Gears and gearing apparatus

Abstract

In a gear G 1 according to the present invention, which is provided with a plurality of teeth 1 to be mated with teeth of a mating gear to thereby transmit a rotational motion, a predetermined region A in at least one tooth flank 7 of each tooth 1 is formed in a configuration such that, from at least one place in a tooth width direction on a crossing 8 of the tooth flank 7 and a tooth tip surface 3 , the mating with the teeth of the mating gear is started with the point contact or the line contact shorter than the total tooth width, and thereafter, is gradually shifted to the line contact so that the length of contact line 10 thereof is sequentially increased as the line contact moves from a tooth tip surface 3 side toward a tooth root side.

1 . Gears comprised of one and the other mutually engaged gears, each having a plurality of teeth to be mated with teeth of the other engaged gear to thereby transmit a rotational motion, 
 wherein a predetermined region in at least one of tooth flanks of each tooth of the one gear is formed in a configuration such that mating of said each tooth of the one gear with the teeth of the other engaged gear starts with a point contact or a line contact shorter than a total length of a tooth width of the one gear from at least one place in a tooth width direction on a crossing of said tooth flank and a surface of tooth tip of said one gear and thereafter, gradually shifts to the line contact so that a length of contact line thereof is continuously increased as the line contact moves from a tooth tip side toward a tooth root side.    
   
   
       2 . Gears according to  claim 1 , wherein said predetermined region in the tooth flank is chamfered, so that a configuration thereof is made to be an inclined plane which extends from at least one place in the tooth width direction on said crossing of the tooth flank and the surface of tooth tip, toward one of end faces of the tooth or both of the end faces thereof.  
   
   
       3 . Gears according to  claim 1 , wherein a chipped portion is formed, so that a configuration of said predetermined region in the tooth flank is made to be an inclined plane which extends from one place or a plurality of places of said tooth flank to both of end faces of the tooth toward said crossing of the tooth flank and the surface of tooth tip.  
   
   
       4 . Gears according to  claim 1 , wherein in a configuration of said predetermined region in the tooth flank, a curved surface which gradually decreases the tooth thickness, is formed toward one of end faces of the tooth or both of the end faces thereof in the tooth width direction of said tooth flank.  
   
   
       5 . Gears according to  claim 1 , wherein said predetermined region in the tooth flank is a region on the tooth tip side from the vicinity of a branching point between the (n+1) teeth mating and the n teeth mating (n is integer of one or more) at the mating time with the teeth of the mating gear.  
   
   
       6 . A gearing apparatus for transmitting a rotational motion from one to the other of two associated shafts by engaging a pair of gears to allow opposite teeth of the engaged gears to be mated with each other, 
 wherein for at least one gear of the pair of engaged gears, a predetermined region in at least one of tooth flanks of each tooth is formed in a configuration such that mating of the each tooth of the one gear with the teeth of the other engaged gear starts with a point contact or a line contact shorter than a total length of a tooth width from at least one place in a tooth width direction on a crossing of the tooth flank and a surface of tooth tip of said one gear and thereafter, gradually shifts to the line contact so that a length of contact line thereof is continuously increased as the line contact moves from a tooth tip side toward a tooth root side.    
   
   
       7 . Gears comprised of one and the other mutually engaged gears, each having a plurality of teeth to be mated with teeth of the other engaged gear to thereby transmit a rotational motion, 
 wherein a predetermined region in at least one of tooth flanks of each tooth is formed in a configuration such that mating of said each tooth of the one gear with the teeth of the other engaged gear starts with a point contact or a line contact shorter than a total length of a tooth width of one gear from at least one place in a tooth width direction on a crossing of said tooth flank and a surface of tooth root of said one gear and thereafter, gradually shifted to the line contact so that a length of contact line thereof is continuously increased as the line contact moves from a tooth root side toward a tooth tip side.    
   
   
       8 . A gearing apparatus for transmitting a rotational motion from one to the other of two associated shafts by engaging a pair of gears to allow opposite teeth of the engaged gears to be mated with each other, 
 wherein for at least one of the pair of engaged gears, a predetermined region in at least one of tooth flanks of each tooth is formed in a configuration such that mating of the each tooth of the one gear with teeth of the other engaged gear starts with a point contact or a line contact shorter than a total length of a tooth width from at least one place in a tooth width direction on a crossing of the tooth flank and a surface of tooth root of said one gear and thereafter, gradually shifts to the line contact so that a length of contact line thereof is continuously increased as the line contact moves from a tooth root side toward a tooth tip side.    
   
   
       9 . Gears comprised of one and the other mutually engaged gears, each having a plurality of teeth to be mated with teeth of the other engaged gear to thereby transmit a rotational motion, 
 wherein a predetermined region in at least one of tooth flanks of each tooth of the one gear is formed in a configuration such that mating of said each tooth of the one gear with the teeth of the other engaged gear starts with a point contact or a line contact shorter than a total length of a tooth width of the one gear from at least one place in a tooth width direction on a crossing of said tooth flank and a surface of tooth tip of said one gear and thereafter, rapidly or in stepwise shifts to the line contact of the total tooth width from a tooth tip side toward a tooth root side so that the length of contact line thereof is increased.    
   
   
       10 . A gearing apparatus for transmitting a rotational motion from one to the other of two associated shafts by engaging of a pair of gears to allow opposite teeth of the engaged gears to be mated with each other, 
 wherein for at least one gear of the pair of engaged gears, a predetermined region in at least one of tooth flanks of each tooth is formed in a configuration such that, mating of the each tooth of the one gear with the teeth of the other engaged gear starts with a point contact or a line contact shorter than a total length of a tooth width from at least one place in a tooth width direction on a crossing of the tooth flank and a surface of tooth tip and thereafter, rapidly or in stepwise shifts to the line contact of the total tooth width from a tooth tip side toward a tooth root side so that a length of contact line thereof is increased.    
   
   
       11 . Gears comprised of one and the other mutually engaged gears, each having a plurality of teeth to be mated with teeth of the other engaged gear to thereby transmit a rotational motion, 
 wherein a predetermined region in at least one of tooth flanks of each tooth is formed in a configuration such that mating of said each tooth of the one gears with the teeth of the other engaged gear starts with a point contact or a line contact shorter than a total length of a tooth width of the one gear from at least one place in a tooth width direction on a crossing of said tooth flank and a surface of tooth root of said one gear and thereafter, rapidly or in stepwise shifts to the line contact of the total tooth width from a tooth root side toward a tooth tip side so that the length of contact line thereof is increased.    
   
   
       12 . A gearing apparatus for transmitting a rotational motion from one to the other of two associated shafts by engaging a pair of gears to allow opposite teeth of the engaged gears to be mated with each other, 
 wherein for at least one gear of the pair of engaged gears, a predetermined region in at least one of tooth flanks of each tooth is formed in a configuration such that mating of the each tooth of the one gear with the teeth of the other engaged gear starts with a point contact or a line contact shorter than a total length of a tooth width from at least one place in a tooth width direction on a crossing of said tooth flank and a surface of tooth root of said one gear and thereafter, rapidly or in stepwise shifts to the line contact of the total tooth width from a tooth root side toward a tooth tip side so that the length of contact line thereof is increased.