FI83454B - Method for determination of torque and power in shafts by measuring an interval dependent on speed and torque - Google Patents

Description

83454

Determination of shaft torque and power by measuring speed- and torque-dependent intervals

The power transmitted by the shaft is the product of the angular velocity and torque of the shaft. The most accurate methods calculate the rotational speed of the shaft by detecting the marks on the shaft on the sensor and counting their number in units of time. Correspondingly, the frequency of the crystal can be calculated in an interval limited by the pulses received from the sensor examining the axis marks.

The torque is measured, for example, as the rotation of the shaft by means of strain gauge strips or as described in DE 2952082 or by optical methods as described in U.S. Pat. No. 4,433,585. Methods suitable for microprocessor technology are disclosed in GB 2049169 or GB 2191287, where angular velocity and torque are determined by intervals.

In the present invention, the rotational speed of the shaft is determined in a known manner: The shaft has one or more triggers (3) which produce transients for the fixed sensor (1). The intervals between the transients are inversely proportional to the rotational speed.

What's new: The braking or power-generating machine part is mounted on the axis of rotation so that it can rotate freely around the axis. To limit the friction to the torque, a counterforce is constructed, the dependence of which on the angle of rotation must be known. A sensor (2) is attached to this part of the machine so that it radars the triggers (3). As the shaft rotates, the triggers (3) then produce transients for the sensor (2). Due to the rotation caused by the torque, the transients 2 shift in time with respect to the transients 1. Taking into account the speed, the displacement can be used to calculate the rotation and determine the torque.

In many cases, the method is the most accurate and simplest way. Measurements using microprocessor technology have the great advantage if the measured quantities are obtained directly as digital signals. The invented measuring principle is characterized by the arrangement set out in the claim.

2 83454 Practical implementation

From the timing signals obtained from the sensors of the measuring device described above, the angular velocity, torque and power of the energy transmitting shaft can be calculated as follows.

Let, t2 (i), t3 (i) correspond to successive time instants at which a transient is generated: t ^ (i) to a fixed sensor t2 (i) to a moving sensor t3 (i) the following transient to a fixed sensor. The rotational angle speed is then 00 (i) =! 2w / n / [t3 (i) -t1 (i)], where n is the number of evenly spaced triggers.

1. Braking torque = 0 during the measurement time t3 (0), t2 (0), t3 (0) During the intervals t2 (0) and tj ^ O), the axis of rotation rotates at an angle Θ (0) = ° o (0) · [t2 (0 ) -t1 (0)] when the trigger moves from the fixed sensor (1) to the moving sensor (2). This is stored in the memory as a fixed O-calibration constant.

2. Braking torque = M during the measurement time t ^ M), t2 (M), t3 (M) Then the rotation of the axis of rotation is θ (Μ) = ° ο (Μ) · [t2 (M) -t1 (M)].

The rotation of the sensor (2) caused by the torque M is then 2.1. θ = θ (Μ) -θ (0) if the movable sensor is attached to a braking machine part, 2.2. θ = θ (0) -θ (Μ) if the sensor (2) is attached to the power-producing machine part.

The power is thus «ο (Μ) · Τ (θ), where Τ (θ) describes the dependence of the torque on the rotation.

Claims (1)

3 83454 A device based on this measurement method can be constructed as follows, for example. The braking (or power-producing) machine part is mounted on the axis of rotation so that it can rotate freely due to the torque and gravity causes the required counter-torque. In most cases, the machine part can be constructed appropriately without the use of additional weights. At the equilibrium position, the torque is given by the formula Τ (θ) = g-M-1 · sin (Θ) [Nm], where Θ is the angle of rotation, M is the mass of the machine part and 1 is the distance of the center of gravity from the center line of the axis. The value of M1 can be easily measured experimentally in a ready-made device. A method for determining torque and shaft power by measuring speed- and torque-dependent intervals is characterized in that it has triggers (one or more) on the axis of rotation or a part attached thereto which produce transients on the rotating sensor (1) (2). 4 83454 Methods for determining the torque and axial effects of a genome with a constant interval between the torque and the torque are determined by means of a rotation saxel or a rotating shaft or a mask with a single axis. These transceivers are fastened to a high speed transducer (1) and to a high speed transducer (2) which is masked, which can be measured at the moment.