The present invention provides certain additional improvements for such mechanical-type multi-axis machine tools. These improvements include: (1) permitting the spindles to be rotated about their respective axes relative to the member independently of one another, (2) providing a low-cost, and yet highly-effective, sensor apparatus for determining the angular position of the member relative to the frame without the use of an expensive encoder or the like, (3) mounting the rotatable member more precisely relative to the frame, and (4) providing a zero-backlash tool slide on the frame for imparting an action to a workpiece.

The present invention provides certain additional improvements for such mechanical-type multi-axis machine tools. These improvements include: (1) permitting the spindles to be rotated about their respective axes relative to the member independently of one another, (2) providing a low-cost, and yet highly-effective, sensor apparatus for determining the angular position of the member relative to the frame without the use of an expensive encoder or the like, (3) mounting the rotatable member more precisely relative to the frame, and (4) providing a zero-backlash tool slide on the frame for imparting an action to a workpiece.

A rotational force transmission mechanism includes a shaft and an engagement member. The shaft is rotatable about a first axis. The shaft includes a leading end portion having a second groove and a first groove which is configured to receive a rotatable portion of a tool holder so that the shaft rotates the rotatable portion about the first axis. The engagement member is movable along the first axis between a first position and a second position and rotatable about the first axis together with the shaft. The engagement member includes an engagement portion configured to be received in the second groove. At least one of the shaft and the engagement member has an inclined surface that moves the engagement portion in a direction toward the first axis when the engagement member moves from the first position to the second position.

A chuck unit as a rotating member of a spindle device includes a base portion fixed to one end of the spindle shaft, an attaching portion detachably attached to a side of the base portion that is located on an opposite side of the base portion from the one end of the spindle shaft, and an accommodation space arranged on a communication passage so as to accommodate a filter.

A chuck unit as a rotating member of a spindle device includes a base portion fixed to one end of the spindle shaft, an attaching portion detachably attached to a side of the base portion that is located on an opposite side of the base portion from the one end of the spindle shaft, and an accommodation space arranged on a communication passage so as to accommodate a filter.

Disclosed is a built-in type electric driving system of a machine tool. The system is capable of directly connecting a motor, which drives a spindle in a lathe which processes a workpiece, to an outer surface of the spindle without using a belt to rotate the spindle, and is capable of selectively transferring the power of the motor to a rotation system including a drawbar and a spindle for driving a chuck using a clutch device.

Disclosed is a built-in type electric driving system of a machine tool. The system is capable of directly connecting a motor, which drives a spindle in a lathe which processes a workpiece, to an outer surface of the spindle without using a belt to rotate the spindle, and is capable of selectively transferring the power of the motor to a rotation system including a drawbar and a spindle for driving a chuck using a clutch device.

In a method for automated positioning of a blank in a processing machine provided with a housing and a spindle unit with an electric motor, a control unit for control and electrical supply of the processing machine, a computer producing processing programs for manufacturing workpieces, a workpiece holder, and an image recording unit that optically records image data of a blank received in the workpiece holder, a blank is fixed in the processing machine and the image recording unit produces an image of the blank. A division of the blank into an already processed region and into an unprocessed region based on the image data of the image is performed. A workpiece geometry to be produced is assigned to the unprocessed region of the blank, and a milling operation is performed on the unprocessed region. In a variant of the method, the image recording unit is separate from the processing unit.

In a method for automated positioning of a blank in a processing machine provided with a housing and a spindle unit with an electric motor, a control unit for control and electrical supply of the processing machine, a computer producing processing programs for manufacturing workpieces, a workpiece holder, and an image recording unit that optically records image data of a blank received in the workpiece holder, a blank is fixed in the processing machine and the image recording unit produces an image of the blank. A division of the blank into an already processed region and into an unprocessed region based on the image data of the image is performed. A workpiece geometry to be produced is assigned to the unprocessed region of the blank, and a milling operation is performed on the unprocessed region. In a variant of the method, the image recording unit is separate from the processing unit.

A fan-equipped motor includes: a motor for rotating a spindle, the motor including a hollow-shaped motor shaft in which a through hole is formed; and a fan for cooling the motor, the fan including a hollow-shaped rotary shaft in which a through hole is formed, and a plurality of blades attached to the rotary shaft, the fan being disposed on the side of the motor that is opposite to the spindle. The motor shaft and the rotary shaft are disposed so that cooling air produced by the fan flows in a different passage and in a different direction from a gas supplied into the through hole of the rotary shaft and flowing in the through hole of the motor shaft.