EWDKO Series Double Worm Gear Reducer

Input: IEC B5 Flange — Motor Direct

Motor bolts to IEC B5 flange — no input coupling, no motor base, no coupling guard. Motor shaft and first-stage worm shaft co-axial at 0.05 mm TIR by machined datum.

Output: Co-Axial Dual Hollow Bores — Both Faces

Two bores on the same rotational axis exit from opposite output faces. Both rotate at exactly matched speed from one worm wheel. Both driven shafts seat directly into bores — no output couplings.

Three-End Zero Couplings at 200–900:1

IEC motor bolts to input flange — no input coupling. Each driven shaft slides into its hollow bore — no output couplings. Three connection points, zero coupling bodies, zero coupling guards, zero alignment procedures. In enclosed actuator housings, sealed digester head penetrations, and remote outdoor tracker installations, eliminating all coupling bodies from the installation envelope simplifies both mechanical design and safety compliance obligations.

Exact Co-Axial Synchronisation — Hardware Guaranteed

Both bores share one worm wheel — the 1:1 speed ratio between them is exact, permanent, and physically impossible to drift. At 1.6–7.25 rpm output, any timing error between co-axial shafts becomes immediately visible as mechanical misalignment. The EWDKO makes drift impossible by sharing one wheel between both bores rather than relying on chain, belt, or VFD algorithm synchronisation that accumulates error over time.

Double Self-Locking — Both Bores Held on Power-Off

Both worm stages self-lock simultaneously. Both driven shafts are locked against back-drive from either bore on power-off — without any external brake. For twin-stem gate mechanisms where both stems must hold simultaneously against flow-induced torque, this double self-locking delivered through both bores simultaneously provides positive mechanical hold at both outputs without any electrical or hydraulic locking system.

Replaces Two EDA Units + Synchronisation Mechanism

Achieving co-axial twin slow-speed hollow-bore drives with EDA units requires two complete EDA housings, two IEC motors, two VFDs, plus an inter-unit synchronisation shaft, coupling, and bearing support. The EWDKO replaces all of this with one housing, one motor, one VFD, zero synchronisation hardware, and two oil fill points within one unit. The hardware reduction is substantial in both cost and maintenance scope.

One Motor + One VFD Controls Both Output Speeds

One motor and one VFD controls both output bore speeds simultaneously. Both bores change speed proportionally when the VFD frequency changes; the 1:1 ratio between them is preserved at all VFD frequencies. Two separate EDA units with two VFDs require synchronisation programming and still have algorithm-dependent timing accuracy. The EWDKO provides hardware-guaranteed synchronisation that cannot be disrupted by control logic, communication delay, or VFD parameter drift.

120-175 Stage Pair — Ø80 mm Dual Bore at 2.2 kW

The EWDKO 120-175 with dual Ø80 mm bores at 2.2 kW input covers large-diameter co-axial shaft drives at ultra-high ratios. At 600:1 with 2.2 kW input and combined efficiency ≈ 50%, the combined theoretical output torque from both bores exceeds 5,500 Nm — covering large twin-stem gate valve mechanisms and heavy bilateral solar tracker arrays from one IEC motor and one VFD.

Motor Power — Combined Bore Load

Motor power must cover the combined torque from both bores: P_input = (T₁ + T₂) / (ratio × η). Using single-bore torque for motor sizing results in thermal overload during normal combined operation. This is the most common EWDKO commissioning error — always calculate from combined bore load.

Dual Shrink Discs — Both Bores

Both output bores require individual shrink discs for all EWDKO stage pairs 70-120 and above. Torque both discs in cross-pattern sequence simultaneously to maintain symmetric clamping pressure on both bore faces. Asymmetric clamping can generate lateral force on the second-stage worm wheel affecting bearing pre-load.

PAO Synthetic Oil — Both Stages

Two separate oil fill points — one per stage. For continuous duty at ratios ≥ 400:1 in 40°C+ Australian ambient, PAO synthetic ISO VG 220 in both stages extends the thermal ceiling by 10–15% and the service interval to 5,000 hours. The combined load from both bores increases first-stage heat generation vs. single-bore EDA at the same power.

Torque Arm — Combined Reaction + Weight

Torque arm must resist combined reaction torque (T₁ + T₂) plus gravitational moment of motor plus reducer assembly. At EWDKO 120-175 with motor, combined assembly may exceed 100 kg — always specify torque arm for the combined load, not reaction torque alone.

Thermal — Combined Load Assessment

The combined load from both bores increases heat generation versus an equivalent EDA. Thermal rating must be verified at the combined input power, not single-bore power. Submit combined input power, ratio, duty cycle, and Australian ambient temperature to the technical team before finalising specification.

Oil Orientation — Vertical Bore Config

Non-standard orientation (vertical bore axis for gate valve stem drives) requires orientation-specific oil fill levels for both stages independently. Submit your installation orientation drawing to the technical team before commissioning — oil starvation in the second stage under vertical bore orientation is the leading failure cause in gate actuator EWDKO installations.