A gear machining apparatus causes a machining tool and a workpiece to rotate at a high speed in synchronization with each other to machine a highly accurate gear through cutting. The machining tool is manufactured such that each of pitches between tool blades of the machining tool is an integer multiple of a pitch between teeth of the gear, the integer multiple being equal to or larger than double. By using the machining tool for cutting performed by the gear machining apparatus, the number of the tool blades of the machining tool, which are brought into contact with the workpiece at the same time, is reduced. Thus, it is possible to suppress occurrence of self-excited vibrations during cutting by reducing the cutting resistance. Thus, it is possible to enhance the tooth trace accuracy of the gear.

The invention relates to a peeling wheel for manufacturing a toothing on a gear wheel by skiving. The peeling wheel includes a toothing, which is formed by a plurality of equally shaped cutting teeth arranged and distributed around the rotational axis of the peeling wheel at a first pitch and at least one deviating cutting tooth, whose shape is different from the shape of the equally shaped cutting teeth. The cutting teeth include cutting edges with which they come into chip removing engagement with the material of the gear wheel during the skiving processing. In order to be able to produce toothings with such a peeling wheel with increased freedom in the design, the invention proposes that the deviating cutting tooth is arranged outside of the first pitch (p). The invention also relates to a method for producing a toothing on a gear wheel by skiving using a peeling wheel.

The invention relates to a peeling wheel for manufacturing a toothing on a gear wheel by skiving. The peeling wheel includes a toothing, which is formed by a plurality of equally shaped cutting teeth arranged and distributed around the rotational axis of the peeling wheel at a first pitch and at least one deviating cutting tooth, whose shape is different from the shape of the equally shaped cutting teeth. The cutting teeth include cutting edges with which they come into chip removing engagement with the material of the gear wheel during the skiving processing. In order to be able to produce toothings with such a peeling wheel with increased freedom in the design, the invention proposes that the deviating cutting tooth is arranged outside of the first pitch (p). The invention also relates to a method for producing a toothing on a gear wheel by skiving using a peeling wheel.

Disclosed is a skiving tool for machining teeth where machining marks are produced at unequal distances. Some cutting edges of a skiving tool at least partially extend at different heights along a tool axis. During machining, cutting edges arranged at different axial heights relative to the workpiece axis successively engage on a tooth flank. The engagement of the cutting edges occurs at different time intervals and at different distances in the width direction of the tooth flank. The effects of the engagement of the cutting edges on the machining process and the excitation of vibrations when the teeth produced are used therefore have a frequency spectrum of greater width and lower amplitude than if the cutting edges were to engage at equal time intervals and equal distances. The more irregular surface structure of the teeth have a positive effect on noise excitation behavior when teeth are engaging with other teeth.

Disclosed is a skiving tool for machining teeth where machining marks are produced at unequal distances. Some cutting edges of a skiving tool at least partially extend at different heights along a tool axis. During machining, cutting edges arranged at different axial heights relative to the workpiece axis successively engage on a tooth flank. The engagement of the cutting edges occurs at different time intervals and at different distances in the width direction of the tooth flank. The effects of the engagement of the cutting edges on the machining process and the excitation of vibrations when the teeth produced are used therefore have a frequency spectrum of greater width and lower amplitude than if the cutting edges were to engage at equal time intervals and equal distances. The more irregular surface structure of the teeth have a positive effect on noise excitation behavior when teeth are engaging with other teeth.

A coating film has a lamination unit including a first layer and at least one of a second layer and a third layer. The first layer is a nitride or the like of a first material represented by (Cr.sub.1-a-b-cAl.sub.a[Ni.sub.1-dZr.sub.d].sub.bX.sub.c). X is at least one element selected from Ti, Nb, Si, B, W, and V. a, b, c, and d represent atomic concentrations. The second layer is a nitride or the like of the second material represented by (Al.sub.eCr.sub.1-e-fZ.sub.f). Z is at least one element selected from Si, Y, and B. e and f represent atomic concentrations. The third layer is a nitride or the like of the third material represented by (Al.sub.gCr.sub.1-g).