Spur & Helical Gears Description Symbol Unit Equation Normal Module m n Transverse Module m t = m n / cos b Axial Module m x = m n / sin b Normal Pressure Angle a n degrees = 2 Transverse Pressure Angle a t degrees = tan 1 (tan a n / cos b) Helix Angle b degrees = 15 Lead Angle l degrees = 9 b Number of Teeth z Profile Shift Coefficient x = zero for Ondrives standard gears Addendum h a mm = 1. m n (for Ondrives standard gears) Dedendum h f mm = 1.25 m n (for Ondrives standard gears) Tooth Depth h mm = 2.25 m n (for Ondrives standard gears) Gear Ratio u = z 2 / z 1 Centre Distance a mm = (d 1 +d 2 ) / 2 Pitch Circle Diameter d mm = z m t = (z m n ) / cos b Tip Diameter d a mm = d + (2m n x) + (2 m n ) Root Diameter d r mm = d a (2 h) Normal Pitch p n mm = p m n Transverse Pitch p t mm = p m t = (p m n ) / cos b Axial Pitch p x mm = p m x = (p m n ) / sin b Normal Tooth Thickness in Pitch Circle s n mm = (p n / 2) + 2m n x tan a n Transverse Tooth Thickness in Pitch Circle s t mm = (p t / 2) + 2m t x tan a t = s n / cos b When working with a pair of gears the subscript 1 and 2 denotes input (drive) and output (driven) gear. Tip diameter is the theoretical diameter of the gear without tooth thickness tolerance applied. H7 Tolerance is applied. Root diameter is the theoretical diameter of the gear without tooth thickness tolerance applied. Actual root diameter will be less due to manufacturing profile shift coefficient calculated from DIN 5845/97 tooth thickness tolerance. Root and root fillet radius is full ground. Root fillet radius shape is trochoid. Tooth thickness (s n & s t ) is the theoretical value. Actual tooth thickness will be less due to DIN 5845/97 tolerance applied. The subscript e is for upper allowance values and i for lower allowance values. For two helical gears to run together one must be left hand and the other right angle helix. d a1 d 1 d r1 s t a b p t Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Spur & Helical Gears Manufacture All gears are form ground including root and root fillet radius resulting in no step at the start of the involute profile. Root fillet radius shape is trochoid. True circle radius and other shapes can be produced as required. Gears can be manufactured with profile modifications. Examples include: Tip and Root relief (Linear, Arc, Progressive, and Linear with radii transition) Profile Crowning (Barrelling) Pressure Angle Modification Tip Chamfer Gears can be manufactured with tooth trace (lead) modifications. Examples include: End relief (Linear and Arc) Crowning Helix Angle Modification End and Tip End Chamfer Gear Quality Gears are manufactured to quality grade 4 DIN 91 for 1 module and above. Below 1 module the quality grade is 5 DIN 91. Onboard machine and stand alone CMM measurement inspection allows testing and certification. Dual and single flank testing is available on request. Gears can be manufactured to a range of different quality grades and standards (ISO, AGMA, BS). Please contact our Technical department to discuss. Standard: DIN ISO AGMA Grade: 4 4 1 Pitch total deviation: Fp µm 1.. Pitch single deviation: fp µm 4. 4. 4. Concentricity deviation: Fr µm 11. 14. 15. Pitch error: fu µm 5.5 Total profile deviation: Fα µm 5..5 5. Total helix deviation: Fβ µm.5.5 4.7 Double flank composite transmission error: Fi" µm 1. 21. 2. Double flank toothtotooth transmission error: fi" µm 5.5 7.5 7.1 Backlash and Tooth thickness Value stated on catalogue page is theoretical circumferential backlash per DIN 97 for two identical gears with the same number of teeth, running at JS7 centre distance tolerance. Where DIN 5845 applies base tangent length allowances are converted to tooth thickness allowances and the formula per DIN 97 used. Torque The stated torque value is the maximum load for two identical gears running at a input speed of 5rpm, to achieve Root factor of safety SF min = 1.4 or Flank (Hertzian) factor of safety SH min = 1. (whichever is reached first) using ISO 2 method B. The following was used: Application factor Ka = 1 Required service life 12, hours Type of mounting for the pinion ISO Figure 1e Material BS 85M2 case hardening steel. ISO 5 Figure 9/1 (MQ), core strength >=HRC Fatigue strength for tooth root stress σ Flim = 5N/mm² Fatigue strength for Hertzian pressure σ Hlim = 15N/mm² Lubrication grease: Mineraloil base, Kinematic viscosity v 4 = 12. Kinematic viscosity v 1 = 12 Grade DIN 91: 7 5 4 ISO 128: 7 5 4 AGMA 2A88: 1 11 12 1 AGMA 2151A1: A7 A A5 A4 Example: DIN 4 helical, module, 5 teeth, mm face width, 15 helix. Scuffing (integral or flash temperature) and wear is not considered. Values for 174PH gears are 8% of the case hardened steel gears. Other factors including shaft deflection, duty cycle and temperature will effect maximum allowable torque and service life. Wear and scuffing is dependent on lubrication. We recommend that each user compute their own values based on actual operating conditions and test in application. Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Worms & Wheels Description Symbol Unit Equation Axial Module m x Normal Module m n = m x cos l Normal Pressure Angle a n degrees = 2 Transverse Pressure Angle a t degrees = tan 1 (tan a n / cos l) Lead Angle l degrees = tan 1 ((m x z 1 ) / d 1 ) Helix Angle b degrees = 9 l Number of Starts on Worm z 1 Number of Teeth on Wheel z 2 Profile Shift Coefficient x = zero for Ondrives standard worms Addendum h a mm = 1. m x (for Ondrives standard worms) Dedendum h f mm = 1.25 m x (for Ondrives standard worms) Tooth Depth h mm = 2.25 m x (for Ondrives standard worms) Gear Ratio u = z 2 / z 1 Centre Distance a mm = (d 1 +d 2 ) / 2 Reference Diameter of Worm d 1 mm = (m x z 1 ) / tan l Reference Diameter of Wheel d 2 mm = m x z 2 Tip Diameter of Worm d a1 mm = d 1 + (2 m x ) Root Diameter of Worm d r1 mm = d a1 (2 h) Tip Diameter of Wheel d a2 mm = d 2 + (2 m x ) Root Diameter of Wheel d r2 mm = d a2 (2 h) Outside Diameter of Wheel d e2 mm = d a2 + m x Normal Pitch p n mm = p m n Axial Pitch p x mm = p m x Normal Tooth Thickness in Pitch Circle s n mm = s x cos l Transverse Tooth Thickness in Pitch Circle s x mm = (p x / 2) Quality Gear Quality: Worm = DIN 974, Wheel = 7 DIN 974 When working with a gear set, the subscript 1 denotes a worm and 2 a wormwheel. Tip diameter is the theoretical diameter of the gear without tooth thickness tolerance applied. For s n and s x, when x = zero, this is the theoretical tooth thickness. Actual tooth thickness will be less. The subscript e is for upper allowance values and i is for lower allowance values. d 2 d r2 d a2 d e2 a d 1 X N N X l Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Worms & Wheels p n Normal Section s n p x s x Axial Section d r1 d 1 d a1 Manufacture Wheels are precision hobbed. Ground worms are CBN form ground including root and root fillet radius resulting in no step at the start of the involute profile. Reference profiles DIN 87 1.25/.2/1. form ZI for worms and DIN 87 1.25/.2/1./.2 for wheels. Backlash and Tooth thickness Value stated on catalogue page is theoretical circumferential backlash per DIN 97 for two identical gears with the same number of teeth, running at JS7 centre distance tolerance. Where DIN 5845 applies base tangent length allowances are converted to tooth thickness allowances and the formula per DIN 97 used. Torque Stated value is maximum torque based on lowest figure from surface durability, tooth root strength or wear. Value is output torque T2 at wheel. Tooth root failure of teeth on wheel before teeth of worm is assumed. Worm 817M4 steel. Other factors including worm shaft deflection, duty cycle and temperature will effect maximum allow torque and service life. Wear is dependent on lubrication. We recommend that each user compute their own values based on actual operating conditions and test in application. See BS 7212, AGMA 4B92, DIN 99 or ISO/TR 14521 standards. Input Speed Life Limiting Stress N/mm 2 (CA14) Limiting Stress N/mm 2 (GG25) Lubrication Lubrication Viscosity Application Factor When selecting worm application factors should be applied to required torque. T 2 > T required x K a Application factor K a Working characteristics of driving machine Uniform Light Shocks Moderate Shocks Heavy Shocks h f Uniform 1. 1.1 1.25 1.5 h a Surface Durability Tooth Root Strength 1 rpm Uniform Speed 25, hours 15.2 9 4.1 4 Mineral Oil Between mm 2 /s and 1mm 2 /s at C 1. Working characteristics of driven machine Light Moderate Shocks Shocks 1.25 1.5 1.5 1. 1.5 1.75 1.75 2. Heavy Shocks 1.75 1.85 2. 2.25+ Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Worms & Wheels Efficiency The following allows an approximate value for the efficiency of the gears to be found allowing required input torque and gear forces to be calculated. Efficiency is dependent on lubrication and the figures below do not include bearing, seal and other losses. h = tan l / tan (l+ pz) pz = arctan (µ) vg = (d1 n1) / (1998. cos l) T1 = (T2 / u) * h Coefficient of friction µ (Mineral Oil) Velocity Range (m/s)..9 1.1.9 2.2.9..9 4.4.9 5.5.9..9 7.7.9 8.8.9 9.9.9 1.1.9 11.11.9 12.12.9 1.1.9 14.14.9 15.15.9 1.1.9 17.17.9..9 19.19.9 2.2.9 21.21.9 22.22.9 2.2.9 24.24.9 25.25.9 2.2.9 27.27.9 28.28.9 29.29.9..15.48.29.27.242.219.22.7.17.19.11.155.149.14.14.141.19.17.15.14.12.11.1.129.128.127.12.125.124.12.12.1.8.42.22.272.29.217.2..175..1.154.149.14.14.141..1.14.1.11.1.129.129.128.127.12.125.124.12.2.94.41.1.28.2.215.199.5.174.1.159.154.149.14.14.141..1.14.1.11.1.129.128.127.12.125.124.124.12 T1 = Input Torque (Nm) T2 = Output Torque (Nm) u = Ratio h = Efficiency l = Lead Angle (degrees) m = Coefficient of Friction pz = Angle of Friction vg = Sliding Velocity (m/s) n1 = rpm of Worm d1 = Reference Diameter of Worm (mm) µ for Velocities m/s..2.9.9.25.24.214.197.4.17.1.159.15.148.145.142.14..1.14.1.11.1.129.128.127.12.125.124.124.12.4.58.82.4.21.22.212.19..17.14.159.15.148.145.142.14..1.14.1.11.1.129.128.127.12.125.124.124.12.5.54.9.297.257.229.21.194.2.172.14.158.152.147.144.142.19..1.14.1.11.1.129.128.127.12.125.124.124.12..521.59.29.254.22.29.19.1.172.14.157.151.147.144.142.19.17.15.14.12.11.1.129.128.127.12.125.124.124.12.7.5.52.289.251.224.27.192.179.17.1.15.151.147.144.142.19.17.15.14.12.11.1.129.128.127.12.125.124.124.12.8.48.44.28.248.22.25.19.178.19.12.15.15.14.144.141.19.17.15.14.12.11.1.129.128.127.12.125.124.12.12.9.459..28.245.221.2.9.177.19.12.15.15.14.144.141.19.17.15.14.12.11.1.129.128.127.12.125.124.12.12 Example: if Vg = 1.2 then µ =.41 Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Worms & Wheels Gear Forces and Direction of Rotation F tm1 = F xm2 Ftm1 = 2*(T1 / d1) = Fxm2 Ftm2 = 2*(T2 / d2) = Fxm1 Frm1 = Ftm1*[tan 2 / (sin l + pz) ] = Frm2 F rm1 = F rm2 pz = arctan (m) Ftm = Tangential force (N) Fxm = Axial force (N) Frm = Radial force (N) When working with a gear set, the subscript 1 denotes a worm and 2 a wormwheel. Ondrives worm and wheel gears are supplied right hand lead as standard. The arrows show the direction of rotation. F tm2 = F xm1 Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Racks & Pinions Description Symbol Unit Equation Normal Module m n Transverse Module m t = m x / cos b Axial Module m x = m x / sin b Normal Pressure Angle a n degrees = 2 Transverse Pressure Angle a t degrees = tan 1 (tan a n / cos b) Helix Angle b degrees Number of Teeth z Profile Shift Coefficient x = zero for Ondrives standard gears Addendum h a mm = 1. m x (for Ondrives standard gears) Dedendum h f mm = 1.25 m x (for Ondrives standard gears) Tooth Depth h mm = 2.25 m x (for Ondrives standard gears) Pitch Height of Rack H o Height of Rack B Reference Diameter of Mating Gear d mm = z m t = (z m n ) / cos b Centre Distance a mm = H o + d + x d H o Manufacture Racks are induction hardened and precision ground to DIN 87 tooth form. Racks can be butt jointed end to end to create longer lengths as required. Mounting gauges are available on request. UPHGR helical racks are right hand helix 19 1' 42". Mating gears for UPSGR spur racks are RUPSG. Mating gears for UPHGR helical racks are RUPHG and must be left hand helix. B H o Gear Quality and Tooth thickness Racks are manufactured to quality grade h2 DIN 92/9/97. Backlash Value stated on catalogue page is theoretical circumferential backlash per DIN 97 for gear and rack running at H7 centre distance tolerance. a Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Materials Ondrives can manufacture gears in a range of additional materials including bronzes, engineering plastics, special steels and stainless steels. Gears can be heat treated by a range of methods to improve performance. Please contact our Technical department who will be happy to discuss your specific requirements. Material 85M2 817M4T 8M4 722M24T S21 1S1 174PH CA14 PB2 Brass CZ121 PEEK GF Delrin POM Cast Iron GG25 Titanium TiAL4V Material Equivalents B.S. 97 817M4T 85M2 S21 1S1 8M4 55M1 722M24 PB2 CA14 Brass CZ121 B.S. 1452 Cast Iron 25 Titanium TiAL4V Case Hardened Nitride Hardened Cold Drawn Cold Drawn Condition A Sand Cast Continuous Cast Grade 5 En 24T 2 58 58J 8 4B ISO Cu89Sn11 GZCuAL1Ni CuZn9Pb En ENGJL25 B.S. 2TA11 Density (Kg/m ) 7,85 7,85 7,85 7,85 8, 8, 7,78 7,58 8, 8,47 1,49 1,41 7,2 4,42 DIN 4NiCrMo84 / 4CrNiMo 2NiCrMo22 / 2NiCrMo2 X1CrNiS9 X5CrNiMo171 C4 14NiCr14 2CrMo12 DIN CuSn12 CuAL1Ni DIN DIN 191 GG25 UNS R54 Elongation after Fracture 11% 5 1% 7 17% 1% 5 45% 4% 1% 15% 5% 2% 2.7% % 1 % Tensile Strength (N/mm 2 ) 98 85 1 51 85 1 48 51 515 11 75 5 41 15 7 145 195 895 1 Werkstoff 1.52, 1.582 1.52 1.45 1.44 1.511 1.5752 1.71 Werkstoff.715.2% Proof Stress (N/mm 2 ) 785 8 4 5 2 25 1 4 17 28 2 828 91 SAE/AISI 44, 47 82 1 14 415, 1, 914 SAE/AISI SAE 4 ASTM B15 UNC C2 UNC C85 AMS 4911/4928 Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Backlash The backlash figure given for spur and helical gears is the theoretical backlash for two identical gears (or gear and rack) at standard centre distance to a centre distance tolerance As. It is given as circumferential backlash in mm measured on pitch circle diameter. An upper and lower value is quoted. Backlash is calculated according to DIN 97. Ondrives can manufacture gears to a wide range of tolerances to suit customer application. Please contact our Technical department who will be happy to discuss your specific requirements. A sn = Tooth thickness allowance which is the difference between measured gear tooth thickness and theoretical value measured in the normal section. When working with a pair of gears the subscript 1 and 2 denotes input (drive) and output (driven) gear. For worm and wheel, 1 relates to the worm and 2 to the wormwheel. The subscript e is for upper allowance and i for lower allowance. T sn = Tooth thickness tolerance measured in the normal section. (mm) A sne = S n S ne A sni = A sne T sn = S n S ni Circumferential Backlash j t This is the length of arc on the pitch circle diameter through which each can be rotated whilst the other is held stationary. It is measured in the transverse section. Units = mm & degrees Normal Backlash j n This is the shortest distance between the flanks of the gears when the opposite flanks are in contact. It is measured in the transverse section. For spur, helical, crossed axis helical gear Units = mm & degrees Change in Circumferential due to Centre Distance Tolerance Dj a Angular Backlash j q x p x d 2 Units = mm & degrees Units = mm & degrees d 2 = Reference diameter (mm) A s = Centre distance tolerance (i.e. a = mm Js7, As = ±.15mm) a n = Normal pressure angle (a n = 2 ) b = Helix angle (b = zero for spur gears) Replace helix angle b with lead angle l for worm and wheel. 1 = arc minutes Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Backlash Tooth and Centre Distance Tolerance UPSG Spur Gear UPHG Helical Gear RUPSG Spur Rack Gear UPSGR Spur Rack RUPHG Helical Rack Gear UPHGR Helical Rack PWG Wormwheel UPW, UPSW Worm Module.5 to.8 5f DIN 5845 5f DIN 5845 7e DIN 5845 e DIN 5845 Module 1. and above f24 DIN 97 f24 DIN 97 f24 DIN 97 h2 DIN 97 f24 DIN 97 h2 DIN 97 e25 DIN 97 e25 DIN 97 Centre Distance Tolerance As JS7 JS7 H7 H7 H7 H7 JS8 JS8 DIN 97 Reference Dia. d f24 e25 h2 Over Including A sne T sn A sne T sn A sne T sn 1 5 125 28 1 5 125 28 5.1.14.19.2.5 +.12 +.2 +.25 +. +.4.22..4.5.75 +.2 +. +.4 +.5 +...... DIN 5845 Reference Dia. d.5 Module 5f.8 Module 5f Over Including A sne T sn A sne T sn 12 25 5 1 2 12 25 5 1 2 4.12.14.1..2.22.24 +. +.7 +.8 +.9 +.11 +.12 +.1.14.1..2.22.24.28 +.8 +.12 +.1 +.2 +.25 +.7 +.8 +.9 +.11 +.12 +.1 +.14 Reference Dia. d.5 Module 7e.8 Module 7e Over Including A sne T sn A sne T sn 12 25 5 1 2 12 25 5 1 2 4..5.4.45.5 +.12 +.14 +.17 +. +.2.5.4.45.5.55..7 +.14 +.1 +. +.2 +.22 +.24 +.29 For racks d is assumed to be 1 normal module. Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Backlash Example: UPHG2RHK mating with UPHG8LHK at JS7 Distance Tolerance. 1. Calculate reference diameter for each gear UPHG.2RHK d1 = (z. mn) / cos β = (2. ) / cos 15 = 2.117mm UPHG.8RHK d2 = (z. mn) / cos β = (8. ) / cos 15 = 248.4mm 2. Find A sne and T sn from tables on previous page UPHG.2RHK A sne =.19mm T sn =.25mm UPHG.8RHK A sne =.2mm T sn =.mm. Calculate A sni for each gear A sni = A sne T sn UPHG.2RHK A sni1 =.44mm UPHG.8RHK A sni2 =.5mm 4. Calculate centre distance and centre distance tolerance a = (d1 + d2) / 2 = (2.117 + 248.4) / 2 = 155.291mm A s = ±.2mm 5. Calculate the change in backlash due to centre tolerance. Calculate the maximum backlash Remove the minus sign on A sn 7. Calculate the minimum backlash Remove the minus sign on A sn 8. Convert to angular backlash 1 = arc minutes 88 d 2.549 to.148 degrees Output backlash, i.e. input gear UPHG2RHK fixed. Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Modifications Bore Size d Over 8 1 12 17 22 8 44 Keyways to DIN 885 Js9 sliding fit. D1 free fit and P9 tight fit available on request. Woodruff keyways available on request. Standard bore tolerance H7 ISO 28. Other tolerances available. Special bore shapes available including square and hexagon. Key b x h 2 x 2 x 4 x 4 5 x 5 x 8 x 7 1 x 8 12 x 8 Bore Size d Including 8 1 12 17 22 8 44 5 Width Shaft b Bore b N9 Js9.4/.29 +.12/.12.4/.29 +.12/.12 +./. +.15/.15 +./. +.15/.15 +./. +.15/.15 +./. +./. +./. +./. +./.4 +.21/.21 Keyway Size b x h 2 x 2 x 4 x 4 5 x 5 x 8 x 7 1 x 8 12 x 8 14 x 9 Nominal 1.2 1.8 2.5..5 4. 5. 5. Depth Pin Hole 1.5 2.. 4. 5.. 8. 1. 1. 1. Shaft t 1 Bore t 2 Tolerance Nominal +.1/. 1. +.1/. 1.4 +.1/. 1.8 +.1/. 2. +.1/. 2.8 +.2/.. +.2/.. +.2/.. Tolerance +.1/. +.1/. +.1/. +.1/. +.1/. +.2/. +.2/. +.2/. Tapped Hole M x.5 M x.5 M x.5 M4 x.7 M5 x.8 M x 1. M8 x 1.25 M1 x 1.5 M1 x 1.5 M12 x 1.75 Radius r Max Min.1.8.1.8.1.8.25.1.25.1.25.1.4.25.4.25 t 1 t 2 b r h r Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Lubrication The selection of correct lubrication for gears involves a wide range of factors to be considered. It is advised you consult lubrication manufacturers/suppliers with your application or review DIN 51591 for oil lubrication or DIN 51592 for grease (semifluid) lubrication or ISO TR 792 Lubrication of industrial gear drives or the America standard ANSI/AGMA 95E2. Greases and oils are available with a range of properties to suit materials used in the gears and environmental conditions. These properties help with antifoaming, corrosion, oxidation and wear. Plus extreme pressure (EP) additives to help with severe loading conditions. One of the key factors is choosing the correct Kinematic viscosity of the lubrication. The following equation gives an initial starting point and is based on the pitch line velocity of a spur or helical gear only. The equation assumes an ambient temperature of 125 C. Over this the Kinematic viscosity must be increased. Kinematic viscosity at 4 C (cst) = 5. vg.5 vg = pitch line velocity m/s = (η. d. n)/ n = speed in rpm. d = reference diameter in mm The widely recognised units of viscosity are the centistoke (cst). It is used by ISO (International Organization for Standardization) to create a classification grade of viscosity. Once a designer has an idea on the viscosity needed, lubrication products can be quickly sorted by checking for the viscosity class. ISO Viscosity class Kinematic viscosity at 4 C [mm 2 /s = cst] Minimum Midpoint ISO VG 2 2 28.8 5.2 ISO VG 4 4 41.4 5. ISO VG 8 8 1.2 74.8 ISO VG 1 1 9. 11. ISO VG 15 15 15. 15. ISO VG 22 22 198. 242. ISO VG 2 2 288. 52. ISO VG 4 4 414. 5. ISO VG 8 8 12. 748. ISO VG 1 1, 9. 1,1. ISO VG 15 1,5 1,5. 1,5. Maximum For grease a similar classification called NLGI consistency number is used to expresses a measure of the relative hardness of grease. It is measured at 25 C. Due to the sideway sliding motion in worm and wheel gear pairs, and the resulting higher temperatures, they tend to require oils with an ISO VG of 4 and higher. They also require good thermal and oxidative stability. The types of oils used to lubricate worm and wheel gear pairs are compounded mineral oils, EP mineral gear oils and synthetics. See International Standards for a more detailed study. Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Lubrication Three methods of lubrication are widely used. Grease Lubrication: Used on low speed, low load applications up to pitch velocities of 5m/s in some cases. Can be used for open or enclosed systems and is applied directly to the gear teeth. As with oils, amount applied is important. Over fill will result in excess losses in the system and temperature build up. The fluidity of the grease is an important factor. Too high or low and lubrication will not be maintained on the gear teeth. Too low and the grease can be lost in the structure of the system. Too high and the gear teeth can simply dig out channels in the lubrication. A key measure of this is core penetration. Splash (Oil Bath) Lubrication: Used on enclosed systems, one or more gears sit in a bath of oil. Pitch velocities of m/s and above are needed to make the system effective. Oil level and temperature limitations must be considered. The temperature of the system (gears, lubrication, and structure) will increase in operation. As temperature increases, viscosity lowers. Care must be taken to ensure temperatures do not rise above limits of the lubrication and the viscosity does not drop to lower than at the required operating conditions. Excess temperature will degrade the lubrication plus cause deformation of gears, shafts and structure leading to reduced backlash and higher friction in the system. For oil level, if too high there will be excess losses in the system. Too low and effective lubrication will not be formed on the teeth plus heat cannot be removed from the meshing teeth. Note the oil level will be lower in the system when operating compared to static. Static levels may have to be increased to maintain the level due in operation. General guidance on oil levels is as follows below. Vertical Shaft Horizontal Shaft 1 h h 1/ h 1 h 1/2 d 1/ d 1 2 1/4 d 1 Forced Oil System: In a forced oil system lubrication is applied to the contact area of the mating gears by an oil pump. This can be in the form of drops, spray or an oil mist. This method is used on high speed gearing and large sized gearboxes. The method is applicable to pitch line velocity of approximately 12m/s and above for spur or helical and 1m/s for worm and wheel. We recommend you contact lubrication manufacturers/suppliers if considering this method. Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Shaft and Bore Limits & Fits Housing Bore Tolerances (deviation from nominal dimensions) Nominal Tolerance of Housing Shaft Diameter (Unit =.1mm) Diameter mm d e f g5 h5 h Over Incl. High Low High Low High Low High Low High Low High Low 1 4 5 5 8 1 12 14 1 2 225 25 28 15 55 4 45 1 4 5 5 8 1 12 14 1 2 225 25 28 15 55 4 45 5 2 4 5 5 8 8 1 1 12 12 145 145 145 17 17 17 19 19 21 21 2 2 2 8 49 1 78 9 9 119 119 142 142 17 17 17 199 199 199 222 222 24 24 27 27 14 2 25 2 4 5 5 72 72 85 85 85 1 1 1 11 11 125 125 15 15 2 28 4 4 5 79 79 94 94 11 11 11 129 129 129 142 142 11 11 175 175 1 1 1 2 25 25 4 4 4 5 5 5 5 5 2 2 8 8 Nominal Tolerance of Housing Bore Diameter (Unit =.1mm) Diameter mm F F7 G G7 H H7 Over Incl. High Low High Low High Low High Low High Low High Low 1 4 5 5 8 1 12 14 1 2 225 25 28 15 55 4 45 1 4 5 5 8 1 12 14 1 2 225 25 28 15 55 4 45 5 +27 + +41 +41 +49 +49 +58 +58 +8 +8 +8 9 9 9 +88 +88 +98 +98 Micro Inch (Cla) 1 2 4 8 1 2 125 25 5 1, + +1 +1 +1 +2 + + + + +4 +4 +4 +5 +5 +5 +5 +5 +2 +2 +8 +8 +1 +28 +4 +41 +5 +5 + + 1 1 +8 +8 +8 +9 +9 +9 +119 +119 +11 +11 + +1 +1 +1 +2 + + + + +4 +4 +4 +5 +5 +5 +5 +5 +2 +2 +8 +8 +8 +17 +2 +29 +29 +4 +4 +9 +9 +9 +44 +44 +44 +49 +49 +54 +54 + + 12 22 27 41 41 49 49 58 58 8 8 8 79 79 79 88 88 98 98 +2 +4 +5 + +9 +9 +1 +1 +15 +15 +15 +17 +17 +2 +2 2 4 5 7 9 9 1 1 12 12 14 14 14 15 15 15 17 17 2 2 +1 +2 +24 +28 +4 +4 +4 +4 +47 +47 +54 +54 +54 +1 +1 +1 +9 +9 5 5 +8 +8 Surface Finish Conversion Chart Metric (microns) Equivalent (Ra).25.5.1.2.4.81 1...5 12.7 25.4 9 11 14 1 2 2 2 2 27 27 2 2 2 5 5 5 4 4 4 4 47 47 +2 +4 +5 + +9 +9 +1 +1 +15 +15 +15 +17 +17 +2 +2 + +8 +9 +11 +1 +1 +1 +19 +19 +29 +29 +29 +2 +2 + + +4 +4 4 5 8 9 11 11 1 1 15 15 2 2 2 2 2 25 25 27 27 European N1 N2 N N4 N5 N N7 N8 N9 N1 N11 +1 +15 +21 + + +5 +5 +4 +4 +4 +4 +4 +4 +52 +52 +57 +57 + + 8 9 11 1 1 1 19 19 22 22 25 25 25 29 29 29 2 2 4 4 Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.
Shaft and Bore Limits & Fits Housing Bore Tolerances (deviation from nominal dimensions) Nominal Tolerance of Housing Shaft Diameter (Unit =.1mm) Diameter mm h7 h8 h9 h1 j5 j Over Incl. High Low High Low High Low High Low High Low High Low 1 4 5 5 8 1 12 14 1 2 225 25 28 15 55 4 45 1 4 5 5 8 1 12 14 1 2 225 25 28 15 55 4 45 5 1 12 15 21 25 25 5 5 4 4 4 4 4 4 52 52 57 57 14 22 27 9 9 4 4 54 54 72 72 72 81 81 89 89 97 97 Nominal Diameter Tolerance of Housing Bore Diameter (Unit =.1mm) mm H8 H9 H1 J J7 Over Incl. High Low High Low High Low High Low High Low 1 4 5 5 8 1 12 14 1 2 225 25 28 15 55 4 45 1 4 5 5 8 1 12 14 1 2 225 25 28 15 55 4 45 5 over 1 5 +27 + +9 +9 +4 +4 +54 +54 + + + 2 2 2 +81 +81 +89 +89 +97 +97 + + +4 +52 +2 +2 4 4 +87 +87 +1 +1 +1 +115 +115 +115 +1 +1 +155 +155 25 4 52 2 2 74 74 87 87 1 1 1 115 115 115 1 1 14 14 155 155 +4 +48 +58 +84 +1 +1 +1 +1 +1 5 5 5 +21 +21 +2 +2 4 48 58 7 84 1 1 12 12 14 14 1 1 1 5 5 5 21 21 2 2 25 25 Tolerance Band in Microns (.1mm) Units incl. m +2 / +8 +4 / 1 + / +15 / +8 / +21 5 +9 / 8 +11 / + +2 +5 +5 + +8 +1 +1 +1 +1 +1 +1 +29 +29 + + +2 + +4 +5 +5 + + + + + + 4 4 5 5 7 7 7 7 7 7 7 7 7 7 7 7 2 2 2 4 5 5 7 7 9 9 11 11 11 1 1 1 1 1 2 2 +4 + +8 +1 +2 +2 +2 + + + + + +9 +9 +4 +4 +4 + +8 +9 +11 +11 +1 +1 +1 +1 +1 +1 +1 +2 +2 S7 / 1 1 / 22 1 / 28 1 / 4 2 / 41 25 / 5 / 2 2 2 4 5 5 7 7 9 9 11 11 11 1 1 1 1 1 2 2 7 8 9 11 11 12 12 1 1 14 14 14 1 1 1 1 1 2 2 Product information updated April 215 and subject to change. Please contact Sales for the latest prices and availability.