Apparatus and method for measuring tooth surface deviation, apparatus and method for forming grinding tool, and gear meshing method for gear grinding apparatus

A tooth surface deviation measuring method of measuring a deviation of a tooth surface of a gear with respect to a helical grinding tooth surface of a grinding tool when the grinding tool and the gear rotate in synchronism with each other while the grinding tooth surface of the grinding tool and the tooth surface of the gear are capable of being held in contact with each other, comprising the steps of:

• a detecting step of detecting contact between the grinding tooth surface and the tooth surface with a contact detector;
• a rotational speed changing step of changing a rotational speed of either one of the grinding tool and the gear such that the detection result by the contact detector falls within a prescribed range;
• and
• measuring an amount of phase change of the grinding tool and the gear, which are made in the rotational speed changing step, along an entire circumference of the gear.

A grinding tool forming apparatus comprising:

• a dresser gear having dresser tooth surfaces for contacting grinding tooth surfaces of a helical grinding tooth of a grinding tool, the dresser gear being rotatable in synchronism with the grinding tool while the grinding tooth surface and the dresser tooth surfaces are capable of being held in contact with each other;
• a contact detector for detecting contact between the grinding tooth surface and the dresser tooth surface;
• a rotational speed changing device that is adapted to change a rotational speed of either one of the grinding tool and the dresser gear such that the detection result by the contact detector falls within a prescribed range;
• and
• a recording device that is adapted to record an amount of phase change of the grinding tool and the dresser gear along a prescribed range of the dresser gear;
• wherein the grinding tool and the dresser gear are rotated in synchronism with each other based on information recorded by the recording device.

A grinding tool forming method comprising the steps of:

• a synchronous rotating step of rotating a grinding tool and a dresser gear in synchronism with each other while grinding tooth surfaces of a helical grinding tooth of the grinding tool and dresser tooth surfaces of the dresser gear are capable of being held in contact with each other;
• a detecting step of detecting contact between the grinding tooth surfaces and the dresser tooth surfaces with a contact detector;
• a rotational speed changing step of changing a rotational speed of either one of the grinding tool and the dresser gear such that the detection result by the contact detector falls within a prescribed range;
• and
• a recording step of recording an amount of phase change of the grinding tool and the dresser gear along a prescribed range of the dresser gear;
• wherein the grinding tool and the dresser gear are rotated in synchronism with each other based on information recorded in the recording step.

A gear meshing method for a gear grinding apparatus, comprising the steps of:

• a synchronous rotating step of rotating a grinding tool and a workpiece gear in synchronism with each other while a helical grinding tooth of the grinding tool and a tooth of the workpiece gear are capable of being held in contact with each other;
• a detecting step of detecting contact between the grinding tooth and the tooth with a contact detector;
• a first rotational speed changing step of changing a rotational speed of either one of the grinding tool and the workpiece gear such that the detection result by the contact detector falls within a prescribed range, thereby bringing a right tooth surface of the tooth into contact with the grinding tooth;
• a second rotational speed changing step of changing a rotational speed of either one of the grinding tool and the workpiece gear such that the detection result by the contact detector falls within a prescribed range, thereby bringing a left tooth surface of the tooth into contact with the grinding tooth;
• a recording step of recording an amount of phase change of the grinding tool and the workpiece gear, which are made in the first and second rotational speed changing steps along the entire circumference of the workpiece gear;
• and
• a calculating step of calculating a central position of the tooth with respect to the grinding tooth when the grinding tooth and the tooth are held in mesh with each other, based on information recorded in the recording step.