Face hob hypoid gear tooth top-land radius by common chamfer tool

Abstract

A ring gear or pinion common outside chamfer tool and a common inside chamfer tool are disclosed. The common chamfer tools comprise a shank, a tip end and a chamfering edge. The shank is attachable to a gear cutter and has a tip end formed on the distal end thereof. The chamfering edge is positioned within the tip end and is configured to form a tooth top-land radius of multiple gear ratios. A method of designing a ring gear or pinion common outside chamfer tool and common inside chamfer tool for multiple gear ratios is also described.

1 . A common chamfer tool comprising:
 a shank attachable to a gear cutter;   a tip end formed at a distal end of the shank, and   a chamfering edge positioned within the tip end, wherein the chamfering edge forms a tooth top-land radius of multiple gear ratios.   
     
     
         2 . The tool of  claim 1 , wherein the chamfering edge forms a tooth top-land radius of multiple gear ratios in a family. 
     
     
         3 . The tool of  claim 1 , wherein the chamfering edge includes a shoulder radius cutting edge. 
     
     
         4 . The tool of  claim 3 , wherein the shoulder radius cutting edge forms a curved tooth top-land radius. 
     
     
         5 . The tool of  claim 2 , wherein the tooth top-land radius is formed from a toe of a gear to a heel of the gear. 
     
     
         6 . The tool of  claim 1 , wherein the tool is designed to form a tooth top-land radius on a drive side of a gear tooth. 
     
     
         7 . The tool of  claim 1 , wherein the tool is designed to form a tooth top-land radius on a coast side of a gear tooth. 
     
     
         8 . A method of forming a common chamfer tool for multiple gear ratios comprising:
 selecting a gear family;   obtaining an outside chamfer tool for each ratio in the family;   selecting an initial design for a common outside chamfer tool from the outside chamfer tools of multiple ratios; and   matching a shoulder radius cutting edge of the common outside chamfer tool and a shoulder radius cutting edge of each of the outside chamfer tools.   
     
     
         9 . The method of  claim 8 , wherein the outside chamfer tool of the ratio with a smallest gear whole depth is selected as the initial design for the common outside chamfer tool. 
     
     
         10 . The method of  claim 8 , wherein the method of forming the common chamfer tool for multiple gear ratios further comprises:
 obtaining an inside chamfer tool for each ratio in the family;   selecting an initial design for a common inside chamfer tool from the inside chamfer tools of multiple ratios; and   matching a shoulder radius cutting edge of the common inside chamfer tool and a shoulder radius cutting edge of each of the inside chamfer tools.   
     
     
         11 . The method of  claim 10 , wherein the inside chamfer tool of the ratio with a smallest gear whole depth is selected as an initial design for the common inside chamfer tool. 
     
     
         12 . The method of  claim 8 , wherein a plurality of parameters of the initial common outside chamfer tool are varied until the shoulder radius cutting edge of the common outside chamfer tool matches the shoulder radius cutting edge of the outside chamfer tools. 
     
     
         13 . The method of  claim 10 , wherein a plurality of parameters of the initial common inside chamfer tool is varied until the shoulder radius cutting edge of the common inside chamfer tool matches the shoulder radius cutting edge of the inside chamfer tools. 
     
     
         14 . An apparatus for chamfering a gear tooth top-land radius of multiple gear ratios comprising:
 a gear cutter tool having multiple blade attachments;   a plurality of outside cutter blades attached to a plurality of the blade attachments, wherein the outside cutter blade forms a drive side surface of a pinion gear and a coast side surface of ring gear;   a plurality of inside cutter blades attached to a plurality of the blade attachments, wherein the inside cutter blade forms a coast side surface of a pinion gear and a drive side surface of a ring gear;   a plurality of common outside chamfer blades attached to a plurality of the blade attachments, wherein the ring gear or pinion common outside chamfer blade forms a ring gear coast side or pinion drive side tooth top-land radius of multiple gear ratios; and   a plurality of common inside chamfer blades attached to a plurality of the blade attachments, wherein the ring gear or pinion common inside chamfer blade forms a ring gear drive side or pinion coast side tooth top-land radius of multiple gear ratios.   
     
     
         15 . The apparatus of  claim 14 , wherein the blades are mounted on the gear cutter in groups. 
     
     
         16 . The apparatus of  claim 15 , further comprising a device for rotating the gear cutter tool and rotating a stock, wherein the device is programmable to selectively vary the spatial orientation of the gear cutter tool relative to the stock. 
     
     
         17 . The apparatus of  claim 14 , wherein the tooth top-land radius is formed from a toe to a heel of the gear tooth.