claimed in  claim 6 , characterised in that the rotating means ( 5 ) comprise the fastening means ( 6 ). 
   
   
       9 . Split gear as claimed in  claim 1 , characterised in that the rotating means ( 5 ) comprise an engaging set of an at least partly annular protrusion ( 19 ) protruding from a substantially first radially extending side of one of the first ( 2 ) or second ( 3 ) gear in direction of the rotational axis ( 5 ) and engaging means ( 20 ) provided in a second radially extending side, adjacent to the first radially extending side, of respectively the second or first gear engaging around the protrusion ( 19 ). 
   
   
       10 . Split gear as claimed in  claim 9 , characterised in that the engaging means ( 20 ) are provided in the form of a recess ( 21 ) provided in the gear ( 2 ,  3 ) provided with the engaging means ( 20 ). 
   
   
       11 . Split gear as claimed in  claim 9 , characterised in that the protrusion ( 19 ) is provided in the first gear ( 2 ) and the engaging means ( 20 ) are provided on the second gear ( 3 ) wheel. 
   
   
       12 . Split gear as claimed in  claim 9 , characterised in that the protrusion ( 19 ) comprises a hooked part for engaging an end part of the spring ( 10 ) when rotating the first gear ( 2 ) with respect to the second gear ( 3 ). 
   
   
       13 . Split gear as claimed in  claim 1 , characterised in that the split gear ( 1 ) comprises means for temporarily interlocking the angular position of the first gear ( 2 ) with respect to the second gear ( 3 ) upon alignment of the teeth ( 12 ,  13 ) of the first ( 2 ) and second gear ( 3 ) wheel. 
   
   
       14 . Split gear as claimed in  claim 1 , characterised in that the negative moment is between 8-30 Nm. 
   
   
       15 . Split gear as claimed in  claim 1 , characterised in that the first gear ( 2 ) is rotatable with respect to the second gear ( 3 ) along an angle of between 5°-15°, preferably 8°-12°, measured between a first position of the first gear ( 2 ) with respect to the second gear ( 3 ) upon creation of the negative moment and a second position of the first gear ( 2 ) with respect to the second gear ( 3 ) in which the teeth of the first ( 2 ) and second ( 3 ) gear are aligned for mounting the split gear ( 1 ) to the mating gear  4 .