{"id":731,"date":"2026-06-03T01:03:16","date_gmt":"2026-06-03T01:03:16","guid":{"rendered":"https:\/\/planetary-gearboxes.com\/?p=731"},"modified":"2026-06-03T01:03:16","modified_gmt":"2026-06-03T01:03:16","slug":"high-reduction-ratio-planetary-gearbox-selection","status":"publish","type":"post","link":"https:\/\/planetary-gearboxes.com\/ar\/high-reduction-ratio-planetary-gearbox-selection\/","title":{"rendered":"\u0627\u062e\u062a\u064a\u0627\u0631 \u0639\u0644\u0628\u0629 \u062a\u0631\u0648\u0633 \u0643\u0648\u0643\u0628\u064a\u0629 \u0628\u0646\u0633\u0628\u0629 \u062a\u062e\u0641\u064a\u0636 \u0639\u0627\u0644\u064a\u0629"},"content":{"rendered":"
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\u0643\u0648\u0631\u064a\u0627 \u0642\u0648\u0629 \u062f\u0627\u0626\u0645\u0629<\/span>
\nHigh Ratio Engineering Guide<\/span><\/div>\n

High Reduction Ratio Planetary Gearbox Selection \u2014 From 64:1 to 516:1, What Changes and What Does Not<\/h1>\n

Once you cross above 64:1, you enter 3-stage \u0639\u0644\u0628\u0629 \u062a\u0631\u0648\u0633 \u0643\u0648\u0643\u0628\u064a\u0629 \u062f\u0642\u064a\u0642\u0629<\/a> territory \u2014 and the selection principles change in ways most guides do not explain. The output torque ceiling no longer scales linearly with ratio. The backlash does not compound across stages the way most engineers expect. And the motor speed constraint begins to dominate the ratio selection at very low output speeds. This guide addresses all three, plus the four simultaneous functions a high gear ratio performs that most selection guides reduce to one.<\/p>\n

Get High-Ratio Specification Support \u2192<\/a><\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

The Four Functions a High Gear Ratio Simultaneously Performs<\/h2>\n

Most engineers select gear ratio by calculating: T_output = T_motor \u00d7 i \u00d7 \u03b7, then choosing the smallest i that delivers the required output torque. This is correct for the torque function \u2014 but a gear ratio performs three additional functions simultaneously, and for high-ratio applications (i \u2265 64:1) these additional functions often drive the specification more strongly than torque alone.<\/p>\n

\n
\n
FUNCTION 1 \u2014 TORQUE<\/div>\n
T_out = T_motor \u00d7 i \u00d7 \u03b7<\/div>\n

Scales linearly with ratio. Standard selection calculation. Limited by the gearbox output torque ceiling \u2014 increasing i beyond the point where motor torque \u00d7 i \u00d7 \u03b7 equals the output ceiling gives no additional torque benefit.<\/p>\n<\/div>\n

\n
FUNCTION 2 \u2014 INERTIA \u2605 Most Powerful<\/div>\n
J_\u0627\u0646\u0639\u0643\u0627\u0633\u064a = J_\u062d\u0645\u0644 \/ i\u00b2<\/div>\n

Scales with i squared<\/em>. At i=100, the load inertia is reduced 10,000\u00d7 at the motor shaft. This is why high-ratio applications can use small motors without inertia matching problems \u2014 a 50 kg\u00b7m\u00b2 rotary table reflected through i=200 becomes just 0.00125 kg\u00b7m\u00b2 at the motor shaft.<\/p>\n<\/div>\n

\n
FUNCTION 3 \u2014 SPEED<\/div>\n
n_out = n_motor \/ i<\/div>\n

At i=320, a motor running at 3,000 rpm produces only 9.4 rpm at the output. For very slow tracking applications (solar azimuth \u2248 0.25 rpm, antenna \u2248 0.05 rpm), high ratio is the only way to achieve these output speeds while keeping the motor in its stable servo operating range.<\/p>\n<\/div>\n

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FUNCTION 4 \u2014 ENCODER RESOLUTION<\/div>\n
Resolution \u00d7 i at output<\/div>\n

A 10,000-line encoder produces 40,000 counts\/rev of the motor shaft. Through i=100, this becomes 4,000,000 counts\/output-rev \u2014 giving 0.000090\u00b0 (0.32 arcsecond) theoretical positioning resolution. This is why heavy rotary tables achieve sub-arcsecond positioning without expensive absolute encoders on the output shaft.<\/p>\n<\/div>\n<\/div>\n

\n

\u0627\u0644\u0622\u062b\u0627\u0631 \u0627\u0644\u0645\u062a\u0631\u062a\u0628\u0629 \u0639\u0644\u0649 \u0627\u0644\u062a\u0635\u0645\u064a\u0645:<\/strong> For slow-speed, high-inertia applications \u2014 rotary tables, solar trackers, antenna drives \u2014 the ratio specification is often driven by Functions 3 and 2 (output speed and inertia) rather than Function 1 (torque). The motor needed for a 500 N\u00b7m output through i=200 is only 2.78 N\u00b7m rated torque (545W at 3,000 rpm) \u2014 far smaller than the torque magnitude suggests. Start the ratio selection from output speed and inertia, not from torque.<\/p>\n<\/div>\n<\/section>\n

<\/p>\n

\n

EP Series Complete Ratio Table \u2014 All Standard Ratios from 3:1 to 516:1<\/h2>\n

The EP series precision planetary gearboxes cover 27 standard gear ratios across three stage counts. Non-standard ratios are available for volume orders \u2014 contact Korea Ever-Power application engineering with your exact ratio requirement and the nearest standard ratio will be identified or a custom stage combination confirmed.<\/p>\n

\n\n\n\n\n\n\n\n
Stage Count<\/th>\n\u0627\u0644\u0646\u0633\u0628 \u0627\u0644\u0645\u062a\u0627\u062d\u0629<\/th>\n\u0627\u0644\u0643\u0641\u0627\u0621\u0629 \u03b7<\/th>\nHeat at 1 kW input<\/th>\n\u0631\u062f\u0648\u062f \u0641\u0639\u0644 \u0639\u0646\u064a\u0641\u0629<\/th>\nPrimary Use Case<\/th>\n<\/tr>\n<\/thead>\n
\u0627\u0644\u0645\u0631\u062d\u0644\u0629 \u0627\u0644\u0648\u0627\u062d\u062f\u0629<\/td>\n3 \u00b7 4 \u00b7 5 \u00b7 8 \u00b7 10<\/td>\n96%<\/td>\n40 W<\/td>\n\u0623\u0642\u0644 \u0645\u0646 8 \u062f\u0642\u0627\u0626\u0642 \u0642\u0648\u0633\u064a\u0629<\/td>\nHigh speed, light load, maximum efficiency<\/td>\n<\/tr>\n
\u0645\u0631\u062d\u0644\u062a\u0627\u0646<\/td>\n9 \u00b7 12 \u00b7 15 \u00b7 16 \u00b7 20
\n25 \u00b7 32 \u00b7 40 \u00b7 64<\/td>\n		94%<\/td>\n60 W<\/td>\n<8\u201312 \u062f\u0642\u064a\u0642\u0629 \u0642\u0648\u0633\u064a\u0629<\/td>\nMost servo automation: robot joints, CNC, AGV, packaging<\/td>\n<\/tr>\n
3-Stage \u2605<\/td>\n60 \u00b7 80 \u00b7 100 \u00b7 120
\n160 \u00b7 200 \u00b7 256 \u00b7 320 \u00b7 516<\/td>\n		90%<\/td>\n100 W<\/td>\n<8\u201315 arcmin<\/td>\nHigh-torque\/slow-speed: rotary tables, solar, antenna, conveyors<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n
Why 3-stage efficiency is 90%, not 96%\u00b3 = 88.5%<\/div>\n

Three independent stages at 96% each would give 0.96\u00b3 = 88.5%. The published 90% for EP 3-stage units reflects that intermediate stages in a compound planetary unit share some mechanical elements and operate at lower relative speeds \u2014 the per-stage friction is not fully independent. The 90% figure is the certified efficiency at rated load; at light load, efficiency can be somewhat lower due to fixed friction losses (seals, bearing drag) dominating at low transmitted power.<\/p>\n<\/div>\n<\/section>\n

<\/p>\n

\"Precision<\/p>\n
The ring gear is the fixed outer element in a planetary stage \u2014 its internal tooth form geometry directly determines per-stage efficiency loss and the backlash specification of the stage. In 3-stage EP series units (60:1 to 516:1), the last-stage ring gear quality dominates the overall output backlash, because earlier-stage backlash is divided by the subsequent stage ratios before reaching the output shaft. View EP series 3-stage specifications \u2192<\/a><\/div>\n<\/div>\n

<\/p>\n

\n

The Output Torque Ceiling \u2014 The Constraint Most High-Ratio Guides Omit<\/h2>\n

The most common misconception in high-ratio planetary gearbox selection is that increasing the gear ratio indefinitely increases the available output torque. In reality, the gearbox output shaft, output bearing, and final-stage planet carrier have a maximum torque capacity set by the size of the mechanical components \u2014 the output torque ceiling. Above this ceiling, increasing ratio brings no additional torque: the gearbox will fail before the motor can transmit more torque through it.<\/p>\n

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The Output Torque Ceiling Rule<\/div>\n
\n
T_actual_out = MIN( T_motor \u00d7 i \u00d7 \u03b7 , T_output_ceiling )<\/div>\n
where T_output_ceiling = rated torque of the gearbox frame at that stage count<\/div>\n
Example: EP-ZDE-80, 3-stage i=100, \u03b7=0.90<\/div>\n
T_output_ceiling = 50 N\u00b7m (ZDE-80 rated output torque)<\/div>\n
Motor producing 0.5 N\u00b7m: T_available = 0.5 \u00d7 100 \u00d7 0.90 = 45 N\u00b7m \u2264 50 N\u00b7m \u2705 OK<\/div>\n
Motor producing 2.0 N\u00b7m: T_available = 2.0 \u00d7 100 \u00d7 0.90 = 180 N\u00b7m > 50 N\u00b7m \u274c OVERLOAD<\/div>\n
\u2192 For 180 N\u00b7m output at i=100: must use ZDE-120 (110 N\u00b7m ceiling) or ZDE-160 (450 N\u00b7m ceiling)<\/div>\n<\/div>\n<\/div>\n
\n\n\n\n\n\n\n\n\n\n\n\n
EP Series Frame<\/th>\n\u0639\u0632\u0645 \u0627\u0644\u062f\u0648\u0631\u0627\u0646 \u0627\u0644\u0646\u0627\u062a\u062c
\nCeiling (N\u00b7m)<\/th>\n		Max Motor T
\nat i=100, \u03b7=0.90<\/th>\n		Max Motor T
\nat i=200, \u03b7=0.90<\/th>\n		Max Motor T
\nat i=320, \u03b7=0.90<\/th>\n		Typical Motor Class<\/th>\n<\/tr>\n<\/thead>\n
EP-ZDE-60<\/td>\n16 \u0646\u064a\u0648\u062a\u0646 \u0645\u062a\u0631<\/td>\n0.18 N\u00b7m<\/td>\n0.09 N\u00b7m<\/td>\n0.06 N\u00b7m<\/td>\n50\u2013100W servo motor<\/td>\n<\/tr>\n
EP-ZDE-80<\/td>\n50 \u0646\u064a\u0648\u062a\u0646 \u0645\u062a\u0631<\/td>\n0.56 N\u00b7m<\/td>\n0.28 N\u00b7m<\/td>\n0.17 N\u00b7m<\/td>\n100\u2013200W servo motor<\/td>\n<\/tr>\n
EP-ZDE-120<\/td>\n110 N\u00b7m<\/td>\n1.22 N\u00b7m<\/td>\n0.61 N\u00b7m<\/td>\n0.38 N\u00b7m<\/td>\n400\u2013750W servo motor<\/td>\n<\/tr>\n
EP-ZDE-160<\/td>\n450 N\u00b7m<\/td>\n5.00 N\u00b7m<\/td>\n2.50 N\u00b7m<\/td>\n1.56 N\u00b7m<\/td>\n750W\u20132.2kW servo<\/td>\n<\/tr>\n
EP-ZDS-115<\/td>\n210 N\u00b7m<\/td>\n2.33 N\u00b7m<\/td>\n1.17 N\u00b7m<\/td>\n0.73 N\u00b7m<\/td>\n400\u20131,500W servo + IP65<\/td>\n<\/tr>\n
EP-ZDS-142<\/td>\n910 \u0646\u064a\u0648\u062a\u0646 \u0645\u062a\u0631<\/td>\n10.1 N\u00b7m<\/td>\n5.06 N\u00b7m<\/td>\n3.16 N\u00b7m<\/td>\n2.2\u20137.5kW servo + IP65<\/td>\n<\/tr>\n
EP-ZDS-190<\/td>\n1800 \u0646\u064a\u0648\u062a\u0646 \u0645\u062a\u0631<\/td>\n20.0 N\u00b7m<\/td>\n10.0 N\u00b7m<\/td>\n6.25 N\u00b7m<\/td>\n7.5\u201322kW servo + IP65<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Max motor T = output ceiling \/ (i \u00d7 \u03b7). These are the motor torque ratings that will exactly load the gearbox output to its rated ceiling at the given ratio. Exceeding these values overloads the gearbox regardless of whether the motor can supply more. ZDE 3-stage available up to i=516:1; ZDS 3-stage availability \u2014 consult Korea Ever-Power application engineering.<\/p>\n<\/section>\n

<\/p>\n

\n

Backlash Across Multiple Stages \u2014 The Answer Most Engineers Get Wrong<\/h2>\n

A common concern about multi-stage planetary gearboxes is backlash accumulation: if each stage has <8 arcmin of backlash, does a 3-stage unit have <24 arcmin of total backlash at the output? The answer is definitively no \u2014 and the correct understanding of this principle is essential for high-ratio precision applications.<\/p>\n

\n
Backlash Referred to Output Shaft<\/div>\n
\n
BL_output = BL_stage_k \/ (i_{k+1} \u00d7 i_{k+2} \u00d7 \u2026 \u00d7 i_{last})<\/div>\n
Example: 3-stage, i_total = 100 (stages: 4\u00d75\u00d75)<\/div>\n
Each stage BL = 8 arcmin<\/div>\n
Stage 1 BL at output: 8 \/ (5\u00d75) = 8\/25 = 0.32 arcmin \u2190 negligible<\/div>\n
Stage 2 BL at output: 8 \/ 5 = 1.60 arcmin \u2190 small<\/div>\n
Stage 3 BL at output: 8 \/ 1 = 8.00 arcmin \u2190 dominates<\/div>\n
Total output BL \u2248 9.92 arcmin \u2014 essentially equal to last-stage BL alone<\/div>\n<\/div>\n

Earlier stages contribute progressively less to output backlash because their dead-band is divided by all subsequent stage ratios. In practice, the EP series published backlash for multi-stage units (<8 arcmin for ZDE\/ZDS at the output) already accounts for all stages’ contributions. A 3-stage EP-ZDE-160 at 320:1 has the same <8 arcmin output backlash specification as a 1-stage EP-ZDE-160 at 3:1 \u2014 because the first two stages’ backlash contribution is reduced by ratios of 8\u00d7 and 40\u00d7 respectively before reaching the output.<\/p>\n<\/div>\n

\n
\n
\u2705 What this means for specification<\/div>\n

When specifying a 3-stage EP-ZDE or EP-ZDS unit for a precision rotary table or positioning application, the backlash specification is not degraded relative to the single-stage version. Specify backlash as you would for any EP series unit: <8 arcmin (ZDE\/ZDS standard) is the correct figure regardless of stage count. The certified value applies to the output shaft.<\/p>\n<\/div>\n

\n
\u26a0 What does change at high ratios<\/div>\n

At very high ratios (i \u2265 200:1), the angular equivalent<\/em> of backlash as seen at the motor shaft becomes extremely small \u2014 barely detectable. However, the physical backlash at the output<\/em> shaft is unchanged. For slow-speed precision positioning, the output-side backlash remains the relevant specification, and EP series <8 arcmin remains applicable.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

Motor Speed Constraint \u2014 The Lower Bound on Practical Gear Ratio<\/h2>\n

In most servo applications, the constraint on ratio selection comes from the upper side \u2014 maximum motor speed limits how high the ratio can be. For slow-speed tracking and positioning applications, the constraint comes from the lower side: the motor must run fast enough for stable servo control. Below approximately 50 rpm motor speed, servo current ripple, encoder resolution per unit time, and velocity loop stability all degrade. This sets a minimum practical motor speed that, combined with the required output speed, sets a minimum practical gear ratio.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
\u0637\u0644\u0628<\/th>\n\u0645\u0637\u0644\u0648\u0628
\nn_output<\/th>\n		i=64
\nn_motor<\/th>\n		i=100
\nn_motor<\/th>\n		i=200
\nn_motor<\/th>\n		i=320
\nn_motor<\/th>\n		Min viable i<\/th>\n<\/tr>\n<\/thead>\n
Rotary table (fast index)<\/td>\n30 rpm<\/td>\n1,920 \u2705<\/td>\n3,000 \u2705<\/td>\n6,000 \u26a0<\/td>\n9,600 \u274c<\/td>\ni\u2264100<\/td>\n<\/tr>\n
Robot J1 (moderate speed)<\/td>\n8 rpm<\/td>\n512 \u2705<\/td>\n800 \u2705<\/td>\n1,600 \u2705<\/td>\n2,560 \u2705<\/td>\ni=64 typical<\/td>\n<\/tr>\n
Heavy conveyor drive<\/td>\n15 \u062f\u0648\u0631\u0629 \u0641\u064a \u0627\u0644\u062f\u0642\u064a\u0642\u0629<\/td>\n960 \u2705<\/td>\n1,500 \u2705<\/td>\n3,000 \u2705<\/td>\n4,800 \u26a0<\/td>\ni=80\u2013200<\/td>\n<\/tr>\n
\u0633\u0645\u062a \u062c\u0647\u0627\u0632 \u062a\u062a\u0628\u0639 \u0627\u0644\u0634\u0645\u0633<\/td>\n0.25 rpm<\/td>\n16 \u274c<\/td>\n25 \u26a0<\/td>\n50 \u2705<\/td>\n80 \u2705<\/td>\ni\u2265200<\/td>\n<\/tr>\n
Antenna tracking<\/td>\n0.05 rpm<\/td>\n3.2 \u274c<\/td>\n5 \u274c<\/td>\n10 \u274c<\/td>\n16 \u26a0<\/td>\ni\u2265320, or stepper<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

\u2705 n_motor \u2265 100 rpm: stable servo operation. \u26a0 n_motor 25\u2013100 rpm: marginal, requires low-speed-optimised servo drive. \u274c n_motor < 25 rpm: servo velocity loop unstable; use stepper motor or direct-drive with servo on position only. Motor max speed 4,500 rpm; recommended continuous \u2264 3,000 rpm.<\/p>\n

\n

Solar tracker design insight:<\/strong> A solar azimuth drive requires 0.25 rpm output (one full rotation in 24 hours \u00d7 some tracking margin). At i=100, the motor runs at 25 rpm \u2014 below the stable servo range. At i=200, the motor runs at 50 rpm \u2014 marginal but achievable with a modern servo drive that supports low-speed operation. At i=320, the motor runs at 80 rpm \u2014 well within standard servo control range. This is why 200:1 to 320:1 ratios are standard in precision solar tracker drive designs<\/strong>, not because the torque requires it (a modest motor handles the wind load at high ratio) but because the output speed requires it for servo stability.<\/p>\n<\/div>\n<\/section>\n

<\/p>\n

\"Korea<\/p>\n
High reduction ratio inline planetary gearboxes cover conveyor drives, heavy rotary table indexers, robot base joints, and industrial machinery requiring 64:1 to 516:1 gear ratios in a compact, coaxial package. The 90% efficiency of 3-stage units far exceeds the 42\u201360% of equivalent worm gear reducers, and the sealed lifetime lubrication eliminates oil change maintenance over the 20,000h service life.<\/div>\n<\/div>\n

<\/p>\n

\n

Position Resolution at the Output \u2014 From i=32 to i=320 with a 10,000-Line Encoder<\/h2>\n

One of the least-discussed benefits of high gear ratio in precision positioning applications is the multiplication of encoder resolution at the output shaft. A 10,000-line motor encoder (40,000 counts\/rev after \u00d74 quadrature decoding) produces a theoretical minimum step size at the output that decreases linearly with ratio. This is why heavy rotary tables can achieve sub-arcsecond positioning without a dedicated output encoder \u2014 the motor encoder resolution, multiplied through the gear ratio, provides sufficient resolution for most positioning requirements.<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n
\u0646\u0633\u0628\u0629 \u0627\u0644\u062a\u0631\u0648\u0633 i<\/th>\nTotal encoder counts
\nper output revolution<\/th>\n		Degrees per count<\/th>\nArcseconds per count<\/th>\nMargin vs
\n\u00b10.01\u00b0 tolerance<\/th>\n		Suitable for<\/th>\n<\/tr>\n<\/thead>\n
32:1<\/td>\n1,280,000<\/td>\n0.000281\u00b0<\/td>\n1.01\u2033<\/td>\n35\u00d7<\/td>\nIndexer, robot joints J3\u2013J6<\/td>\n<\/tr>\n
64:1<\/td>\n2,560,000<\/td>\n0.000141\u00b0<\/td>\n0.51\u2033<\/td>\n71\u00d7<\/td>\nRobot J1\/J2, precision indexer<\/td>\n<\/tr>\n
100:1<\/td>\n4,000,000<\/td>\n0.000090\u00b0<\/td>\n0.32\u2033<\/td>\n111\u00d7<\/td>\nRotary table, heavy conveyor<\/td>\n<\/tr>\n
200:1<\/td>\n8,000,000<\/td>\n0.000045\u00b0<\/td>\n0.16\u2033<\/td>\n222\u00d7<\/td>\nSolar tracker, antenna, slow index<\/td>\n<\/tr>\n
320:1<\/td>\n12,800,000<\/td>\n0.000028\u00b0<\/td>\n0.10\u2033<\/td>\n356\u00d7<\/td>\nTelescope, precision antenna<\/td>\n<\/tr>\n
516:1<\/td>\n20,640,000<\/td>\n0.000017\u00b0<\/td>\n0.063\u2033<\/td>\n573\u00d7<\/td>\nMax EP ratio; very slow rotation<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Encoder: 10,000-line incremental, \u00d74 quadrature = 40,000 counts\/motor-rev. Margin column: ratio of \u00b10.01\u00b0 tolerance to resolution per count. Actual achievable positioning accuracy is limited by backlash (<8 arcmin = 0.133\u00b0) \u2014 encoder resolution is not the binding constraint. With CNC backlash compensation active, achievable accuracy approaches 3\u20135\u00d7 of encoder resolution in practice.<\/p>\n<\/section>\n

<\/p>\n

\n

High-Ratio Application Matrix \u2014 Recommended EP Series by Use Case<\/h2>\n
\n\n\n\n\n\n\n\n\n\n\n\n
\u0637\u0644\u0628<\/th>\nT_req
\n(\u0646\u064a\u0648\u062a\u0646 \u0645\u062a\u0631)<\/th>\n		n_out
\n(\u062f\u0648\u0631\u0629 \u0641\u064a \u0627\u0644\u062f\u0642\u064a\u0642\u0629)<\/th>\n		\u0627\u0644\u0646\u0633\u0628\u0629 i<\/th>\n\u0645\u062d\u0631\u0643
\n\u0645\u0642\u0627\u0633<\/th>\n		EP Recommendation<\/th>\nSelection Driver<\/th>\n<\/tr>\n<\/thead>\n
Heavy rotary table (500mm \u03a6, 50kg)<\/td>\n250<\/td>\n2<\/td>\n80:1<\/td>\n400W<\/td>\nEP-ZDE-160, 80:1<\/a><\/td>\nTorque + slow speed<\/td>\n<\/tr>\n
Robot J1 base (heavy, 200kg arm)<\/td>\n400<\/td>\n8<\/td>\n64:1<\/td>\n1.5kW<\/td>\nEP-ZDS-142, 64:1<\/a><\/td>\nTorque + stiffness<\/td>\n<\/tr>\n
Heavy conveyor (1,000kg load)<\/td>\n800<\/td>\n15<\/td>\n100:1<\/td>\n1.5kW<\/td>\nEP-ZDS-142, 100:1<\/td>\nHigh torque + IP65<\/td>\n<\/tr>\n
\u0633\u0645\u062a \u062c\u0647\u0627\u0632 \u062a\u062a\u0628\u0639 \u0627\u0644\u0634\u0645\u0633<\/td>\n500<\/td>\n0.25<\/td>\n200:1<\/td>\n750W<\/td>\nEP-ZDE-160, 200:1<\/td>\nSpeed constraint<\/td>\n<\/tr>\n
Antenna positioning drive<\/td>\n300<\/td>\n0.05<\/td>\n320:1<\/td>\n400W<\/td>\nEP-ZDE-120, 320:1<\/td>\nSpeed + resolution<\/td>\n<\/tr>\n
Screw tightening (M30+)<\/td>\n350<\/td>\n5<\/td>\n100:1<\/td>\n400W<\/td>\nEP-ZDE-120, 100:1<\/td>\nTorque, SF=2.5<\/td>\n<\/tr>\n
\u0645\u062d\u0631\u0643 \u062a\u0648\u062c\u064a\u0647 \u062a\u0648\u0631\u0628\u064a\u0646\u0627\u062a \u0627\u0644\u0631\u064a\u0627\u062d<\/td>\n50,000<\/td>\n0.01<\/td>\n516:1<\/td>\n22kW<\/td>\nEP-ZDS-190, 516:1<\/td>\nHighest ratio + torque<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n

<\/p>\n

\"AER<\/p>\n
Right-angle output configurations are available for high-ratio applications where the 90\u00b0 geometry saves installation space \u2014 robot joint packaging, antenna azimuth drives, and compact rotary actuators where inline coaxial layout is not feasible. The right-angle input EP-ZDWE\/ZDWF series can be cascaded with high-ratio EP-ZDE stages for combined right-angle + high ratio configurations.<\/div>\n<\/div>\n

<\/p>\n

\n

High-Ratio Selection Checklist \u2014 Five Questions Before Specifying Above 64:1<\/h2>\n
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Q1<\/div>\n
What is the primary driver \u2014 torque, speed, or inertia?<\/div>\n

If torque: calculate T_motor \u00d7 i \u00d7 \u03b7 and verify against output ceiling. If speed: calculate n_motor = n_out \u00d7 i and check \u2265 50 rpm. If inertia: J_reflected = J_load \/ i\u00b2 \u2014 for large loads, high ratio solves inertia matching that no other method achieves. Identify which constraint drives i before calculating torque.<\/p>\n<\/div>\n

\n
Q2<\/div>\n
Does motor torque \u00d7 i \u00d7 \u03b7 exceed the output torque ceiling?<\/div>\n

Check: T_motor_rated \u00d7 i \u00d7 \u03b7 \u2264 T_output_ceiling for the selected EP frame. If it exceeds the ceiling, either select a larger frame (ZDE-120 vs ZDE-80) or reduce motor size. Do not exceed the output torque ceiling \u2014 it causes premature gear and bearing failure regardless of service factor.<\/p>\n<\/div>\n

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Q3<\/div>\n
Is n_motor at max output speed within servo range?<\/div>\n

n_motor = n_out_max \u00d7 i. Verify n_motor \u2264 3,000 rpm recommended (4,500 rpm absolute). For very slow output speeds, verify n_motor \u2265 50\u2013100 rpm minimum for stable servo operation. If n_motor falls below minimum, increase ratio or consider stepper motor.<\/p>\n<\/div>\n

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Q4<\/div>\n
Is 3-stage efficiency (90%) adequate for the duty cycle?<\/div>\n

Calculate annual energy cost difference: 3-stage loses 100W per kW vs 40W for 1-stage. For continuous 1kW duty, this is 525 kWh\/year = $52.5\/year at Korean industrial rate. For intermittent duty, this is negligible. Confirm motor sizing accounts for 90% efficiency (not 96%).<\/p>\n<\/div>\n

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Q5<\/div>\n
Is an encoder on the output shaft needed, or is motor encoder sufficient?<\/div>\n

At i=100, a 10,000-line motor encoder gives 0.32\u2033 resolution at the output \u2014 adequate for most industrial positioning. If backlash (<8 arcmin = 480\u2033) must be compensated to better than 10% (48\u2033), a direct output encoder is needed.<\/p>\n<\/div>\n<\/div>\n<\/section>\n


\n<\/span><\/p>\n

\n
\n
\n
Need High-Ratio EP Series Specification Support?<\/div>\n

Korea Ever-Power application engineering provides high-ratio selection support including output torque ceiling verification, motor speed constraint analysis, encoder resolution calculation, and 3-stage efficiency cost estimation. Provide your required output torque, output speed, and positioning tolerance for a complete EP series 3-stage recommendation in Korean and English.<\/p>\n<\/div>\n

Request High-Ratio Specification \u2192<\/a><\/p>\n
sales@planetary-gearboxes.com<\/div>\n<\/div>\n<\/div>\n

<\/p>\n

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EP Series \u2014 High Reduction Ratio Configurations<\/div>\n
\n
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\u0633\u0644\u0633\u0644\u0629 EP-ZDE<\/div>\n
3-stage: 60:1 to 516:1<\/strong> \u00b7 2-stage: 9\u201364:1 \u00b7 \u03b7=90%\/94% \u00b7 <8\u201315 arcmin BL \u00b7 rotary tables, conveyors, solar, antenna<\/div>\n

\u0639\u0631\u0636 \u0627\u0644\u0645\u0648\u0627\u0635\u0641\u0627\u062a \u2192<\/a><\/p>\n<\/div>\n

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\u0633\u0644\u0633\u0644\u0629 EP-ZDS<\/div>\n
High-ratio + IP65 + high stiffness<\/strong> \u00b7 1,800 N\u00b7m output ceiling \u00b7 Ct=130 N\u00b7m\/arcmin \u00b7 for heavy-load high-ratio applications in washdown or high-force environments<\/div>\n

\u0639\u0631\u0636 \u0627\u0644\u0645\u0648\u0627\u0635\u0641\u0627\u062a \u2192<\/a><\/p>\n<\/div>\n

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\u0633\u0644\u0633\u0644\u0629 EP-ZDF<\/div>\n
Square-flange inline \u00b7 same ratios as ZDE \u00b7 bolt-on plate mount<\/strong> \u2014 for high-ratio conveyor and rotary table frames without precision bore machining<\/div>\n

\u0639\u0631\u0636 \u0627\u0644\u0645\u0648\u0627\u0635\u0641\u0627\u062a \u2192<\/a><\/p>\n<\/div>\n<\/div>\n

Browse all planetary gearboxes \u2192<\/a><\/div>\n<\/div>\n<\/section>\n

\u0627\u0644\u0645\u062d\u0631\u0631: Cxm<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

Korea Ever-Power High Ratio Engineering Guide High Reduction Ratio Planetary Gearbox Selection \u2014 From 64:1 to 516:1, What Changes and What Does Not Once you cross above 64:1, you enter 3-stage precision planetary gearbox territory \u2014 and the selection principles change in ways most guides do not explain. The output torque ceiling no longer scales […]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[965],"tags":[],"class_list":["post-731","post","type-post","status-publish","format-standard","hentry","category-application-and-technical-guid"],"_links":{"self":[{"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/posts\/731","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/comments?post=731"}],"version-history":[{"count":2,"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/posts\/731\/revisions"}],"predecessor-version":[{"id":733,"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/posts\/731\/revisions\/733"}],"wp:attachment":[{"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/media?parent=731"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/categories?post=731"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/ar\/wp-json\/wp\/v2\/tags?post=731"}],"curies":[{"name":"\u0648\u0648\u0631\u062f\u0628\u0631\u064a\u0633","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}