Electrical generator or motor structure – Non-dynamoelectric – Piezoelectric elements and devices
Patent
1992-06-16
1993-11-23
Budd, Mark O.
Electrical generator or motor structure
Non-dynamoelectric
Piezoelectric elements and devices
310323, 310316, 310 49R, H01L 4108
Patent
active
052647552
DESCRIPTION:
BRIEF SUMMARY
STATE OF THE ART
The invention relates to a step motor to drive a body, especially a shaft, through small angles of rotation, having the characteristics of the preamble of claim 1.
There is a multitude of step motors, also those with small steps.
Often reducing gears in the most varied forms are used for this. Gears mostly have the disadvantage of blocking the drive when the motor fails and, with a few exceptions, of only rarely permitting redundancy.
Another disadvantage of gears lies in the manufacturing cost and in the gear play which is always required and makes steps through very small angular ranges impossible.
OBJECT
It is the object of the invention to provide a step motor to drive a body, especially a shaft, through small angles of rotation per step, where the mentioned disadvantages are avoided.
This object is attained by the features recited in the characterizing part of claim 1. Advantageous embodiments of the invention ensue from the dependent claims and from the description.
DESCRIPTION
The step motor in accordance with the invention permits the transfer of large moments in very small steps to a body to be rotated, in particular to a shaft. In this case the sequence of steps is relatively slow. An encoder can be used for determining the exact momentary position of the body or the shaft.
The step motor in accordance with the invention contains a stator, a rotor, which rotates a body, and a drive acting on the rotor. At least one spring element, which acts counter to the rotation of these parts in relation to each other, is provided between the rotor and the stator. In this case, a rotor is understood to be a ring with at least two spring elements and active, movable elements also disposed on the ring, which are connected with the body for moving the body out of an initial position. A similar structure is provided for the stator. The drive for performing a rotational step is triggered together with the connection of the rotor with the body. After performing the step, and overlapping the triggering of the connection of the rotor to the body, the stator is connected with the body to maintain the body in the position reached.
Two rings, disposed concentrically in relation to each other and to the body, are connected with each other via a spring element having great axial rigidity and, at the same time, great tangential flexibility. One of the two rings is fixedly connected with the stator.
On the outside of the two rings facing away from the body at least one lever is provided on each ring. Both levers are connected with each other at their ends via a flexible connecting piece. The connecting piece can be bent radially in respect to the body, for example by means of a piezo element or of an electromagnet.
In an embodiment in accordance with the invention, at least two connections, actively movable with the rings, are fixedly connected on the inside of the two rings facing the body or the shaft. The free ends of the connections are adapted to the surface of the shaft and are polished for a better transfer of force. At least one piezo element is disposed on the movable connections. If the piezo element of the movable connection which is not connected with the stator is triggered, the movable connections come to lie against the shaft. The piezo element or the electromagnet on the flexible connecting piece is triggered overlapping the triggering of the piezo element on the movable connections. Because of the bending of the connecting piece caused by this, the ring not connected with the stator and thus the shaft connected with the ring via the movable connections moves by a small rotational step in one direction against the effect of the spring element and of the second ring supported on the stator. The direction of rotation depends on the piezo element or the triggering of the piezo element. The size of the angle of rotation per step on the voltage applied to the piezo element or to the electromagnet.
After performing the step, the piezo elements of the movable connections of the ring connecte
REFERENCES:
patent: 3211931 (1965-10-01), Tehon
patent: 4468583 (1984-08-01), Mori
patent: 5027028 (1991-06-01), Skipper
patent: 5063321 (1991-11-01), Carter
patent: 5107162 (1992-04-01), Yamaguchi
patent: 5144187 (1992-09-01), Culp
Lueger, Lexikon Der Technik, In:Vierte, Vollstandig neu bearbeitete und erweiterte Auflage in 17 Banten; by Ehrhardt et al.; Deutsch Verlags-Anstalt, Stuttgart, 1960, S. 416-418.
Eckardt Thomas
Hettlage Eckart
Ruff Gerd
Budd Mark O.
Teldix GmbH
LandOfFree
Stepping motor to drive a body, especially a shaft, through smal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stepping motor to drive a body, especially a shaft, through smal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stepping motor to drive a body, especially a shaft, through smal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1851869