EDA Series Double Worm Gear Reducer

Input: IEC B5 Flange

Motor bolts directly — no input coupling. Motor shaft and first-stage worm shaft co-axial at 0.05 mm TIR. Any IEC B5 frame motor of correct power fits without a motor base or alignment jig.

Output: WA-Class Deep Hollow Bore

Driven shaft seats directly into keyed bore — no output coupling. Deep bore engagement (WA-class HL) distributes output torque over large key face area. Shrink disc locking recommended for shock loads.

Only Unit Combining All Three: 200-900:1 + IEC Flange + Hollow Bore

The EDA is the only catalogue unit that simultaneously achieves ultra-high reduction, IEC motor-direct input, and shaft-mount hollow bore output. The EA/FCEA achieves high ratio with either flange input OR solid shaft output but not hollow bore. The WDKA/WDKS achieve IEC flange + hollow bore but only to 60:1 single stage. The EDA crosses both limits.

Double Self-Locking Through the Hollow Bore

Both worm stages self-lock simultaneously on power-off. The self-locking torque is transmitted directly to the driven shaft through the hollow bore key connection — no output coupling slip risk can compromise the locked state. For gate valve stems and loaded hoist drums, the double self-locking delivered through the bore connection provides more secure load-holding than any external brake arrangement.

135-200 Stage Pair — 3.0 kW at 900:1

The 135-200 stage pair extends the EDA to the widest power and torque coverage in the D-variant E-series hollow-bore range. At 900:1 with 3.0 kW input, the theoretical output torque exceeds 8,500 Nm before service factor — one of the highest output-torque-to-input-power ratios achievable in a single shaft-mount unit. This covers large gate valve stems, heavy industrial stirrer drives, and large-diameter antenna elevation drives that would require multi-tonne helical gearbox sets in competing specifications.

IEC Flange — Any Standard Motor, No Motor Base

The EDA IEC B5 flange accepts any standard motor from the local electrical stock. In remote Australian gate valve actuator installations where motor replacement must be possible without specialist parts sourcing, the IEC standard flange is a direct availability advantage. Any IEC 63–100 frame motor in the correct power range bolts directly; no custom motor bracket, no alignment jig, no coupling spider inspection.

WA-Class Bore Depth — Shock-Tolerant Connection

The EDA output bore is WA-class — deeper than the standard WK bore, providing more key face engagement length and proportionally lower surface pressure at the same output torque. At the high torques that the EDA produces at 400:1+ (which can exceed 2,000–5,000 Nm at larger stage pairs), the WA bore depth is essential to keep bore fretting within tolerable levels. A shallower bore at these torque levels would fail through key fretting within months.

Single-Unit Maintenance — Both Stages One Service Point

The EDA integrated housing services both worm stages from a single oil fill/drain system. In gate actuator and slow-speed infrastructure applications where the unit is accessed infrequently and each service visit carries travel cost, a single oil change per service interval versus two separate service points on an equivalent multi-unit arrangement is a visible lifecycle cost reduction.

IEC Motor — Small Frame, High Torque Multiplied

At EDA 40-60, the input flange accepts IEC 63–71 frame motors (0.12–0.18 kW). These small motors produce very large output torques when multiplied by 200–900 reduction. Before specifying, confirm the motor shaft length against T×V bore depth — small IEC frame motor shaft lengths vary significantly between manufacturers and a bottomed-out shaft prevents correct flange seating on the compact first-stage housing.

Shrink Disc — Mandatory at Large Stage Pairs

For EDA 80-135 and above, output torques at high ratios can exceed 1,000–5,000+ Nm. A set screw cannot reliably transfer these torques without progressive loosening. Shrink disc locking is mandatory for stage pairs 80-135 and above — specify by bore diameter S and the calculated torque with service factor. For stage pairs 40-60 to 70-120 at smooth loads, a set screw is acceptable; for any shock load at any stage pair, always use a shrink disc.

PAO Synthetic Oil — Both Stages

Two fill/drain points — one per stage. For EDA units in continuous duty in Australian summer ambient above 35°C, PAO synthetic ISO VG 220 in both stages extends the thermal ceiling and the service interval simultaneously. Mineral oil at 40°C ambient with high-ratio continuous duty commonly constrains the EDA before mechanical torque limits are reached — PAO removes this constraint in most practical applications.

Torque Arm — Large Housing Weights

EDA 120-175 and 135-200 are large units (estimated 90–150+ kg with motor). In shaft-mount configuration, the torque arm must carry both the reaction torque (which is enormous at high ratios) and the gravitational weight moment of the assembly. Use a heavy-duty dual-rubber-bush arm; specify for the combined load, not just reaction torque. This is the most commonly under-specified component on large EDA shaft-mount installations.

Temperature Monitoring — Large Stage Pairs

For EDA 100-155 and 135-200 in continuous duty, a PT100 sensor at the housing gives advance warning of thermal overload before worm wheel failure — which in a unit of this size is a costly and difficult repair. SCADA-connected monitoring on large gate actuator installations pays for itself in avoided emergency service calls, particularly in remote Australian water infrastructure where repair travel is a significant cost.

Oil Orientation — Both Stages Independently

Non-standard installation orientations change the effective oil level in both stages independently. Both stages must have correct oil levels for the installed orientation — failure in either stage results in partial oil starvation with rapid bronze wheel wear. Submit your orientation drawing to the technical team before commissioning on any non-horizontal installation.