Woodward SMM40 1766-541 Speed Adjusting Motor
Woodward, Inc.
New product
The Woodward SMM40 Speed Adjusting Motor, Part No. 1766-541, is a permanent-magnet synchronizing motor used for remote speed adjustment of Woodward UG, PSG and SG governors.
Woodward’s official Manual 03026 describes the permanent-magnet synchronizing motor as the device used to remotely adjust governor speed settings. It allows an operator to match alternator frequency to other generators or change load distribution when operating governors in droop mode. The manual identifies the SMM40 as the current model, following earlier S40, MM40 and MM4A designs.
The photographed SM MARINE SERVICE™ stock unit is clearly identified as:
Brand / Application: WOODWARD GOVERNOR
Motor Manufacturer: SAWAMURA DENKI KOGYO
Type: SMM40
Part Number: 1766-541
Voltage: 24VDC
Current: 0.15A
Speed: 4 RPM
Safe Torque: 0.2 N·m
Power: 5W
Insulation Class: B
Protection: IP44
Country of Manufacture: Japan
The SMM40 is not simply a general-purpose DC motor.
It is a specialized governor speed-setting motor designed to slowly rotate the governor’s speed-setting mechanism so that engine speed can be increased or decreased remotely.
Woodward describes the motor as a Permanent Magnet Synchronizing Motor. Its function is to provide controlled remote speed adjustment for selected governors.
Marine and industrial buyers therefore search for it using different names, including:
Speed Adjusting Motor
Synchronizing Motor
Governor Motor
Permanent Magnet Motor
Governor Speed Setting Motor
Remote Speed Control Motor
All of these are relevant search descriptions for the same product family.
Woodward’s official manual specifically states that the SMM40 is used with:
UG Governors
PSG Governors
SG Governors.
This is one of the most important technical details for the blog because many buyers search by governor model rather than the motor model.
Common searches therefore include:
Woodward UG governor motor
UG-8 SMM40 motor
Woodward PSG synchronizing motor
Woodward SG speed adjusting motor
A marine spare-parts reference also specifically lists 1766-541 as the permanent-magnet synchronizing motor for UG, PSG and SG governors.
One of the SMM40’s most important applications is generator frequency adjustment.
Woodward explains that the motor allows the switchboard operator to adjust governor speed so an alternator’s frequency can be matched with other alternators before synchronization.
In a diesel-generator installation, the SMM40 can therefore be involved in:
Generator synchronization
Frequency matching
Remote RPM adjustment
Governor speed reference adjustment
This is why the same item is often called a Synchronizing Motor.
Woodward’s manual also states that the motor can be used to change load distribution between generators operating in droop mode.
When generators are running in parallel, small changes in governor speed reference can affect the real-power load carried by each generator.
The SMM40 therefore plays an important mechanical role in older generator load-sharing arrangements.
This makes search terms such as:
Woodward Load Sharing Motor
Generator Load Sharing Governor Motor
Droop Adjustment Motor
technically relevant.
The exact photographed unit carries the following specifications:
| Specification | Value |
|---|---|
| Product | Speed Adjusting / Synchronizing Motor |
| Type | SMM40 |
| Part No. | 1766-541 |
| Voltage | 24VDC |
| Current | 0.15A |
| Speed | 4 RPM |
| Safe Torque | 0.2 N·m |
| Power | 5W |
| Insulation Class | B |
| Protection | IP44 |
| Manufacturer | Sawamura Denki Kogyo |
| Application | Woodward Governor |
| Country | Japan |
Current market references for exact 1766-541 repeat the same 24VDC, 0.15A, 4 RPM, 0.2 N·m and 5W specifications.
The nameplate specifies only:
4 RPM
which may look unusually slow for an electric motor.
That low speed is intentional.
Governor adjustment must be gradual and controlled. If the speed-setting mechanism were moved too quickly, engine RPM or generator frequency could change abruptly.
The SMM40’s geared low-speed movement allows precise adjustment of the governor reference.
Woodward’s official documentation states that standard synchronizing motors operate on nominal 24VDC power.
The photographed 1766-541 unit is also directly marked:
VOLTS: 24V DC
This makes it suitable for the common 24VDC control systems used in marine engine rooms and generator control arrangements.
However, other SMM40-family variants exist with different electrical supplies, so voltage must always be checked before replacement.
The SMM40 family appears under several part numbers and voltage/speed configurations.
Related market references include:
1766-523 – SMM40 24VDC
1766-541 – SMM40 24VDC, 4 RPM
1766-825 – SMM40 110VAC variant
1765-867 – SMM40 110VAC variant
Marine-market documentation lists these different configurations separately.
Therefore, 1766-523, 1766-541, 1766-825 and 1765-867 should not automatically be treated as identical replacements.
Voltage, speed, mechanical arrangement and governor application must be checked.
One particularly useful point from Woodward’s official manual is that the SMM40 is the current successor to earlier governor speed-setting motors.
Woodward identifies earlier models:
S40
MM40
MM4A
and states that the SMM40 can replace former speed-adjusting motor models as a complete unit, although internal parts are not necessarily interchangeable.
This gives the blog additional valuable related search terms:
Woodward S40 replacement
Woodward MM40 replacement
Woodward MM4A replacement
SMM40 replacement motor
The UG-8 is one of the most important marine governor families associated with SMM40 motors.
Marine spare-parts records list the 1766-541 motor together with Woodward UG-8 governors and even show governor assemblies combining:
UG-8 Governor + 1766-541 Motor.
This makes the following buyer searches especially important:
UG8 Governor Motor
UG-8 Speed Adjusting Motor
Woodward UG8 SMM40
Woodward UG8 1766-541
The photographed unit is clearly labelled:
SAWAMURA DENKI KOGYO – MADE IN JAPAN
and states that the motor was:
Made expressly for Woodward Governor (Japan) Ltd.
Current exact-model references also identify Sawamura Denki Kogyo as the manufacturer of the 1766-541 SMM40 motor supplied for Woodward applications.
This means buyers may search either by:
Woodward
or
Sawamura SMM40
and both keyword groups should be covered.
The motor is mechanically linked to the governor speed-setting mechanism.
When a remote increase or decrease command is applied, the motor runs in the required direction and moves the speed-setting mechanism gradually.
This changes the governor reference and therefore changes engine speed.
The governor itself continues to regulate engine fuel and speed dynamically; the SMM40 changes the desired speed setting, rather than directly controlling the fuel rack as a primary actuator.
That distinction is important technically.
The SMM40 can be encountered in:
Marine Auxiliary Diesel Generators
Main or Auxiliary Engines with Woodward Governors
Emergency Generator Sets
Shipboard Power Generation Systems
Parallel Generator Systems
Remote Governor Control Arrangements
Industrial Diesel Generator Sets
Its most common marine role is remote governor speed adjustment for generator frequency and load control.
Check the 24VDC supply and control command first.
Inspect:
Power wiring
Increase/decrease command circuit
motor terminals
control relay
mechanical governor linkage
If the correct command voltage reaches the motor but the shaft does not move, internal motor or gearbox diagnosis may be required.
Inspect the mechanical coupling between:
SMM40 output
governor speed-adjusting mechanism
A loose coupling or damaged linkage can allow the motor to run without moving the governor setting.
Check the reversing control circuit.
The problem may come from:
one missing command polarity/direction
control relay contacts
wiring
internal motor switching/mechanical issue
before replacing the entire motor.
The photographed 1766-541 is intentionally rated at 4 RPM.
Slow movement alone is therefore not evidence of a fault.
Compare actual output speed with the correct specification before condemning the unit.
Check:
governor mechanical condition
SMM40 movement
linkage
remote switch circuit
24V supply
If the motor moves correctly but frequency remains unchanged, the governor or linkage may be the actual problem.
Inspect:
mechanical binding
excessive duty cycle
incorrect voltage
governor adjustment mechanism
A jammed governor speed-setting mechanism can place excessive mechanical load on the motor.
Before replacing a Woodward SMM40, verify:
Type: SMM40
Part No.: 1766-541
Voltage: 24VDC
Current: 0.15A
Speed: 4 RPM
Torque: 0.2 N·m
Power: 5W
Governor Model: UG / PSG / SG / exact installed governor
Mechanical connection
Mounting arrangement
Part number matching is particularly important because other SMM40 versions have different speeds and supply voltages.
SM MARINE SERVICE™ supports worldwide sourcing and supply of Woodward SMM40 Speed Adjusting Motors, synchronizing motors and governor spare parts.
Depending on current stock, equipment may be available as:
New / New Old Stock
Used Tested Working
Refurbished
Reconditioned
Relevant requirements can include:
SMM40 P/N 1766-541
SMM40 P/N 1766-523
Woodward UG-8 Governors
Governor repair kits
Synchronizing motors
Governor speed-setting components
Mechanical governor spare parts
SM MARINE SERVICE™ also has an existing Woodward SMM40 Governor Control page covering this motor family, and a separate SMM40 24VDC Part No. 1766-523 page for a related variant.
Many ships continue to operate reliable Woodward mechanical/hydraulic governors.
Replacing the entire governor or generator control architecture may be unnecessary if the failure is limited to the remote speed-adjusting motor.
A correct SMM40 replacement allows the vessel to retain:
remote speed control
generator frequency adjustment
synchronizing capability
load-distribution adjustment
without redesigning the complete governor system.
Woodward still hosts the official SMM40 synchronizing-motor manual, showing the technical importance of this legacy design.
The SMM40 is a permanent-magnet synchronizing / speed-adjusting motor used for remote speed adjustment of Woodward governors.
1766-541 is a documented Woodward/Sawamura SMM40 24VDC speed-adjusting motor used with Woodward governor applications.
The photographed unit is rated 24VDC.
The nameplate specifies 0.15A.
The photographed 1766-541 is rated at 4 RPM.
The nameplate specifies 0.2 N·m.
The photographed unit is rated 5W.
The photographed unit is marked IP44.
The unit is manufactured by Sawamura Denki Kogyo, Japan, expressly for Woodward Governor.
Woodward officially specifies the motor for UG, PSG and SG governors.
Yes. Marine spare-parts references document SMM40/1766-541 with Woodward UG-8 governor assemblies.
It changes the governor speed reference remotely, allowing generator frequency matching and adjustment of load distribution.
They are related SMM40 part numbers, but direct interchangeability should not be assumed solely from the SMM40 type. Exact speed, voltage and application must be checked.
Woodward’s official manual states that SMM40 is the current model and can replace former speed-adjusting motor models as a complete motor, although internal parts are not necessarily interchangeable.
SM MARINE SERVICE™ supports worldwide sourcing of Woodward SMM40 1766-541 speed-adjusting motors and related governor spare parts, subject to current stock availability.
Woodward SMM40 P/N 1766-541 is a Japan-made 24VDC permanent-magnet speed-adjusting / synchronizing motor used for remote speed setting of Woodward UG, PSG and SG governors. The photographed Sawamura Denki Kogyo unit is rated 24VDC, 0.15A, 4 RPM, 0.2 N·m safe torque, 5W, Class B and IP44. Woodward uses this type of motor for remote alternator-frequency matching and load-distribution adjustment in droop operation. SM MARINE SERVICE™ supplies Woodward SMM40 motors and marine governor spare parts worldwide in new, used, refurbished and reconditioned condition.
SM MARINE SERVICE™
Marine Automation & Navigation Equipment Supplier
Available Condition:
• New Equipment • Used Equipment • Refurbished Equipment • Reconditioned Equipment
Stock Location:
• Bangladesh • China
Services:
• Worldwide Shipping • Technical Support • Spare Parts Supply • Marine Equipment Sourcing
Contact Information
SM MARINE SERVICE™ Samir Market, DT Road, Pahartali, beside CDA Market, Chattogram, Bangladesh
Mobile / WhatsApp / Viber: +88 01818 929292
Email: info@smmarineservice.com
Website: www.smmarineservice.com
0
BDT 0
BDT 0
BDT 0
BDT 0
Marine Equipment Supplier