{"id":1973,"date":"2026-06-29T06:35:42","date_gmt":"2026-06-29T06:35:42","guid":{"rendered":"https:\/\/speed-reducer-gearbox.com\/worm-gearbox-for-belt-conveyor-speed-ratio-and-torque-guide\/"},"modified":"2026-06-29T06:35:42","modified_gmt":"2026-06-29T06:35:42","slug":"worm-gearbox-for-belt-conveyor-speed-ratio-and-torque-guide","status":"publish","type":"post","link":"https:\/\/speed-reducer-gearbox.com\/de\/worm-gearbox-for-belt-conveyor-speed-ratio-and-torque-guide\/","title":{"rendered":"Worm Gearbox for Belt Conveyor: Speed Ratio and Torque Guide"},"content":{"rendered":"
\n

Belt conveyors shift everything from quarried aggregate to chilled ready-meals, yet the gearbox question is often treated as an afterthought until a burned-out unit halts a line on a Saturday night. This guide works through the numbers that matter when specifying a DA series worm gear reducer<\/a> for a belt conveyor \u2014 torque, ratio, frame size, and the service factor that ties it all together.<\/p>\n

How Belt Load Translates to Output Torque<\/h2>\n

The starting point is not motor power \u2014 it is the tangential force the drive pulley must apply to the belt. Multiply effective pull (in newtons) by pulley radius (in metres) and you have the raw torque demand at the gearbox output shaft. For a horizontal 650 mm wide belt running at 0.5 m\/s carrying 120 kg\/m of product, effective pull typically falls between 800 and 1 200 N. At a 150 mm radius drive pulley, that equals 120\u2013180 N\u00b7m before any service or temperature correction.<\/p>\n

\"WP<\/p>\n

Choosing the Right Speed Ratio<\/h2>\n

Ratio selection follows a straightforward chain: output rpm equals motor rpm divided by ratio, and belt speed equals output rpm multiplied by pulley circumference. A 4-pole 1440 r\/min motor driving through a 1:30 reducer produces 48 r\/min at the output shaft. With a 200 mm pulley (628 mm circumference), that gives a belt speed of roughly 30 m\/min \u2014 well-suited to carton-handling, printing, and light-assembly lines.<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n
Ratio<\/th>\nOutput RPM<\/th>\nBelt Speed (200 mm pulley)<\/th>\nTypical Application<\/th>\n<\/tr>\n<\/thead>\n
1:10<\/td>\n144<\/td>\n90 m\/min<\/td>\nSortation, high-speed packaging<\/td>\n<\/tr>\n
1:20<\/td>\n72<\/td>\n45 m\/min<\/td>\nCarton sealing, filling lines<\/td>\n<\/tr>\n
1:30<\/td>\n48<\/td>\n30 m\/min<\/td>\nGeneral conveying, assembly<\/td>\n<\/tr>\n
1:40<\/td>\n36<\/td>\n23 m\/min<\/td>\nCooling conveyors, inspection<\/td>\n<\/tr>\n
1:50<\/td>\n29<\/td>\n18 m\/min<\/td>\nAccumulation, oven exit<\/td>\n<\/tr>\n
1:60<\/td>\n24<\/td>\n15 m\/min<\/td>\nSlow cooling, drying tunnels<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Input speed 1440 r\/min; 200 mm drive pulley assumed.<\/p>\n<\/div>\n

Frame Size and Cantilever Load<\/h2>\n

Centre-to-centre distance determines both torque capacity and the shaft diameter that carries the sprocket or coupling. At a 1:30 ratio a WPA 80 frame delivers 151 N\u00b7m output torque \u2014 fine for a 500 mm wide belt pulling 1 200 N. A WPA 100 at the same ratio yields 277 N\u00b7m, suited to 800 mm wide belts under moderate load. The cantilever load table in the WP catalogue sets hard limits on how much overhung sprocket weight the output shaft can take \u2014 exceeding those limits accelerates bearing failure faster than any torque overload.<\/p>\n

\"WP<\/p>\n

Service Factor: Where Most Sizing Errors Happen<\/h2>\n

Catalogue torque ratings assume steady load, clean ambient air at roughly 20\u00b0C, and fewer than twelve start\/stop cycles per hour. A recycling plant belt running 16 hours per day and subject to shock loads from irregular scrap pieces needs a service factor of 1.5, turning a 180 N\u00b7m theoretical requirement into a 270 N\u00b7m selection target. Inclined belts lifting bulk bags at 20\u00b0 justify another 20\u201330% on top of that. Ambient temperatures above 40\u00b0C add a further 10% per 10\u00b0C above the baseline.<\/p>\n

Rule of thumb:<\/strong> when the calculated torque sits within 15% of the next frame size up, take the larger one. The cost difference between adjacent WP frames is modest; the cost of a premature failure rarely is.<\/div>\n

Foot-Mounted vs Hollow-Shaft Configuration<\/h2>\n

The classic WPA foot-mount with a chain or coupling to the head shaft suits conveyors where the motor and gearbox must be serviced independently. The KA series hollow shaft worm gearbox<\/a> slides over the head shaft directly, eliminating the coupling, the second bearing housing, and the alignment procedure. Installation time drops from several hours to under an hour on a modular conveyor \u2014 a meaningful saving when the machine is one of thirty identical lines in a distribution centre.<\/p>\n

\"Hollow<\/p>\n

Lubrication Grade for Continuous Conveyor Duty<\/h2>\n

Worm gearing runs on sliding contact that demands a heavier oil than rolling-element gears. ISO VG 220 is acceptable only for lightly loaded units at low ambient temperatures; VG 320 is the standard choice for most conveyor applications at 15\u201340\u00b0C. Above 40\u00b0C ambient \u2014 roof-mounted outdoor belts, bakery ovens, or foundry environments \u2014 switch to VG 460 mineral or a synthetic polyglycol. Change oil at 100 operating hours initially, then every 2 500 hours. For high-ambient applications, the NMRV aluminium-housed unit<\/a> dissipates heat faster, while the WP iron housing provides superior rigidity under shock loads.<\/p>\n

Frequently Asked Questions<\/h2>\n
\n
\n1. What output torque do I need for a 1 tonne\/hour inclined belt at 0.4 m\/s?+<\/span><\/summary>\n
For a 15\u00b0 incline at 1 t\/h, effective belt pull is roughly 1 400\u20131 800 N. With a 120 mm radius pulley, that gives 168\u2013216 N\u00b7m. Apply a service factor of 1.4 for moderate shock \u2014 selection torque reaches around 270\u2013350 N\u00b7m. A WPA 120 at 1:30 (rated 413 N\u00b7m) covers that with adequate margin.<\/div>\n<\/details>\n
\n2. Can I use a VFD with a worm gearbox on a conveyor?+<\/span><\/summary>\n
Yes, and it is common on speed-variable sortation lines. Keep the VFD output above 20 Hz to maintain adequate motor cooling. The gearbox is unaffected by variable input speed as long as the worm shaft stays within 600\u20131 600 r\/min.<\/div>\n<\/details>\n
\n3. How long should a correctly selected worm unit last on a conveyor?+<\/span><\/summary>\n
Under correct lubrication and within torque limits, bronze wheel life typically exceeds 20 000 operating hours. Keeping the oil clean and changed on schedule is the single biggest factor in achieving that figure.<\/div>\n<\/details>\n
\n4. Does a worm gearbox hold the belt when power is cut?+<\/span><\/summary>\n
At ratios of 1:30 and above, the worm pair is effectively self-locking on horizontal and shallow-incline belts. Above 15\u00b0 incline, or where human safety is involved, a separate motor-mounted brake is required under Australian WHS standards.<\/div>\n<\/details>\n
\n5. What is the efficiency difference between 1:10 and 1:50 ratio?+<\/span><\/summary>\n
Single-stage worm efficiency falls from roughly 88% at 1:10 to about 65% at 1:50. For a 5 kW motor on a continuous belt, that difference amounts to around 1.15 kW of extra heat in the housing.<\/div>\n<\/details>\n<\/div>\n
\n

Get a Sized Recommendation<\/h3>\n

Share your load data and target speed \u2014 our team at Condell Park NSW returns torque calculations and a stock check within one business day.<\/p>\n

\n
\n
ADDRESS<\/div>\n

27 Harley Crescent
Condell Park NSW 2200<\/div>\n

\n
PHONE<\/div>\n

+61 2 9708 3322<\/p><\/div>\n

\n
EMAIL<\/div>\n

sales@speed-reducer-gearbox.com<\/p><\/div>\n<\/div>\n

Send Enquiry →<\/a><\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"

Belt conveyors shift everything from quarried aggregate to chilled ready-meals, yet the gearbox question is often treated as an afterthought until a burned-out unit halts a line on a Saturday night. This guide works through the numbers that matter when specifying a DA series worm gear reducer for a belt conveyor \u2014 torque, ratio, frame […]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[2903],"tags":[],"class_list":["post-1973","post","type-post","status-publish","format-standard","hentry","category-conveyor-handling"],"_links":{"self":[{"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/posts\/1973","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/comments?post=1973"}],"version-history":[{"count":0,"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/posts\/1973\/revisions"}],"wp:attachment":[{"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/media?parent=1973"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/categories?post=1973"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/speed-reducer-gearbox.com\/de\/wp-json\/wp\/v2\/tags?post=1973"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}