Work spindle

A work spindle for a machine tool, comprising:

• a spindle guard tube rotatably mounted in spindle bearings,
• the spindle guard tube being drivable by a motor,
• a clamping arrangement disposed at an end of the spindle guard tube,
• a clamping force generator, which is arranged on the spindle guard tube and operates the clamping arrangement, and which has at least one first cylinder chamber enclosed by a first cylinder housing and a first piston, which in order to generate a clamping force in the clamping arrangement, is subjected to a pressurized medium, and
• a connection between the clamping force generator and the clamping arrangement, wherein:
• the clamping force generator has a second cylinder chamber enclosed by a second cylinder housing and a second piston;
• for operation of the clamping arrangement, always both cylinder chambers are subjected to a pressurized medium;
• and
• in order to generate different clamping forces, the clamping force generator is switchable over from a first working mode, in which at least the first piston operates the clamping arrangement, into a second working mode, in which at least the second piston operates the clamping arrangement.