Werkzeugmaschinenfabrik Oerlikon-buhrle Ag

Oerlikon Geartec Ag

Oerlikon-buhrle Ag

Erich Kotthaus

Otto Hildinger

Hans Jaeger

Ulrich Raess

Hans J Spiess

The rotary form tool for finish machining tooth flanks of longitudinally curved teeth of a rough machined bevel gear blank of a hypoid or non-hypoid gear pair, comprises a tool body having the configuration of a hypoid helical bevel gear. Each tooth of the tool body is helically curved and has a longitudinally concave tooth flank and a longitudinally convex tooth flank. At least one tooth flank of the longitudinally concave tooth flanks and the longitudinally convex tooth flanks are coated with an abrading medium.

Tool for grinding the teeth of bevel gears having longitudinally curved

The apparatus for grinding rough-cut longitudinally curved gear teeth of a helical bevel gear, comprises two spindles for respectively mounting a tool and a workpiece, and structure for translatably and adjustably arranging at least one spindle of these two spindles. A separate electric motor arranged coaxially with each of the two spindles serves for driving the tool and for driving the workpiece, respectively. The separate electric motors are mutually interconnected by an electric shaft.

Method of grinding the teeth of bevel gears having longitudinally curved

This method is for finish machining the teeth of rough machined bevel gears having longitudinally curved teeth where finish machining is undertaken subsequent to case hardening. To permit economical fabrication of such bevel gears at least in mass production, the bevel gears are ground as workpieces by a tool designed as a hypoid gear and provided with at least one abrading surface on tooth flanks of its toothing. The workpiece and the tool are brought into mesh and positively and synchronously rotarily driven in the ratio of their respective tooth numbers. Displacement of the tool axis relative to the workpiece axis as well as speeds of the tool and the workpiece are selected such that a relative sliding velocity arising between the tool and the workpiece lies within the range of conventional surface speeds for grinding. All concave tooth flanks of the workpiece or all convex tooth flanks of the workpiece or both are continuously ground in a single operation with a feed motion. The gear employed as the grinding tool exhibits curved helical bevel gear teeth. These gear teeth are provided with an abrading coating on their tooth flanks. The tool is arranged in axial displacement relative to the workpiece. In order that both the workpiece and the grinding tool can be driven synchronously at the requisite rotary speeds, both the tool and the workpiece are each connected to a respective electric motor and the two electric motors are interconnected by a so-called 'electric shaft'.

In order to increase the working range of existing designs of gear cutting machines upon which gear teeth based upon an extended epicycloid are cut according to the continuous gear-cutting process, the workpiece and cutter spindles of a gear cutting machine are driven in identical directions of rotation by a reversing drive train. A reversible auxiliary drive is connected to an end of a primary drive train remote from a main drive for maintaining the primary drive train interconnecting the workpiece and cutter spindles under constant load, i.e. for suppressing backlash in the primary drive train. This permits the practical fabrication of gears (i.e. the practical cutting of gear teeth) based upon a hypocycloid instead of an epicycloid.

Gear cutting method and machine for cutting spiral bevel gears and

To provide better possibilities for shaping or forming the tooth bearing pattern or localized tooth contact the cutting edges, i.e. the outer and the inner cutting edges, of the cutters are inserted into the face cutter head such that an end of the cutting edge which faces the base of the tooth leads the other end of the same cutting edge.

Gear cutter

A method of manufacturing bevel and hypoid gear pairs according to an imaginary mating gear cutting process. The tooth spaces are cut by means of a face-mill cutter head rotating about an axis of rotation. In order to overcome heretofore prevailing limitations on the gear diameter, cone angle and shaft angle of gear pairs, either the gear or the cutter head performs an arcuate generating movement about a generating axis in order to produce one of the gears, whereby a machining axis is adjusted relative to the generating axis in accordance with the position of the axes of both gears of the gear pair. In one advantageous embodiment, the same machining axis adjustment is also employed for fabricating the mating, non-generated gear.

Method for fabricating bevel and hypoid gear pairs

In an end cutter head for a gear cutting machine for fabricating gears by cutting out tooth gaps or slots, cutters are provided for the purpose of increasing the cutting output or rate, which cutters each have two cutting or chip faces. In the method for refacing or regrinding the cutters, the flank clearance surfaces or faces and a top clearance surface or face of each cutter are conjointly refaced with the cutters inserted in the end cutter head which is chucked to a grinding machine.

End cutter head, for gear cutting machines, cutters for end cutter heads

Tooth flanks of a gear are produced with a cutter head rotating about a cutter head axis and equipped with cutters having internal or inner cutting edges and external or outer cutting edges. In order to obtain a further increase in the gear cutting capacity or output, while avoiding the therewith usually associated tooth flank errors, the cutter head axis is pivoted out of a normal within or into a plane, as the case may be. At the cutter head the external cutting edges are arranged at a first circle, the internal cutting edges at a second circle and such respective cutting edges are arranged in offset relationship from a uniform angle division or pitch through a predetermined respective angle. The external cutting edges and the internal cutting edges form with a normal to a tangential plane a respective predetermined angle.

Method for fabricating gears

In a method of manufacturing gears with rolled or generated tooth flanks by cutting-out tooth slots or spaces with at least one face-mill cutter head performing a rotational movement about a cutter head axis, wherein the production capacity or efficiency is increased in that for rough cutting the tooth slots, during a first working step, the face-mill cutter head and the workpiece perform a plunge-cut movement with respect to one another. Hence, the cutters of the face-mill cutter head initially contact the workpiece at a predeterminable plunge-cut position between end regions of a tooth slot or space which is to be fabricated. For finish cutting the tooth slots, during a further working step, there is performed a generating movement between the face-mill cutter head and the workpiece.

Method for fabricating gears with generated tooth flanks

A clamping or chucking apparatus is provided wherein the cutter blades or cutters, for the grinding thereof, are mounted in a cutter head. The cutter head is rotatable in the clamping apparatus about a cutter head axis, and further, is pivotably arranged for pivotable movement about a pivot axis. To provide a clamping apparatus having compact external dimensions and which, during adjustment of the cutter blades, requires very little freedom of movement room or space, and also possesses a good adjustment accuracy, the pivot axis is inclined and arranged at an acute angle with respect to the cutter head axis, such that the smallest spacing between the pivot axis and the cutter head axis is located externally of the clamping apparatus.

Clamping apparatus for clamping cutter blades of a gear cutting machine

A pair of mating spur gears, wherein the teeth of the one spur gear element possess an involute-shaped tooth depth profile and the teeth of the mating spur gear element possess a straight tooth depth profile.

Mating spur gears

A method of producing pairs of mating spur gears by cutting tooth gaps with a rotating end cutter head, wherein, in order to manufacture the one spur gear, one of the elements--the spur gear or the end cutter head--carries out an arcuate or circular rolling movement about an axis which coincides or approximately coincides with the gear axis of the other gear, and the other gear is produced by a cutting-in depth or plunge cut operation without any rolling movement.

Method of manufacturing pairs of spur gears

An apparatus for producing pairs of spur gears by cutting tooth gaps with a rotating end cutter head or face milling cutter, wherein, in order to manufacture the one spur gear, one of the elements--the spur gear or the end cutter head--carries out an arcuate or circular rolling movement about an axis which coincides or approximately coincides with the gear axis of the other gear, and the other gear is produced by a cutting-in depth or plunge cut operation without any rolling movement.

Apparatus for manufacturing pairs of spur gears

A method of, and apparatus for, grinding cutting tools attached to a cutter head for gear cutting machines, the cutter head having sets of cutting tools encompassing three respective groups of cutting tools, specifically inner cutters, outer cutters and auxiliary cutters. Two groups of the cutting tools are removed from the cutter head, the first group of cutting tools is completely ground at the cutter head, the second group of cutting tools is inserted into the cutter head and completely ground, and then the third group of cutting tools is inserted in the cutter head and completely ground.

Method for grinding cutting tools and grinding machines for the

An apparatus for driving the generating or rolling cradle of a gear-cutting machine, comprising a variable-speed motor for changing the generating or rolling speed. A cam plate is secured to the rolling cradle in order to control the variable-speed motor as a function of the position of the rolling cradle.

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Wallisellen, Switzerland

Erich Kotthaus