Dressing device and gear grinding device

A gear grinding device comprising:

• a work gear spindle by which a work gear is rotatably supported;
• and
• a gear grinding tool spindle by which a threaded grinding wheel configured to grind the work gear is rotatably supported and which is parallel to a direction orthogonal to the work gear spindle,
• the gear grinding device being configured to perform bias adjustment of the work gear by using the threaded grinding wheel, wherein
• a tool in which a pressure angle varies from one end side to the other end side in a tooth trace direction and a lead varies from the one end side to the other end side in an axial direction is used as the threaded grinding wheel,
• the work gear and the threaded grinding wheel are rotationally driven and at least one of the work gear and the threaded grinding wheel is moved from the one end side to another end side in the axial direction of the threaded grinding wheel so that a tooth face of the threaded grinding wheel in which the pressure angle varies comes into contact with a tooth face of the work gear, and
• a number of revolutions of the work gear is varied to correspond to variation of a lead of the threaded grinding wheel according to a relative movement of the work gear from the one end side to the other end side of the threaded grinding wheel.

A dressing device comprising:

• a rotatably supported gear grinding tool spindle for driving a threaded grinding wheel for machining of a gear;
• and
• a rotatably supported dressing tool which is parallel to the gear grinding tool spindle and which dresses the threaded grinding wheel,
• the dressing device being configured to rotationally drive the threaded grinding wheel;
• to bring the threaded grinding wheel and the dressing tool into contact with each other;
• and to move at least one of the threaded grinding wheel and the dressing tool relative to the other in an axial direction of the threaded grinding wheel and the dressing tool, wherein
• the dressing device is configured to move at least one of the threaded grinding wheel and the dressing tool in the axial direction at a constant speed while changing a rotating speed of the threaded grinding wheel according to a relative movement of the dressing tool from one end side to another end side of the threaded grinding wheel;
• or to change a moving speed of at least one of the threaded grinding wheel and the dressing tool in the axial direction according to a relative movement of the dressing tool from one end side to the other end side of the threaded grinding wheel while rotating the threaded grinding wheel at a constant speed, whereby a dressing process performed on the threaded grinding wheel varies a pressure angle from the one end side to the other end side in a tooth trace direction and varies the lead from the one end side to the other end side in the axial direction.