Patent classifications
G01L3/103
Load measuring arrangement for magnetostrictive measurement of a load on a test object as well as manufacturing method
For more accurate load measurement, a load measuring arrangement includes a test object and a load measuring device for measuring a load on the test object. The load measuring device includes at least one magnetic field detection device for detecting a magnetic field parameter changing due to load at a measuring zone of the test object. The test object is work-hardened, at least at the measuring zone and at least in a near-surface region extending from a surface facing the magnetic field detection device to a depth of 20 m, in such a way that it has a dislocation density of at least 5e8/cm.sup.2 and/or a residual stress of at least 400 MPa in amount.
Device and method for sensing torques, torsional natural frequencies, and/or torsional oscillations without contact
The invention relates to a device (14) and to a method for the contactless detection of a torque of a shaft (10) and/or torsional natural frequencies and/or torsional oscillations. The shaft (10) contains a ferromagnetic material. A measurement head (16) facing toward a shaft wall (12) comprises an excitation coil (22) which couples a magnetic field into the shaft (10). The measurement head (16) furthermore contains a number of measurement coils (24, 26, 28, 30), which measure the magnetic field emerging from the shaft (10).
Method for manufacturing magnetostrictive torque sensor shaft
Provided is a method for manufacturing a magnetostrictive torque sensor shaft mounting a sensor portion of a magnetostrictive torque sensor. The method includes conducting heat treatment on a shaft material including chrome steel or chrome-molybdenum steel by carburizing, quenching and tempering, and conducting shot peening on the shaft material after the heat treatment at least on a position where the sensor portion is to be mounted. The shot peening is conducted by firing shot with a particle size of not less than 0.6 mm and a Rockwell hardness of not less than 60 at a jet pressure of not less than 0.4 MPa for a jet exposure time of not less than 2 minutes.
MAGNETOSTRICTION TYPE TORQUE DETECTION SENSOR
There is provided a magnetostriction type torque detection sensor capable of detecting a torque which is generated at the entire circumference of a side surface of a detected object, in a uniform manner and with an improved detection sensitivity, and also capable of being reduced in size of the sensor in the axial direction of the detected object.
A plurality of cores having at least three or more leg portions connected to each other by a bridging portion located at an outer circumferential surface side of an insulating tubular body is arrayed while being inclined at a predetermined angle to the axis of a detected object and is attached in such a manner that a plurality of leg portion end surfaces face the detected object via an inner circumferential surface of the insulating tubular body.
Magnetostriction type torque detection sensor
There is provided a magnetostriction type torque detection sensor which is improved in torque detection sensitivity by increasing respective magnetic paths which are formed between a detected object and a plurality of cores attached to an insulating tubular body in such a manner that a magnetic path which is formed at the detected object is at a predetermined angle to an axis of the detected object. A plurality of cores is arrayed while being inclined at a predetermined angle to an axis of a detected object, and end surfaces of two-side leg portions are attached in such a way as to face the detected object via an inner circumferential surface of an insulating tubular body.
Integration of proximity sensors with magnetostrictive torque sensors
A gap compensated torque sensing system and methods for using the same are provided. The system can include a magnetostrictive torque sensor and at least one proximity sensor in communication with a controller. The proximity sensor can be substantially rigidly coupled to a sensor head of the torque sensor, either contained within the sensor head or mounted proximate to the sensor head using a bracket or other coupling mechanism. The torque sensor can sense magnetic flux passing through the target and the proximity sensor can measure a gap between itself and the target. The controller can estimate torque applied to the target from magnetic flux sensed by the torque sensor. The estimated torque can be modified by the gap measurement to compensate for changes in magnetic properties of the target due to variations in the gap. In this manner, the accuracy of the torque measurements can be increased.
Torque sensor
A torque sensor for sensing the torque applied to a first shaft has a multipolar magnet rotated therewith and is connected to a second shaft via a torsion bar. The torque sensor includes a pair of magnetic yokes adapted to be disposed in a magnetic field of the multipolar magnet and adapted to be rotated together with the second shaft. A magnetic detection element has a detection surface and is capable of detecting a magnetic flux in a direction parallel to the detection surface.
Load measuring arrangement, method for producing said arrangement and load measuring method which can be carried out with said arrangement
In order to be able to carry out an accurate and simple contactless load measurement on test objects made from materials which are optimized with respect to the intended purpose thereof, the test object (14) and a load measuring apparatus for measuring a load on the test object, wherein the load measuring apparatus (12) has a magnetic field generating device (18) for generating a magnetic field in a measuring region (11) of the test object (14) and a first and a second magnetic field capturing device (20, 22) for capturing a magnetic field parameter which changes on account of the load, characterized in that the measuring region (11) has a layer (13) made of a ferromagnetic amorphous or nanocrystalline metal alloy with maximum particle sizes of less than 1 m.
Magnetostrictive sensor, magnetic structure and production method thereof, motor drive device provided with magnetostrictive sensor, and motorassisted bicycle
A magnetostrictive sensor including a magnetic structure. The magnetic structure has a columnar substrate extending along an axis, and a magnetostrictive portion disposed on an outer peripheral surface of the substrate. The magnetostrictive portion includes a plurality of portions that have different concentrations of at least one of a plurality of elements, the portions being so arranged as to satisfy at least one of a first requirement that in a first cross sectional view of the magnetostrictive portion orthogonal to the axis, the portions are arranged clockwise about the axis, a second requirement that in the first cross sectional view, the portions are arranged in a thickness direction of the magnetostrictive portion, and a third requirement that, in a second cross sectional view of the magnetostrictive portion that is orthogonal to the first cross sectional view and passes through the axis, the portions are arranged along the axis.
MAGNETOSTRICTIVE MATERIAL AND MAGNETOSTRICTION TYPE DEVICE USING THE SAME
A magnetostrictive material includes a FeGaBa alloy that is represented by Expression (1),
Fe.sub.(100-x-y)Ga.sub.xBa.sub.y(1) (in Expression (1), x and y are respectively a content rate (at. %) of Ga and a content rate (at. %) of Ba, and satisfy that y0.012x0.168, y0.05x+1.01, and y0.04/7x+0.87/7).