EP-TMR Precision Right-Angle Helical Planetary Gearbox

When a machine axis must turn 90° between the servo motor and the load, the conventional approach is an external right-angle bevel gearbox or a worm reducer bolted onto a standard gearbox. Both introduce additional components, additional backlash sources, and efficiency losses. The EP-TMR integrates the spiral bevel 90° turn and the helical planetary reduction into a single sealed housing. Seven frame sizes (042–220 mm) cover output torques from 17 N·m to 2,000 N·m with gear ratios i=3 to i=200 in single and dual stage configurations. The motor input direction — left, right, up, or down — is fixed at manufacture, so the correct direction must be specified at ordering.

Right-angle helical planetary gearbox · Spiral bevel 90° direction change · Universal servo motor adapter · Korea warehouse stock

Adding a right-angle bevel reducer to a standard planetary gearbox introduces a second housing, a second bearing system, a second lubrication requirement, and a second source of backlash. EP-TMR integrates both the helical planetary reduction and the spiral bevel 90° turn in a single forged-alloy housing with one sealed grease fill. The assembled unit is shorter, lighter, and has fewer wear components than a two-box solution at the same torque rating.

The bevel stage uses ground spiral bevel gears — not straight bevel gears — with a 25–35° helix angle and 58–62 HRC surface hardness. Spiral bevel contact sweeps progressively across the tooth face rather than impacting instantaneously; the result is 4–6 dB lower bevel stage noise than straight bevel at the same tooth load. EP-TMR noise at 3,000 rpm ranges ≤61–74 dB(A) across frames — typically 5 dB above the equivalent EP-TM inline at the same frame.

The planet carrier and bevel pinion shaft are machined as one integrated component — the planetary output flows directly into the bevel pinion without an intermediate coupling. Eliminating this coupling removes the runout that would accumulate at the carrier-to-pinion joint in an assembled design. The bevel stage noise and backlash are lower than competing right-angle units that use a separate coupling between the planetary carrier and the bevel pinion shaft.

The bevel stage housing can be specified with the motor input pointing left, right, upward, or downward relative to the output shaft. This is set by the bevel housing orientation at manufacture and cannot be changed in the field. The flexibility eliminates custom-shafting arrangements that otherwise add length, alignment error, and maintenance complexity when a motor must exit a machine frame in a specific direction. Specify the required input direction — L, R, U, or D — in the model code at time of order.

EP-TMR dual-stage reaches i=200, versus i=100 for EP-TM. The extended range is particularly relevant for right-angle conveyor drives, slew ring actuators, and slow-speed solar tracker drives where the combination of 90° direction change and high ratio is needed in the same unit. At i=200, a 3,000 rpm motor drives the output at 15 rpm — appropriate for heavy rotary table positioning and worm gear pre-stages where the EP-TMR adds the high-efficiency primary reduction before a self-locking worm final stage.

A conventional inline gearbox plus an external right-angle bevel adapter has a combined axial length equal to both units in series. The EP-TMR's single-housing design is shorter — the 90° turn is inside the gearbox, not outside it. For machine columns, robot joint housings, and conveyor side frames where axial depth behind the output shaft is constrained, EP-TMR reduces the overall drive assembly depth by the length of the external bevel adapter that would otherwise be required. For installations where the motor must also fold sideways to save depth, see the EP-TNR right-angle flange series.

Internal pre-load from the bevel stage: In normal operation, the spiral bevel gear mesh generates a separation force, a tangential force, and an axial force on the bevel shaft. These internal forces are present regardless of any external load applied to the output shaft end. The EP-TMR bearing system is designed with pre-loaded angular contact bearings that neutralise these internal forces — but they consume a portion of the bearing's rated capacity. This is why the permissible external radial force at the EP-TMR output shaft is slightly lower than at the EP-TM output shaft of the same frame.

Overhang position factor K_b: When the external radial load is applied at the shaft centre (x = L/2xL), the full permissible radial force applies. As the load is applied further from the bearing (x increasing beyond L/2xL), the bending moment on the output shaft increases and the permissible radial force decreases according to the position factor K_b. The relationship is not linear — refer to the Korea Ever-Power position load coefficient chart or the radial load calculation guide for the full chart and calculation methodology.

Korean lathe and turning centre tool turrets require the servo motor to be positioned perpendicular to the turret rotation axis to clear the spindle envelope. EP-TMR060/090 at i=10–25 is the standard configuration — the motor mounts laterally, the turret indexes on the output shaft axis. The low backlash (P1 ≤6 arcmin) allows encoder-based position confirmation without additional reference sensor hardware.

Korean pharmaceutical blister packaging and carton folding machines use EP-TMR to drive folding arms and sealing platens from a servo positioned behind or beside the machine frame — not in line with the motion. The 90° output eliminates a coupling-and-shaft extension assembly, reducing accumulated angular error in the folding mechanism and simplifying machine frame design.

Korean e-commerce logistics AGVs with Mecanum or omni wheels use TMR042/060 at the wheel corner to drive from a vertically-mounted motor. The compact body of the TMR042 (109 mm total length, □42 square section) fits within the constrained wheel-corner envelope that a standard inline unit cannot. The i=5–10 single-stage ratio maintains high efficiency appropriate for battery-powered AGV operation.

Front-opening unified pod transfer robots in Korean fab corridors must fit within the SEMI E84 footprint standard. The TMR060/090 allows mounting the servo motor parallel to the robot base plate — reducing the robot's frontal depth by the motor body length compared to an inline configuration. The high-precision P1 version ensures FOUP positioning accuracy within the ±1 mm SEMI standard requirement.

Korean food processing lines (kimchi, ready-meal, packaged snack) use TMR090/115 to drive conveyor belt head drums from the side wall of the conveyor frame. The motor mounts vertically on the conveyor side face — keeping the top of the conveyor clear for product handling — while the output shaft connects directly to the drum shaft. IP65 rating handles food processing washdown environments.

Korean grain dryers, chemical agitators, and concrete mixer plants use TMR115/142/180 at i=25–100 to drive horizontal screw conveyors from a perpendicular motor. The high-ratio dual-stage (i=100–200) accommodates very slow screw conveyor speeds (5–30 rpm) from standard induction motors. For these high-cycle low-speed applications, the TMR's sealed-grease construction eliminates the oil-bath maintenance that worm reducers require in the same configuration.

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Can I replace my existing EP-TM inline gearbox with an EP-TMR at the same frame size without changing the motor adapter plate?

Yes — the motor adapter plate (connecting plate) is identical between EP-TM and EP-TMR at every frame size. The motor adapter bolt circle, pilot bore, and register dimensions are shared across the entire EP-TM/TMR family. When changing from inline to right-angle, you keep the motor, motor adapter plate, and motor shaft coupling — only the gearbox body and output section change. The output side of the machine will need to accommodate the 90° change in shaft orientation, but the motor side installation is a direct swap. Confirm the output shaft diameter and keyway dimensions are identical between your current EP-TM and the EP-TMR before ordering — these are generally the same but should be verified on the dimensional drawing for your specific model and ratio.

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The EP-TMR efficiency is ≥95% for single-stage. What causes the ~2% efficiency reduction compared to the EP-TM (≥97%)?

The 2% efficiency difference is the friction loss in the spiral bevel gear stage. The bevel gear pair always meshes at 1:1 ratio — it redirects direction without changing speed — but the meshing process itself dissipates approximately 1.5–2% of transmitted power as heat regardless of the transmitted torque level. This loss is inherent to the bevel gear mechanism and cannot be eliminated by design. The spiral bevel geometry minimises it (straight bevel pairs lose 3–5% in the same configuration) but does not eliminate it. For continuous high-power Korean industrial drives where this 2% matters financially, see the efficiency ROI calculation guide to quantify the annual energy cost of the bevel stage at your specific operating conditions.

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For a Korean CNC machine feed axis with a rack-and-pinion drive, should I use EP-TMR or a standard EP-TM with an L-bracket?

The EP-TMR eliminates the L-bracket entirely — the gearbox itself performs the direction change with higher precision than a separate bracket and coupling can achieve. An L-bracket introduces at least one additional shaft coupling and two additional bearing sets, each adding a small angular error and a failure point. The EP-TMR performs the same direction change internally with the spiral bevel stage, maintaining sub-3-arcmin total system backlash from the motor shaft to the pinion. For a rack-and-pinion axis where the pinion is mounted on the EP-TMR output shaft, the output shaft radial load from the rack contact force must be checked against the overhang-corrected permissible radial force using the position factor Kb. At high overhang distances, the EP-TNR with its larger-diameter output flange provides higher radial load capacity in the same right-angle configuration.

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Korean food processing facilities require regular high-pressure washdown. Can the EP-TMR withstand this environment without additional sealing?

The EP-TMR is rated IP65 as standard — protected against low-pressure water jets from any direction per IEC 60529. This covers standard Korean food processing washdown using cleaning hoses at typical pressures (up to approximately 30 kPa). For Korean KFDA-compliant food facilities that use high-pressure steam cleaning or chemical spray at pressures above 30 kPa, IP65 may not be sufficient and the EP-TMR should be positioned in a location away from direct high-pressure spray, or covered during cleaning operations. IP67 rated right-angle gearboxes (immersion rated) are available on the Korea Ever-Power EP-TNR series with the IP67 option for the most demanding Korean food and beverage hygiene zone applications.

EP-TMR090 P1 i=20 on a side-drive conveyor head where the motor had to exit the machine frame laterally — no space inline. Previous solution used a right-angle worm reducer at the same position, which consumed 70% efficiency and ran at 65°C housing temperature in summer. EP-TMR090 efficiency ≥95% dropped that to 43°C steady-state. Also eliminated the quarterly oil change on the worm. 18 months in three-shift operation, zero maintenance events. Korea Ever-Power confirmed the motor adapter for our Yaskawa SGMGV-09A same day.

EP-TMR115 P1 i=25 for a horizontal milling machine Z-axis where the servo motor had to point toward the rear of the machine rather than downward. The 90° output freed up 160 mm of vertical headroom that allowed us to increase the Z-axis travel. Spiral bevel noise at 3,000 rpm was completely acceptable — ≤68 dB as rated. Four input direction options saved us from a custom shafting arrangement. 12 months on the production line, backlash unchanged versus delivery certificate.

EP-TMR142 P2 i=40 dual-stage for the base rotation (J1) of a heavy-payload spot welding robot. The 90° output let us mount the motor vertically inside the base column instead of protruding rearward, reducing the robot's floor footprint by 220 mm depth. At 3× rated torque (T₂max = 1,950 N·m) during weld gun clamp the gearbox handled the impulse across 36,000 cycles per year without measurable backlash growth. Received the delivery certificate — actual measured value 7.2 arcmin, well within P2 ≤10 arcmin spec.