Short answer: For packaging conveyors and belt scale lines, the three SEAPARKS light duty drum motors cover three different load windows rather than three price points. TM80M (roller diameter 80 mm) is the narrow-belt, low-speed option, rated 0.034–0.11 kW with 2.71–25.9 Nm torque and 630 N maximum belt pull. TM113A (113 mm) is available as a single-phase unit rated 0.12–0.23 kW with 1410 N maximum belt pull and as a three-phase unit rated 0.12–0.55 kW with 1469 N. DM138A (138 mm) is a three-phase synchronous unit rated 0.75–1.5 kW with 27.69–273.58 Nm torque and 3965 N maximum belt pull. Selection therefore starts with the belt pull and belt speed your conveyor actually needs, not with the roller diameter alone.

Figure 1 — TM113A light duty drum motor, the mid-frame model in this three-way comparison.

Tianjin Seaparks Machinery-Electronics Co., Ltd. (SEAPARKS) is a Tianjin-based manufacturer of motorized conveyor drums, founded in 2002 and operating a 50,000 m² plant with an annual capacity of 380,000 units. Its portfolio is organised into hygienic, light duty and heavy duty series. The three models compared here sit in the light duty group, which SEAPARKS lists for packaging conveyors, belt scale conveyors, general belt conveyors, airport baggage handling systems and security screening conveyors at airports and railway stations.

This guide compares the three models on the attributes that decide whether a conveyor runs or stalls: roller diameter, minimum roller width, rated power, rated torque, maximum belt pull, nominal belt speed, protection class and housing material. It then converts those numbers into a selection sequence you can apply to a packaging line or a belt scale frame, and closes with the questions buyers usually ask before requesting a sample or a quotation.

Problem definition: three look-alike models and four numbers that decide the outcome

In a catalogue, TM80M, TM113A and DM138A look almost interchangeable. All three are light duty conveyor drum motors, all three are offered with carbon steel or 304 stainless steel housings, and all three list IP66/IP67/IP69 protection. The differences sit in four numbers, and each one can disqualify a model for a given conveyor:

• Maximum belt pull. 630 N for TM80M, 1410 N for the single-phase TM113A configuration, 1469 N for the three-phase TM113A configuration and 3965 N for DM138A. A conveyor whose steady running pull approaches or exceeds this value will slip, stall or overheat regardless of how the motor is wired.
• Nominal belt speed window. 0.05–0.85 m/s for TM80M, 0.08–0.71 m/s (single-phase) or 0.09–1.4 m/s (three-phase) for TM113A, and 0.37–1.83 m/s for DM138A. The lower bound matters as much as the upper bound.
• Minimum roller width. 260 mm for TM80M, 335 mm for TM113A and 340 mm for DM138A. A belt narrower than the minimum cannot be driven by that frame.
• Rated power and phase. 0.034–0.11 kW single-phase for TM80M, 0.12–0.23 kW single-phase or 0.12–0.55 kW three-phase for TM113A, and 0.75–1.5 kW three-phase for DM138A.

Three practical failure patterns follow from ignoring those numbers.

Selecting by diameter alone. Choosing the largest frame on the assumption that more capacity is always safer creates a different problem: DM138A starts at a nominal belt speed of 0.37 m/s, while TM80M can run down to 0.05 m/s. On a slow-moving packaging transfer or a scale infeed that must hold a low, stable speed, the Ø138 frame may sit above the required operating point while the Ø80 or Ø113 frame sits inside it.

Ignoring the width floor. A 300 mm belt cannot be driven by TM113A or DM138A, whose minimum roller widths are 335 mm and 340 mm. In that case the geometry, not the load, decides the model.

Ignoring the electrical supply. A site wired for single-phase power can reach 1410 N of belt pull with TM113A, but the step to DM138A requires a three-phase supply and a synchronous motor.

Industry background: where light duty drum motors sit

A drum motor is a conveyor belt drive in which the electric motor and the gear reducer are built inside the conveyor pulley. The drum shell becomes the driving pulley, which removes the external gearbox, chain, guard and coupling arrangement of a conventional drive. For packaging and belt scale conveyors, that compact footprint is the main structural reason the format is specified.

Market data provides context for how the category is developing. Market.us projects the global drum motor market to grow from USD 2.0 billion in 2025 to USD 3.1 billion by 2035. Dataintelo reports that AC motor types held a 52.3% revenue share of the market in 2025, and identifies Interroll Group and Rulmeca Group as the largest global suppliers at 14.8% and 11.2% market share respectively. Both figures are commercial research estimates rather than audited industry totals, but they indicate a category in which AC asynchronous drives remain the dominant volume technology.

Within that market, the light duty tier is defined by the load it carries rather than by a single specification. SEAPARKS describes its light duty asynchronous series as intended for lighter conveyed materials, favourable operating conditions and low-noise requirements, offered in roller diameters of 80, 113 and 138 mm. That positioning is a company description of the product family, not a measured noise or efficiency benchmark: no dB(A) values or efficiency class declarations for these models are published in the source material, so noise and energy claims should be tested against datasheets before a decision is made.

Two specification layers separate light duty models from hygienic ones:

• Protection class. The three light duty models list IP66/IP67/IP69. IP69K, the highest ingress protection rating under IEC 60529, is associated with high-pressure, high-temperature washdown up to 1450 psi at 80 °C and is listed on the separate hygienic series, in which the equivalent frames (for example TM113F and DM138F) carry IP69K.
• Housing and gear material. Light duty models are offered in carbon steel or 304 stainless steel. Hygienic models are built in 304 stainless steel with 316 stainless steel as an option. Gear material also differs by model, which is why it belongs in the quotation rather than in an assumption.

For a packaging conveyor in a dry hall or a belt scale on a general production line, the light duty tier is usually the correct starting point. Where the line is washed down with high-pressure water, the hygienic tier is the relevant comparison, and the light duty models in this guide should not be substituted.

Detailed solution: what each model is built for

TM80M — the narrow, slow, light option

Figure 2 — TM80M cross-section: a single-phase asynchronous light duty drum motor with polymer gearing.

TM80M is a single-phase asynchronous light duty drum motor with a roller diameter of 80 mm, a minimum roller width of 260 mm and polymer gears, in a carbon steel or 304 stainless steel housing with IP66/IP67/IP69 protection. Rated power is 0.034–0.11 kW, rated torque 2.71–25.9 Nm, maximum belt pull 630 N and nominal belt speed 0.05–0.85 m/s.

Two attributes make it structurally distinct in this group. The 260 mm minimum roller width is the lowest of the three, so it is the only model that can drive belts narrower than 335 mm. The 0.05 m/s lower speed bound is also the lowest of the three, which suits transfers that must move slowly, such as a small-pitch packaging infeed or a scale approach section where the belt must settle before the weighing zone.

TM113A — the mid-frame model with two electrical configurations

Figure 3 — TM113A parts diagram. The same 113 mm frame is offered in single-phase and three-phase configurations.

TM113A is a light duty drum motor with a 113 mm roller diameter and a 335 mm minimum roller width, in a carbon steel or 304 stainless steel housing with IP66/IP67/IP69 protection. It is listed in two configurations:

• Single-phase asynchronous: rated 0.12–0.23 kW, 10.34–79.67 Nm, maximum belt pull 1410 N, nominal belt speed 0.08–0.71 m/s.
• Three-phase asynchronous: rated 0.12–0.55 kW, 10.34–82.99 Nm, maximum belt pull 1469 N, nominal belt speed 0.09–1.4 m/s.

The three-phase configuration is the more capable of the two on both power and speed: it reaches 0.55 kW against 0.23 kW, and its upper speed bound is 1.4 m/s against 0.71 m/s. The belt pull difference between the two configurations is small (1469 N versus 1410 N), so the choice between them is usually driven by the available power supply and the required belt speed rather than by load capacity.

In practice TM113A is the widest-aperture model in this group. It covers roughly twice the belt pull of TM80M while still reaching speeds below 0.1 m/s, and it sits below DM138A on cost-driving attributes such as rated power and gear specification.

DM138A — the highest-capacity light duty frame

Figure 4 — DM138A: a three-phase synchronous light duty drum motor with a 138 mm roller and alloy steel gears.

DM138A is a synchronous, three-phase light duty drum motor with a 138 mm roller diameter, a 340 mm minimum roller width and alloy steel gears, in a carbon steel or 304 stainless steel housing with IP66/IP67/IP69 protection. Rated power is 0.75–1.5 kW, rated torque 27.69–273.58 Nm, maximum belt pull 3965 N and nominal belt speed 0.37–1.83 m/s.

DM138A carries roughly 2.7 times the maximum belt pull of the three-phase TM113A and reaches a higher top speed, which makes it the correct choice when a wide packaging conveyor or a scale frame has to move heavier loads or run faster than the Ø113 frame allows. It also has the highest minimum belt speed in the group at 0.37 m/s, so it is not a drop-in replacement for a slow-moving line driven by TM80M or TM113A. Where a slow speed and a high belt pull are both required, the speed requirement should be verified against the DM138A speed window before the model is committed.

Step-by-step breakdown: matching a model to conveyor load and speed

Step 1 — Establish the maximum belt pull the conveyor needs

The starting figure is the belt pull required at the drum, not the motor power. Compare that figure with the model maximum: 630 N for TM80M, 1410 N for single-phase TM113A, 1469 N for three-phase TM113A and 3965 N for DM138A. A model should be selected with margin below its maximum rather than at the limit, because the published figure is a maximum rather than a continuous operating target.

Step 2 — Check the required belt speed against the model window

Belt speed is a function of drum diameter and drum rotational speed, so the same drive speed produces a different belt speed on an Ø80 drum and an Ø138 drum. The published nominal belt speed ranges are the practical window:

• TM80M: 0.05–0.85 m/s
• TM113A single-phase: 0.08–0.71 m/s; three-phase: 0.09–1.4 m/s
• DM138A: 0.37–1.83 m/s

The common error is checking only the upper bound. A packaging transfer specified at 0.2 m/s is inside the TM80M, single-phase TM113A and three-phase TM113A windows, but below the DM138A minimum of 0.37 m/s.

Step 3 — Fix minimum roller width against the belt width and frame

The drum must be at least as wide as the model minimum: 260 mm for TM80M, 335 mm for TM113A and 340 mm for DM138A. Check this against the actual belt width and the available space in the conveyor end, since moving from an Ø80 to an Ø138 drum also changes the frame opening around the pulley.

Step 4 — Match rated power and phase to the site supply

TM80M is single-phase only, rated 0.034–0.11 kW. TM113A is available in single-phase (0.12–0.23 kW) and three-phase (0.12–0.55 kW). DM138A is three-phase only, rated 0.75–1.5 kW. If the site has no three-phase supply, the ceiling is the single-phase TM113A configuration at 1410 N belt pull.

Step 5 — Select protection class and housing material for the environment

All three models list IP66/IP67/IP69 in either carbon steel or 304 stainless steel. For a dry packaging hall, carbon steel is the lower-specification option; for a splash-prone area or a humid room, 304 stainless steel is the listed upgrade. For high-pressure washdown the relevant comparison is the hygienic series with IP69K and optional 316 stainless steel, not these models.

Step 6 — Confirm the specification in writing before ordering

Before committing a frame size, request a written datasheet confirming roller diameter, minimum roller width, rated power, rated torque, maximum belt pull, nominal belt speed, protection class, housing material and gear material for the exact model and configuration. Gear material in particular varies across the range and should be confirmed per model rather than inferred from a catalogue family page.

Use cases: where each model is typically specified

Packaging conveyors and case transfer sections

Packaging lines use drum motors where the drive must sit inside the conveyor profile. TM80M suits narrow transfer belts and slow-moving infeed sections at 0.05–0.85 m/s and up to 630 N. TM113A covers the main packaging conveyor body, where belt pull requirements are moderate and a 0.71 m/s or 1.4 m/s top speed covers the line rate. DM138A is specified where a wide packaging conveyor carries heavier units or runs above 1.4 m/s and the belt pull approaches the Ø113 frame limit.

Belt scale and checkweigher infeed conveyors

Scale frames are typically narrow and run at a low, steady speed, so the binding constraints are usually the width floor and the lower speed bound rather than the power rating. TM80M at a 260 mm minimum roller width and a 0.05 m/s minimum speed is the structurally closest match for narrow scale belts. TM113A applies where the belt is at least 335 mm wide and the required speed sits inside 0.08–1.4 m/s depending on configuration. DM138A is relevant on wide, faster scale conveyors where belt pull is the dominant requirement, and its 0.37 m/s speed floor must be checked first.

Security screening and baggage handling conveyors

SEAPARKS lists all three models for security screening conveyors at airports and railway stations, airport baggage handling systems and general belt conveyors. The application data for airport X-ray security screening describes continuous 24/7 operation with frequent start-stop capability, high-precision speed control, low vibration, anti-electromagnetic interference and flame-retardant requirements, supported by X-ray scanners, baggage trays, metal detectors and conveyor guide rails. Where the tray pitch and belt width are small, the Ø80 frame is the natural fit; where the belt is wide and carries loaded trays at higher speed, the Ø138 frame is the appropriate specification.

General light duty conveying with moderate duty cycles

For general belt conveyors moving light goods in favourable operating conditions, the selection usually falls to TM113A as the central option, with TM80M used where the frame is space-constrained and DM138A where belt pull and speed exceed the Ø113 window.

Side-by-side comparison table

Table 1 — Specification comparison of the three light duty drum motor models. Figures are as published for each listed configuration; confirm the exact configuration at quotation.

FAQ

Figure 5 — SEAPARKS manufacturing facility, Ninghe District, Tianjin.

Conclusion

TM80M, TM113A and DM138A are not three grades of the same drive; they are three operating windows inside the SEAPARKS light duty range. TM80M answers the narrow-belt, low-speed case with a 260 mm minimum roller width, a 0.05 m/s minimum speed and 630 N maximum belt pull. TM113A is the central model, covering 1410 N in single-phase form or 1469 N and up to 1.4 m/s in three-phase form on a 335 mm minimum width. DM138A takes the top of the light duty range at 3965 N and 1.83 m/s, with a 0.37 m/s floor that rules it out of slow-speed duties. Applied in that order — belt pull, then speed window, then width, then power and phase, then protection and housing — the comparison resolves to one model rather than a preference. Final confirmation should always come from the model datasheet for the exact configuration being ordered.

Reviewed October 2026. Specifications are as published for the configurations listed and should be reconfirmed at quotation.