Spur Gears Description Symbol Unit Equation Normal Module m n Transverse Module m t = m n Normal Pressure Angle a n degrees = 2 Transverse Pressure Angle a t degrees = a n 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 n 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 Normal Tooth Thickness in Pitch Circle s n mm = (p n / 2) + 2m n x tan a n 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. For sn 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 for lower allowance values. d a1 d 1 d r1 s n p n a Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Spur Gears Gear Quality Standard metal gears are supplied to quality Grade 7 DIN 31 based on Pitch total deviation Fp, Pitch deviation fp, Radial runout Fr and Pitch error fu. Skive hobbed gears are supplied to quality Grade DIN 31. GG25 Cast Iron, PEEK GF3 and Delrin (POM) are supplied to quality Grade DIN 31. Ondrives can manufacture gears to higher grades on request. Ondrives can offer testing certification for a gear s individual parameters using the latest CMM machine with gear measuring software. Double and single flank testing is available on request. Please contact our technical department for details. Comparisons of Grade Standards Example 3 mod, 5 teeth, 3mm face width spur gear. Standard DIN 31 DIN 31 ISO 132 AGMA Grade 7 7 1 Pitch total deviation F p µm 32 5 51 Pitch deviation f p µm 13 13 Radial runout F r µm 22 31 1 Pitch error f u µm 1 Double flank composite transmission error F i " µm 2 3 1 1 Double flank toothtotooth transmission error f i " µm 11 21 2 Torque Stated value for metal spur gears is maximum torque (T 2 ) based on two identical gears with the same number of teeth running at standard centres. Value is minimum from surface stress or bending stress. Other factors including duty cycle and temperature will affect maximum allowable torque and service life. Wear is dependant on lubrication. We recommend that each user compute their own values based on actual operating conditions and test in application. Materials 17M 5M2 33 Stainless 31 Stainless GG25 Cast Iron Input Speed 1 rpm Uniform, hours running per day Bending Stress Factor S b 32, 5, 2,, 7, Surface Stress Factor S c 3, 11, 1, 1, 1,35 Stated value for plastic spur gears is maximum torque (T 2 ) based on two identical gears with the same number of teeth running at standard centres. Value is minimum from surface stress, bending stress or bulk/surface temperature using method from BS :17. The torque capacity of plastic gears is highly dependant on operating condition. All values are reference only. We recommend that each user test in application under specific operation conditions of application. Materials Input Speed / No. of Load Cycles Limiting Bending Stress Limiting Surface Stress Initial Temperature Max. Bulk or Surface Temperature Coefficient of Friction. (Dry) * Reference Only ** Approximate value based on initial light greasing. Maximum torque for titanium gears is approximately 3% of 17M steel gears. Due to lack of stress factors we are unable to offer specific values. Testing in application is required. Torque for antibacklash spur gears is limited by the spring rating. Please contact our Technical department for details. When selecting gears application factors should be applied to required torque. T 2 > T required x K a Working characteristics of driving machine Uniform Light Shocks Moderate Shocks Heavy Shocks Application factor K a Uniform 1. 1.1 1.25 1.5 Delrin POM (White) 1 rpm / 1 22. N/mm 2 22. N/mm 2 2 C C PEEK GF3 (Light Brown) 1 rpm / 1 3 N/mm 2* N/mm 2* 2 C C.25** Working characteristics of driven machine Light Shocks 1.25 1.35 1.5 Moderate Shocks 1.5 1. 2. Heavy Shocks 1.5 2. 2.25+ Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Parallel 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 = Lead Angle l degrees = 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 n 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. For sn & st 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 for lower allowance values. For two helical gears to run together one must be left hand and the other right hand helix. d a1 d 1 d r1 s t p t a b Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Parallel Helical Gears Gear Quality Standard gears are supplied to quality grade 7e25 DIN 31 based on the following parameters Radial Runout F r = Pitch Deviation f p = Total Pitch Deviation F p = Pitch Error f u = Ondrives manufacture gears to higher quality grades on request. Ondrives can offer testing certification of a gears individual parameters using the latest CMM machine with gear measuring software. Double and single flank testing is available on request. Please contact our technical department for details. Comparisons of Grade Standards Example 3 mod, 5 teeth, 3mm face width helix parallel helical gear. Standard DIN 31 ISO AGMA Grade 7 7 1 Pitch total deviation F p µm 7 5 55 Pitch deviation f p µm 13 Radial runout F r µm 31 Pitch error f u µm Double flank composite transmission error F i " µm 3 1 5 Double flank toothtotooth transmission error f i " µm 21 2 Torque Stated value for metal spur gears is maximum torque (T 2 ) based on two identical gears with the same number of teeth running at standard centres. Value is minimum from surface stress or bending stress. Other factors including duty cycle and temperature will affect maximum allowable torque and service life. Wear is dependant on lubrication. We recommend that each user compute their own values based on actual operating conditions and test in application. Materials Input Speed Bending Stress Factor S b Surface Stress Factor S c Working characteristics of driving machine Uniform Light Shocks Moderate Shocks Heavy Shocks 17M 5M2 33 Stainless 31 Stainless 1 rpm Uniform, hours running per day 32, 3, 5, 11, 2, 1,, 1, When selecting gears application factors should be applied to required torque. T 2 > T required x K a Application factor K a Uniform 1. 1.1 1.25 1.5 Working characteristics of driven machine Light Shocks 1.25 1.35 1.5 Moderate Shocks 1.5 1. 2. Heavy Shocks 1.5 2. 2.25+ Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Crossed Axis 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 = tan1 (tan a n / cos b) Helix Angle b degrees = 5 Lead Angle l degrees = 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 + (2mn x) + (2 mn) 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 n x tan a t 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. For sn & st 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 for lower allowance values. For two crossed axis helical gears to run together both must be right hand or left hand helix. p x d a1 s t p t d 1 a b l Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Crossed Axis Helical Gears Direction of Rotation Right Hand Helix Left Hand Helix Torque Stated value is maximum torque (T 2 ) based on two identical gears with the same number of teeth running at standard centres. Crossed axis helical gears transmit load by point contact. The limiting condition is typically surface stress. Other factors including duty cycle and temperature will affect maximum allowable torque and service life. Wear is dependant on lubrication. We recommend that each user compute their own values based on actual operating conditions and test in application. Materials Input Speed Bending Stress Factor S b Surface Stress Factor S c Lubrication Lubrication Viscosity When selecting gears 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 Uniform 1. 1.1 1.25 1.5 17M 32, 3, 5M2 (SAE 2) Case Hardened 1 rpm uniform speed 5, 11, Mineral Oil Between mm2/s and 13mm2/s at C Working characteristics of driven machine Light Shocks 1.25 1.35 1.5 Moderate Shocks 1.5 1. 2. Heavy Shocks 1.5 2. 2.25+ Product information updated March 217 and subject to change. Please click the product links for 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 = tan1 (tan a n / cos l) Lead Angle l degrees = tan1 ((m x z 1 ) / d 1 ) Helix Angle b degrees = 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 da1 mm = d 1 + (2 m x ) Root Diameter of Worm dr1 mm = d a1 (2 h) Tip Diameter of Wheel da2 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 Steel and Stainless Steel worm = Quality, DIN 37. Bronze wormwheel = Quality 7, DIN 37. PEEK and Delrin worms = Quality 7, DIN 37. PEEK and Delrin wormwheel = Quality, DIN 37. 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 sn & sx 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 for lower allowance values. d 2 d r2 d 1 d a2 d e2 a X N N X l Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Worms & Wheels hf h a d r1 d 1 d a1 p n s n p x s x Normal Section Axial Section Torque Stated value is maximum torque based on lowest figure from surface durability, tooth root strength or wear. Values for bronze and cast iron wheel are for matching with steel 17M worm. Value is output torque (T 2 ) at wheel. Tooth root failure of teeth on wheel before teeth of worm is assumed. Other factors including worm shaft deflection, duty cycle and temperature will affect maximum allowable torque and service life. Wear is dependant on lubrication. We recommend that each user compute their own values based on actual operating conditions and test in application. Maximum torque as % of CA1 Aluminium Bronze Wheel Maximum Wheel Temperature Working characteristics of driving machine Uniform Light Shocks Moderate Shocks Heavy Shocks Uniform 1. 1.1 1.25 1.5 Delrin POM 5%* C PEEK GF3 55 5%* C * Approximate value based on plastic wheel running with steel worm to allow initial selection. Testing in application will be required. Torque for anti backlash wormwheel gears is limited by the spring rating. Please contact our Technical department for details. When selecting gears application factors should be applied to required torque. T 2 > T required x K a Application factor K a Working characteristics of driven machine Light Shocks 1.25 1.35 1.5 Moderate Shocks 1.5 1. 2. Heavy Shocks 1.5 2. 2.25+ Product information updated March 217 and subject to change. Please click the product links for 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 dependant on lubrication and the figures below do not include bearing, seal and other losses. h = tan l / tan (l+ pz) pz = arctan (µ) vg = (d 1 n 1 ) / (1. cos l) T 1 = (T 2 / u) * h Coefficient of friction µ (Mineral Oil) Velocity Range (m/s).. 1.1. 2.2. 3.3... 5.5... 7.7..... 1.1. 11.11... 13.13. 1.1... 1.1. 17.17... 1.1. 2.2. 21.21. 22.22. 23.23. 2.2. 25.25. 2.2. 27.27. 2.2. 2.2. 3...3.32.27.22.21.22.7.17.1.11.5.1.1.13.11.13.137.135.13.132.131.13...7..5..3.3.1.3.23.322.272.23.217.2..175..1..1.1.13.11.13.13.13.133.131.13....7..5..3.2..1.31.2.23.2.1.5.17.1...1.1.13.11.13.13.13.133.131.13...7..5...3 µ for Velocities 3m/s..53.32.3.21.232.2.1.3.173.1..3.1..12.1.13.13.13.133.131.13...7..5...3.5.53.3.27.257.22.21.1.2.172.1..2.17.1.12.13.13.13.13.133.131.13...7..5...3.3.23.3.3.25.23.21.17..173.1..3.1..12.1.13.13.13.133.131.13...7..5...3 T 1 = Input Torque (Nm) T 2 = Output Torque (Nm) u = Ratio h = Efficiency l = Lead Angle (degrees) m = Coefficient of Friction pz = Angle of Friction v g = Sliding Velocity (m/s) n 1 = rpm of Worm d 1 = Reference Diameter of Worm (mm)..521.35.23.25.22.2.13.1.172.1.7.1.17.1.12.13.137.135.13.132.131.13...7..5...3.7.5.352.2.251.22.27.12.17.17.13..1.17.1.12.13.137.135.13.132.131.13...7..5...3...3.2.2.223.25.1.17.1....1.1.11.13.137.135.13.132.131.13...7..5..3.3..5.33.2.25.221.23..177.1....1.1.11.13.137.135.13.132.131.13...7..5..3.3 Example: if Vg = 1.2 then µ =.1 Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Worms & Wheels Gear Forces and Direction of Rotation F tm1 = F xm2 F tm1 = 2* (T 1 / d 1 ) = F xm2 F tm2 = 2* (T 2 / d 2 ) = F xm1 F rm1 = F tm1 * [tan 2 / (sin l + pz) ] = F rm2 F rm1 = F rm2 pz = arctan (m) F tm = Tangential force (N) F xm = Axial force (N) F rm = 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 March 217 and subject to change. Please click the product links for prices and availability.
Bevel Gears Description Symbol Unit Equation Normal Module m n Pressure Angle a degrees = 2 Shaft Angle S degrees = ( for Ondrives standard gears) Number of Teeth z 1, z 2 Gear Ratio u = z 2 / z 1 Pitch Diameter of Worm d 1, d 2 mm = z m n Pitch Cone Angle d 1 degrees = d 1 = tan1 (sin S / (u + cos S)) Pitch Cone Angle d 2 degrees = d 2 = S d 1 Cone Distance R e mm = d 2 / 2 sin d 2 Addendum h a mm = 1. mn (for Ondrives standard gears) Dedendum h f mm. to 1.m n = 1.25 m n (standard gears) 1.5 to 2.m n = 1.22 m n (standard gears).m n = 1.2 m n (standard gears) Outside Diameter d a mm = d + 2 h a cos d Pitch Apex to Crown X mm = R e cos d h a sin d Quality Grade 7 DIN 35 d a d X d 1 h ahf d 2 F Torque Stated value is maximum torque (T 2 ) based on two identical gears with the same number of teeth running at standard centres. Value is minimum from surface stress or bending stress. Other factors including duty cycle and temperature will affect maximum allowable torque and service life. Wear is dependant on lubrication. We recommend that each user compute their own values based on actual operating conditions and test in application. Materials Input Speed Bending Stress Factor S b Surface Stress Factor S c R e 17M 5M2 33 Stainless 31 Stainless 1 rpm Uniform, hours running per day 32, 3, 5, 11, 2, 1,, 1, Product information updated March 217 and subject to change. Please click the product links for 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 sales team who will be happy to discuss your specific requirements. Material 5M2 17MT M 722M2T 33S21 31S1 17PH CA1 PB2 Brass CZ1 PEEK GF3 Delrin POM Cast Iron GG25 Titanium TiALV Material Equivalents B.S. 7 17MT 5M2 33S21 31S1 M 55M13 722M2 PB2 CA1 Brass CZ1 B.S. 2 Cast Iron 25 Titanium TiALV Case Hardened Nitride Hardened Cold Drawn Cold Drawn Condition A Sand Cast Continuous Cast Grade 5 En 2T 32 5 5J 3 B ISO CuSn11 GZCuAL1Ni CuZn3Pb3 En ENGJL25 B.S. 2TA11 Density (Kg/m 3 ) 7,5 7,5 7,5 7,5,, 7,7 7,5,,7 1, 1,1 7,2,2 Elongation after Fracture 11% 5 13% 7 17% 13% 35 5% % 1% % 5% 2% 2.7% 3% 1 % DIN NiCrMo / 3CrNiMo 2NiCrMo22 / 2NiCrMo2 X1CrNiS X5CrNiMo17133 C 1NiCr1 32CrMo DIN CuSn CuAL1Ni DIN DIN 11 GG25 UNS R5 Tensile Strength (N/mm 2 ) 5 1 51 5 1 51 5 113 75 3 5 1 7 5 1 Werkstoff 1.52, 1.52 1.523 1.35 1.3 1.511 1.5752 1.731 Werkstoff 3.7.2% Proof Stress (N/mm 2 ) 75 3 5 2 25 1 3 17 2 2 2 1 SAE/AISI 3, 337 2 33 31 1 3, 331, 31 SAE/AISI SAE ASTM B UNC C32 UNC C35 AMS 11/2 Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Materials Delrin POM (White) DIN EN ISO 131: POM C polyacetal comopolymer. Very good dimensional stability compared to Nylon & Hostaform. Minimal absorption of moisture. Good sliding properties. High wear resistance. High surface hardness. High mechanical strength and stiffness compared to Nylon & Hostaform. Can be in contact with food (FDA). Delrin gears can be run dry or greased/oiled to improve wear. General Properties Density Absorption of Moisture Mechanical properties Yield Stress/ Tensile Strength Elongation at Break Tensile Modulus of Elasticity Ball Indentation Hardness Shore Hardness Coefficient of Friction against hardened and ground steel (dry) Thermal Properties Melting Temperature Thermal Properties Coefficient of Linear Thermal Expansion Service Temperature, long term (min.) Service Temperature, long term (max.) Service Temperature, short term Heat Deflection Temperature Electrical Properties Dielectric Constant Dielectric Dissipation Factor Specific Volume Resistivity Surface Resistivity Comparative Tracking Index (test solution A) Dielectric Strength PEEK GF3 (Light Brown) DIN EN ISO 131: PEEK polyetheretherketone. Excellent dimensional stability. Outstanding high mechanical strength and hardness over a broad temperature range. Shows only a slight distortion under the impact of mechanical load and high temperature. Good electrical insulating properties. Extremely high flame resistance. Selfextinguishing. Very low smoke emission in a case of a fire. Can be run dry for slow speed hand operation. Gears should be greased/oiled for all other operating conditions. kg/m 3 N/mm 2 N/mm 2 N/mm 2 Skala D C W / (m K) 1 K 1 C C C C W cm W kv/mm Delrin POM 11.2% 7 3.% 2 1.1.3.31 11 5 1 1 11 3..2 113 113 PEEK GF3 1.1% 2.7% 7 23.3. 33.3 3 2 25 31 3 3.2.1 11 113 175 2 Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Backlash The backlash figures given for spur, helical and crossed axis helical gears is the theoretical backlash for two identical gears at standard centre distance to the ISO 2 centre distance tolerance. It is given as circumferential backlash in mm measured on pitch circle diameter. An upper and lower value is quoted. Theoretical backlash is the difference between tooth thickness without and with tolerance applied. Backlash is calculated according to DIN 37 Ondrives can manufacture gears to a wide range of tolerances to suit customer application. Please contact our Technical Sales team who will be happy to discuss your specific requirements. Tooth Thickness Tolerances Gear Type Spur Spur (Skive hobbed) Pinion Parallel Helical Crossed Axis Helical Worm & Wormwheel Gear Type Bevel Module.5 to. 7e/e DIN 55 e DIN 55 7e DIN 55 7e DIN 55 7e DIN 55 7e/e DIN 55 Module. to. Module 1. to 3. e25 DIN 37 e25 DIN 37 e25 DIN 37 e25 DIN 37 e25 DIN 37 e25 DIN 37 Centre Distance Tol. Js7 Js7 Js7 Js Js 7f2 DIN 35/37 Asn = 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. Tsn = Tooth thickness tolerance measured in the normal section. (mm) Asne = Sn Sne Asni = Asne Tsn = Sn Sni 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 jn 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 Units = mm & degrees Spur Gear Deviation from Change in Parallel Helical Gear Deviation from Change in Crossed Axis Helical Gear Deviation from Change in Centre Distance As (mm).1.1..2.25.3.35..5.5 Backlash Dja (mm).1.7.11...22.25.2.33.3 Centre Distance As (mm).1.1..2.25.3.35..5.5 Backlash Dja (mm).1..11..1.23.2.3.3.3 Centre Distance As (mm).1.1..2.25.3.35..5.5 Backlash Dja (mm).1.1..21.2.31.3.1..51 Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Backlash Angular Backlash j q 3 x Units = mm & degrees p x d 2 d 2 = Reference diameter (mm) A s = Centre distance tolerance (i.e. a = 3mm Js7, A s = ±.mm) 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 e25 DIN 37 Reference Diameter d (mm) Over Upto 1 1 5 5 5 5 2 7e DIN 55 Reference Diameter d (mm) from 3 to > to > to 25 >25 to 5 >5 to 1 >1 to 2 >2 to Upper Tooth Thickness Allowance Normal Module m sn >.1 to.25 >.25 to. >. to 1. >.1 to.25 >.25 to. >. to 1. >.1 to.25 >.25 to. >. to 1. >1. to 3 >.1 to.25 >.25 to. >. to 1. >1. to 3 >.1 to.25 >.25 to. >. to 1. >1. to 3 >. to 1. >1. to 3 >. to 1. >1. to 3 A sne.22mm.3mm.mm.5mm *Asne is converted from base tangent length allowance (Aw) according to Aw = Asn * cos 2 Tooth Thickness Tolerance T sn.2mm.3mm.mm.5mm Upper Tooth Tooth Thickness Allowance Thickness Tolerance A sne.2.3.35.3.35..35..5.5..5.5.55.5.5.55.3.3.7.7. T sn.11..1..1.1.1.1..2.1..2.22..2.22.2.2.2.2.32 Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Backlash Example for Calculating Backlash for Two NonIdentical Gears Input Gear PSG.52 7e Output Gear PSG.5 7e 1. Calculate the reference diameter d for each gear PSG.52 d 1 = z * mn = 1.mm PSG.5 d 2 = 2.mm 2. Find A sne and T sn from the tables overleaf PSG.52 A sne =.35mm T sn =.1mm PSG.5 A sne =.mm T sn =.1mm 3. Calculate A sni for each gear PSG.52 A sni = A sne T sn =.35.1 =.21mm PSG.5 A sni = A sne T sn =..1 =.2mm. Calculate the centre distance of the two gears and the centre distance tolerance centre distance = (1 + 2) / 2 = mm Js7 = ±.mm 5. Calculate the change in backlash due to centre distance. Calculate the maximum backlash Remove the minus sign on A sn 7. Calculate the minimum backlash Remove the minus sign on Asn. Convert to angular backlash 3 x 1 = arc minutes p x d 2 2.2 to 13.72 arc minutes Product information updated March 217 and subject to change. Please click the product links for prices and availability.
Product information updated March 217 and subject to change. Please click the product links for prices and availability. PRECISION GEARS Over Inc. F F7 G G7 H H7 H H H1 H11 J J7 J JS JS7 JS K M M7 3 1 22 1 1 3 75 5 3 1 2 1 1 22 13 2 13 1 5 2 5 22 3 5 5 7 1.5.5 7.5 7.5 11 11 2 7 3 1 27 1 3 1 17 2 11 27 3 7 11 5 1 5.5 5.5 13.5 13.5 2 3 33 2 1 2 2 7 2 7 13 21 33 52 13 5 2 13.5.5 1.5 1.5 1.5 1.5 2 11 17 21 3 5 5 5 5 1 1 1 1 1 3 3 3 3 1 5 1 25 3 1 1 25 7 2 1 1 22.5.5 2 2 31.5 31.5 21 33 1 2 2 225 7 5 5 1 2 72 1 5 2 22 7 3 1 7 25 1.5 1.5 23 23 3 3 5 2 37 225 25 1 25 5 25 25 3 1 25 3 2 1 1 1 1 11 2.5.5 1.5 1.5 3 13 2 25 3 3 2 1 1 1 3 7 1 13 2.5.5 23 23 5 2 3 5 3 71 3 3 7 22 35 5 7 1 22 1 22 13 3 2 11 11 17.5 17.5 27 27 2 35 Hole Sizes (mm) Micrometres (1 3 m) Limits and Fits
Product information updated March 217 and subject to change. Please click the product links for prices and availability. PRECISION GEARS Over Inc. f f7 g5 g g7 h h7 h h h1 h11 j j7 js5 js js7 k m m7 3 1 1 22 1 3 75 2 2.5 2.5 1 1 1 13 22 13 2 5 11 5 1 5 2 22 3 5 7 2 1 5 3 3.5.5 7.5 7.5 1 1 21 1 1 27 1 3 1 17 2 11 27 3 7 11 3 5.5 5.5 1 7 25 7 3 2 33 2 1 7 1 7 2 7 2 13 21 33 52 13 13.5.5.5.5 1.5 1.5 2 21 2 3 5 5 5 5 1 1 1 1 1 3 3 3 1 32 1 3 1 5 25 3 1 1 25 1 11 22.5.5 2 2 2 3 55 1 2 2 225 5 7 5 35 1 2 72 1 5 2 1 13 25 21 1 1 1.5 1.5 23 23 33 17 3 17 225 25 25 1 25 5 2 25 3 1 25 3 2 1 1 11 5 1 5.5 5.5.5.5 2 25 3 3 3 1 23 1 2 1 1 3 7 1 7.5.5.5.5 21 2 3 11 1 11 3 5 3 71 27 3 7 22 35 5 7 1 22 13 2 7.5 7.5 11 11 17.5 17.5 25 3 35 13 13 Hole Sizes (mm) Micrometres (1 3 m) Limits and Fits
Modifications Bore Size d Over 1 17 22 3 3 Bore Size d Including 1 17 22 3 3 5 Keyway Size b x h 2 x 2 3 x 3 x 5 x 5 x x 7 1 x x 1 x Keyways to DIN 5 Js sliding fit. D1 free fit and P tight fit available on request. Woodruff keyways available on request. Standard bore tolerance H7 ISO 2. Other tolerances available. Special bore shapes available including square and hexagon. Key b x h 2 x 2 3 x 3 x 5 x 5 x x 7 1 x x Width Shaft b Bore b N Js./.2 +./../.2 +./. +./.3 +./. +./.3 +./. +./.3 +./. +./.3 +./. +./.3 +./. +./.3 +.21/.21 Nominal 1.2 1. 2.5 3. 3.5. 5. 5. t 1 t 2 Pin Hole 1.5 2. 3.. 5... 1. 1. 1. Depth Shaft t 1 Bore t 1 Tolerance Nominal Tolerance +.1/. 1. +.1/. +.1/. 1. +.1/. +.1/. 1. +.1/. +.1/. 2.3 +.1/. +.1/. 2. +.1/. +.2/. 3.3 +.2/. +.2/. 3.3 +.2/. +.2/. 3.3 +.2/. b Tapped Hole M3 x.5 M3 x.5 M3 x.5 M x.7 M5 x. M x 1. M x 1.25 M1 x 1.5 M1 x 1.5 M x Radius r Max Min.1..1..1..25.1.25.1.25.1..25..25 r h r Product information updated March 217 and subject to change. Please click the product links for prices and availability.