Reishauer Ag

Walter Wirz

Erich Ronneberger

Helmut F Jager

Armin Feisel

Erwin Sennhauser

Jurg Griesbach

Disclosed is a method for dressing a single- or multi-thread grinding worm () in which a main rolling movement between the grinding worm and a gear-like dressing tool () is brought about. In order to create flank modifications on the grinding worm, an additional relative movement is superimposed on the main rolling movement. In addition, an auxiliary drive specifically designed for such a method, a correspondingly designed machine tool and a dressing tool for carrying out the method are disclosed.

Method and devices for the rapid and flexible dressing of grinding worms

In a process for the aligning of the tooth spaces of a workpiece with precut teeth, which is set up on the work spindle of a gear finishing machine, the workpiece () is brought into no-backlash double flank mesh with a pilot gear (). The workpiece () is rotated, and during this rotation both the angular position of the tooth space centre lines of the pilot gear () and the centre distance between the pilot gear () and the workpiece () are measured. This allows the workpiece () to be tested with respect to radial run-out, flank material allowance, helix angle, and any possible irregularities.

Process for the aligning of tooth spaces of a workpiece with precut teeth

The invention concerns a device for the automatic loading of workpieces into a gear manufacturing machine, in particular a hard state finishing machine, by means of a swivel device arranged on the machine, where simultaneous with the machining process of a work piece blank () clamped on the work spindle () a finish machined work piece () on the transfer platform () located opposite the work spindle is de-oiled in a work piece loading lock, removed, and a fresh work piece blank fed in. The transfer platform () is designed as a centrifuge station.

Gear manufacturing machine and process for the operation of such a gear manufacturing machine

A detachable fixture of a rotary machining tool () on the tool spindle () of a machine tool and in particular of a grinding wheel flange () on the spindle nose () of a grinding spindle () is provided with two clamping rings. By means of the Cardanic located clamping rings (), the clamping force F generated by turning a clamping screw () is distributed uniformly on the spindle flange (). The tool fixture according to the invention permits even large and heavy driven tools with high demands on stiffness and repeatability with respect to radial and axial runout and quality of balance to be changed with little time expenditure.

Device for the fixture of a tool holder

The invention concerns a device for the non-contact measurement of the position of the teeth () of a workpiece () with precut teeth on a gear finishing machine. The measuring probe, retractable from the measuring position into a position of rest protected against soiling, is arranged in a holder () for radial and axial adjustment relative to the workpiece, the said holder () being a kinematic member of a parallelogram linkage (A) and by means of a hydraulic, pneumatic or electromechanical swivel drive () is swivellable from stop to stop between measuring position and position of rest in a plane containing the workpiece axis, such that in the advancement action from the lower end position to the top end position motions of the measuring probe () tangential to the workpiece circumference are completely avoided. The parallelogram kinematics moreover afford adequate protection against swarf and grinding dust, and lends the device a high stiffness and reliability.

Tooth aligning device for the aligning of workpiece with pre-cut teeth on gear finishing machines

The process describes how transmission gears ( ) can be manufactured in a highly economical and highly precise manner. In one single mounting, the complete hard fine-machining on all of the most important functional surfaces of the workpiece is conducted simultaneously. This multi-process is made possible through the combined use of a continuous generating grinding process for the machining of gearing, a known method for the machining of the boring and possibly of a frontal surface, and the fixing of workpieces ( ) on form elements such as chamfers or plane surfaces by means of centering elements ( ) which are designed in such a way that they do not block the free access of the individual tools ( ) to the surfaces ( ) to be machined.

Process for the fine machining of the toothed gears of a gearbox

On account of the constructional form of the tool head ( ) according to the invention, the opposite sides ( ) of a tool ( ) attached to the tool spindle ( ) of a numerically controlled continuously generating gear grinding or hobbing machine are capable of machining the upper and lower sets of teeth ( ) of a double-sided face-gear ( ) in one and the same set-up and without disturbing the synchronization between the rotations of the grinding worm and workpiece maintained during the grinding of the first set of teeth, without risk of collision. This eliminates the need to reset the workpiece ( ) between the machining of the two sets of teeth ( ), thereby shortening the overall machining time substantially, and allowing the avoidance of accuracy losses due to the resetting of the workpiece ( ).

Machining the teeth of double sided face gears

Determining of the starting and end positions of the machining programme of a gear making machine with respect to the axial position of the workpiece ( ) by means of a laser light line ( ) projected at right angles to the workpiece axis, the position of which light line relative to the reference point of the tool ( ) is known. By mutual displacement parallel to the workpiece axis, the light line ( ) and one or both of the workpiece end faces ( ) are brought to coincide. The axial positions thus obtained are transmitted to the machine control system. The determining of the axial tool position takes place analogously by the projection of a laser light line onto the circumference surface of the tool ( ) at right angles to the tool axis.

Setting up process for a tool or workpiece on a gear making machine

A profiling tool ( ) is used for profiling or dressing the grinding worm thread, wherein said tool has a simple basic geometric shape, for example in the shape of a rod. The profiling tool ( ) has on its active, abrasive surface ( ) a transformed topology as needed for the grinding worm ( ). The tool passes the grinding worm profile ( ) during the profiling process in such a manner that points on the active profiling tool surface are matched in advance and brought into contact with corresponding points on the grinding worm flanks. Thereby topologically modified grinding worms may be essentially profiled faster than in traditional methods.

Topological profiling of grinding worms for continuous generating grinding of gear teeth

In a housing ( ), a hollow shaft ( ) is located for rotation, driven by a motor ( ). Rigidly attached to the shaft ( ) is a pressure vessel ( ). Fitted to the shaft ( ) inside the vessel ( ) is a filter comprising a number of tube-shaped filter elements ( ). The liquid to be filtered is fed into an upper chamber ( ) of the shaft ( ) via an inlet ring ( ), and flows through transverse holes ( ) into the vessel ( ). After passing through the filter ( ), the purified liquid is discharged via holes ( ) in the hollow shaft ( ) through an outlet ring ( ). To clean the filter the residual liquid in the vessel ( ) is pressed out through the filter with compressed air. Subsequently the deposit adhering to the filter tubes ( ) is flung off by rotating the shaft ( ) and propelled to the bottom of the vessel by feeding compressed air or clean oil to cleaning nozzles ( ). An outlet ring ( ) is raised slightly and the deposit at the vessel wall is dried by centrifuging. After opening the ring ( ) completely, the dried deposit is flung out through the gap between ring ( ) and the vessel base ( ).

Process for the filtration and drying of solid particles out of liquids

Process and device for the fine machining of the toothed gears of a gearbox

The gear consists of a housing ( ) to which a drive motor ( ) is flanged. Its shaft ( ) carries a sun wheel ( ) on which multiple planets ( ) roll off. The planets ( ) are positioned on a planetary carrier ( ) which is rigidly connected to the output shaft ( ). The shaft ( ) is supported in the housing ( ) coaxial to the shaft ( ). Mounted to the housing ( ) is a flange ( ) of a cup-shaped annular wheel ( ). Its lower rim ( ) has a running surface ( ) inside, on which the planets ( ) roll off. The diameter of the running surface ( ) is smaller than the sum of the diameter of the sun wheel ( ) and twice the diameter of the planets ( ), so that the rim ( ) is elastically deformed. The planets ( ) are supported rigidly in the circumferential direction and flexibly in the radial direction on the planetary carrier ( ). Through this implementation, a backlash-free, rotationally very rigid gear is obtained with which high torques can be transferred in smooth operation.

Backlash-free gear

In a first step, the grinding worm profile is dressed according to the requirements of the workpiece that is to be machined. In a second step, the thereby shaped grinding worm, which has been slightly deformed by the effects of the centrifugal force, is measured at operating speed. In a third step, the measured values are converted into control data for a correcting, redressing process of the grinding worm flanks. Finally in a fourth step, the grinding worm flanks are redressed in such a manner that form errors, which are caused by various influences during grinding, are used as correction factors in the machining of the worm profile. The measuring of the grinding worm flanks may be performed directly without contact by means of a distance sensor or indirectly, whereby a sample toothed wheel is ground and this wheel is then measured by means of a tooth-flank measuring machine. The described process makes possible a highly precise tooth-flank grinding process at high grinding worm speed and thereby cost-effective machining is achieved.

Process and device for dressing high-speed grinding worms

The device has a holder (,) in which an arbor (,) is located displaceably in direction z&prime;. The arbor (,) is centralized by springs (,) and damped by damping elements (,). Located on the arbor (,) is a sleeve (,), displaceable in the x-direction at right angles to the z&prime;-direction. The sleeve (,) is centralized by further springs, and damped by damping elements (,). Located for rotation in radial roller bearings (,) on the sleeve (,) is a further ring (,). The axis of rotation (,) is parallel to the z&prime;-direction. Clamped on the ring (,) is a honing tool (,). With this device, vibrations arising during honing can be effectively damped. The machining of the gear is thereby improved, and the honing tool life prolonged.

Device for the honing of gears

The profiling tool (10) has a segment (12) of a worm thread. Its active zone (13) is coated with grains of hard material (16) and is crowned in cylinder sections coaxial to the tool axis (26). During profiling, the grinding spindle (2) and the tool (10) rotate synchronously. By appropriate correction of the coupling ratio by means of a CNC control when moving the tool (10) in axial direction of the grinding worm (2), the grinding worm flank (1) can be dressed with any desired topology. The method makes it possible to profile topologically modified grinding worms (2) at the grinding worm (2) rotational speed used for grinding, which was previously not possible.

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Pfaffikon, Switzerland

Walter Wirz