Abstract: A screw device is provided which can detect damage to a groove of a screw shaft, the damage being hidden by a nut, with a high probability. At least two circulation components are mounted on a nut in such a manner as to form at least two circulation circuits that circulate rolling elements. The nut is provided with a sensor that detects a displacement of a groove of a screw shaft between the adjacent circulation circuits.

Abstract: A screw device is provided which can detect damage to a groove of a screw shaft, the damage being hidden by a nut, with a high probability. At least two circulation components are mounted on a nut in such a manner as to form at least two circulation circuits that circulate rolling elements. The nut is provided with a sensor that detects a displacement of a groove of a screw shaft between the adjacent circulation circuits.

Abstract: A digital data transmitting apparatus including a reproducing device classifies serial packet data that are read at a variable rate from a digital data medium and demodulates into at least picture data, audio data and other data, an MPEG transport stream (MPEG-TS) generating device generates an MPEG-TS based on the digital data, and a digital interface device converts the generated MPEG-TS into digital transmission data and transmits the digital transmission data at a predetermined transmission rate. A digital data receiving apparatus including a digital interface device is operable at a predetermined transmission rate, a digital data receiving device receives digital data via the digital interface device, an MPEG-TS reproducing device reproduces an MPEG-TS from the received digital data, a reproducing device classifies the reproduced MPEG-TS into at least picture data, audio data, and private data, and a control device controls the reproducing device based on the private data.