Short answer: Every Winsmith D-90 Type SE reducer carries a nameplate with its
end unit part number, and Winsmith states that this number completely describes the unit: size, input style, model, reduction, shaft arrangement, motor frame, output style and ratio. Record it exactly and you can identify a like-for-like replacement. Before you order, confirm the original unit still suits the job, especially if the load, the running hours or the motor speed has changed.
A worm gear reducer is usually replaced after it has already stopped a machine: a seized output shaft, a seal that leaked until the unit ran dry, a cracked housing. For a Winsmith speed reducer replacement, the quickest route back to running is the part number on the nameplate. The risk is copying a unit that was undersized to begin with, or bolting it to a motor that now runs at a different speed.
This guide shows how to read a Winsmith part number position by position, how Winsmith itself sizes a reducer, and what to collect before you ask for a replacement.
How a Winsmith D-90 Type SE part number is built
Winsmith's D-90 Type SE catalog decodes its part numbers with one worked example: a D-90 Series reducer with a 3.50 in (about 89 mm) center distance, worm on top, single reduction, double-extended output shaft, 143TC frame C-face motor input and a 30:1 ratio. Its end unit part number is
935MDTS22000EK. Read left to right:
- Series: 9 = D-90 Series.
- Center distance (unit size): 35 = 3.50 in between worm and gear centers. Other codes: 10, 13, 17, 20, 24, 26, 30, 43 (1.00 in to 4.25 in).
- Input style: M = C-face with quill motor adapter. Other codes: C = C-face with coupling adapter; no letter = non-motorized (separate input shaft).
- Basic model: DT = Worm on top. Other codes: DB worm on bottom, DV vertical output shaft, DN footless solid output, DSF flange-mount hollow output, and others.
- Reduction: S = Single reduction. Other codes: D double, T triple, X helical primary.
- Shaft arrangement: 2 = Solid output shaft extended on both sides. Other codes: 3 extended right, 4 extended left; vertical and hollow-output units have their own codes.
- Motor frame: 2 = 143–145TC / 182–184C frame. Other codes: W 42C, V 48C, 1 56C, 3 182–184TC, X none (input shaft).
- Output style: 00 = Solid output shaft. Other codes: 08, 09, 10 = hollow bore of 0.50, 0.563 and 0.625 in; the code rises by one for each 1/16 in of bore.
- Final digit: 0 = Shown as 0 in Winsmith's example; the guide gives no separate code table for it.
- Ratio: EK = 30:1. Other codes: DN 20:1, FA 40:1, FT 50:1, GC 60:1.
Two details catch people out. First, the
ratio is a letter code, not a number: "EK" is 30:1, and nothing else in the part number states the ratio. Second, the same unit appears in catalog listings in a longer form (935, MDT, LR, 143TC, 30:1). The nameplate carries the compact end unit part number.
Winsmith notes that its chart covers most standard configurations and options, and that double and triple reduction arrangements should be checked with the factory. The breakdown above applies to the D-90 Type SE line. Other Winsmith product lines use their own numbering, so decode them with the catalog for that line.
Reading a worn or partial nameplate
Copy the part number exactly as stamped, including every letter and zero. Photograph the whole plate, then take views of the reducer that show how it mounts and where the shafts come out. If a character is unreadable, mark it as unreadable rather than guessing. A single wrong character can change the mounting or the ratio.
The fixed structure helps when only part of the plate survives. If you can read "935" at the start and "EK" at the end, you already know the size and the ratio. Mounting, shaft direction and motor frame can then be confirmed from photos and from the motor's own nameplate.
How Winsmith sizes a worm gear reducer
A matching part number reproduces the old unit. It does not prove the old unit was right for the job. Winsmith's catalog sets out a selection procedure, summarized here:
- Service factor. Take it from Winsmith's table for the application and daily running hours, and adjust it for the type of prime mover and for frequent starting and stopping.
- Ratio. Ratio = input rpm ÷ output rpm. The
gearbox ratio calculator handles the arithmetic.
- Unit size. Multiply the applied horsepower or torque by the service factor to get the design load. Then choose the size whose mechanical rating at that ratio and input speed meets or exceeds it.
- Thermal capacity. For continuous operation, confirm the load does not exceed the unit's thermal rating. If it does, consider the next size up or synthetic oil.
- Overhung and thrust loads. Check the loads on the shafts from sprockets, sheaves or couplings against the catalog ratings.
- Fit. Check dimensions, shaft arrangements and motor frame sizes.
Winsmith's own conveyor example: a non-uniformly loaded belt conveyor runs 24 hours a day with a headshaft speed of 30 rpm, driven by a 3/4 HP (about 0.56 kW) motor at 1,750 rpm. The service factor is 1.50. The ratio works out to 1,750 ÷ 30 = 58.33, so a standard 60:1 is used, giving about 29 rpm at the output. The design load is 0.75 × 1.50 = 1.125 HP (about 0.84 kW). A size 930 unit meets that at 60:1 and 1,750 rpm input, and its thermal capacity is not exceeded.
If a conveyor like this has since gained load or moved to longer shifts, rerun the same steps before ordering an identical unit.
Motor speed: the 50 Hz vs 60 Hz trap
A replacement ordered by the same part number keeps the same ratio, so its output speed depends entirely on the motor. A 4-pole motor runs at about 1,750 rpm on 60 Hz power and about 1,450 rpm on 50 Hz power. The 60:1 reducer from the example turns about 29 rpm on 60 Hz, but only about 24 rpm on 50 Hz. That is a meaningful drop in conveyor speed.
Capacity also shifts with input speed. Winsmith's rating tables list each size at several input speeds, so check the rating at the speed the motor will actually run. This matters whenever a machine is relocated or a replacement is shipped to a plant on 50 Hz power. Jealco has handled export orders since 1950, and supply frequency is one of the first questions we ask on an international replacement.
When the exact unit is not available or the arrangement has changed
A different basic model, shaft arrangement, input style or motor frame means the unit is not a direct swap, even at the same size and ratio. Compare the replacement's dimension drawing against the installed unit: center distance, ratio, mounting position, shaft diameters and extensions, keyways, motor frame and clearance around the unit.
As an independent distributor, we can cross-reference a reducer across multiple manufacturers when the original configuration cannot be sourced. The same data drives that search: the part number, the application and the measured fit.
What to send us for a replacement quote
- Full Winsmith end unit part number from the nameplate, exactly as stamped
- A clear photo of the nameplate and photos of the reducer as mounted
- Ratio, if the ratio code is unreadable
- Motor HP, motor rpm, frame size and supply frequency (50 or 60 Hz)
- Mounting position and which side the output shaft extends
- Input style: C-face motor mount or separate input shaft
- Output shaft diameter, or hollow-bore size
- What the reducer drives, and hours of operation per day
Frequently asked questions
Where is the part number on a Winsmith reducer?
On the nameplate pinned to the unit. Winsmith notes it is sometimes called the "serial number". It is the end unit part number that fully describes the reducer.
How do I find the ratio from a Winsmith part number?
Read the two-letter code at the end and look it up in the catalog's ratio table. For example, EK is 30:1, FT is 50:1 and GC is 60:1.
What does "935" mean at the start of the part number?
The 9 is the D-90 Series. The 35 is the center distance, 3.50 in, which sets the unit size.
Can I replace a reducer with the same part number and skip sizing?
Only if nothing about the application has changed. If the load, running hours, motor speed or supply frequency differs from the original installation, rerun the selection steps first.
What if the nameplate is unreadable?
Send photos of the plate and of the reducer as mounted, plus the motor nameplate and any readable characters. The size and ratio can often be confirmed from partial markings and measurements.
Summary
The Winsmith end unit part number is the most useful single piece of information for a replacement: it gives size, input style, model, reduction, shaft arrangement, motor frame, output style and ratio in one string. Decode it with the catalog, confirm the application still matches the original selection, and check motor speed and supply frequency before ordering.
Sources & References
For a replacement Winsmith reducer or a cross-reference, see our
Winsmith speed reducers page or browse our
gearing products, and send us your nameplate details.
Related Reading:
