An expandable handheld pneumatic belt grinder includes a body, an expansion component and an operation component. The body has a receiving space, a pneumatic motor, and a rotating wheel driven by the pneumatic motor. The expansion component has an expansion pipe and an expansion rod which are connected. The expansion rod is coupled to the receiving space. The operation component has a support rod with one end carrying a driven wheel and the other end coupled to the receiving space or expansion pipe. A grinding belt fits around the driven wheel and rotating wheel collectively. A user changes the distance between the rotating wheel and driven wheel by choosing between two options: coupling the support rod of operation component and the receiving space; and coupling the expansion rod of expansion component and the receiving space, and then coupling the support rod of operation component and the expansion pipe.

An expandable handheld pneumatic belt grinder includes a body, an expansion component and an operation component. The body has a receiving space, a pneumatic motor, and a rotating wheel driven by the pneumatic motor. The expansion component has an expansion pipe and an expansion rod which are connected. The expansion rod is coupled to the receiving space. The operation component has a support rod with one end carrying a driven wheel and the other end coupled to the receiving space or expansion pipe. A grinding belt fits around the driven wheel and rotating wheel collectively. A user changes the distance between the rotating wheel and driven wheel by choosing between two options: coupling the support rod of operation component and the receiving space; and coupling the expansion rod of expansion component and the receiving space, and then coupling the support rod of operation component and the expansion pipe.

Disclosed is an oscillatingly driven machine tool including a tool spindle that is mounted pivotably about its longitudinal axis, further including a drive motor that is coupled to a hydraulic generator for generating an oscillating fluid flow which drives a hydraulic motor being configured as a rotor blade motor. The rotor blade motor drives the tool spindle in such a way that the tool spindle rotates oscillatingly about its longitudinal axis. The rotor blade motor includes symmetrically arranged rotor blades that are disposed at regular angular distances with respect to each other.

Disclosed is an oscillatingly driven machine tool including a tool spindle that is mounted pivotably about its longitudinal axis, further including a drive motor that is coupled to a hydraulic generator for generating an oscillating fluid flow which drives a hydraulic motor being configured as a rotor blade motor. The rotor blade motor drives the tool spindle in such a way that the tool spindle rotates oscillatingly about its longitudinal axis. The rotor blade motor includes symmetrically arranged rotor blades that are disposed at regular angular distances with respect to each other.

A device and a method for machining of a flat side of an optical workpiece. The device has two flat guides and a side guide for fluidic guidance of a spindle unit and/or a slide. A linear drive with an assigned tool is located on a slide with a turntable. Highly accurate machining is enabled.

A device and a method for machining of a flat side of an optical workpiece. The device has two flat guides and a side guide for fluidic guidance of a spindle unit and/or a slide. A linear drive with an assigned tool is located on a slide with a turntable. Highly accurate machining is enabled.

A grinding machine includes a rotatable spindle having a lower end to which a grindstone for grinding a wafer is attached; linear guides supporting the spindle slidably to a column; a spindle feeding mechanism feeding the spindle in a vertical direction; and constant-pressure feeding mechanism interposed between the spindle feeding mechanism and the column and suspending the spindle feeding mechanism. The constant-pressure feeding mechanism raises the spindle feeding mechanism in the vertical direction when a friction force acting on the grindstone is higher than a predetermined value

A grinding machine includes a rotatable spindle having a lower end to which a grindstone for grinding a wafer is attached; linear guides supporting the spindle slidably to a column; a spindle feeding mechanism feeding the spindle in a vertical direction; and constant-pressure feeding mechanism interposed between the spindle feeding mechanism and the column and suspending the spindle feeding mechanism. The constant-pressure feeding mechanism raises the spindle feeding mechanism in the vertical direction when a friction force acting on the grindstone is higher than a predetermined value

Pneumatic machining device includes a fixing plate, a hollow piston shell, a piston group, a machining tool, a first sealing group, and a second sealing group. The piston shell is fixed to the fixing plate and coupled to a first external pressure source and second external pressure source to feed gas into the piston shell to drive the piston group and the machining tool, respectively. The piston group and the first and second sealing groups are received inside the piston shell. The piston group is driven by the first external pressure source to move away from the fixing plate. The first and second sealing groups divide the piston shell into a number of chambers for controlling a gas pressure. The machining tool is coupled to the piston group and extends out of the piston shell to machine a workpiece as the piston group moves away from the fixing plate.

Pneumatic machining device includes a fixing plate, a hollow piston shell, a piston group, a machining tool, a first sealing group, and a second sealing group. The piston shell is fixed to the fixing plate and coupled to a first external pressure source and second external pressure source to feed gas into the piston shell to drive the piston group and the machining tool, respectively. The piston group and the first and second sealing groups are received inside the piston shell. The piston group is driven by the first external pressure source to move away from the fixing plate. The first and second sealing groups divide the piston shell into a number of chambers for controlling a gas pressure. The machining tool is coupled to the piston group and extends out of the piston shell to machine a workpiece as the piston group moves away from the fixing plate.