摘要:
The present invention generally relates to both an apparatus, a test form and a method for evaluating sock-drop. More particularly, the present invention relates to an apparatus able to simulate particular forces exerted by human movements, a test form resembling a human leg as well as a method for testing sock-drop so that properties such as compression and comfort can be balanced.
摘要:
A method for estimating a friction coefficient between a tire of a vehicle and a road surface, which may be used in obtaining a safety distance for an adaptive vehicle, estimating the friction coefficient by using state variables that are measured by means of RPM sensors normally equipped on vehicles. A device for estimating a friction coefficient has a control section receiving signals from a braking/steering monitoring section and outputting the friction coefficient stored in a friction coefficient value storage when both or either of a braking action and a steering action are applied to the vehicle, and outputting the friction coefficient estimated by a friction coefficient estimator when the braking action and the steering action are not applied to the vehicle.
摘要:
A device for testing the take off speed of a thrust bearing in a disk drive spindle motor is disclosed. The device has a stationary torsion transducer that is used to support a drive shaft of the spindle motor. A load motor located adjacent to the transducer rotates the motor about the shaft while applying a radial load to the spindle motor through a belt. The load motor is attached to a linear stage which generates selected radial loads. In one version, the device also uses a ring magnet to attract the housing of spindle motor. The magnetic attraction imposes an axial force on the spindle motor and an equal reactive load on the thrust bearing. The axial load is such that the take off speed for the thrust bearing is much greater than that for the journal bearings. Under these conditions, the friction torque is dominated by the thrust bearing so that an accurate assessment of its quality may be assessed. As an alternative to the magnet, air jets may be used to apply a similar axial load to the thrust bearing.
摘要:
A friction testing machine and method for measuring friction characteristics between a test sample and a friction surface. The machine and method are particularly suited for measuring the coefficient of friction between a rubber specimen or a tread element and different friction surfaces at different sliding velocities, contact pressures and orientations. A preferred embodiment of machine is self-contained and portable, configured for easy and quick changing of the friction surface, and provides for rotating the test sample about an axis normal to the sliding surface and the direction of movement of the sample relative to the friction surface. In general, a friction test machine according to the invention comprises a sample holder configured to hold a sample in frictional engagement with a friction surface, and a motion device for effecting relative movement between the friction surface and sample holder in a first direction. Also provided is a variable weight loading device on the sample holder for loading the sample holder such that a selected load can be applied to the sample normal to the friction surface, and a force measurement device for obtaining a measurement indicative of the frictional force resisting such relative movement between the sample holder and the friction surface effected by the motion device.
摘要:
The device consists of a rigid pendulum (1) pivoted at its upper end (2) and upon which a ball (5) is retained at its lower end in a holder (6), so that the center of the ball lies on or close to the longitudinal axis of the pendulum. The holder itself is attached to a shoe (3) which pivots about a point (4) on a projection offset from the bottom end of the pendulum, such that the shoe moves in an arc which lies in a vertical plane perpendicular to the vertical plane in which the pendulum swings. Movement of the shoe about this pivot allows the ball holder (6) and thus the ball (5) to move in an approximately radial direction with respect to the pendulum pivot (that is, along the axis of the pendulum when the ball center is on that axis) and the degree of movement of the shoe about its pivot is limited by stops (7a, 7b) provided on the pendulum. The complete pendulum device is supported in a tripod framework or alternative rigid support.
摘要:
The invention relates to a process and a measuring apparatus for determining the friction characteristics of sheet metal during forming. To do this, a strip-shaped sample of sheet metal (1) is clamped between two gripping jaws (2, 3) and drawn by a drawing device (9), for preference at a constant drawing speed. During the drawing, the surface pressure (FN)is continually increased. From the values allocated to the surface pressure (FN)and to the drawing force (FZ), applying the known formula &mgr;=FR/FN, the friction characteristics dependent on the surface pressure are calculated.
摘要:
Surface irregularity of a semiconductor device is measured with high accuracy, without being affected by the material properties of a semiconductor film forming the surface. Surface irregularity is evaluated when the semiconductor device is fabricated. This is accomplished using a plate-like element, which has a contact surface brought into contact with the surface of a test specimen. The plate-like element is then moved across the surface of the test specimen by a driving mechanism. The driving mechanism moves either the plate-like element or the test specimen relative to the other. A force caused by the motion is detected, and converted into a parameter equivalent to the friction coefficient between the test specimen and the contact surface. From the friction coefficient, surface irregularity is determined.
摘要:
The present invention relates to a process and device for determining the surface friction coefficients of bodies, in particular of catheters. In the invented process, the to-be-examined catheter (1) is pulled with a defined velocity through a gel-like viscoelastic substance (2) and the frictional force required therefor is measured. A defined pressure is applied to this viscoelastic substance in such a manner that a defined surface normal force acts on the catheter surface. By applying a given, defined pressure on the substance, the surface pressure on each area element of the catheter surface is precisely given and can be held constant. By holding the area to which pressure is applied constant, the entire acting normal force can also be held constant and the friction coefficient can be determined for any catheter diameter and for any catheter consistency. Determination of the friction coefficient is reproducible and only depends on the surface friction.
摘要:
When a seal is inserted onto a shaft, load applied to a chuck is detected by a load cell, and based on the detected load, the turnover of a lip is judged. More specifically, an operation of inserting and pulling out the seal is performed several times on the shaft. Pull-out force is detected at the time of the last pull-out operation and insertion force is detected at the time of the last insertion operation. If the detected value is greater than a predetermined value, it is judged that the lip has been turned over. Also, a ratio between the aforementioned pull-out force and insertion force is computed. If the value of the computed ratio is less than a predetermined value, it is judged that the lip has been turned over.
摘要:
An assembly that provides for the mounting of paired sets of lubricant sample holders into balanced, opposed contact with a rotating rotor and whereby comparative data pertaining to measured load, speed and elicited thermal, audio and visual responses are obtained. The coded data is stored for digital comparison. In one assembly, a metal disc is mounted to rotate from a motor drive shaft in a cylinder block and in contact with calibrated sample support bushings biased to contact upper and lower surfaces of the disc. In another construction, an annular cylinder block supports several radially directed, opposed pairs of sample support bushings in biased, tangential contact with a circumferential wall of a cylindrical race or spherical rotor. Pneumatic or hydraulic pressure may be used to augment or load each bushing. In yet another construction, an annular cylinder block supports a pair of opposed weighted lever arms and sample support bushings in tangential contact with a rotor surface. A turnbuckle assembly coupled to the weights permits an adjustment of the center of gravity position of the weights.