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Question 44265

posted 10 months ago

11-1 Timken rates its bearings for 3000 hours at 500 rev/min. Determine the catalog rating for a ball bearing running for 10,000 hours at 1800 rev/min with a load of 2.75 kN with a 90% reliability.

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Question 44267

posted 10 months ago

11-34 The figure shown is a geared counter shaft with an overhanging pinion at C. Select an angular contact bearing from Table 11-2 for mounting at O and an 02-series cylindrical roller bearing from Table11-3 for mounting at B. The force on gear A is FA = 600 Ibf, and the shaft is to run at a speed of 420rev/min. Solution of the statics problem gives force of bearings against the shaft at O as RO = -387j +467k Ibf, and at B as RB = 316j – 1615k Ibf. Specify the bearings required, using an application factor of1.2, a desired life of 40,000 hours, and a combined reliability goal of 0.95, assuming distribution data from manufacturer 2 in Table 11-6.

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Question 44266

posted 10 months ago

11-26 An 02-series single-row deep-groove ball bearing is to be selected from table 11-2 for the following application conditions (I'll write them out there is a table in the book). Radial Load = 8 kN,Axial Load = 3 kN, Design Live = 108 rev, Ring rotating = Outer, Desired Reliability = 90%. Specify the smallest bore size from table 11-2 that can satisfy these conditions.

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Question 44977

posted 10 months ago

A full journal bearing has a journal diameter of 34 mm, with a unilateral tolerance of -0.012 mm. The bushing bore has a diameter of34.05 mm and a unilateral tolerance of 0.032 mm. The bearing is 68 mm long. The journal load is 1 kN, and the journal runs at403.7907 rev/min. Using an average viscosity of 55.6 mPa-s, find the minimum film thickness, the maximum film pressure, and the total oil-flow rate for the minimum clearance assembly.
The minimum film thickness ismm.
The maximum film pressure is___Mpa.
The total oil-flow rate for the minimum clearance assembly is___mm3/s.

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Question 44978

posted 10 months ago

A full journal bearing is 29 mm long. The shaft journal has a diameter of 58 mm with a unilateral tolerance of-0.012 mm. The bushing bore has a diameter of 58.05 mm with a unilateral tolerance of 0.012 mm. The load is 2 kN, and the journal speed is 658.1786 rev/min.For the minimum clearance assembly, find the minimum oil-film thickness, the power loss, and the side flow if the operating temperature is 65°C and SAE 40 lubricating oil is used.
The power loss is___W.
The minimum oil-film thickness is___mm.
The side flow is____mm3/s.

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Question 45451

posted 10 months ago

In the figure shown, shaft OA, made of AISI 1030 hot-rolled steel, is welded to a fix support at 0 and subjected to loading by forces F1, F2, F, and the external moment Me as shown below. The shaft has a20 mm. Any possible deformation of the shaft will take place along the x-axis only, and diameter d axial stresses are neglected. Stresses are to be considered at support O.
The forces are F120 N, F230 N, and F350 N, and Me= 10 N.m.
1. Find the moment(s) and torque(s) that each force will produce on the shaft at O [4.5 Marks]
4. Find the factor of safety for shaft OA by using the Maximum Shear Stress theory and specify whether the structure is safe or not 3.5 Marks]
3. Find the bending and shear stresses at O [3 Marks]
2. Find the resultant moment and resultant torque at O [4 Marks

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Question 45500

posted 10 months ago

3. (20 points) Design a plain surface bearing using the full-film hydro dynamically lubricated bearing approachable to carry 1500lb from a shaft having a diameter of2.5in and rotating at 1000rpm. Start with a nominal pressure of 240psi. Identify the required minimum lubricant viscosity, and calculate the friction torque (inIb in) and the frictional power loss (hp).

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Question 45726

posted 10 months ago

A countershaft carrying two V-belt pulleys is shown in the figure has a diameter d=33 mm. Pulley A receives power from a motor through a belt with the belt tensions shown. The power is transmitted through the shaft and delivered to the belt on pulley B.Assume the belt tension on the loose side at B is 9 percent of the tension on the tight side. T1=1925 N, T2=385 N.
1- Find the tension T3=
2- Find the tension T4 =
3- Find the reaction at the support C in y direction, Cy,=___N
4- Find the reaction at the support O in y direction,oy=n
5- Find the reaction at the support C in z direction cz=___N
6- Find the reaction at the support O in z direction, 0z =____N
7- Find the total resultant moment at point A, MA____N.mm
8- Find the total resultant moment at point B, MB=---N.mm
9- Calculate the normal stress at point A, theta A____mpa
10- Calculate the normal stress at point b theta =mpa
11- Calculate the torque at point A, TA=_____N.mm
12- Calculate the torque at point B, TB=______N.mm
13- Calculate the shear stress at point A, TA=____MPa
14- Calculate the shear stress at pointВ, Тв-----MPа
15- Calculate the maximum principal stress, theta 1 =MPa
16- Calculate the minimum principal stress, o2 =___MPa
17- Calculate the maximum shear stress, Tmax____MPa
19- Calculate the angle to the maximum shear stress planes, theta =___ deg
18- Calculate the angle to the principal planes,theta p=__ deg

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Question 45725

posted 10 months ago

Explain the following items by writinga paragraph and drawing figures
a) Yield strength,
b) Ultimate tensile strength
c) Principal stresses,
d) Maximum shear stress
e) Mohr circle

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Question 45727

posted 10 months ago

a) Draw the FBD of pulley at B and pulley at A using compasses for circles
b) Use torque equilibrium, to find the tensions in the belt on pulley A assuming the shaft is running at a constant speed
c)find the magnitudes of the bearing reaction forces at O and C, assuming Draw the FBD of the shaft and the bearings act as simple supports
d) Draw shear-force, bending-moment and torque diagrams for the shaft. If needed, make one set for the horizontal plane and another set for the vertical plane.
e)Find the critical point on the shaft and, determine the bending stress and the torsional shear stress. Why is this point critical?
f)Draw the stress state for this point and show the stresses on an infinitesimal square element
g) Draw the Mohr circle on a scaled paper with rulers and compasses
h) Find the principal stresses and maximum shear stress at this point
i)Show the stress state at the principal and at maximum shear stress planes

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