Z-axis drive assembly

Claim 2

In a machine tool having spindle support means for supporting a spindle, and guide means adapted to guide movement of said support means in a direction parallel to the axis of said spindle; a variable speed drive for driving said support means relative to said guide, comprising, in combination, a rack secured to said support means, a pinion in engagement with said rack, a harmonic drive unit supported in fixed relation relative to said guide for driving said pinion, and a variable speed electric motor mounted in fixed relation relative to said harmonic drive unit for driving said harmonic drive and for moving said support means relative to said guide.

Claim 3

Apparatus according to claim 1, wherein said spindle support means includes a turret for supporting a plurality of spindles at equally spaced locations about the periphery of the spindle.

Claim 4

Apparatus according to claim 1, including means for mounting said harmonic drive unit in fixed relation to said guide means and means for mounting said variable speed motor directly to said harmonic drive unit, whereby the assembly of guide means, harmonic drive unit and motor form a rigid unit with said harmonic drive unit and said motor supported in coaxial alignment.

Claim 5

Apparatus according to claim 3, wherein the member of said guide means upon which is mounted said harmonic drive unit is provided with an aperture in coaxial alignment with said harmonic drive unit, for receiving a pinion supporting shaft of said harmonic drive unit.

Claim 6

Apparatus according to claim 4, including a bearing mounted in said aperture for supporting said pinion shaft.

Claim 7

Apparatus according to claim 3, including a panel for supporting a manual control for said variable speed motor, and means for mounting said panel in fixed relationship to said motor.

Claim 8

Apparatus according to claim 1, including a base including a supporting column, a carriage supported on said column and adapted for vertical movement relative thereto, and mounting means for mounting said harmonic drive unit and said variable speed electric motor on said carriage.

Claim 9

Apparatus according to claim 7, including manual control means supported on said carriage for controlling the speed of said variable speed motor.

Claim 10

Apparatus according to claim 1, wherein said guide means includes a pair of parallel, spaced guide members for guiding the movement of said spindle support means.

Claim 11

In a turret type machining center having a plurality of spindles supported on a turret, means for indexing said turret so that one of said spindles is in operating position, drive means for rotating the spindle in operating position, and slide means for moving said turret in a spindle feed direction parallel to the spindle axis, a spindle feed drive comprising, in combination, a speed reducing harmonic drive unit mounted in fixed relationship with said slide means for moving said turret in said spindle feed direction, and a variable speed DC motor mounted in fixed relationship with said harmonic drive unit for controlling the speed of said spindle feed.

Claim 12

In a turret type machining center having a plurality of spindles supported on a turret, means for indexing said turret so that one of said spindles is in operating position, drive means for rotating the spindle in operating position, and slide means for moving said turret in a spindle feed direction parallel to the spindle axis, a spindle feed drive comprising, in combination, a speed reducing harmonic drive unit mounted in fixed relationship with said slide means for moving said turret in said spindle feed direction, and a variable speed DC motor mounted in fixed relationship with said harmonic drive unit for controlling the speed of said spindle feed.

Claim 13

Apparatus according to claim 10, including a plurality of adjustable controls for regulating the speed of said motor in each individual position of said turret, and a plurality of switches, one for each of said controls, for individually rendering said controls operative in response to the position of said turret.

Claim 14

Apparatus according to claim 11, wherein said controls comprise variable resistors, and including a motor control unit for said DC motor regulating the speed of said motor in accordance with the resistance included in a control circuit, and means including said switches for connecting one of said variable resistors in operative relation with said control circuit.

Claim 15

Apparatus according to claim 10, wherein said harmonic drive comprises a cup-shaped flex spline member having a generally cylindrical portion and an end portion, a case surrounding said flex spline member, bearing means supported by said case for supporting the end portion of said flex spline member, a pinion shaft connected to said end member and extending through an aperture in said case, means for mounting said DC motor on said case with a motor shaft of said motor coaxially extending into the cylindrical portion of said flex spline member, a wave generator mounted on said motor shaft within the cylindrical portion of said flex spline, and a fixed circular spline secured to said case at a position encircling said cylindrical portion and said wave generator.