A power tool includes an outer housing having a drive unit support portion and a handle portion, an inner housing positioned at least partially within the handle, and a drive unit positioned in the drive unit support portion. The drive unit includes an output shaft extending at least partially through the handle portion. The power tool also includes a ball screw mechanism having a nut supported at least partially within the inner housing and a screw coupled to the nut for relative axial displacement therewith in response to relative rotation between the screw and the nut. Torque from the output shaft is applied to one of the nut and the screw to cause the relative rotation. The handle portion exerts a reaction torque on the inner housing in response to the relative rotation between the nut and screw to prevent the inner housing from rotating relative to the outer housing.

The present application provides a servo motor drive circuit and a 3D printing apparatus, a motion controller is configured to send a drive enable signal to the timer; a pulse period providing unit is configured to send a pulse period value to the timer and the first comparing unit at beginning of each pulse period; the timer is configured to perform initialization in response to the received pulse period value during enabling of the drive enable signal, perform cyclic timing by taking the pulse period value as a timing period, and send a timing duration to the first comparing unit; and the first comparing unit is configured to acquire current level information that satisfies a preset duty ratio according to the preset duty ratio, the pulse period value, and the timing duration, and send a drive signal to a servo motor according to the current level information.

A servo motor controller includes: a servo motor; a driven member which is driven by the servo motor and in which a load acting on a drive axis is varied depending on the position of the driven member; a position detection portion and a speed detection portion for the driven member; and a motor control portion, where the motor control portion includes: a position control portion which calculates a speed command based on a positional error between a position command for the driven member and the position FB; a speed control portion which calculates a torque command by multiplying a speed error between the speed command and the speed FB by a speed gain and/or adding a torque offset to the speed error; and a change portion which changes at least one of the speed gain and the torque offset according to the position of the driven member.

A power tool includes an outer housing having a drive unit support portion and a handle portion, an inner housing positioned at least partially within the outer housing, and a drive unit positioned in the drive unit support portion, the drive unit including an output member. The power tool also includes a power screw mechanism with a nut fixed relative to the outer housing and a screw coupled for co-rotation with the output member and axially movable relative to the output member. The screw is in threaded engagement with the nut such that the screw moves axially in response to rotation of the screw relative to the nut. The power tool also includes a working assembly coupled to the inner housing for movement in response to axial movement of the screw.

A numerical control apparatus includes: a thread-whirling motor controller controlling, based on a thread lead representing a movement amount of a thread whirling tool per rotation of a workpiece, a reference differential speed representing a difference between a predetermined reference rotational speed of the thread whirling tool and a rotational speed of the workpiece, the number of tool blades of the thread whirling tool, and a workpiece spindle speed representing the rotational speed of the workpiece, a first motor moving the thread whirling tool, a second motor rotating the thread whirling tool, and a third motor rotating the workpiece. The thread-whirling motor controller controls: the first motor based on the thread lead and the reference differential speed; the second motor based on the thread lead, the reference differential speed, the number of tool blades, and the workpiece spindle speed; and the third motor based on the workpiece spindle speed.

A numerical control apparatus includes: a thread-whirling motor controller controlling, based on a thread lead representing a movement amount of a thread whirling tool per rotation of a workpiece, a reference differential speed representing a difference between a predetermined reference rotational speed of the thread whirling tool and a rotational speed of the workpiece, the number of tool blades of the thread whirling tool, and a workpiece spindle speed representing the rotational speed of the workpiece, a first motor moving the thread whirling tool, a second motor rotating the thread whirling tool, and a third motor rotating the workpiece. The thread-whirling motor controller controls: the first motor based on the thread lead and the reference differential speed; the second motor based on the thread lead, the reference differential speed, the number of tool blades, and the workpiece spindle speed; and the third motor based on the workpiece spindle speed.

A motor control device capable of promptly positioning a driven object at a target position, while suppressing backlash. The motor control device includes an operation command generation section for generating a first operation command and a second operation command for first and second motors to move the driven object; a preload command generation section for generating a first preload command which is added to the first operation command and a second preload command which is added to the second operation command in order that drive axes of the first motor and the second motor provide the driven object forces in opposite directions; and a preload command adjustment section for adjusting the first preload command and the second preload command in order that an absolute value of the above forces is decreased when an operation amount exceeds a predetermined threshold value.

The present application provides a servo motor drive circuit and a 3D printing apparatus, a motion controller is configured to send a drive enable signal to the timer; a pulse period providing unit is configured to send a pulse period value to the timer and the first comparing unit at beginning of each pulse period; the timer is configured to perform initialization in response to the received pulse period value during enabling of the drive enable signal, perform cyclic timing by taking the pulse period value as a timing period, and send a timing duration to the first comparing unit; and the first comparing unit is configured to acquire current level information that satisfies a preset duty ratio according to the preset duty ratio, the pulse period value, and the timing duration, and send a drive signal to a servo motor according to the current level information.

A power tool includes an outer housing having a drive unit support portion and a handle portion, an inner housing positioned at least partially within the outer housing, and a drive unit positioned in the drive unit support portion, the drive unit including an output member. The power tool also includes a power screw mechanism with a nut fixed relative to the outer housing and a screw coupled for co-rotation with the output member and axially movable relative to the output member. The screw is in threaded engagement with the nut such that the screw moves axially in response to rotation of the screw relative to the nut. The power tool also includes a working assembly coupled to the inner housing for movement in response to axial movement of the screw.

A motor control device capable of promptly positioning a driven object at a target position, while suppressing backlash. The motor control device includes an operation command generation section for generating a first operation command and a second operation command for first and second motors to move the driven object; a preload command generation section for generating a first preload command which is added to the first operation command and a second preload command which is added to the second operation command in order that drive axes of the first motor and the second motor provide the driven object forces in opposite directions; and a preload command adjustment section for adjusting the first preload command and the second preload command in order that an absolute value of the above forces is decreased when an operation amount exceeds a predetermined threshold value.