New Semester
Started
Get
50% OFF
Study Help!
--h --m --s
Claim Now
Question Answers
Textbooks
Find textbooks, questions and answers
Oops, something went wrong!
Change your search query and then try again
S
Books
FREE
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Tutors
Online Tutors
Find a Tutor
Hire a Tutor
Become a Tutor
AI Tutor
AI Study Planner
NEW
Sell Books
Search
Search
Sign In
Register
study help
engineering
machine elements in mechanical design
Theory Of Machines Kinematics And Dynamics 3rd Edition Sadhu Singh - Solutions
Find the minimum number of teeth on gear wheel to avoid undercutting when the addendum for stub teeth is 0.84 module, if(a) gear ratio is \(3: 1\), and(b) the wheel is used to engage a rack.
The circular pitch of a spur gear is defined as(a) \(\pi d / z\)(b) \(d / z\)(c) \(z / d\)(d) \(z / \pi d\).where \(d=\) pitch circle diameter and \(z=\) number of teeth
What are the causes for interference in gears?
A pair of involute spur gears having 20 and 40 teeth are in mesh, the speed of smaller wheel being \(2000 \mathrm{rpm}\). Calculate the sliding velocity between gear teeth faces(a) at the point of engagement,(b) at the pitch point, and(c) at the point of disengagement, if smaller wheel is the
The diametral pitch of a spur gear is defined as(a) \(\pi d / z\)(b) \(d / z\)(c) \(z / d\)(d) \(z / \pi d\).
How interference is gears can be minimized?
The thickness of an involute gear tooth is \(8 \mathrm{~mm}\) at a radius of \(90 \mathrm{~mm}\) and a pressure angle of \(14.5^{\circ}\). Calculate the tooth thickness and radius at a point on the involute which has a pressure angle of \(25^{\circ}\). Also calculate the tooth thickness at the base
The module of a spur gear is defined as(a) \(\pi d / z\)(b) \(d / z\)(c) \(z / d\)(d) \(z / \pi d\).
Explain path of recess and path of approach.
A \(20^{\circ}\) pinion having a module of 2.5 and 40 teeth meshes with a rack with no backlash. If the rack is pulled out \(1.25 \mathrm{~mm}\), calculate the backlash error.
Choose the correct relationship(a) \(p P=\pi\)(b) \(p / P=\pi\)(c) \(P / p=\pi\)(d) \(p P=1 / \pi\).
Compare involute and cycloidel tooth profiles.
A \(20^{\circ}\) pressure angle pinion with a module of 2 and 18 teeth drives a gear of 54 teeth. If the centre distance at which the gear operates is \(75 \mathrm{~mm}\), calculate the operating pressure angle, and backlash produced.
Module of a spur gear teeth is(a) \(1 / P\)(b) \(1 / p\)(c) \(P / \pi\)(d) \(p / \pi\).
Define contact ratio.
The centre distance between the two shafts connected by two left-handed helical gears is \(0.4 \mathrm{~m}\). The shaft angle is \(60^{\circ}\) and normal module is \(6 \mathrm{~mm}\). The gear ratio is 2 and larger gear is having 70 teeth. Find the helix angles of the two gears.
The range of pressure angle for spur gears is(a) 10 to \(14^{\circ}\)(b) 14.5 to \(20^{\circ}\)(c) 21 to \(25^{\circ}\)(d) 26 to \(30^{\circ}\).
How many are the minimum number of teeth on the pinion for a rack of 20° pressure angle?
Two left-handed helical gears connect two shafts \(60^{\circ}\) apart. The normal module is \(6 \mathrm{~mm}\). The larger gear has 60 teeth and the velocity ratio is 0.5 . The centre distance is \(0.3 \mathrm{~m}\). Find the helix angles of the two gears.
Choose the correct statement for involute profile in regard to pressure angle(a) minimum value when contact begins(b) maximum value when contact ends(c) remains same for all points of contact(d) interference is zero.
What is the law for velocity of sliding between a gear pair?
Two right-handed helical gears connect two shafts \(70^{\circ}\) apart. The larger gear has 50 teeth and the smaller 20. The centre distance is \(167 \mathrm{~mm}\). Determine the helix angle of the gears. The normal module is \(4 \mathrm{~mm}\).
In case of cycloidal tooth profile gears(a) the pressure angle is always constant through the contact(b) the path of contact is a straight line(c) the variation in centre distance affects the angular speed ratio(d) interference is more.
What is the effect of centre distance variation on speed ratio in gears?
A pair of bevel gears is mounted on two intersecting shafts at an angle of \(72^{\circ}\). The velocity ratio of the gears is 2 . Calculate the pitch angles.
The involute function in terms of pressure angle \(\phi\) is(a) \(\tan \phi-\phi\)(b) \(\tan ^{-1} \phi\)(c) \(\tan ^{-1} \phi-1\)(d) \(\phi-\tan \phi\).
What is a rack?
A \(6 \mathrm{~mm}\) module, straight bevel pinion of 17 teeth drives a gear of 25 teeth. The shaft angle is \(90^{\circ}\). Calculate the virtual number of teeth on the pinion and gear.
The minimum number of teeth for involute rack of \(20^{\circ}\) pressure angle is(a) 17(b) 24(c) 32(d) 34.
What are the advantages of standard gears?
Two spiral gears A and B have 45 and 15 teeth at spiral angles of \(20^{\circ}\) and \(50^{\circ}\) respectively. Both gears are of same hand. A is \(150 \mathrm{~mm}\) in diameter. Find the centre distance between the shafts and the angle between the shafts. If the teeth are of \(20^{\circ}\)
Path of contact in case of cyclodial tooth profile gears is a(a) Straight line(b) circle(c) complex curve(d) parabola.
What are the advantages of gear drive?
Two spiral gears of diameter ratio 1.5 are used on a machine tool. The angle between the shafts is \(76^{\circ}\) and approximate centre distance is \(115 \mathrm{~mm}\). Speed ratio is 1.5 and normal diametral pitch is \(10 \mathrm{~mm}\). Calculate the number of teeth on each gear and spiral
What is backlash in gears?
A pair of spiral gears is required to connect two shafts, the angle between the non-intersecting axes is \(90^{\circ}\). The speed ratio is 3 and pitch circle diameters of the gears are equal. If approximate centre distance is \(250 \mathrm{~mm}\), estimate the helix angle of gears and number of
What are the characteristics of involute action?
A drive on a machine tool is to be made by two spiral gears of the same hand and normal pitch of \(12.5 \mathrm{~mm}\). The gears are of equal diameters and centre distance between the shafts is approximately \(134 \mathrm{~mm}\). The angle between the two shafts is \(80^{\circ}\) and speed ratio
What are herringbone gears? What is their advantages?
A three-start worm has a pitch diameter of \(80 \mathrm{~mm}\) and a pitch of \(20 \mathrm{~mm}\). It rotates at \(600 \mathrm{rpm}\) and drives a 40 tooth worm gear. If coefficient of friction is 0.05 , find the(a) helix angle of worm,(b) speed of the gear,(c) centre distance, and(d) efficiency
Explain virtual number of teeth on helical gears.
Define axial pitch, normal module and normal pressure angle of helical gears.
What are crown and miter bevel gears?
Where do we use spiral gears?
What are worm gears? Where they are used?
Two coaxial shafts \(A\) and \(B\) are geared together through an intermediate parallel shaft \(C\). The wheels connecting \(A\) and \(C\) having a module of \(2 \mathrm{~mm}\) and those connecting \(C\) and \(B\) have a module of \(3.5 \mathrm{~mm}\). Speed of \(B\) is less than \(1 / 10\) th that
A reverted gear train is one in which the(a) direction of rotation of first and last gear is the same(b) direction of rotation of first and last gear is opposite(c) first and last gear are on the same shaft(d) first and last gear are essentially on separate but parallel shafts.
What is a gear train?
Two spur gears \(A\) and \(B\) of an epicyclic gear train shown in Fig. 15.44 have 25 and 35 teeth respectively. The arm \(C\) rotates at \(105 \mathrm{rpm}\) in clockwise direction. Find speed of gear \(B\) on its own axis, when gear \(A\) is fixed. If gear \(A\) rotates at \(200 \mathrm{rpm}\) in
To connect hour hand to minute hand in a clock mechanism, we use(a) epicyclic gear train(b) reverted gear train(c) simple gear train(d) all of the above.
What is the difference between a simple and compound gear train?
In an epicyclic gear train shown in Fig. 15.45 the number of teeth on gears \(A, B\) and \(C\) are 50, 25 and 55 respectively. The arm rotates at \(450 \mathrm{rpm}\) clockwise. Calculate(a) the speed of gear \(C\) when \(A\) is fixed, and(b) speed of gear \(A\) when \(C\) is fixed. A B Arm C
What are the types of gear trains?
In a gear train, where the axes of gears have motions, is called(a) simple gear train(b) compound gear train(c) epicyclic gear train(d) reverted gear train.
What is a reverted gear train? Where it is used.
In an epicyclic gear train shown in Fig 15.46 the \(\operatorname{arm} A\) is fixed to shaft \(S\). The wheel \(B\) having 90 teeth rotates freely on shaft \(S\) and wheel \(F\) with 135 teeth is separately driven. If arm \(A\) runs at \(240 \mathrm{rpm}\) clockwise and wheel \(F\) at \(120
In a simple gear train, if number of idlers is odd, then the direction of rotation of first and last gear shall be(a) opposite(b) same(c) depends on type of gears(d) depends on number of teeth on gears.
What are epicyclic gears? What are their uses?
In an epicyclic gear train shown in Fig. 15.47 the internal wheels \(A\) and \(F\) and compound wheel \(C-D\) rotate about the axis \(O\). The wheel \(B\) and \(E\) rotate on pins fixed to arm \(L\). The wheels have the same module and number of teeth are: \(Z_{b}=Z_{e}=20, Z_{c}=30\), and
If the axes of first and last gear of a compound gear train are co-axial, the gear train is called(a) simple(b) compound(c) reverted(d) epicyclic
Write the formula for speed ratio of a simple gear train.
A compound epicyclic gear train is shown in Fig.15.48 The gears \(A, D\) and \(E\) are free to rotate on axis \(P\). The compound gear \(B\) and \(C\) rotate together on axis \(Q\) at the end of arm \(F\). All the gears have equal module, \(Z_{a}=20, Z_{b}=50, Z_{c}=25\). Gears \(D\) and \(E\) are
The train value of a simple gear train having \(\mathrm{m}\) gears is(a) \(\frac{N_{1}}{N_{m}}\)(b) \(\frac{N_{m}}{N_{1}}\)(c) \(N_{1} \times N_{m}\)(d) \(N_{m}-N_{1}\)where \(N=\mathrm{rpm}\)
What is the law for the speed ratio of a compound gear train?
In an epicyclic gear of the sun and planet type shown in Fig. 15 , the annular gear \(A\) has 56 teeth and meshes internally. Here planet wheels of equal size mesh with annular gear \(A\) and sun wheel \(S\). When gear \(A\) is stationary, the spider \(C\) which carries the planet wheels is to make
In a compound gear train having \(\mathrm{m}\) gears, the ratio of speed of last gear to first gear is(a) \(\frac{\text { product of teeth of driving gears }(\mathrm{X})}{\text { product of teeth of driven gears }(Y)}\)(b) \(y / x\)(c) \(X-Y\)(d) \(\left(\frac{x}{y}\right)^{2}\)
What is the fixing torque of a gear in an epicyclic gear train?
The annulus \(A\) in the gear train shown in Fig. 15.50 rotates at \(300 \mathrm{rpm}\) about the axis of the fixed wheel \(S\) having 80 teeth. The three arm spider is driven at \(180 \mathrm{rpm}\). Determine the number of teeth required on the wheel \(P\). Spider. S Fig.15.50 Sun and planet type
What is a compound epicyclic gear train?
Fig. 15.51 shows an epicyclic gear train arrangement wheel \(E\) is fixed and gears \(C\) and \(D\) are integrally cost and mounted on one pin. If the arm \(A\) makes one revolution per second counter clockwise, determine the speed and the direction of rotation of wheels \(B\) and \(F\). D, 15 B,
What is a seen and planet gear?
In a reverted epicclic gear train, as shown in a Fig. 15.52 the arm \(A\) carries two gears \(B\) and \(C\) and compound gear \(D, E\). The gear \(B\) meshes with gear \(D\). The number of teeth on gears \(B, C\) and \(D\) are 75, 30 and 90 respectively. Find the speed and direction of gear \(C\)
Differentiate between a pole and a relative pole of a coupler link of four-bar mechanism.
Transmission angle is the angle between the(a) Coupler and driven link(b) Coupler and driving link(c) Driving link and fixed link(d) Driven link and fixed link.
Determine the mobility of the linkages shown in Fig.16.36 (a) to (c). (a) H E (c) D C B (b)
Define kinematic synthesis.
Determine the degrees of freedom of the linkage shown in Fig. 16.37 (a) (a)
Transmission angle is maximum when input angle is(a) \(0^{\circ}\)(b) \(90^{\circ}\)(c) \(180^{\circ}\)(d) \(45^{\circ}\)
What do you understand by movability of a mechanism?
Transmission angle is minimum when input angle is(a) \(0^{\circ}\)(b) \(45^{\circ}\)(c) \(90^{\circ}\)(d) \(180^{\circ}\)
Fig. 16.38 shows a plane mechanism with link lengths given in some unit. If slider \(A\) is the driver, will link \(C G\) revolve or oscillate? Justify your answer. 4.5 B E 4 5 3 2 D 3 G 3 F
State Grashof’s law.
The minimum number of links in a kinematic chain are(a) 3(b) 4(c) 5(d) 6
Synthesize a four-bar mechanism so that \(\theta_{12}=45^{\circ}\) and \(\phi_{12}=55^{\circ}\). Both input and output cranks should move in the ccw direction.
When do we get double crank and crank-rocker mechanism?
Relative pole of a moving link is its centre of rotation relative to a(a) Fixed link(b) moving link(c) any link
Synthesis a four-bar linkage that will, in one of its positions, satisfy the following values for the angular velocities and accelerations:\[ y=x^{1.2} \text { for } 1 \leq x \leq 5 \]using Chebyshev's spacing for three precision points. Take \(\phi_{\mathrm{o}}=30^{\circ},
What is a class-II double-rocker mechanism?
Pole of a moving link is its centre of rotation relative to a(a) Fixed link(b) moving link(c) any link
Synthesize a four-bar mechanism to generate a function \(y=\sin x\) for \(0^{\circ} \leq x \leq 90^{\circ}\). The range of the output crank may be chosen as \(60^{\circ}\) while that of input crank be \(120^{\circ}\). Assume three precision points which are to be from Chebyshev's spacing. Length of
What are the properties of pole points?
In function generation, a mechanism is designed to correlate the motion of:(a) Input and output links(b) Input link and coupler(c) Output link and coupler(d) Coupler to fixed link.
Synthesize a four-bar linkage to generate \(y=\log _{10} x\) in the interval \(1 \leq x \leq 10\). The input crank length is to be \(5 \mathrm{~cm}\). The input crank is to rotate from \(45^{\circ}\) to \(105^{\circ}\) while the output crank moves from \(135^{\circ}\) to \(225^{\circ}\). Use three
What do you mean by function generation?
Freudenstein's equation for a four-bar linkage is:(a) \(k_{1} \cos \phi+k_{2} \cos \theta+k_{3}-\cos (\theta-\phi)=0\)(b) \(k_{1} \cos \phi+k_{2} \cos \theta+k_{3}+\cos (\theta-\phi)=0\)(c) \(k_{1} \cos \phi+k_{2} \cos \theta+k_{3}-\cos (\theta-\phi)=1\)(d) \(k_{1} \cos \phi+k_{2} \cos
A four-bar mechanism is required such that the input and output angles are coordinated as given in the following table:Synthesize the four-bar mechanism. Input crank angle 30 50 80 Output crank angle 0 30 60
What are Chebyshev’s spacing for precision points?
Synthesize a four-bar mechanism using Freudenstein's equation to generate the function \(y=x^{1.5}\) for the interval \(1 \leq x \leq 4\). The input crank is to start from \(\theta_{2}=30^{\circ}\) and is to have a range of \(90^{\circ}\). The output crank angle is to vary from \(90^{\circ}\). Take
Write the Freudenstein’s equation of three precision points of a four-bar chain.
Design a four-bar mechanism such that\[ \theta_{12}=120^{\circ}, \theta_{13}=170^{\circ} \text { and } \phi_{12}=70^{\circ}, \phi_{13}=100^{\circ} \]Input moves anti-clockwise and output also moves anti-clockwise.
Showing 700 - 800
of 1879
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Last
Step by Step Answers
Get 50% OFF
Claim Now
