Star gear TSSG

Ingenieurbüro für Getriebetechnik also supports on gear types which are not (yet) such common in the market like the star gear (known also under the names power distribution gear or multi layshaft gear). This coaxial gear unit has many similarities to a compound planetary gear. By replacing the annulus ring of a compound planetary against a low speed sun gear a star gear unit is obtained.

The star gear combines the advantages of epicyclic and parallel shaft gears and is therefore the first choice for applications with high power and speed. The star gear TSSG is an in-house development of a star gear with a focus on simplicity and competitive manufacturing costs.

The abbreviation stands for Two Sun Star Gear. This abbreviation differentiates the gear unit against the common words “star gear” and “compound star planetary gear” for planetary gears with stationary planet carriers. The TSSG layout is simple and allows the optional integration of high and low speed coupling and coupling cover into the gear design. The typical gear ratio range is from 1.2 to 18, in special cases up to 25.

Advantages of TSSG

• The TSSG star gear combines the advantages of epicyclic and parallel shaft gears. The coaxial layout and the power split design are similar to epicyclic gears. A TSSG gear set consists only of external gears. This allows high pitch line velocities known from parallel shaft gears.
• Simple and robust gear design
• Weight and cost advantage against parallel shaft and epicyclic gear units
• High speed coupling and coupling guard are typically integrated in the gear design, low speed coupling and coupling guard can be optionally integrated as well: Compact design and reduction of interfaces and number of suppliers.
• A coaxial and compact design reduces foundation cost
• High efficiency, mostly above 99% and low lubrication oil flow
• Short delivery times: Gear set consists out of small external gears.
• High reliability: The power split leads to low bearing circumference speeds and low pitch line velocities.
• Favorable rotor dynamics (a result from the floating sun gear design)
• No coupling reaction forces in axial direction
• Easy monitoring of bearing temperatures and shaft vibrations possible
• Easy inspection of tooth contact patterns possible