A shaft shown in Figure 1, pulley A receives power and pulley B delivers power to the load. Assume, nd=1.5n_d =1.5nd=1.5, and the belt tension in loose side at B is 15% of the tension on tight side. Compute the size of the shaft at the critical location based on fatigue loading.
A block type hand brake with 3 cm face width is present in Figure 2. The associated mean co-efficient of friction is 0.25. Due to environmental factor the standard deviation of co-efficient of friction is σ^f=0.025\hat{\sigma}_f = 0.025σ^f=0.025. For an estimated actuating force of 400N, find the brake torques corresponding to ±3σ^f\pm 3\hat{\sigma}_f±3σ^f.
It is required to design a chain drive to connect 50 hp, 1800 rpm electric motor to a drilling machine. The drill machine will rotate at 900 rpm. The speed reduction ratio is 2:1 and the smaller sprocket has 19 teeth. Consider design factor of 1.1 and smooth load. Specify a chain-sprocket system that will have a service life of 50 Kh.
A pair of identical straight bavel gears of 30 tooth and 6 in of pitch dia, 1.2 inch face width, 20° normal pressure angle, the gears are graded steel through hardened with a core and case hardness of 180 BHN, quality number of 6, uncrowned for general purpose use. For 10710^7107 cycle life at 600 rpm and 99% reliability, Find the power rating based on AGMA Bending strength.
An O2 series single row deep grove ball bearing is to be selected to carry 10 kN of radial load and 5 kN of axial load for a life of 12 Kh at 300 rpm for a centrifugal pump at the both ends with a reliability of 95%. Specify the smallest bore size and base rating.
A 60 hp (44.75 kW) four cylinder IC engine is used to drive a medium shock brick making machine under a schedule of two shifts per day. The derive consists of two 26 in (660 mm) sheaves spaced about 12ft (3.65m) apart with 400 rpm. Select a Gate Rubber V-belt arrangement. Find the factor of safety.
A steel spur pinion and gear have a diametral pitch of 12 teeth/in, milled teeth, 17 and 30 teeth respectively, a 20° pressure angle, a face width of 7/8 in and a pinion speed of 525 rpm. Use design factor 2.25. What is the power rating of the gearset? ( Here, sy=42s_y = 42sy=42 Kpsi, sut=76s_{ut}=76sut=76 Kpsi and Brinell hardness =149).
A set of sleeve bearings has a journal of 31.25 mm dia with a unilateral tolerance of -0.025mm. The bushing has a diameter of 31.3 mm with a unilateral tolerance of 0.075 mm. The bearing length is 31.25 mm. The applied radial load on a shaft rotating at 1750 rpm is 1113 N. SAE 10 oil is used at axial groove, sump temperature at steady state of 49°C. For the maximum clearance assembly, find the magnitude and location of the minimum film thickness, the co-efficient of friction, the power loss rate, the side flow rate and total flow rate.
Two gears B and C are attached on a shaft, is supported by two bearings A and D as shown in figure: 1. The pitch diameter of the gear B and C are 900 mm and 600 mm respectively. The material of the shaft is AISI 1040 steel. Determine the shaft diameter using conservative approach of fatigue loading. Assume, krk_rkr = 2.4, kbk_bkb = 2.1 and design factor = 2.5
The flywheel of a compressor operating at 170 rev/min has following dimensions: Diameter = 1.5 m; Width = 350 mm. An eight pole squirrel case induction motor has nameplate readings 37 kW and 875 rev/min. Design V-belt drive.
The figure shows a 400 mm diameter brake drum with four internally expanding shoes. Each of the hinge pins A and B support a pair of shoes. The actuating mechanism is to be arranged to produce the same force F on each shoe. The face width of the shoe is 75 mm. The maximum pressure is 1000 kPa and coefficient of friction f= 0.24. Determine the maximum actuating force, brake capacity and hinge-pin-reaction.
A 800 rev/min 24 hp squirrel case induction motor is to drive a two cylinder reciprocating pump with moderate shock, 2-shifts duty, dirty environment, hazardous environment. The pump speed 160 rev/min. Select a suitable chain and sprocket size, considering liberal approach.
Define sommerfeld number and write down its significance.
A full journal bearing is 28 mm long. The shaft journal has diameter of 56 mm with unilateral tolerance of -0.012 mm. The bushing bore has diameter of 56.05 mm with unilateral tolerance of 0.012 mm. The load 2.4 kN and the journal speed is 900 rev/min. For the minimum clearance assembly, find the minimum oil film thickness and position of the minimum film thickness, if operating temperature is 65°C and SAE - 40 lubricating oil is used.
Select two bearings for point O and point C for the gear reduction unit shown in figure: 6. The bearings are to be angular contact ball bearings having desired life 50 kh when used at 300 rev/min. [Assume, application factor 1.2 and reliability goal for the bearing pair is 0.96]
A spur gear set has 17 teeth and 51 teeth. The pressure angle is 20° and the overload factor kok_oko = 1. The diametral pitch is 6 teeth/in and face width is 2 in. The pinion speed is 1120 rev/min and life of 10810^8108 cycles at a reliability of 99%. The quality no. is 5. The material is through hardened steel, grade 1, BHN 232 core and case of both gear. For a design factor of 2, rate the gear set based on bending.
An uncrowned straight bevel-pinion has 30 teeth, a diametral pitch of 6, and a transmission accuracy number of 6. The driven gear has 60 teeth. Both are made of No. 30 cast iron. The shaft angle is 90°. The face width is 1.25 in, the pinion speed 900 rev/min and the normal pressure angle is 20°. The pinion is mounted outboard of its bearings; the bearing of the gear straddles it. What is the power rating based on AGMA bending strength? (For cast iron gear sets, reliability information has not been developed yet. We say life is greater than 10710^7107 revolutions; set KtK_tKt = 1, CLC_LCL = 1, CRC_RCR = 1, KRK_RKR = 1; and apply a factor of safety. Use, SFS_FSF = 2 and SHS_HSH = 2\sqrt{2}2)
A catalog of stock bevel gears lists a power rating of 5.2 hp at 1200 rev/min pinion speed for a straight-bevel gearset consisting of a 20-teeth pinion driving a 40-teeth gear. This gear pair has a 20∘20^{\circ}20∘ normal pressure angle, a face width of 0.71 in, and a diametral pitch of 10 teeth/in and is through-hardened to 300 BHN. Assume the gears are for general industrial use, are generated to a transmission accuracy number of 5, and are uncrowned. The gears are rated for a life of 3×1063 \times 10^63×106 revolutions with a 99 percent reliability. Given your opinion on the stated catalog power rating.
The Figure 2 depicts a band brake whose drum rotates counterclockwise at 200 rev/min. The drum diameter is 16 in and the band lining 3 in wide. The coefficient of friction is 0.20. The maximum lining interface pressure is 70 psi.
Find the maximum brake torque, necessary force P, and steady-state power.
Complete the free-body diagram of the drum. Find the bearing radial load that a pair of straddle-mounted bearings would have to carry.
What is the lining pressure p at both ends of the contact arc?
Two shafts 20 ft apart, with axes in the same plane, are to be connected with a flat belt drive powered by 100 Bhp induction motor at 1140 rev/min, drives the second shaft with speed ratio 2:1. The driven shaft drives light-shock machine. Select a flat belt.
A mine hoist uses a 2-in 6×196 \times 196×19 monitor-steel wire rope. The rope is used to haul loads of 4 tons from the shaft 480 ft deep. The drum has a diameter of 6 ft, the sheaves are of good-quality cast steel, and the smallest is 3 ft in diameter. Using a maximum hoisting speed of 1200 ft/min and a maximum acceleration of 2 ft/s22 \text{ ft/s}^22 ft/s2, estimate the stresses in the rope. Estimate the various factors of safety.
Select a suitable antifriction bearing for a desire life of 12 kh at a speed of 300 rev/min to carry a radial load of 10 kN and axial load of 5 kN used in an industrial motor drive.
Design a full hydraudynamic journal bearing of journal diameter = 75 mm, radial load = 10 kN, journal speed = 1400 rpm, inlet temperature = 40∘C40^{\circ}\text{C}40∘C to satisfy minimum film thickness and radial clearance of 0.001r.
The Figure 7 shows a solid rotating shaft supported by bearings at points B and C, is driven by a Gear D with 150 mm pitch diameter. The force F acts at a pressure angle of 20∘20^{\circ}20∘ and transmits torque Ta=340 N-mT_a = 340 \text{ N-m}Ta=340 N-m. The shaft is machined from AISI 1040 steel. Perform a fatigue failure analysis to determine the minimum allowable diameter of the 250 mm section of the shaft, assume sharp fillet radii at the bearing shoulders.
A 20∘20^{\circ}20∘ spur pinion with 20 teeth and a module of 2.5 mm transmits 120 W to a 36 teeth gear. The pinion speed is 100 rev/min, and the gears are grade 1, 18 mm face width through hardened steel at 200 BHN, uncrowned and quality No. 6. Asses the weak part based on bending.
An 02-series single-row deep-groove ball bearing with a 65-mm bore is loaded with a 3-kN axial load and a 7-kN radial load for a loading like ceiling fan, with 500 rev/min. Determine whether this bearing should be expected to carry this load with a 95% reliability for 10kh.
A full journal bearing has a shaft journal with a diameter of 1.25 in and a unilateral tolerance of -0.0006 in. The bushing bore has a diameter of 1.252 in with a unilateral tolerance of 0.0014 in. The bushing bore is 2 in long. The bearing load is 620 lbf and the journal rotates at 1120 rev/min. Analyze the minimum clearance assembly and find the minimum film thickness, the coefficient of friction.
A 20∘20^{\circ}20∘ full-depth steel spur pinion rotates at 1145 rev/min. It has a module of 6 mm, a face width of 75 mm, and 16 milled teeth. The ultimate tensile strength at the involute is 900 MPa exhibiting a Brinell hardness of 260. The gear is steel with 30 teeth and has identical material strengths. For a design factor of 1.3 find the power rating of the gearset based on the pinion and the gear resisting bending and wear fatigue.
The block-type hand brake shown in the Figure Q.4 has a face width of 1.25 in and a mean coefficient of friction of 0.25. For an estimated actuating force of 90 lbf, find the maximum pressure on the shoe and find the braking torque.
A flat-belt drive consists of two 48 in diameter cast-iron pulleys spaced 16 ft apart. Select a belt type to transmit 60 hp at a pulley speed of 380 rev/min for a moderate shock application.
A single V belt is to be selected to deliver engine power to the wheel-drive transmission of a riding tractor. A 5-hp single-cylinder engine is used. At most, 60 percent of this power is transmitted to the belt. The driving sheave has a diameter of 6.2 in, the driven, 12.0 in. The belt selected should be as close to a 92-in pitch length as possible. The engine speed is governor-controlled to a maximum of 3100 rev/min. Select a satisfactory belt and assess the factor of safety and the belt life in passes.
The block type hand brake shown in the Figure 1 has a face width of 1.25 in and a mean coefficient of friction of 0.25. For an estimated actuating force of 90 lb, find the maximum pressure on the shoe and find the braking torque.
Two B85 V-belts are used in a drive composed of a 5.4 in driving sheave, rotating at 1200 rev/min, and a 16-in driven sheave. Find the power capacity of the drive based on a service factor of 1.25 and find the center to center distance.
The section of shaft shown in the Figure 3 is to be designed to approximate relative sizes of d=0.75Dd = 0.75Dd=0.75D and r=D/20r = D/20r=D/20 with diameter d conforming to that of standard metric rolling-bearing bore sizes. The shaft is to be made of SAE 2340 steel, heat treated to obtain minimum strengths in the shoulder area of 1226 MPa ultimate tensile strength and 1130 MPa yield strength with a Brinell hardness not less than 370. At the shoulder the shaft is subjected to a completely reversed bending moment of 70 N.m accompanied by a steady torsion of 45 N.m. Use a design factor of 2.5 and size the shaft for an infinite life.
A spur gear set has 17 teeth on the pinion and 51 teeth on the gear. The pressure angle is 20∘20^{\circ}20∘ and the overload factor ko=1k_o = 1ko=1. The diametral pitch is 6 teeth/in and the face width is 2 in. The pinion speed is 1120 rev/min and its cycle life is to be 10810^8108 revolutions at a reliability R=0.99R = 0.99R=0.99. The quality number is 5. The material is a through hardened steel grade 1 with Brinell hardness of 232 core and case of both gears. For a design factor of 2, rate the gear set for these conditions using the AGMA method.
A double strand no 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and 52 tooth driven sprocket. What is allowable horsepower of this drive? Estimate center to center distance if the chain length is 82 pitches. Estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30% less than the corrected (allowable) power.
A full journal bearing has a shaft diameter of 3.00 in with a unilateral tolerance of 0.0004 in. The l/d ratio is unity. The bushing has a bore diameter of 3.00 in with a unilateral tolerance of 0.0012 in. The SAE 40 oil supply in an axial groove sump with a steady state temperature of 140∘F140^{\circ}F140∘F. The radial load is 675 lbf. Estimate the average film temperature, the minimum film thickness and the head loss rate for the minimum clearance assembly, if the journal speed is 10 rev/s.
An uncrowned straight – bevel pinion has 22 teeth, a module of 4 mm and a transmission accuracy number of 5. The pinion and the gear are made of through -hardened steel, both having core and case hardness of 180 Brinell. The pinion drives the 24 tooth bevel gear. The shaft angle is 90∘90^{\circ}90∘, the pinion speed is 1800 rev/min, the face width is 25 mm, and the normal pressure angle is 20∘20^{\circ}20∘. Both gears have an outboard mounting. Find the power rating based on AGMA pitting resistance if the life goal is 10910^9109 revolutions of the pinion at 0.999 reliability.
Shown in the Figure 8 is a gear -driven squeeze roll that mates with an idler roll. The roll is designed to exert a normal force of 35 lbf/in of roll length and a pull of 28 lbf/in on the material being produced. The roll speed is 350 rev/min and a design life of 35 kh is desired. Use an application factor of 1.2, and select a pair of angular -contact 02 --series ball bearings to be mounted at O an A. Use the same size bearings at both locations and a combined reliability of at least 0.92.