Selection of Gear Box

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Bertram Morton
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1 orm Speed educers Selection of ear ox or ood performance of ear ox, The right selection is very important. The ear Unit Selection is made by comparing actual transmitted loads with catalogue ratings are based on standard set of load conditions, which invariably changes for different conditions. Therefore service factor must be used to calculate a theoretical transmitted load or equivalent load, before comparing the same, apply the formula : Equivalent oad = ctual oad x Service actor echanical atings & Service actors : echanical ratings measure capacity in terms of life and / or strength, assuming hours per day continuous running under uniform load conditions, when lubricated with an approved oil and working at a maximum oil temperature of 0 for normal application lubricant equivalent to IS V 0 should be used. hen a unit transmits less than catalogue rating, its life is increased. If the running time is more than hours per day, a service factor from Table of echanical Service actor ensure selection of a unit which transmits less than the catalogue rating, its life is thus increased consistent with the increased daily running time. atalogue ratings allow 0% overload at starting, braking or momentarily during operation, up to times per day. The unit selected must therefore have a catalogue rating equal to, or greater than half the maximum overload. If the unit is subjected to sustained overloads or to shock loads, these must be reflected in the chosen service factor. If overloads can be calculated or estimated then the actual loads should be used instead of a factor. Thermal atings and Service actors : Thermal ratings measure the unit's ability to dissipate heat. If they are exceeded the lubricant may overheat and break down, with consequent life failure. oth mechanical and thermal ratings are given on next page. Thermal ratings are effected by ambient temperature and not by mechanical consideration such as increased running time or shock loads. atalogue ratings assume 20 running temperature, the oil temperature then rising as the unit transmits power and generate heat. If the ambient temperature is more than 20, a lower temperature rise is allowed therefore less power may be transmitted. Similarly in cooler temperatures the thermal ratings may be exceeded. hen selecting unit use a service factor from Table of Thermal Service actor to calculate equivalent loads. or unit sizes 40 to, the relevant mechanical and thermal service factors are selected from tables and whichever is higher is applied to find out the equivalent output power and output torque. or unit size to 3, mechanical service factor should be applied to mechanical ratings and thermal service factor should be applied to thermal ratings. igher of these should be considered for selection of the unit. Thermal ratings assume fan cooling which is standard feature of all EE Speed eduction Units. or intermittent running with ample cooling time during rest periods, thermal ratings may be exceeded without overheating and since fan it ineffective, it can usually be removed. Enquiries It is recommended that as much as possible of the following information be given in the enquiry or order so that a check can be made and advice given on the most suitable size of EE orm Speed educer for any application. 1. Type of prime mover. 2. orsepower of prime mover. 3. utput torque required from driven member. 4. Input speed of gear unit. 5. utput speed of gear unit. 6. onfiguration of drive required and shaft disposition. 7. Total daily hours of running. If running is intermittent, details of duty cycle should be given.

2 orm Speed educers hen selecting units use the actual load transmitted and not the rating of the prime mover. atalogue gives input power (.P.), eing the power which the prime mover must provide to allow for losses in the gear unit. hen unit transmit less than rated output torgue the input power is reduced, and although a gear unit is marginally less efficient at part load, a prorota reduction is usually sufficiently accurate to decide the capacity of the prime mover. Prime over Electric otor Steam Turbine ydraulic otor echanical Service actor uration of Service hours per day Under 3 3 to ver oad lassification riven achine Uniform oderate eavy Shock Shock Shock Single ylinder Internal ombustion Engine Under 3 3 to ver Thermal Service actor mbient Temperature Temp in * actor orse Power ating ominal atio* Input P utput P aximum Prime over s Power in orse Power odels : : : : : : : : : : * The atios mentioned above are nominal and the actual may very by upto ±% ** The odel os. to 5 are available in daptable odels. or verdriven units in these sizes it is necessary to derate by 5% for all ratios upto 30 : 1 inclusive and by 15% for 35 : 1 and higher ratios. orm Shaft and orm ear heel without ody are also available.

3 orm Speed educers imension etails of ear oxes EE Single eduction Speed educers daptable Type Sizes of EE 40 to EE E1 E1 ST I 1 1 P ia. ole P1 1 2 dia. oles ia etric oles 1 ia. holes dia. 2 E E dia. 2. ia. oles o. 1 Type of oot is shown below the sketch of ear box o. 2 Type of oot is shown on the left hand side of ear box sketch o. 3 Type of oot is shown below Principal imensions (mm) Y IESIS SIZE E E SIZE ST IESIS UTI IESIS UE 1 T UTI IESIS UE 2 T SIZE E P P UE 3 T SIZE 4 3 P s Improvements in design are continually being made, this specification is not to be regarded as binding detail, and dimensions are subject to alteration without notice o. 3 Type of oot 4 2 ia ols P

4 orm Speed educers ip Stick EE Single eduction Speed educers orizontal Type Sizes of EE 0 to EE 430 E E Input Shaft ST ETIS utput Shaft ia. ST I ia. P dia. ole Principal imensions (mm) SIZE Y IESIS E UTI IESIS P ST IESIS EE Single eduction Speed educers Vertical Type Sizes of EE V to EE V430 1 ia. STETIS Input Shaft utput Shaft ia. E STI VU VU VU ia. ole 1 V V V Y IESIS UTI IESIS SIZE E Principal imensions (mm) ST IESIS s Improvements in design are continually being made, this specification is not to be regarded as binding detail, and dimensions are subject to alteration without notice 15.7

5 orm Speed educers eneral EE orm Speed eduction ear oxes have liberal ribbing for increasing heat dissipation area, streamlined sump for carrying more oil and fan of ample size which is effective in both side of rotation. esign Standards herever applicable, ritish as well as Indian esign standards are used. orm Shafts conform to casehardening lloy Steels, orm heels conform to phosphorous bronze as per S 0, hile ear ase conforms to.i. rade 20, IS 2. ear ase ear ase is of streamlined design, rugged in construction, made of close grain ast Iron. It is completely air tight, dust proof and capable of being installed in open without any cover. The faces and bores are accurately bored and machined to last precision to ensure perfect alignment and interchangeability. orm & orm heels The orm is made of case hardening / alloy steel, duly hardened, ground and lapped and is integral with the shaft. earing journals are accurately ground. orm heels is made of chill cast phosphorous bronze and tightly fitted with the.i. entres. orm heels teeth are generated on precision hobbing machines and high accuracy hobs. earings The orm and orm heels are supported on Extra eavy uty Taper roller antifriction bearings of ample margin of safety to allow adequate journals as well as thrust loads. verhung loads arising out of sprocket or pinion drive are case and bearing are designed for this duty. In case of heavy overhung loads, and extra roller bearing can be provided. heel Shafts The orm wheel Shafts are made of high tensile carbon steel, duty hardened and ground. It is of large diameter of carry the torsional as well as the bending loads which may be induced by overhung drives. ubrication ubrication of orm and worm wheels is by splash of oil from the sump. Thus, no special care is required except for the occasional oil topping of the oil to the required level. n oil filler cum breather plug is provided along with the drain plug and level plug. il seals of appropriate size are provided on all input and output shafts. or very low input speed of below P, and heavy loads in sizes above 3 mm, forced lubrication is required. ooling ir cooling is effected by means of standard propylene or metal fans which direct air over the ribbed surface of the case. The fan is designed to operate in both the direction of rotation and is so arranged in conjunction with the ribbing of the case to allow maximum heat dissipation. verload atings ll the conponents of the ear Unit are so designed that they can withstand 0% overload for 15 seconds % overload for one minute 40% overload for 15 minutes 25% overload for 1 hour EE TSISSIS (II) PVT. T. IS ompany 5,oad o. 6, Inderprasth Industrial rea,, ota4005, ajasthan, India. Tel.:+(91) ax: +(91) info@agneetransmissions.com ebsite: atalogue ref. no. E/T/S/003 : Selection of orm ear oxes

INVOLUTE TOOLING CORPORATION

INVOLUTE TOOLING CORPORATION MANUFACTURERS OF DRIVES AND TRANSMISSIONS OFFICE: 13, JORBAGH, NEW DELHI - 110 003, INDIA, TEL: +91(011)24621453 FAX: +91(011) 24603609 WORKS: PLOT-65, SEC-27C, FARIDABAD - 121 003. INDIA, TEL: +91(0129)