Device for detecting the number of revolutions of an irregularly rotating shaft (spindle) of a mechanical measurement mechanism (measuring element)

摘要

In order to detect the number of revolutions of an irregularly rotating shaft (2) of a measurement mechanism, a coupling disc (3) which has a cam (3.1) and a stop (3.2) is mounted thereon. A transmitter support disc (4) is freely rotatably mounted over the coupling disc (3). The transmitter support disc (4) has a cam (4.1) which is operationally connected to the cam (3.1) and the stop (3.2) of the coupling disc (3). Mounted on the transmitter support disc (4) is a permanent magnet (8) which operates a reed tube (5) arranged next to the transmitter support disc (4). A stationary permanent magnet (7) is polarised for repulsion with respect to the transmitter magnet (8) and arrests the rotary movement of the transmitter support disc (4) as soon as the transmitter magnet (8) approaches the force magnet (7), and accelerates the rotary movement of the transmitter support disc (4) as soon as the transmitter magnet (8) withdraws from the force magnet (7). The accelerated rotary movement of the transmitter support disc (4) terminates at the stop (3.2). An additional stationary permanent magnet (6) defines the rest position of the transmitter support disc (4). <IMAGE>