{"id":3259,"date":"2026-04-01T06:54:43","date_gmt":"2026-04-01T06:54:43","guid":{"rendered":"https:\/\/acgearmotor.top\/?p=3259"},"modified":"2026-04-01T06:54:43","modified_gmt":"2026-04-01T06:54:43","slug":"ac-gear-motor-for-palletizing-robots","status":"publish","type":"post","link":"https:\/\/acgearmotor.top\/id\/ac-gear-motor-for-palletizing-robots\/","title":{"rendered":"AC Gear Motor for Palletizing Robots"},"content":{"rendered":"


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AC Gear Motor for Palletizing Robots<\/h1>\n

Hundreds of reversals per hour, high-inertia arm loads, and regenerative braking energy that must go somewhere \u2014 palletizing is where motor endurance meets physics.<\/p>\n

Specify Your Palletizing Motor<\/a><\/p>\n<\/div>\n<\/section>\n

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Why Palletizing Is the Most Punishing Motor Application at End-of-Line<\/h2>\n

An end-of-line palletizing robot picks finished cartons, cases, bags, or trays from the packaging line conveyor and stacks them onto a pallet in a programmed layer pattern. Each cycle involves reaching forward to grip the product, lifting it (often 10 to 25 kg per case), swinging across to the pallet position, lowering the product onto the stack, releasing, and swinging back to the pickup point. A typical palletizer running at 10 to 15 cycles per minute reverses the direction of every joint motor 20 to 30 times per minute \u2014 that is 1 200 to 1 800 reversals per hour, or roughly 15 000 to 25 000 reversals per 16-hour shift.<\/p>\n

Each reversal involves decelerating a high-inertia load (the arm plus the product), stopping the shaft, and accelerating it in the opposite direction. During deceleration, the motor acts as a generator \u2014 converting the kinetic energy of the moving arm into electrical energy that flows back through the VFD. If the VFD does not have a mechanism to absorb this regenerative energy, the DC bus voltage rises until the overvoltage protection trips and the robot halts mid-cycle. This is one of the most common failure modes on improperly specified palletizer drives: not a motor failure, but a VFD trip caused by regenerative energy that the system was not designed to handle.<\/p>\n

Our AC gear motor<\/a><\/b> YE3 series, combined with properly sized braking resistors and a planetary gearbox<\/b><\/a> at each joint, provides the torque density, thermal capacity, and dynamic response that palletizing duty demands.<\/p>\n

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Regenerative Energy: The Invisible Challenge<\/h2>\n

When a palletizer arm decelerates, kinetic energy converts to electrical energy in the motor winding and flows back into the VFD DC bus. The amount of energy per deceleration event depends on the total inertia of the arm-plus-load and the square of the angular velocity at the start of deceleration. On a medium-size palletizer with a 2-meter reach, the reflected inertia at the motor shaft (through the gearbox) is typically 0.01 to 0.05 kg-m-squared. At a motor speed of 1400 rpm, each deceleration dumps approximately 50 to 250 joules into the DC bus \u2014 enough to raise the bus voltage by 30 to 80 volts if no dissipation path exists.<\/p>\n

A standard VFD has a DC bus capacitor bank that can absorb a small amount of regenerative energy, but not enough for a continuous stream of decelerations at palletizing rates. The solution is a braking resistor \u2014 an external power resistor connected across the DC bus through a chopper transistor. When the bus voltage exceeds a threshold (typically 700 to 750 V on a 380 V supply), the chopper switches on and routes the excess energy through the resistor, converting it to heat. Sizing this resistor correctly requires knowing the deceleration energy per cycle, the cycle rate, and the duty cycle \u2014 data that our engineering team provides as part of every palletizer motor quotation.<\/p>\n

Without a properly sized braking resistor, the VFD will trip on overvoltage every 5 to 20 cycles, bringing the palletizer to a halt and causing product backlog on the packaging line. We have seen this happen repeatedly at facilities that specified the motor and VFD independently, without coordinating the regenerative energy budget. Our quotation process prevents this by treating the motor, gearbox, VFD, and braking resistor as a single matched system rather than four separate purchases.<\/p>\n

Joint Torque Mapping: Matching Motor Size to Each Axis<\/h2>\n

A 4-axis palletizing robot has different torque requirements at each joint. The base rotation (axis 1) swings the entire arm assembly \u2014 the highest inertia, the highest torque, and the largest motor. The shoulder joint (axis 2) lifts the arm and product against gravity \u2014 high continuous torque but moderate speed. The elbow joint (axis 3) extends and retracts the forearm \u2014 moderate torque, higher speed. The wrist rotation (axis 4) orients the product for placement \u2014 low torque, highest speed.<\/p>\n

A common specification error is using the same motor on all four axes. This results in axis 1 and 2 being under-powered (causing VFD current-limit trips during acceleration) and axis 3 and 4 being over-powered (wasting capital and adding unnecessary weight to the moving arm). Our approach maps the torque, speed, and inertia requirement of each axis individually, then selects the smallest YE3 three phase motor<\/b> that meets each axis requirement with a 15 percent torque margin. The result is a lighter, faster, more energy-efficient palletizer that runs within the thermal and dynamic limits of every motor in the system.<\/p>\n

\n\n\n\n\n\n\n\n\n
Axis<\/th>\nFunction<\/th>\nTypical Motor<\/th>\nGearbox Ratio<\/th>\nRegeneration Level<\/th>\n<\/tr>\n<\/thead>\n
Axis 1 (Base)<\/td>\nFull-arm rotation<\/td>\nYE3, 5.5\u201311 kW<\/td>\n30:1 to 50:1<\/td>\nHigh<\/td>\n<\/tr>\n
Axis 2 (Shoulder)<\/td>\nArm lift\/lower<\/td>\nYE3, 4\u20137.5 kW<\/td>\n40:1 to 80:1<\/td>\nMedium-High<\/td>\n<\/tr>\n
Axis 3 (Elbow)<\/td>\nForearm extend\/retract<\/td>\nYE3, 2.2\u20134 kW<\/td>\n20:1 to 40:1<\/td>\nMedium<\/td>\n<\/tr>\n
Axis 4 (Wrist)<\/td>\nProduct orientation<\/td>\nYE3, 1.1\u20132.2 kW<\/td>\n10:1 to 20:1<\/td>\nLow<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

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Cycle Time Optimization: Getting More Pallets Per Hour<\/h2>\n

Palletizer throughput is measured in cycles per minute \u2014 how many cases the robot picks and places per unit time. The theoretical maximum cycle rate is determined by the time to execute one complete pick-swing-place-return sequence. Each phase of this sequence depends on the acceleration and deceleration capability of the joint motors and the maximum angular velocity the gearbox and motor can sustain.<\/p>\n

The acceleration capability is governed by the ratio of available motor torque to total reflected inertia at the motor shaft. A higher-torque motor or a higher gear ratio increases acceleration \u2014 but increasing the gear ratio also reduces the maximum joint speed proportionally, so there is an optimum ratio that balances fast acceleration against adequate top speed. Our engineering team models each axis using the actual arm geometry, product weight, and target cycle time to find this optimum point. The result is typically a 10 to 20 percent cycle-time improvement over a generic motor-and-gearbox selection, because every axis is tuned to its specific dynamic requirement rather than over-sized with safety margins stacked on safety margins.<\/p>\n

For palletizers that handle mixed case sizes on the same line \u2014 common in food distribution centers that palletize multiple SKUs simultaneously \u2014 the motor must handle the heaviest case at full speed and the lightest case without overshooting the placement position. Sensorless vector VFD control with auto-tuning provides this adaptability: the VFD measures the load inertia on the first cycle after a product change and automatically adjusts its acceleration ramp parameters to match. No operator reprogramming is needed when the product changes \u2014 the drive adapts in real time.<\/p>\n

Planetary Gearbox: The Only Reducer for Palletizing Joints<\/h2>\n

Palletizing joints are not an application where reducer type is negotiable. A worm gear reducer<\/b><\/a> \u2014 acceptable for conveyors and filling machines \u2014 fails on palletizers for two reasons. First, the 75 to 90 percent mechanical efficiency of a worm stage means 10 to 25 percent of the motor power is lost as heat inside the gearbox housing. On a palletizer running 15 000 reversals per shift, this heat accumulates faster than the gearbox housing can dissipate it, causing the lubricant to break down and the gears to wear at an accelerated rate. Second, the inherent backlash of a worm mesh (15 to 30 arc-minutes) translates into placement error at the pallet position \u2014 potentially 5 to 10 millimeters on a 2-meter arm, which exceeds the 2 to 3 mm tolerance that retailers demand for stable, shippable pallets.<\/p>\n

A planetary gearbox<\/b><\/a> solves both problems. Its 97+ percent efficiency per stage generates minimal heat even under continuous reversal duty. Its backlash \u2014 under 6 arc-minutes on a precision-grade unit \u2014 keeps placement error well within spec. And its coaxial (inline) shaft arrangement produces zero lateral reaction force on the motor bearing, extending motor bearing life compared to offset reducer configurations. For palletizing, planetary is not the premium option \u2014 it is the only option that works.<\/p>\n

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Customer Performance<\/h2>\n
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“Four-axis palletizer on our rice bag line \u2014 25 kg bags, 12 cycles per minute, three shifts. The axis 1 motor was tripping the VFD on overvoltage every 15 to 20 minutes because the braking resistor was undersized. We contacted Ever-Power with the arm dimensions and cycle profile. They specified the YE3-132S-4 (5.5 kW) with a matched braking resistor and planetary gearbox for axis 1, and appropriately smaller motors for axes 2 through 4. Total system cost was 28 percent lower than the European integrator quoted us. We have completed 8 months of three-shift operation with zero VFD trips and zero motor issues.”<\/p>\n

Jeong Hyun-woo, Automation Engineer<\/p>\n

Rice processing plant, Icheon, Gyeonggi-do, Korea (Q4 2024)<\/p>\n<\/div>\n

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“We build gantry-type palletizers for the pet food industry \u2014 heavy bags, high cycle rates. We tested YE3 motors against two Japanese brands on our dynamometer. The YE3 delivered equivalent torque density and thermal capacity at about 35 percent less cost per motor. Over 50 palletizer units shipped in 2024, we used approximately 200 YE3 motors with a field failure rate of zero. The consistent frame accuracy (within 0.1 mm of IEC spec) eliminated the fit-up problems we occasionally had with another supplier.”<\/p>\n

Michael Chen, VP Engineering<\/p>\n

Palletizing equipment manufacturer, Suzhou, China (Q2 2025)<\/p>\n<\/div>\n

Palletizing Motor FAQ<\/h2>\n
\nDo you supply the braking resistor as part of the motor package?<\/summary>\n
Yes. When you provide the arm geometry, product weight, and target cycle rate, our engineering team calculates the regenerative energy per cycle and specifies a matched braking resistor. We supply the resistor, mounting bracket, and pre-cut cables as a kit that ships with the motor and gearbox. This eliminates the sizing-mismatch problem that causes VFD overvoltage trips on improperly specified systems.<\/div>\n<\/details>\n
\nWhy YE3 instead of YVF2 for palletizing?<\/summary>\n
Palletizing stations are typically clean, ambient-temperature end-of-line areas \u2014 no dust, no washdown, no extreme heat. The standard IC0141 self-cooling on the YE3 is adequate because the motor runs at or near rated speed during the acceleration and deceleration phases (the VFD varies speed, but the average is close to base speed). The IC416 independent cooling of the YVF2 adds cost without adding value in this application. If your palletizer operates in a dusty or high-temperature environment, we would recommend the YVF2 instead.<\/div>\n<\/details>\n
\nWhat placement accuracy can I expect?<\/summary>\n
With our precision-grade planetary gearbox (under 6 arc-minutes backlash) and a closed-loop vector VFD with encoder feedback, placement repeatability is typically within plus or minus 1 to 2 mm on a standard 2-meter reach palletizer. This is well within the plus or minus 3 mm tolerance that major Korean and Japanese retailers require for stable pallet stacks.<\/div>\n<\/details>\n
\nCan I order a complete motor-gearbox-VFD package for all four axes?<\/summary>\n
Yes. Send us the arm geometry, maximum product weight, target cycle rate, and your preferred VFD brand. We return a complete bill of materials covering all four axes: motor, planetary gearbox, VFD, braking resistor, and cables. Everything ships in a single consolidated order with coordinated delivery.<\/div>\n<\/details>\n
\nWhat is the lead time for a 4-axis motor set?<\/summary>\n
Standard YE3 motors from 1.1 to 11 kW are stocked at our Korean warehouse. A complete 4-axis set with planetary gearboxes ships within 10 to 15 working days. Custom specifications add 5 to 10 days. Email sales@acgearmotor.top with your palletizer model and we confirm availability within 24 hours.<\/div>\n<\/details>\n
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Get a Matched Motor-Gearbox Package for Every Axis<\/p>\n

Send us your arm reach, product weight, and target cycles per minute. We map the torque requirement for each axis and return a complete drive specification \u2014 motors, planetary gearboxes, VFDs, and braking resistors \u2014 as a single coordinated package.<\/p>\n

Request Palletizer Drive Package<\/a><\/p>\n<\/section>\n

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Editor: Cxm<\/p>","protected":false},"excerpt":{"rendered":"

AC Gear Motor for Palletizing Robots Hundreds of reversals per hour, high-inertia arm loads, and regenerative braking energy that must go somewhere \u2014 palletizing is where motor endurance meets physics. Specify Your Palletizing Motor Why Palletizing Is the Most Punishing Motor Application at End-of-Line An end-of-line palletizing robot picks finished cartons, cases, bags, or trays […]<\/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":[5047],"tags":[],"class_list":["post-3259","post","type-post","status-publish","format-standard","hentry","category-food-and-packaging"],"_links":{"self":[{"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/posts\/3259","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/comments?post=3259"}],"version-history":[{"count":1,"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/posts\/3259\/revisions"}],"predecessor-version":[{"id":3260,"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/posts\/3259\/revisions\/3260"}],"wp:attachment":[{"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/media?parent=3259"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/categories?post=3259"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/acgearmotor.top\/id\/wp-json\/wp\/v2\/tags?post=3259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}