The gears are termed as medium velocity gears, if their peripheral velocity is
Two mating spur gears have 70 and 30 teeth respectively. Corresponding to module pitch 6 mm, the center to center distance between gears will be
Spot the wrong relation:
Which aspect is not true for a stub tooth when compared to full depth system?
The interfering portion of the tooth, which is a part of addendum, is removed in stub tooth profile because stub involute system have shorter addendum and dedendum.
Lewis equation in spur gears is applied
The amount of force that can be transmitted to a gear tooth is a function of the Soy product as shown by the Lewis equation. For two mating gears, the weaker will have the smaller S0y value. When two mating gears are to be made of .the same material, the smaller gear (pinion) will be the weaker and control design.
Allowable tooth stress for gear-tooth design depends upon the following parameters:
1. Type of gear material
2. Pitch line velocity
3. Beam strength of gear teeth
Which of the above is/are valid?
σ0 is the endurance strength of material
Cv is the velocity factor
The tooth profiles must not have excessive contact stress as determined by the wear load to insure durability of a gear pair. This wear load is obtained using
Ww = Maximum or limiting load for wear, N
Dp = PCD, mm
b = face width of the pinion , mm
Q = Ratio Factor
K = Load-stress factor or material combination factor, N/mm2
A pair of straight teeth spur gears with 6 mm module, having 20° involute full depth teeth is to transmit 12 kW at 300 rpm of the pinion. The speed ratio is 3:1. The allowable static stresses for gear of cast irion and pinion of steel are 60 MPa and 105 MPa respectively.
Assume the following:
Number of teeth on pinion = 16;
Face width = 14 m;
σes - 600 MPa; Ep = 200 GPa; EG = 100 GPa; Service factor, Cs = 1; sin20° = 0.342.
Based on these design data, match the followings:
Pitch line velocity
Load stress factor
Limiting wear load,
The backlash for spur gears depends upon
Cycloidal tooth profile of a cycloidal gear tooth is a combination of
Cycloidal tooth is made of two curves- hypocycloid curve below the pitch circle and epicycloid curve above the pitch curve.