The F37 parallel shaft helical gear unit is the smallest frame of the WGT F series. Unlike a coaxial unit, its output shaft runs parallel to - but offset from - the motor axis, so the drive drops into machine layouts where the driven shaft sits beside rather than behind the motor. Machine builders use the F37 wherever a low-profile gear reducer must hug a machine frame while still delivering two- or three-stage reduction.
A Parallel-Shaft Layout with an Offset Output
Every stage in the F37 is helical, so the mesh runs in rolling contact: efficiency holds at 94~96% across the ratio range, noise stays between 60 and 68 dB, and the offset output keeps the whole drive inside a rectangular envelope that a right-angle gearbox cannot always match. The housing is a single cast-iron or ductile-iron casting at HBS190-240, bored in one setup; gearing is case-hardened 20CrMnTi, ground to grade 6~5, running on 42CrMo shafts tempered to HRC25~30.
F37 Technical Data
| Housing material | Cast iron/Ductile iron |
| Housing hardness | HBS190-240 |
| Gear material | 20CrMnTi alloy steel |
| Surface hardness of gears | HRC58~62 |
| Gear core hardness | HRC33~40 |
| Input / Output shaft material | 42CrMo alloy steel |
| Input / Output shaft hardness | HRC25~30 |
| Machining precision of gears | precision grinding, grade 6~5 (ISO 1328) |
| Lubricating oil | GB L-CKC220~460 / Shell Omala 220~460 |
| Heat treatment | tempering, cementit-ing, quenching, etc. |
| Efficiency | 94%~96% (depends on the transmission stage) |
| Noise (max) | 60~68 dB |
| Temp. rise (max) | 40 C |
| Temp. rise (oil) (max) | 50 C |
| Vibration | ≤20μm |
| Backlash | ≤20Arcmin |
| Brand of bearings | HRB/LYC/ZWZ/C&U (SKF, FAG, INA, NSK optional) |
| Brand of oil seal | NAK -- Taiwan or other brands requested |
Proven in service across these industries:
- Belt and apron conveyors
- Mixers, agitators and digesters
- Food processing and packaging
- Pumps, fans and centrifuges
- Cement and aggregate handling
Ordering and Delivery
State the ratio, output speed and mounting style - foot-mounted F37, hollow-shaft FA37 or flanged FAF37 share the same gear set - and WGT confirms the selection and quotes factory-direct within 24 hours. Units are test-run before packing and leave the plant in a standard export wooden crate from NINGBO or SHANGHAI with a one-year warranty, an installation manual and a test record covering noise, temperature rise and backlash.
Field Applications
Flour mill screw conveyors
A flour mill standardised on gear reducers for its screw conveyor network. One spare-part pool now covers fifteen drives, and the smooth helical input stage keeps noise low in the packing hall.
Automatic car-wash line
A car-wash equipment builder fits hollow-shaft reducers to its conveyor chains. The compact frame hides inside the wash tunnel, and FKM seal options handle the constant moisture.
![where gear reducers are used in industry]()
Where these units are installed across industry.
Selection Example: Packing-table belt drive
Take a 1.5 kW four-pole motor (1400 rpm) driving a packing-table belt that must run at 56 rpm. The ratio follows directly: 1400 / 56 = 25, so i=25 is selected. In this case the parallel-shaft envelope lets the drive sit flat against the table frame. Once the ratio is fixed, check the required output torque against the rating table with the service factor applied - that is what decides the frame, not the ratio alone.
![gearbox selection guide: speed, torque, service factor]()
How a ratio and a frame size are determined, step by step.
Frame Sizes and Typical Duties
| Model | Centre distance | Output | Typical duty |
|---|
| F37 | 37 mm | solid shaft, foot | small conveyors, dosing |
| F47 | 47 mm | solid shaft, foot | packaging, small mixers |
| F57 | 57 mm | solid shaft, foot | belt conveyors, stirrers |
| F67 | 67 mm | solid shaft, foot | feeders, paddle mixers |
| F77 | 77 mm | solid shaft, foot | turntables, hoists |
| F87 | 87 mm | solid shaft, foot | extruders, washers |
| F97 | 97 mm | solid shaft, foot | thickeners, conveyors |
| F107 | 107 mm | solid shaft, foot | heavy material handling |
Read the frame number as the centre distance in millimetres. Shaft and mounting styles are separate choices: solid shaft (F), hollow shaft (FA) and flanged hollow shaft (FAF).
From Duty Point to Delivery in One Working Day
Stop guessing the ratio. Engineers can size the unit themselves in the WGT Motor & Gearbox Online Selection System - input speed, torque and duty, get the model instantly.
Tell us what the machine does and how hard it works; we calculate the ratio, apply the service factor and send back the drawing and quotation within one working day, including sea-freight and air-freight options. Looking for a gearbox for agricultural machine? Tell us the duty point and we will confirm the model in writing.
Common Questions from Buyers
What are the delivery lead times and shipping terms?
Standard lead time is 5-10 weeks ex-works, with popular ratios often available sooner. We quote EXW, FOB NINGBO / SHANGHAI or CIF, and urgent units can be air-freighted within 72 hours of payment.
What materials are used for the gears and shafts?
Gears are 20CrMnTi alloy steel, case-carburised to HRC58-62 over a tough HRC33-40 core. Input and output shafts are 42CrMo, quenched and tempered to HRC25-30. The housing is cast iron at HBS190-240.
Why does low backlash matter, and what is the limit?
Backlash is the small free rotation between input and output. We hold it within 20 arcmin - tight enough for indexing tables, positioning drives and reversing applications, without the cost of a precision servo gearbox.
