Know-how for Oscillating drives
Oscillating drives generate oscillating motions of the output shaft through an evenly formed rotary motion of the drive.
How does it function?
The motion sequence in general:
the input shaft →
rotates continuously, advancing one cycle for each revolution.
The system runs through the index-angle (Schaltwinkel) and dwell-angle (Rastwinkel) ranges as it does so.
← the output shaft
advances one step whenever the system runs through the index angle and stops whenever the system runs through the dwell angle.
Die Größe der Bewegung wird durch den Pendelwinkel bestimmt.
The movement of the output is determined by a motion law. This is a mathematical function which stipulates the respective position of the output for every position of the drive. In case of the specification of a drive rotary speed, the speed and acceleration of the output is also determined.
The laws of motion of our oscillating drives are selected in such a way that an extremely harmonic thrust and jolt-free motion is realized.
The Oscillating angle Ψ determinats the size of output movement. Depending on the construction type of the gear, we supply drives with the following oscillating angles on a standard basis:
CF3: 15°, 20°, 30°, 45°
rotoblock: 15°, 20°, 30°, 45°, 60°, 75°, 90°, 120°
Smaller special oscillating angles are allways realisable without problems.
The impact of the input speed and of the index/dwell angle:
[Translate to en:] If the gear is driven at constant rotary speed, every revolution of the drive lasts for a specific period which is described as cycle time. The amount of time required to pass through the index angle Φ1 respectively Φ3 is referred to as index time t1 bzw. t3. Analogous to this, the amount of time for passing through the dwell angle Φ2 respectively Φ4 referred to as dwell time t2 bzw. t4.
The rotary speed of the drive is determinant to the attainment of a specific cycle time. A modification of the cycle time affects the index times and dwell times in the same proportion at all times.
To attain specific index or dwell times at a given rotary speed of drive, the relation of the index to the dwell angles must be changed.
The structural set-up:
The drive of the gear forms a cam with a specially formed profile. There are different cam types depending on the construction type of the gear.
The output is formed as a roller lever or roller starfitted with cam followers.
The cam followers are attached to the profile of the cam. If the cam is turned, the rollers follow the profile and generate the motion of the output.
The profile of the cam is formed in such a way that this motion of the output corresponds precisely with the specification of the motion law (see above).
