| 摘要 |
Such a position-measuring device for measuring the relative position of a shaft (33) with respect to a machine part (32) consists of a ball bearing having a freewheeling electrically conductive inner ring (23), a row of electrically conductive balls (22) in a cage (30) and of an electrically conductive outer ring (24). The outer ring (24) consists of two ring halves (24a, 24b) each having a shoulder bearing surface (25a, 25b) for the balls (22), which respectively have electrically conductive regions (25a1, 25b1) and electrically non-conductive regions (25a2, 25b2) which follow one another periodically and form two mutually offset divisions (24, 24b). An electrically conductive intermediate ring (26) having a bearing surface (26a) for the balls (22) is situated between the two ring halves (24a, 24b). The intermediate ring (26) is connected for the purpose of supplying power to a contact pin (27c), and the two ring halves (24a, 24b) are connected to one contact pin (27a, 27b) each for the purpose of dissipating power. In the event of rotation of the shaft (33), the cage (30) connected to the shaft (33) drives the balls (22), which scan the electrically conductive regions (25a1, 25b1) and the electrically non-conductive regions (25a2, 25b2) under mechanical contact. The balls (22) have a double function as scanning elements and as switching elements for directly obtaining pulsed scanning signals (Figure 3). <IMAGE>
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