The Gleason Works

Ernst J Hunkeler

Theodore J Krenzer

Robert N Goldrich

Multi-axis bevel and hypoid gear generating machine

A tensioner having screw threads tightened by rotation of a hob drive (15) is used for applying clamping pressure to a hob (10) in a working position in a hobbing machine. The tensioner extends through the hob between the end supports (11 and 12) of the hobbing machine and has threads arranged so that a wrench system can hold part of the tensioner against rotation while the hob drive tightens the threads to a predetermined clamping torque. The tensioner can be a single draw rod (20) extending from driving end support (11), through hob (10), and into threaded engagement with idler end support (12); and the tensioner can include a hob mounting arbor (45) having threaded ends into which a pair of opposed tensioner rods (20 and 46) are threaded.

Hob clamping system

A gear hobbing machine is provided with a hypoid gear set and a spur gear set for reducing the final drive to its work spindle. As a result of this arrangement, a wide range of machine speeds are available and reverse hand hobbing can be carried out.

Drive train for gear hobbing machine

Versatile face-mill cutting tool apparatus particularly useful in the manufacture of relatively large gears having diameters of 2 to 6 feet (0.6 to 2 meters). A single cutter body can be used in combination with one set of cutter blades to satisfy a wide variety of tool parameters: Blades and blade holders can be readily reversed as required for clockwise or counter-clockwise tool rotation. The angle of the cutting edge of each blade can be adjusted through a fairly wide range of settings as required by the design of the tooth slot being cut. Fine radial adjustments of cutting blades can be made for cutter truing and gear tooth development without shims. This latter feature is accomplished by moving the blade holders along respective straight line paths which, when extended, form an equilateral convex polygon about the center of rotation of the cutter body.

Versatile cutting tool for gear manufacture

The invention overcomes undesirable backlash effects in gear generators which cut gears by climb milling (i.e., with cutter blades rotating in the same direction as the work), these undesirable backlash effects being initiated by the intermittent cutting torques that tend to move the work momentarily ahead of the generating drive train as each blade is in the cut. Instead of a conventional spindle brake to oppose the cutting torques, an auxiliary motor in proximity to the work spindle end of the generating train applies torque to the train in the same direction as it is being driven by the main drive motor, and in the same direction as the cutting torques, thereby maintaining tightness in that portion of generating train which controls work spindle rotation by keeping the train gears with their 'coasting' sides in contact rather than trying to keep their 'driving' sides in contact.

Anti-backlash mechanism for generating train of gear cutting machine

Large, coarse pitch gears are cut by a method utilizing incremental plunge-fed or incremental generation motions and a special circular face-mill type cutter having cutting blades spaced apart from each other at angular distances selected so that, when cutting a tooth slot, there can be intervals during the rotation of the cutting tool when no blade is engageable with the workpiece. It is only intermittently, during these short, no-cutting intervals, that required plunge feed or generating motions are made. At other times, i.e., when one or another of the cutting blades is engaged with the workpiece, the machine elements which are moved intermittently relative to each other to provide in-feed or generation, e.g., the oscillating cradle, rotating work-head, and sliding base, are all rigidly clamped to the machine base and to each other. In the preferred embodiment of the machine for carrying out this method, clamping means including the sliding base as well as overhead tie-bar arrangements straddle the workpiece and cutter to achieve exceptional rigidity.

Large gear manufacture

A cutter head assembly for gear cutting machines is described as including an arrangement of blade-receiving slots set at specific angles to a longitudinal axis of the assembly so as to permit removal, resharpening, and replacement of different types of blades into such slots. The blades which are used with the cutter head assembly of this invention are of a type which can be resharpened without removing stock from their cutting faces.

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Fairport, NY, United States of America

Ernst J Hunkeler