A flywheel energy storage system incorporates various embodiments in design and processing to achieve a very high ratio of energy stored per unit cost. The system uses a high-strength steel rotor rotating in a vacuum envelope. The rotor has a geometry that ensures high yield strength throughout its cross-section using various low-cost quenched and tempered alloy steels. Low-cost is also achieved by forging the rotor in a single piece with integral shafts. A high energy density is achieved with adequate safety margins through a pre-conditioning treatment. The bearing and suspension system utilizes an electromagnet that off-loads the rotor allowing for the use of low-cost, conventional rolling contact bearings over an operating lifetime of several years.

A system for torque measurement is generally provided. The system includes a sensor disposed between an outer bearing race and a static structure of a bearing assembly. The sensor is disposed adjacent along a thrust load direction to the outer bearing race. The system further includes a rotor assembly rotatably coupled to the bearing assembly, and a controller communicatively coupled to the sensor. The controller is configured to store and execute operations. The operations include determining a torque measurement from the rotor assembly based at least on an axial thrust load from the rotor assembly.

A foot presence sensor system for an active article of footwear can include a sensor housing configured to be disposed at or in an insole of the article, and a controller circuit, disposed within the sensor housing, configured to trigger one or more automated functions of the footwear based on a foot presence indication. In an example, the sensor system includes a capacitive sensor configured to sense changes in a capacitance signal in response to proximity of a body. A dielectric member can be provided between the capacitive sensor and the body to enhance an output signal from the sensor.

A flywheel energy storage system incorporates various embodiments in design and processing to achieve a very high ratio of energy stored per unit cost. The system uses a high-strength steel rotor rotating in a vacuum envelope. The rotor has a geometry that ensures high yield strength throughout its cross-section using various low-cost quenched and tempered alloy steels. Low-cost is also achieved by forging the rotor in a single piece with integral shafts. A high energy density is achieved with adequate safety margins through a pre-conditioning treatment. The bearing and suspension system utilizes an electromagnet that off-loads the rotor allowing for the use of low-cost, conventional rolling contact bearings over an operating lifetime of several years.

A load cell for determining a radial force acting on a crankshaft having a receiving sleeve for receiving a bearing ring and a fastening ring for attaching the load cell in a transmission housing. Axial support areas are provided on the fastening ring for axially supporting the outer ring of the first bearing. Moreover, measuring regions for receiving radial forces of the receiving sleeve are provided which connect the receiving sleeve with the fastening ring. Strain sensors are attached to at least two of the measuring regions.

A method for fixing a fiber having a fiber Bragg grating sensor segment onto a component configured to undergo changes in strain and/or temperature. The method providing the steps of stretching at least a section of the fiber including the fiber Bragg grating sensor segment by a defined and calibrated preload into a preloaded condition, fixing the section of the fiber including the fiber Bragg grating sensor segment being in the preloaded condition on a carrier element, and fixing the carrier element onto the component, as well as a bearing device with such a fiber.

A sensorized roller of a bearing, the roller having a central bore extending axially therethrough and a sensor module mounted within the bore in a non-fixed manner. The module includes at least four deformation sensors arranged circumferentially around a module center axis, at defined angular intervals. Each deformation sensor measures a radial distance (measured for defined angular positions lying within an angular span of 180) between the center axis and a radially inner bore surface. The module includes a processor which receives each measured radial distance and calculates a radial load (under static or dynamic conditions) acting on the roller by estimating an offset angle of the fixed reference relative to the radial load direction and by using the estimated offset angle and each measured radial distance as inputs to a mathematical model, describing a deformation radius of the bore as a function of angular position and load dependent parameters.

A foot presence sensor system for an active article of footwear can include a sensor housing configured to be disposed at or in an insole of the article, and a controller circuit, disposed within the sensor housing, configured to trigger one or more automated functions of the footwear based on a foot presence indication. In an example, the sensor system includes a capacitive sensor configured to sense changes in a capacitance signal in response to proximity of a body. A dielectric member can be provided between the capacitive sensor and the body to enhance an output signal from the sensor.

A method for monitoring the spindle preload amount of a spindle by: S1 obtaining a spindle preload amount through a PPC Preload Analyzer; and S2 obtaining an axial force sensor output of the spindle through an axial force sensor, wherein the axial force sensor output is calibrated using the spindle preload amount that is obtained through the PPC Preload Analyzer; establishing a relationship between the spindle preload amount and the axial force sensor output, then regarding the axial force sensor output as the spindle preload amount, and then monitoring the spindle preload amount by monitoring the axial force sensor output.

An activation component testing apparatus comprising an outer sleeve, an inner sleeve, a plunger, a number of bearings, and a compression spring. The outer sleeve forms an interior chamber having opposing first and second openings. The plunger, bearings, inner sleeve, and compression spring are disposed in the central cavity. The plunger includes a number of bearing recesses that engage the bearings such that the plunger is configured to transfer a compressive force applied to the activation component through the inner sleeve and compression spring to a load cell via the bearings when the plunger is in an extended position and urge the bearings out of engagement with the bearing recesses when the plunger is in a maximum force position such that the plunger cannot transfer additional compressive force to the load cell when the plunger is moved beyond the maximum force position.