The design going forward had holes drilled into the rear so as to a fix it to the turntable as well as holes drilled to accommodate the mounting of the cross-member. This geometry introduces new points for stress concentrations as such this increases stresses which may necessitate redesign or the selection of a new material. … Continue reading Crane : Boom (Pt. 2 of 2)
Crane : Boom (Pt. 1 of 2)
Now the boom has been adjusted, with the overall design having a cross-member, this introduces new forces and geometries that have to be better taken into consideration. The initial design while demonstrating the basics when applying "the math" (number & formulae) is rather simple not taking into account all the forces at work. The modified … Continue reading Crane : Boom (Pt. 1 of 2)
Cranes : The Trolley (Pt. 1 of 2)
The trolley is the part to which the load is attached to, the trolley also allows for the load to traverse the length or at least a prescribed part of the boom. The load doesn't have to attach directly to the trolley, the trolley can by means of bolt holes can accommodate a motorized winch, … Continue reading Cranes : The Trolley (Pt. 1 of 2)
Crane : Swivel Mechanism (Pt. 3 of 3)
Basic sketch of swivel assembly The swivel mechanism has 3 sections, the upper middle and the lower. The upper section attaches to the I beam boom by way of 4 bolts. The middle section sits between the upper and the lower preventing any contact thus allowing free rotation of the upper. This section is ultimately … Continue reading Crane : Swivel Mechanism (Pt. 3 of 3)
Crane : Swivel Mechanism (Pt. 2 of 3)
The bearing can be made smaller however this would increase the complexity of the mounting mechanism as one would have to be designed to hold the bearing within the mast, by keeping the bearing larger than the mast diameter means that it can fit atop the mast with a lot less modification, or a the … Continue reading Crane : Swivel Mechanism (Pt. 2 of 3)
Crane : Swivel Mechanism (Pt. 1 of 3)
When designing the crane it was necessary for the boom to be able to swing, this adds to its utility allowing it to be better able to lift and move objects over a greater range. The first and simplest mechanism would be a pin hinge and a bushing, this would be the simplest. The bushing … Continue reading Crane : Swivel Mechanism (Pt. 1 of 3)
Crane : The Mast
The mast in this case is the free standing vertical column that that the boom will be cantilevered of. The upper portion of the mast will have the mechanism to allow the boom to rotate, and the lower portion will allow for the crane to be secured to the ground. The basics of the mast … Continue reading Crane : The Mast
Crane : Stress & Deflection
Beam Selection After the continuous trial of different beams, the beam with the appropriate 2nd moment of area is chosen. For selecting the beam we look at the flange width and the beam height. The 3rd factor to consider the beam weight. From the chart on the left we can see that as the beam gets … Continue reading Crane : Stress & Deflection
Crane : The Cross Member
The section we are referring to is E-B, at the point E the joint is fixed to the base of the boom, this allows for the section to move with the boom. At this point, B, their will still be an upward, lateral and resultant force. The member E-B is 2.121m long, and will be … Continue reading Crane : The Cross Member
Crane : Material Selection
Material selection is influenced in BOTH cases by the calculation of the stresses and then applying a safety factor, in this case 2.0, to the stress or to the yield or proof strength. If the safety factor is applied to the stress it is multiplied, this value must still be below the yield or proof … Continue reading Crane : Material Selection
Crane : The Freebody (Pt. 3 of 3)
The new freebody has details that were not included in the original, the first is to the upper boom section , with the addition of the diagonal strut E-B. This was put to help with overall beam deflection. This works by shortening the length of the beam. In calculation the length of the beam was … Continue reading Crane : The Freebody (Pt. 3 of 3)
Crane : The Freebody (Pt. 2 of 3)
The completed freebody has not just the plan of forces and the location of them but has the position of expected cross-members. This freebody will be used to properly and fully calculate the extent of forces acting on the various sections and cross-members of the jib crane. This involves breaking up the jib crane into … Continue reading Crane : The Freebody (Pt. 2 of 3)
Crane : Design
For this project we determined that the deflection should be L/450 so from a length of 4.572m the deflection should be 0.009144m. From this and a load of 10,477N we can calculate the 2nd moment of area needed at a minimum. It was found to be 17.62 x 10-5 m. By keeping the beam 2nd … Continue reading Crane : Design
Crane : The I-Beam (Pt. 2 of 2)
For the selection of the I beam we need to determine both the 2nd moment of area. However for the determination of the starting point we will use the deflection requirement to determine the 2nd moment of area and from there we will have a minimum as to the size of beam that we need. … Continue reading Crane : The I-Beam (Pt. 2 of 2)
Crane : The I-Beam (Pt. 1 of 2)
The I-Beam is what was selected to bee the boom of the crane. To fully analyse the forces, stresses and deflection and general behavior of the beam it is good to have an understanding of the geometric properties of the beam. Typically you wouldn't order a custom beam for a project, you would obtain a … Continue reading Crane : The I-Beam (Pt. 1 of 2)
Crane : The Boom Design
The boom will be 15' or 4.572m long, and should be able to support a 1 tonne load. To this we will add the load of the trolley that will hoist the load, this should be anywhere between 60 and 70kg. The generally agreed upon cross section of the boom would be an I, thus … Continue reading Crane : The Boom Design
Crane : The Freebody (Pt. 1 of 3)
The basic free body diagram is how we are going to take a look at and map the distribution of forces that the crane may experience. The diagram will help to show where the expected forces are located and the expectant reactions of said forces. Accurate calculation and placement of these forces will help to … Continue reading Crane : The Freebody (Pt. 1 of 3)
Crane
The crane is a device that is used for the lifting and moving of a load, this seems similar to that of a hoist, however it must be noted that a hoist can only lift a load vertically, where as a crane can lift a load and move it. The hoist only moves the load … Continue reading Crane
Valve – Mid Section/Body
The central component group of the valve mid-section is essentially the bore, gate and the seals around it. These are the components that are in direct contact with the fluid and thus physically interact with the fluid to control the flow. The valve gate is the component that physically allows or hinders the fluid flow … Continue reading Valve – Mid Section/Body
Valve – Mid Section/Body
The valve mid-section and the body contain the parts that interact with the fluid in question. The upper stem seal seat is where the seal rests and seals the stem preventing fluid migration beyond the valve cavity. The bonnet seal seat is home to the seal that prevents fluid migration between the bonnet and the … Continue reading Valve – Mid Section/Body