Solid-state actuator drive apparatus

#This application is based on and hereby claims priority to PCT Application No. PCT/EP2007/059855 filed on Sep. 18, 2007 and German Application No. 10 2006 045 293.3 filed on Sep. 26, 2006, the contents of which are hereby incorporated by reference.

#An electromechanical motor with a solid-state actuator drive apparatus is disclosed in EP 1 098 429 BI. A rotatably mounted shaft with a first diameter is encompassed by a drive body with a drive body opening in the form of a cylindrical hole. A shaft surface of the shaft is able to roll on the inner surface of the drive body opening, which has a second diameter which is somewhat larger than the first diameter. At the same time, a shaft axis of the shaft and a central axis of the drive body opening are aligned parallel to one another. The rolling movement and therefore the rotation of the shaft are brought about by a circular sliding movement of the drive body or its axis parallel to the shaft axis. In the simplest case, the circular relative movement between the axis of the drive body opening and the shaft axis is produced by two electromechanical actuators in the form of linear actuators, which in particular can be driven independently of one another and the active directions of which, i.e. directions of the utilized change in length, are orthogonal to one another. In the simplest case, the actuators are disposed so that the active directions span a plane perpendicular to the shaft axis or annular hole axis. By a suitable electrical control of the actuators, one of the actuators is excited to produce a sinusoidal deflection and the other actuator to produce a cosinusoidal deflection with the same frequency and amplitude as a function of time. In doing so, the magnitude of the amplitude of the deflection exceeds one-half of the diameter difference of the first and second diameter, thus reliably overcoming the diameter difference between the drive body opening and the shaft. As long as the linear movements of the two linear actuators are superimposed on one another independently, in total the drive body and shaft are displaced with respect to one another in a circular manner and the rotatably mounted shaft rotates.

#If a torque load is applied to the shaft, then a force is transmitted between drive body and shaft, which, in the embodiment described, is by friction. The force transmission can be improved by introducing gearing. As, in this case, no further slip can occur, in addition a very high positioning accuracy and reproducibility of the positioning process is achieved.

#These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:

#FIG. 1 shows schematically components of a preferred solid-state actuator drive apparatus with solid-state actuators in plan view and in side sectional view according to a first embodiment,

#FIG. 2 shows schematically components of a preferred solid-state actuator drive apparatus with solid-state actuators in plan view and in side sectional view according to a second embodiment,

#Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

#As can be seen from FIG. 1, an example of a solid-state actuator drive apparatus wherein a plurality of individual components, wherein the components shown can be supplemented by further components or replaced by similarly acting components of a different design.

#The solid-state actuator drive apparatus has a housing or frame 7, which is sketched only schematically and accommodates or carries the other components. A shaft 1 is disposed in the housing by a bearing arrangement, wherein a shaft axis Z of the shaft 1 extends out of the housing in an axial direction. A drive apparatus is used to cause the shaft 1 to rotate about the shaft axis Z.