Harmonic Drive

Product Development in the 1990's

1990 Integrated Output Bearing

The development did not stop. Since 1990 our component sets have also been available with a high stiffness cross roller bearing. The integration of this high capacity bearing to support output loads will in many applications eliminate the need for the user to design an external output bearing assembly, thus reducing design and production costs.

1992 Shortened Flexspline

A new generation of the well-known Harmonic Drive Gear Component Sets was introduced in 1992. With the new HFUC Series Component Sets and Units the compact design of Harmonic Drive gears could be reduced and the high torque capacity and high stiffness could be increased. In comparison with standard Harmonic Drive gears, the new HFUC series features a shortened Flexspline, which results in a significant reduction of the axial length combined with a reduction of weight. A 20 % weight reduction thus could be realised. This development made the Harmonic Drive Shortened Flexspline Component Sets and Units HFUC Series a very attractive product for industrial robot manufacturers.

1996 Hollow Shaft Units and Component Sets

A further step into the future took place in 1996 with the development of the Hollow Shaft Units and Component Sets Series HFUS. This type of gear offers a compact design with an integrated cross roller output bearing and a large hollow shaft through the gear. The HFUS gears are available in nine sizes with torque capacities ranging from 18 to 1840 Nm and standard reduction ratios from 50:1 to 160:1. The HFUS gears allow a coaxial or parallel assembly to the input motor. The following variants can be delivered:

• Component Set
• Complete gear including a hollow shaft and cross roller output bearing
• Complete gear including an input shaft (without hollow shaft) and cross roller bearing

1997 Digital Hollow Shaft Actuators

As early as in 1990, the demand for complete servo actuator systems consisting of gear, motor and servo control unit resulted in the introduction of the Harmonic Drive AC Hollow Shaft Servo System Series FHA. These servo actuators combine the Harmonic Drive precision gear with a brushless AC servo motor and an encoder mounted directly on the motor shaft. The hollow shaft design allows the feed-through of cables, shafts, or even laser beams.

At the end of the 90s, digital control technology has become state-of-the-art and Harmonic Drive developed a new variant including a Sine/Cosine Encoder as well as a new motor for a 600 V indirect voltage system. An incremental encoder with sinusoidal output signals provides feedback information for the FHA Series Actuator with Sine/Cosine Encoder. The FHA Series Actuator is compatible with a wide variety of currently available digital servo drives for Sin/Cos motor feedback systems (e.g. Simodrive 611D® by Siemens). The FHA Series of digital Hollow Shaft Actuators is available in four sizes with ratios 50:1 up to 160:1. In 1999 a further variant with a HIPERFACE® compatible Sine/Cosine encoder, available as singleturn absolute or multiturn absolute version has been introduced. These AC hollow shaft actuators can be connected with numerous digital servo controllers. This sophisticated concept minimizes the effort regarding project work and design.

Furthermore, the AC Hollow shaft Actuators FHA Series with Sine/Cosine encoder has been extended by a new variant with an output side singleturn absolute encoder.

1999 Compact Servo Actuators

The new FFA series is a further addition to the well known series of AC servo actuators from Harmonic Drive. The FFA actuator consists of an AC servomotor and a Harmonic Drive gear resulting in a very compact design. The FFA actuators are available in five sizes from 20 to 58. They provide torque capacities from 10 to 1800 Nm with ratios from 50:1 to 160:1 and a max. speed of 80 rpm. With a maximum length of 140 mm up to 300 mm (resolver version) the FFA actuator is unbeatable in terms of compactness.