Abstract: A preload detectable screw device is provided which can detect preload with accuracy and can reduce the influence of generated heat on the output of a sensor. A screw device (1) includes a screw shaft (2), a nut member (3), a plurality of rolling elements (7, 8), at least one axial strain sensor (24) (B, D) that is attached to a surface of the nut member (3) and detects strain in an axial direction on the nut member (3), and at least one circumferential strain sensor (24) (A, C) that is attached to the surface of the nut member (3) and detects strain in a circumferential direction on the nut member (3). Preload of the screw device (1) is detected on the basis of outputs of the axial strain sensor (24) (B, D) and the circumferential strain sensor (24) (A, C).

Abstract: A preload detectable screw device is provided which can detect preload with accuracy and can reduce the influence of generated heat on the output of a sensor. A screw device (1) includes a screw shaft (2), a nut member (3), a plurality of rolling elements (7, 8), at least one axial strain sensor (24) (B, D) that is attached to a surface of the nut member (3) and detects strain in an axial direction on the nut member (3), and at least one circumferential strain sensor (24) (A, C) that is attached to the surface of the nut member (3) and detects strain in a circumferential direction on the nut member (3). Preload of the screw device (1) is detected on the basis of outputs of the axial strain sensor (24) (B, D) and the circumferential strain sensor (24) (A, C).

Abstract: Provided is an encoder device capable of reducing interference between a magnetic field generated in a reference mark and a magnetic field generated in a scale. An encoder device is provided with a reference mark and a head. The reference mark has: a first scale coil; and a second scale coil electrically connected to the first scale coil. The head has: a transmission coil that transmits an electromagnetic wave without any contact to the first scale coil; a reception coil that receives an electromagnetic wave without any contact from the second scale coil; and electric circuits that generate a pulse for generating an origin signal from the electromagnetic wave received by the reception coil, if the transmission coil faces the first scale coil and the reception coil faces the second scale coil.

Abstract: Provided is an encoder device capable of reducing interference between a magnetic field generated in a reference mark and a magnetic field generated in a scale. An encoder device is provided with a reference mark and a head. The reference mark has: a first scale coil; and a second scale coil electrically connected to the first scale coil. The head has: a transmission coil that transmits an electromagnetic wave without any contact to the first scale coil; a reception coil that receives an electromagnetic wave without any contact from the second scale coil; and electric circuits that generate a pulse for generating an origin signal from the electromagnetic wave received by the reception coil, if the transmission coil faces the first scale coil and the reception coil faces the second scale coil.

Abstract: A foreign matter detecting device comprises a first yoke portion and a second yoke portion which adjoin a permanent magnet respectively. The both yoke portions are arranged while interposing a reference space therebetween. Further, a detour yoke portion is arranged. A magnetic resistance of the first detour space being smaller than a magnetic resistance of the predetermined reference space, and magnetic resistances of the second detour space and the first detour space being larger than the magnetic resistance of the predetermined reference space. A detection signal in relation to the foreign matter is outputted on the basis of a magnetic flux density provided in at least any one of spaces of the reference space and the first detour space, corresponding to an amount of retention of the foreign matter in a retaining portion which is provided so that the foreign matter is retained in the second detour space.

Abstract: A position detection apparatus is provided which eliminates the necessity of space to affix a scale to a track member. A track member of a motion guide apparatus is provided with a through hole into which a fastening member to fasten the track member to a base can be inserted. A carriage that is movably assembled to the track member via a rolling element is provided with magnets generating a magnetic field toward the track member. Magnetic sensors that detect a change in the magnetic fields of the magnets with the travel of the magnets relative to the track member are placed within the magnetic fields of the magnets.

Abstract: A foreign matter detecting device comprises a first yoke portion and a second yoke portion which adjoin a permanent magnet respectively. The both yoke portions are arranged while interposing a reference space therebetween. Further, a detour yoke portion is arranged. A magnetic resistance of the first detour space being smaller than a magnetic resistance of the predetermined reference space, and magnetic resistances of the second detour space and the first detour space being larger than the magnetic resistance of the predetermined reference space. A detection signal in relation to the foreign matter is outputted on the basis of a magnetic flux density provided in at least any one of spaces of the reference space and the first detour space, corresponding to an amount of retention of the foreign matter in a retaining portion which is provided so that the foreign matter is retained in the second detour space.

Abstract: A position detection apparatus is provided which eliminates the necessity of space to affix a scale to a track member. A track member of a motion guide apparatus is provided with a through hole into which a fastening member to fasten the track member to a base can be inserted. A carriage that is movably assembled to the track member via a rolling element is provided with magnets generating a magnetic field toward the track member. Magnetic sensors that detect a change in the magnetic fields of the magnets with the travel of the magnets relative to the track member are placed within the magnetic fields of the magnets.

Abstract: A magnetic-scale-equipped motion guide apparatus is provided which can scrape iron powder adhered to a magnetic scale by a scraper or seal of a movable member without inviting adverse effects such as wearing away and deformation of the magnetic scale. The magnetic-scale-equipped motion guide apparatus of the present invention comprises a track member 1 having a rolling element rolling portion 1b and also an upper surface where through holes 18 into which fastening members are inserted open, a movable member 2 movably assembled to the track member 1 via a plurality of rolling elements 3, a groove 1a formed in the track member 1 and extended in a longitudinal direction, a magnetic scale 7 accommodated in the groove 1a and having north and south poles alternately formed in the longitudinal direction, and a cover member 8 that covers the magnetic scale 7 and also the through holes 18 of the track member 1.

Abstract: A linear encoder device (60) includes: a synchronization signal generation unit (83) configured to generate a periodic synchronization signal synchronized with a movement distance when a first sensor (66) installed to face a linear scale (61) is moved along the linear scale (61) based on a signal output by the first sensor (66); a reference signal generation unit (82) configured to generate a pulse signal indicating that the reference mark is detected based on a signal output by a second sensor (67) installed along with the first sensor (66); and a reference position detection unit (84) configured to generate a reference position signal indicating that a reference position decided in advance is detected when the synchronization signal is changed to a predetermined value after the reference signal generation unit (82) generates the pulse signal.

Abstract: A magnetic-scale-equipped motion guide apparatus is provided which can scrape iron powder adhered to a magnetic scale by a scraper or seal of a movable member without inviting adverse effects such as wearing away and deformation of the magnetic scale. The magnetic-scale-equipped motion guide apparatus of the present invention comprises a track member 1 having a rolling element rolling portion 1b and also an upper surface where through holes 18 into which fastening members are inserted open, a movable member 2 movably assembled to the track member 1 via a plurality of rolling elements 3, a groove 1a formed in the track member 1 and extended in a longitudinal direction, a magnetic scale 7 accommodated in the groove 1a and having north and south poles alternately formed in the longitudinal direction, and a cover member 8 that covers the magnetic scale 7 and also the through holes 18 of the track member 1.

Abstract: A linear encoder device (60) includes: a synchronization signal generation unit (83) configured to generate a periodic synchronization signal synchronized with a movement distance when a first sensor (66) installed to face a linear scale (61) is moved along the linear scale (61) based on a signal output by the first sensor (66); a reference signal generation unit (82) configured to generate a pulse signal indicating that the reference mark is detected based on a signal output by a second sensor (67) installed along with the first sensor (66); and a reference position detection unit (84) configured to generate a reference position signal indicating that a reference position decided in advance is detected when the synchronization signal is changed to a predetermined value after the reference signal generation unit (82) generates the pulse signal.