Mechanical Systems Stone Crusher Analysis Report - DkIT

This report details an analysis of stone crushers, focusing on the mechanical systems and maintenance practices observed during a six-week placement at Al-Hussien. The study encompasses various aspects, including the functionality of stone crushers, different types like horizontal Pittman and single toggle crushers, and the components that drive their operation, such as jaw plates, eccentric shafts, and flywheels. The report highlights the importance of periodic maintenance in enhancing machine performance and minimizing costs. Several problems encountered during the placement are discussed, including bending of the eccentric shaft and cracking of the toggle plate, along with the solutions implemented. The analysis also covers the working principle of jaw crushers and the factors considered in selecting the appropriate crusher type. The student gained insights into the role of a mechanical engineer in maintenance and the significance of understanding crusher components to improve efficiency and productivity. This report is a valuable resource for understanding stone crusher operations and maintenance practices.

Objective:
To improve the productivity with the less time and cost that could be done with the periodic
maintenance, which increases the performance of the stone crusher machine. The analysis had
been carried out for the duration of six weeks and necessary detect has been determined.
Moreover, we could also able to know about the various types of stone crusher especially
horizontal Pittman stone crusher and the Single toggle stone crusher. Moreover, we’re able to
learn about various components of the machine that draws its function.
Learning outcomes:
At the end of placement we could able to gain knowledge regarding the following:
We come to know about the functionality of the Stone Crushers.
Different components that drive the function of the machine is studied
The work of a mechanical Engineer in the field of maintenance will be well- known at the end of
this analysis.

SNO CONTENT PG.NO
1 Introduction 3
2 Stone crushers 4
3 Jaw crusher Working Principle 5
4 Single toggle stone crusher 7
5 Horizontal Pittman stone crusher 8
6 Selection of jaw crusher with their consideration 9
7 Comparison between Single toggle and 10
Horizontal Pittman stone crusher
8 Conclusion 11
References 12

Introduction:
Several Mining sectors are mainly created with the exploration of oil. They greatly function in
the discovery of mineral as well. One of the most common and highly used machines is known
as the Stone crushers. The word crusher defines the meaning of grinding. This process could be
carried out into the larger rocks, grind them and form them into smaller pieces or gravel or rock
dust. The two larger pieces of rocks are held together and send into the process of crushing thus
reducing them into smaller pieces. They also work effectively in the minimization and effective
disposal of waste materials. These crushers operate with the certain mechanical force that tends
to break the heavy bonding of those molecules inside the rock. Stone crushers find their best
place in the field of mining in various countries.
At the present, many quarrying operations in various countries are attempted by technology that
is past its time. This process is done on a small scale by breaking the rocks with the hand tools.
Moreover, certain inconveniencies occur due to the intensive labor work with the production lag
and limitations that could largely appear. This could be effectively resolved by using several
stone crusher technologies. Stone crushers should be chosen correctly based on various factors.
The factors include either physical or chemical property of the rocks. Based on these factors the
crushers should be chosen for their efficient use in the quarry. This could be collectively termed
as the geological characteristics of the rock (Deepak, 2010). Apart from the above- mentioned
factors, several factors such as hardness, abrasive nature, and structural components are also
included for choosing the right crusher equipment. Based on the requirement of the output the
engineers have to choose the right crusher. Various techniques could provide various outputs,
which run a major role in various applications. In our paper, we are dealing with the effectively
used stone crusher based on the horizontal Pittman stone crusher and the Single toggle stone
crusher. We are going to discuss regarding the problem in industries that could occur due to the
defect in these stone crushers and how we could effectively replace or identify these defects, in
order to improve the efficiency and to minimize the consumption of energy.
The major application of the crusher falls under the category of breaking down the ore particles
in the field of mining. Stone crushers could be categorized based on their usage in the process of
recycling and the load they could carry depending on the application. Another major usage of the

stone crushers falls into the category of recycling and quarrying. In recycling, the rocks are
broken into miniature pieces so that these pieces could be reused one again very effectively.
Stone crushers:
As mentioned earlier, stone crushers could vary based on the type of the load that could be given
to these machines. Depending on the pivot mechanism of the swing jaw these stone crushers
could vary. One of the major types could be Blake crusher, which is pivoted at the top to give a
maximum and fixed quantity of feed. This is again classified as the single toggle and the double
toggle crushers. The other type of crusher that is pivoted at the bottom and that finds the
minimum usage in the industries is the dodge crushers. The swinging crushers pivoted at the
middle, finds its universal application in the field of crushers. Several crushers have its own
advantage as well as disadvantage based on the application that has been used. For instance, if
we consider the single toggle jaw crusher, this could provide a maximum throughput with less
abrasion. On the other hand, double toggle jaw could be used to break larger and abrasive rocks
but this could be limited due to its cost and size. Single toggle jaw could promote a better
crushing capability when compared to the double toggle due to the angle of the positioned jaw
(Gupta and Yan, 2008). They are also capable of handling larger aggregate due to the larger
angle of position as compared to the double toggle.
Stone crushers have an ideal property in the formation of aggregate due t the three main reasons:
 They play an effective role in crushing the stones with the minimum consumption of time
and minimum wastage left over.
 Installation cost may be high for these stone crushers but the cost when compared with
the labor work and profit due to the productivity is very high that could be negotiated.
Hence these technologies lead to the effective cost savings.
 At last, this plays an effective role by providing the desired output, which could be
controlled based on various crusher types. These impacts have a major place in the field
of construction that requires the fixed amount of rock particles for the building and
strength of concretes.
In addition to these advantages, the properties of the crushers should be known effectively to
deal with the application purpose. Several factors should be taken care while we go on with the

selection of crushers. The major factor is the cost. This should be calculated based on the profit
that could be calculated based on the initial cost and their operating cost. They have a major
impact since they should give a maximum yield more than their initial cost. The other major
factor deals with their processing ability that is based on the usage, which deals with the feeding
input and the derived output from these crushers. The comparison between the input and the
output at a predetermined scale should be noted for the decision making process. Finally, the
efficiency of the crusher could be obtained based on these following properties.
Jaw crusher Working Principle:
Several components runs the operation of the stone crusher that is composed by main frame,
eccentric shaft, flywheel, toggle plate, jaw plate, tension rod, fixed jaw, and movable jaw and so
on. The power is transmitted from the belt drive through an internal combustion engine or motor
that runs the moving jaw by an eccentric shaft, which executes a period motion far and near the
fixed jaw. The angle among the moving jaw and the toggle plate could change depending on the
number of cycles the movement occurs. The crushed particles of the rock could be gathered and
accumulated at the bottom of the crusher. This is carried out in the form of batch process not a
continuous one since the moving jaw promotes a periodic crushing and discharging of rock
particles. The components that run the jaw crusher are as follows:
Frame: The frame is composed of material made by strong steel plates that undergoes sturdy
welding process. Welding process is carried out by CO2 shield arc process. Subsequent to the
fabrication the stress could be reassured.
Chamber: The Chamber has a pointed nip angle with the profound crushing container, in order
to have a maximum capacity.
Flywheel: The inertial forces are highly maintained with the help of the flywheel, which is
implemented for the smooth running of the machine.
Swing Jaw and Main Bearing Housing: The strong and hard steel casting that performs as a
supporting sector for the crusher is the swing jaw. Main bearing housing permits the elimination
of particles from frame as an integral sub assembly and allows a change over unit in the event
bearings damage.

Eccentric Shaft: this is a counterfeit from robust and annealed chrome molybdenum steel. The
diameter of the eccentric shaft will be very big thus providing a strong duty application.
Toggle plate: This is made in such a way to protect the machine when any non-crushable
material enters into the equipment.
Bearing: The life of bearing of the equipment inside the quarry could be 8 years that could be
maximized with the fag or SKF heavy duty self-aligning double row bearings on swing jaw and
main frame bath oil for the positive lubrication.
Hydraulic Cylinder: This cylinder could provide a movement in the toggle block with the
perfect settings and it could be used for the uncomplicated regulation of the discharge.
Check plates: They are made up of manganese coated with the steel so that they could be easily
replaced.
Jaw plate: The plate made by the manganese coated with the steel could extend the life of the
machine. Replacing the plate could also be made with the wedge or lug system.
The operation starts with the jaw crusher that has two metal plates where one end is fixed and the
other one is movable. The two jaw plates are inclined at an angle with the fixed plate so both
form into a structure of V shape. The upper end of the opening will be very wide and the bottom
end has a narrow opening (Henan Hongxing Mining Machinery Company Limited, 2013). This
movable plate is referred as swing jaw. During the time of operation, the larger blocks of the
rocks are located at the top opening and with the help of the cyclic reverse motion; the force is
applied in the form of intermittent compressive that breaks the rocks into smaller particles and
these smaller particles of rocks moves through the narrow opening under the effect of gravity.
These smaller lumps of rocks are again broken into fine particles. This process could be repeated
several times until we obtain the stage of extremely fine particles of our requirements. The fixed
jaw remains stable while the movable jaw provides sufficient force to crush these rock lumps.
The aggregates should be capable of falling at the extreme end of the equipment. These
operations are necessarily carried out inside the steel frame box. The jaw crusher can be crawler
track-mounted or trailer-mounted to understand the portable component that could be relocated,
when the requirement emerges.

The main advantage of this jaw crusher is that it is extremely portable that could be stripped and
taken to the necessary places for accessing its purpose. With this extreme portability, these
crushers could be used at the underground or at the surface places. This crusher is highly used in
the industries rather than the Cone crusher and the gyratory crusher since these jaw crushers has
a highly simplified design which is highly reliable with the maximum ability and portability.
Moreover, it could be easily maintained when compared to the other crushers.
Single toggle stone crusher:
These crushers were developed at the year of 1950s. Single toggle stone crushers are very simple
and cheap. The basic operation with the rotation of the plate is carried out in an elliptical motion
that rotates with the compressive force with the rubbing movement, which will grind the larger
lumps of rock particles. This has a feeding effect in the applied force that tends to have a rapid
wear between the surfaces of the jaw plates. Due to their rubbing nature the damages could arise
that could be sufficiently noted. But in comparison with the double toggle, this particular stone
crusher has a low design installation. For the best performance in the quarry it is necessary for
the improved materials and the designs that should be periodically monitored and checked
simultaneously. By the year of 2017, there is a survey saying that the sales of the single toggle
crusher have been rapidly increased when compared to the double toggle crushers. The crushing
action of a jaw crusher is brought about by the motion of its swing jaw and the forces that it
exerts on the material being crushed. Learning the kinematics of the swing jaw is necessarily
important since this impacts the operation of the crusher to work effectively. Figure 1 shows the
single toggle jaw crusher with its crushing operation.

Figure 1: Single toggle jaw crusher
Horizontal Pittman stone crusher:
On the other hand, the Pittman jaw crusher could be most readily and acceptable by any
quarrying operation. There are also the commercially used equipments that could have certain
novice parts such as stamping batteries and spalling hammers. They also have a strong and
robust steel box-like chamber that has a vertical jaw plate at one end with the movable crushing
swing jaw at the other end of the fixed plate. This swing jaw promotes a cyclic operation that
drives continously towards and away from the fixed end (Garnaik, 2010). In performing this
operation with the high compressive force, the materials could be finely crushed into smaller
wave particles. This operation is carried out by a motor or engine that is fixed with the crusher.
The power is transferred through the drive belt that operates the movable jaw by an eccentric
shaft, which performs a periodic motion between the fixed and the movable jaw. Figure 2 shows
the view of the Horizontal Pittman stone crusher

Figure 2: Horizontal Pittman stone crusher
Selection of jaw crusher with their consideration:
Certain consideration should be kept in mind while involving with the operation of jaw crusher
that are as follows:
 The feet size should not exceed the gap at a maximum of eighty percent.
 The close side setting will be the smallest distance among the fixed and the movable late
that could be measured from the plate tip till the end
 The size of the product should be at a maximum of 1.5 times the operating setting of the
crusher. But this is not followed in all the case if the feed is necessarily slab by materials.
 After the process of crushing almost fifty percent of the particles could enter into the
closed setting side of the crusher.
 The ratio of the reduction could be around 6:1 with the jaw crusher (Kalnins, 2009).
 In order to surpass the average capacity of the plant, the primary crushers should be
selected since they perform at a cyclic operation. This could depend on the trucks and
loaders.

 The jaw crusher could be chosen depending of their higher feet size that should be
independent of the capacity. Too feed the machine too fine could lead to the process of
overloading and the machine could face any sort of equipment malfunction.
 The efficiency of the jaw crusher could be increased and improved when necessary feed
lesser than closed side setting is detached from the by-pass of the jaw crushers.
Eccentric Shaft:
This eccentric shaft causes a rotation at an elliptical movement. There is an increase in the throw
when there is a maximum eccentricity of the shaft (SBM Mining and Construction Machinery,
2013). This could maximize the throughput without maximizing the dimension of the crusher by
maximizing the shaft stroke and minimizing the speed by decreasing the crushing force by
increasing the width of the jaw. This is necessary to retain the structural design of the crusher by
decreasing the load of the machine. The displacement happening at the narrow and the wide part
is called as the stroke of the crusher. This was further defined by the swing jaw or the variation
among the opening and the closing side (Monkova, Monka, Hloch and Valicek, 2011). The
increased discharge could be possible at the opening side and the less discharge could be given to
the closing side.
Flywheel:
The machine weight should be sufficiently balanced since any divergence could lead to the
increased vibration with the sufficient twist (Swain, Patra & Roy, 2011). They should be keyed
at the opposite ends of the eccentric shaft. Sufficient inertia is provided by the flywheel, which
supplies energy during the period when the supply is more than the requirement and releases it
when the energy obligation is additional to the supply. This could evolve in crushing of the rock
material.
Comparison between Single toggle and Horizontal Pittman stone crusher:
The necessary study has been carried out between the Single toggle stone crusher and the
Horizontal Pittman stone crusher that has been tabulated in the table given below.
Table 1: Comparison amongst the Single toggle and Horizontal Pittman stone crusher

Single toggle Horizontal Pittman stone crusher
1) Has an oscillatory motion between the fixed
and the movable jaw
The movement takes in the forward and in the
reverse direction by the swing jaw
2) This could promote a rubbing effect among
the swing jaw. This could wear out the teeth of
the swing jaw very faster
No such rubbing effect occurs
3) The acceleration magnitude of the swing
jaw is very high. The magnitudes are attained
at a very faster rate by the crank shaft thus
promoting a better crushing speed on
comparison, which is a necessary factor.
The acceleration magnitude of the swing jaw is
low when compared to the single toggle
4) The overheating that occurs between the
joints of the jaw is the major disadvantage of
the single toggle crusher. Due to their high
speed and excessive rubbing force this tends
the machine to overheat by producing friction
between the joints.
No such overheating is produced due to their
eccentric motion
5) Installation cost is very low but this could
increase the cost of maintenance due to their
abrasive nature.
Cost of maintenance is comparatively low
6) The swing jaw should be sufficiently
replaced more often that increases the cost
Replacement does not occur often
7) The purchase cost is sufficiently low Has a nominal rate but high when compared to
single toggle
8)The work done and the end product could be
sufficiently high
The work done and the end product could be
sufficiently low, since the occurrence of the
second spike could happen only around 252
Conclusion:

Here we have discussed about the essential purpose of the stone crushers with their basic
principle and operations. There are several types of crushers and the sufficient crushers should be
chosen in order to get better efficiency and effective function with its operations.
References:
Deepak, B. B. V. L. (2010). Optimum Design and Analysis of (the) Swinging Jaw Plate of a
Single Toggle Jaw Crusher. A Master of Technology Thesis. Department of Mechanical
Engineering, National Institute of Technology, Rourkela, Odisha, India. Available at
http://www.scribd.com/doc/37399105/Deepak-Project-on-Jaw-Crusher (accessed in May 2013).
Garnaik, Sobhan K. (2010). Computer Aided Design of (the) Jaw Crusher. A Bachelor of
Technology Thesis. Department of Mechanical Engineering, National Institute of Technology,
Rourkela, Odisha, India. Available at http://ethesis.nitrkl.ac.in/1812/1/thesis_sobhan.pdf
(accessed in May 2013).
Gupta, A. and D. S. Yan (2008). Mineral Processing, Design and Operations: An Introduction.
Chapter 4: Jaw Crushers. Elsevier. Monday, 19 August 2013 34 of 35
Henan Hongxing Mining Machinery Company Limited (2013). Available at
http://www.hxjqchina.com/UpLoadFile/01.pdf (accessed in January 2013).
Kalnins, L. M. (2009). Coordinate Systems. Department of Earth Sciences, University of Oxford.
Available at http://www.earth.ox.ac.uk/~larak/MMES/CoordinateSystems.pdf (accessed in July
2013).
Monkova, K., P. Monka, S. Hloch and J. Valicek (2011). Kinematic Analysis of the Quick-
Return Mechanism in Three Various Approaches. Technical Gazette 18, 2(2011), pages 295 to
299. Available at hrcak.srce.hr/file/103770. (downloaded in May 2013).
SBM Mining and Construction Machinery (2013). A brochure available at
http://www.sbmchina.com/pdf/jaw_crusher.pdf (accessed in May 2013).
Swain, A. K., Patra, H., & Roy, G. K. (2011). Mechanical operations. New Delhi: Tata McGraw
Hill.