An eight-cylinder diesel engine has a front main bearing

A full journal bearing has a journal diameter of 25 mm, with a unilateral tolerance of 20.03 mm. The bushing bore has a diameter of 25.03 mm and a unilateral tolerance of 0.04 mm. The lyd ratio is 1y2. The load is 1.2 kN and the journal runs at 1100 rev/min. If the average viscosity is 55 mPa ? s, find the minimum film thickness, the power loss, and the side flow for the minimum clearance assembly.

A full journal bearing has a journal diameter of 32 mm, with a unilateral tolerance of 20.012 mm. The bushing bore has a diameter of 32.05 mm and a unilateral tolerance of 0.032 mm. The bearing is 64 mm long. The journal load is 1.75 kN and it runs at a speed of 900 rev/min. Using an average viscosity of 55 mPa ? s find the minimum film thickness, the maximum film pressure, and the total oil-flow rate for the minimum clearance assembly.

A journal bearing has a journal diameter of 3.000 in, with a unilateral tolerance of 20.001 in. The bushing bore has a diameter of 3.005 in and a unilateral tolerance of 0.004 in. The bushing is 1.5 in long. The journal speed is 600 rev/min and the load is 800 lbf. For both SAE 10 and SAE 40, lubricants, find the minimum film thickness and the maximum film pressure for an operating temperature of 150F for the minimum clearance assembly

A journal bearing has a journal diameter of 3.250 in with a unilateral tolerance of 20.003 in. The bushing bore has a diameter of 3.256 in and a unilateral tolerance of 0.004 in. The bushing is 3 in long and supports a 800-lbf load. The journal speed is 1000 rev/min. Find the minimum oil film thickness and the maximum film pressure for both SAE 20 and SAE 20W-40 lubricants, for the tightest assembly if the operating film temperature is 150F.

A full journal bearing has a journal with a diameter of 2.000 in and a unilateral tolerance of 20.0012 in. The bushing has a bore with a diameter of 2.0024 and a unilateral tolerance of 0.002 in. The bushing is 1 in long and supports a load of 600 lbf at a speed of 800 rev/ min. Find the minimum film thickness, the power loss, and the total lubricant flow if the average film temperature is 130F and SAE 20 lubricant is used. The tightest assembly is to be analyzed.

A full journal bearing has a shaft journal diameter of 25 mm with a unilateral tolerance of 20.01 mm. The bushing bore has a diameter of 25.04 mm with a unilateral tolerance of 0.03 mm. The lyd ratio is unity. The bushing load is 1.25 kN, and the journal rotates at 1200 rev/min. Analyze the minimum clearance assembly if the average viscosity is 50 mPa ? s to find the minimum oil film thickness, the power loss, and the percentage of side flow.

A full journal bearing has a shaft journal with a diameter of 1.25 in and a unilateral tolerance of 20.0006 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 in length. 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, and the total oil flow if the average viscosity is 8.5 mreyn

A journal bearing has a shaft diameter of 75.00 mm with a unilateral tolerance of 20.02 mm. The bushing bore has a diameter of 75.10 mm with a unilateral tolerance of 0.06 mm. The bushing is 36 mm long and supports a load of 2 kN. The journal speed is 720 rev/min. For the minimum clearance assembly find the minimum film thickness, the heat loss rate, and the maximum lubricant pressure for SAE 20 and SAE 40 lubricants operating at an average film temperature of 60C.

A full journal bearing is 28 mm long. The shaft journal has a diameter of 56 mm with a unilateral tolerance of 20.012 mm. The bushing bore has a diameter of 56.05 mm with a unilateral tolerance of 0.012 mm. The load is 2.4 kN and the journal speed is 900 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 65C and SAE 40 lubricating oil is used.

A 11 4- 3 11 4-in sleeve bearing supports a load of 700 lbf and has a journal speed of 3600 rev/ min. An SAE 10 oil is used having an average temperature of 160F. Using Fig. 1216, estimate the radial clearance for minimum coefficient of friction f and for maximum load-carrying capacity W. The difference between these two clearances is called the clearance range. Is the resulting range attainable in manufacture?

A full journal bearing has a shaft diameter of 3.000 in with a unilateral tolerance of 20.0004 in. The lyd ratio is unity. The bushing has a bore diameter of 3.003 in with a unilateral tolerance of 0.0012 in. The SAE 40 oil supply is in an axial-groove sump with a steady-state temperature of 140F. The radial load is 675 lbf. Estimate the average film temperature, the minimum film thickness, the heat loss rate, and the lubricant side-flow rate for the minimum clearance assembly, if the journal speed is 10 rev/s

A 21 2 3 21 2-in sleeve bearing uses grade 20 lubricant. The axial-groove sump has a steady-state temperature of 110F. The shaft journal has a diameter of 2.500 in with a unilateral tolerance bud98209_ch12_609-664.indd Page 661 10/30/13 9:30 PM f-494 /204/MH01996/bud98209_disk1of1/0073398209/bud98209_pagefiles 662 Mechanical Engineering Design of 20.001 in. The bushing bore has a diameter of 2.504 in with a unilateral tolerance of 0.001 in. The journal speed is 1120 rev/min and the radial load is 1200 lbf. Estimate (a) The magnitude and location of the minimum oil-film thickness. (b) The eccentricity. (c) The coefficient of friction. (d) The power loss rate. (e) Both the total and side oil-flow rates. ( f ) The maximum oil-film pressure and its angular location. (g) The terminating position of the oil film. (h) The average temperature of the side flow. (i) The oil temperature at the terminating position of the oil film.

A set of sleeve bearings has a specification of shaft journal diameter of 1.250 in with a unilateral tolerance of 20.001 in. The bushing bore has a diameter of 1.252 in with a unilateral tolerance of 0.003 in. The bushing is 11 4 in long. The radial load is 250 lbf and the shaft rotational speed is 1750 rev/min. The lubricant is SAE 10 oil and the axial-groove sump temperature at steady state Ts is 120F. For the cmin, cmedian, and cmax assemblies analyze the bearings and observe the changes in S, P, f, Q, Qs, DT, Tmax, Tf , and h0.

An interpolation equation was given by Raimondi and Boyd, and it is displayed as Eq. (1216). This equation is a good candidate for a computer program. Write such a program for interactive use. Once ready for service it can save time and reduce errors. Another version of this program can be used with a subprogram that contains curve fits to Raimondi and Boyd charts for computer use.

A natural-circulation pillow-block bearing with lyd 5 1 has a journal diameter D of 2.500 in with a unilateral tolerance of 20.001 in. The bushing bore diameter B is 2.504 in with a unilateral tolerance of 0.004 in. The shaft runs at an angular speed of 1120 rev/min; the bearing uses SAE grade 20 oil and carries a steady load of 300 lbf in shaft-stirred air at 70F with a 5 1. The lateral area of the pillow-block housing is 60 in2 . Perform a design assessment using minimum radial clearance for a load of 600 lbf and 300 lbf. Use Trumplers criteria.

An eight-cylinder diesel engine has a front main bearing with a journal diameter of 3.500 in and a unilateral tolerance of 20.003 in. The bushing bore diameter is 3.505 in with a unilateral tolerance of 10.005 in. The bushing length is 2 in. The pressure-fed bearing has a central annular groove 0.250 in wide. The SAE 30 oil comes from a sump at 120F using a supply pressure of 50 psig. The sumps heat-dissipation capacity is 5000 Btu/h per bearing. For a minimum radial clearance, a speed of 2000 rev/min, and a radial load of 4600 lbf, find the average film temperature and apply Trumplers criteria in your design assessment.

A pressure-fed bearing has a journal diameter of 50.00 mm with a unilateral tolerance of 20.05 mm. The bushing bore diameter is 50.084 mm with a unilateral tolerance of 0.10 mm. The length of the bushing is 55 mm. Its central annular groove is 5 mm wide and is fed by SAE 30 oil is 55C at 200 kPa supply gauge pressure. The journal speed is 2880 rev/min carrying a load of 10 kN. The sump can dissipate 300 watts per bearing if necessary. For minimum radial clearances, perform a design assessment using Trumplers criteria.

Design a central annular-groove pressure-fed bearing with an l9yd ratio of 0.5, using SAE grade 20 oil, the lubricant supplied at 30 psig. The exterior oil cooler can maintain the sump temperature at 120F for heat dissipation rates up to 1500 Btu/h. The load to be carried is 900 lbf at 3000 rev/min. The groove width is 1 4 in. Use nominal journal diameter d as one design variable and c as the other. Use Trumplers criteria for your adequacy assessment.

Repeat design problem Prob. 1218 using the nominal bushing bore B as one decision variable and the radial clearance c as the other. Again, Trumplers criteria to be used.

Table 121 gives the Seireg and Dandage curve fit approximation for the absolute viscosity in customary U.S. engineering units. Show that in SI units of mPa ? s and a temperature of C degrees Celsius, the viscosity can be expressed as m 5 6.89(106 )m0 exp[(by(1.8C 1 127))] where m0 and b are from Table 121. If the viscosity m9 0 is expressed in m reyn, then m 5 6.89m 0 exp[(by(1.8C 1 127))] What is the viscosity of a grade 50 oil at 70C? Compare your results with Fig. 1213.

For Prob. 1218 a satisfactory design is d 5 2.00010 20.001 in b 5 2.00510.003 20 in Double the size of the bearing dimensions and quadruple the load to 3600 lbf. (a) Analyze the scaled-up bearing for median assembly. (b) Compare the results of a similar analysis for the 2-in bearing, median assembly.

An Oiles SP 500 alloy brass bushing is 0.75 in long with a 0.75-in dia bore and operates in a clean environment at 70F. The allowable wear without loss of function is 0.004 in. The radial load is 400 lbf. The shaft speed is 250 rev/min. Estimate the number of revolutions for radial wear to be 0.004 in.

Choose an Oiles SP 500 alloy brass bushing to give a maximum wear of 0.002 in for 1000 h of use with a 200 rev/min journal and 100 lbf radial load. Use h# CR 5 2.7 Btu/(h ? ft2 ? F), Tmax 5 300F, fs 5 0.03, and a design factor nd 5 2. The bearing is to operate in a clean environment at 70F. Table 1213 lists the bushing sizes available from the manufacturer.

A full journal bearing has a journal diameter of 25 mm, with a unilateral tolerance of 20.03 mm. The bushing bore has a diameter of 25.03 mm and a unilateral tolerance of 0.04 mm. The l/d ratio is 1/2. The load is 1.2 kN and the journal runs at 1100 rev/min. If the average viscosity is \(55 mPa \cdot s\), find the minimum film thickness, the power loss, and the side flow for the minimum clearance assembly.

A full journal bearing has a journal diameter of 32 mm, with a unilateral tolerance of 20.012 mm. The bushing bore has a diameter of 32.05 mm and a unilateral tolerance of 0.032 mm. The bearing is 64 mm long. The journal load is 1.75 kN and it runs at a speed of 900 rev/min. Using an average viscosity of \(55 mPa \cdot s\) find the minimum film thickness, the maximum film pressure, and the total oil-flow rate for the minimum clearance assembly.

A journal bearing has a journal diameter of 3.000 in, with a unilateral tolerance of 20.001 in. The bushing bore has a diameter of 3.005 in and a unilateral tolerance of 0.004 in. The bushing is 1.5 in long. The journal speed is 600 rev/min and the load is 800 lbf. For both SAE 10 and SAE 40, lubricants, find the minimum film thickness and the maximum film pressure for an operating temperature of \(150^{\circ} \mathrm{F}\) for the minimum clearance assembly.

A journal bearing has a journal diameter of 3.250 in with a unilateral tolerance of 20.003 in. The bushing bore has a diameter of 3.256 in and a unilateral tolerance of 0.004 in. The bushing is 3 in long and supports a 800-lbf load. The journal speed is 1000 rev/min. Find the minimum oil film thickness and the maximum film pressure for both SAE 20 and SAE 20W-40 lubricants, for the tightest assembly if the operating film temperature is \(150^{\circ} \mathrm{F}\).

A full journal bearing has a journal with a diameter of 2.000 in and a unilateral tolerance of 20.0012 in. The bushing has a bore with a diameter of 2.0024 and a unilateral tolerance of 0.002 in. The bushing is 1 in long and supports a load of 600 lbf at a speed of 800 rev/ min. Find the minimum film thickness, the power loss, and the total lubricant flow if the average film temperature is \(130^{\circ} \mathrm{F}\) and SAE 20 lubricant is used. The tightest assembly is to be analyzed.

A full journal bearing has a shaft journal diameter of 25 mm with a unilateral tolerance of 20.01 mm. The bushing bore has a diameter of 25.04 mm with a unilateral tolerance of 0.03 mm. The l/d ratio is unity. The bushing load is 1.25 kN, and the journal rotates at 1200 rev/min. Analyze the minimum clearance assembly if the average viscosity is \(50 mPa \cdot s\) to find the minimum oil film thickness, the power loss, and the percentage of side flow.

A full journal bearing has a shaft journal with a diameter of 1.25 in and a unilateral tolerance of 20.0006 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 in length. 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, and the total oil flow if the average viscosity is \(8.5 \mu\) reyn.

A journal bearing has a shaft diameter of 75.00 mm with a unilateral tolerance of 20.02 mm. The bushing bore has a diameter of 75.10 mm with a unilateral tolerance of 0.06 mm. The bushing is 36 mm long and supports a load of 2 kN. The journal speed is 720 rev/min. For the minimum clearance assembly find the minimum film thickness, the heat loss rate, and the maximum lubricant pressure for SAE 20 and SAE 40 lubricants operating at an average film temperature of \(60^{\circ} \mathrm{C}\).

A full journal bearing is 28 mm long. The shaft journal has a diameter of 56 mm with a unilateral tolerance of 20.012 mm. The bushing bore has a diameter of 56.05 mm with a unilateral tolerance of 0.012 mm. The load is 2.4 kN and the journal speed is 900 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 \(65^{\circ} \mathrm{C}\) and SAE 40 lubricating oil is used.

A \(1 \frac{1}{4}-\times 1 \frac{1}{4}\)-in sleeve bearing supports a load of 700 lbf and has a journal speed of 3600 rev/min. An SAE 10 oil is used having an average temperature of \(160^{\circ} \mathrm{F}\). Using Fig. 12-16, estimate the radial clearance for minimum coefficient of friction f and for maximum load-carrying capacity W. The difference between these two clearances is called the clearance range. Is the resulting range attainable in manufacture?

A full journal bearing has a shaft diameter of 3.000 in with a unilateral tolerance of -0.0004 in. The l/d ratio is unity. The bushing has a bore diameter of 3.003 in with a unilateral tolerance of 0.0012 in. The SAE 40 oil supply is in an axial-groove sump with a steady-state temperature of \(140^{\circ} \mathrm{F}\). The radial load is 675 lbf. Estimate the average film temperature, the minimum film thickness, the heat loss rate, and the lubricant side-flow rate for the minimum clearance assembly, if the journal speed is 10 rev/s.

A \(2 \frac{1}{2} \times 2 \frac{1}{2}\)-in sleeve bearing uses grade 20 lubricant. The axial-groove sump has a steady-state temperature of \(110^{\circ} \mathrm{F}\). The shaft journal has a diameter of 2.500 in with a unilateral tolerance of 20.001 in. The bushing bore has a diameter of 2.504 in with a unilateral tolerance of 0.001 in. The journal speed is 1120 rev/min and the radial load is 1200 lbf. Estimate (a) The magnitude and location of the minimum oil-film thickness. (b) The eccentricity. (c) The coefficient of friction. (d) The power loss rate. (e) Both the total and side oil-flow rates. ( f ) The maximum oil-film pressure and its angular location. (g) The terminating position of the oil film. (h) The average temperature of the side flow. (i) The oil temperature at the terminating position of the oil film.

A set of sleeve bearings has a specification of shaft journal diameter of 1.250 in with a unilateral tolerance of -0.001 in. The bushing bore has a diameter of 1.252 in with a unilateral tolerance of 0.003 in. The bushing is \(1 \frac{1}{4}\) in long. The radial load is 250 lbf and the shaft rotational speed is 1750 rev/min. The lubricant is SAE 10 oil and the axial-groove sump temperature at steady state \(T_s\) is \(120^{\circ} \mathrm{F}\). For the \(c_{\min }, c_{\text {median }}\), and \(c_{\max }\) assemblies analyze the bearings and observe the changes in S, \(\epsilon\), f, Q, \(Q_s\), \(\Delta T, T_{\max }, \bar{T}_f\), and \(h_0\).

An interpolation equation was given by Raimondi and Boyd, and it is displayed as Eq. (12–16). This equation is a good candidate for a computer program. Write such a program for interactive use. Once ready for service it can save time and reduce errors. Another version of this program can be used with a subprogram that contains curve fits to Raimondi and Boyd charts for computer use.

A natural-circulation pillow-block bearing with l/d=1 has a journal diameter D of 2.500 in with a unilateral tolerance of -0.001 in. The bushing bore diameter B is 2.504 in with a unilateral tolerance of 0.004 min. The shaft runs at an angular speed of 1120 rev/ min; the bearing uses SAE grade 20 oil and carries a steady load of 300 lbf in shaft-stirred air at \(70^{\circ} \mathrm{F}\) with \(\alpha = 1\). The lateral area of the pillow-block housing is \(60 \mathrm{in}^2\). Perform a design assessment using minimum radial clearance for a load of 600 lbf and 300 lbf. Use Trumpler's criteria.

An eight-cylinder diesel engine has a front main bearing with a journal diameter of 3.500 in and a unilateral tolerance of -0.003 in. The bushing bore diameter is 3.505 in with a unilateral tolerance of +0.005 in. The bushing length is 2 in. The pressure-fed bearing has a central annular groove 0.250 in wide. The SAE 30 oil comes from a sump at \(120^{\circ} \mathrm{F}\) using a supply pressure of 50 psig. The sump's heat-dissipation capacity is 5000 Btu/h per bearing. For a minimum radial clearance, a speed of 2000 rev/min, and a radial load of 4600 lbf, find the average film temperature and apply Trumpler's criteria in your design assessment.

A pressure-fed bearing has a journal diameter of 50.00 mm with a unilateral tolerance of 20.05 mm. The bushing bore diameter is 50.084 mm with a unilateral tolerance of 0.10 mm. The length of the bushing is 55 mm. Its central annular groove is 5 mm wide and is fed by SAE 30 oil is \(55^{\circ} \mathrm{C}\) at 200 kPa supply gauge pressure. The journal speed is 2880 rev/min carrying a load of 10 kN. The sump can dissipate 300 watts per bearing if necessary. For minimum radial clearances, perform a design assessment using Trumpler’s criteria.

Design a central annular-groove pressure-fed bearing with an \(l^{\prime} / d\) ratio of 0.5, using SAE grade 20 oil, the lubricant supplied at 30 psig. The exterior oil cooler can maintain the sump temperature at \(120^{\circ} \mathrm{F}\) for heat dissipation rates up to 1500 Btu/h. The load to be carried is 900 lbf at 3000 rev/min. The groove width is \(\frac{1}{4}\) in. Use nominal journal diameter d as one design variable and c as the other. Use Trumpler's criteria for your adequacy assessment.

Repeat design problem Prob. 12–18 using the nominal bushing bore B as one decision variable and the radial clearance c as the other. Again, Trumpler’s criteria to be used.

Table 12-1 gives the Seireg and Dandage curve fit approximation for the absolute viscosity in customary U.S. engineering units. Show that in SI units of \(\mathrm{mPa} \cdot \mathrm{s}\) and a temperature of C degrees Celsius, the viscosity can be expressed as \(\mu=6.89\left(10^6\right) \mu_0 \exp [(b /(1.8 C+127))]\) where \(\mu_0\) and b are from Table 12-1. If the viscosity \(\mu_0^{\prime}\) is expressed in \(\mu\) reyn, then \(\mu=6.89 \mu_0^{\prime} \exp [(b /(1.8 C+127))]\) What is the viscosity of a grade 50 oil at \(70^{\circ} \mathrm{C}\) ? Compare your results with Fig. 12-13.

For Prob. 12-18 a satisfactory design is \(d=2.000_{-0.001}^{+0} \text { in } \quad b=2.005_{-0}^{+0.003} \text { in }\) Double the size of the bearing dimensions and quadruple the load to 3600 lbf. (a) Analyze the scaled-up bearing for median assembly. (b) Compare the results of a similar analysis for the 2-in bearing, median assembly.

An Oiles SP 500 alloy brass bushing is 0.75 in long with a 0.75-in dia bore and operates in a clean environment at \(70^{\circ} \mathrm{F}\). The allowable wear without loss of function is 0.004 in. The radial load is 400 lbf. The shaft speed is 250 rev/min. Estimate the number of revolutions for radial wear to be 0.004 in.

Choose an Oiles SP 500 alloy brass bushing to give a maximum wear of 0.002 in for 1000 h of use with a 200 rev/min journal and 100 lbf radial load. Use \(\hbar_{\mathrm{CR}}=2.7 \mathrm{Btu} /\left(\mathrm{h} \cdot \mathrm{ft}^2 \cdot{ }^{\circ} \mathrm{F}\right)\), \(T_{\max }=300^{\circ} \mathrm{F}, f_s=0.03\), and a design factor \(n_d=2\). The bearing is to operate in a clean environment at \(70^{\circ} \mathrm{F}\). Table 12-13 lists the bushing sizes available from the manufacturer.