1.0 INSTALLATION OF MACHINE TOOLS
a) Principles of installation of a machine tools/ machines
- Consists of checking up the machines for completeness i.e desired accuracy, balancing and proper alignment.
- to achieve those objectives the following factors to be considered carefully;
site selection or location of the machine tool foundation
laying of foundation bolt
placing of machine foundation
aligning the machine with the driving or driven equipment
grouting on the foundation
Testing for normal running at rated capacity with desired accuracy.
b) General requirement/ design of foundation of machine foundation;
- in order to ensure the vibration of a machine is stable and free from producing undesirable vibration;
type of the machines/ machines tool, horizontal or vertical
nature of forces and moment, torque
weight of the machines tool
size of bed plate of the machine tool
speed and power of the machine tool
location of grooves, openings in the foundation for pipe lines
location of the foundation and load bearing capacity of the soil
c) the operation steps to be followed for installation of a lathe in a workshop;
reading of information including drawings generally supplied by the manufacturer of the machine
locating the site of installation
selecting of site of installation
loading and moving the machine to be installed
suspension of the machine for certain time by some means
unloading the item at the proper location
moving the item horizontal to place at exact location
making a foundation for bearing the load of the item and to minimize vibration hazards as far as possible
leveling and aligning the item for smooth running
making a trial run to check a satisfactory operation with desired accuracy after the foundation is set
2.0 CONCRETE FOUNDATION DESIGN- GENERAL
- both the foundation and machine are usually regarded as a single body supported by an elastic underlay
- this concrete foundation system is subject to oscillation at determinable frequency in six degrees of freedom
- the natural frequencies of the foundations due to rocking, yawing and pitching are specially influenced by the dimensions of the foundation itself
3.0 EMPIRC RULES FOR CONCRETE BASE
a) concrete base mass> machine mass
b) common center of gravity for both concrete and machine base, C must be located at the same centerline of centroid, C* for base that contact with soil or < 5% eccentricity
c) to ensure rigidity;
vertical machine: base with , W > H
horizontal machine: base length longer than W
d) properties of length, width and height can prevent rocking happened
4.0 TYPES OF MACHINE BASE
a) Pile: when soil is not suitable to support block base or when natural frequency for block base need to upgrade
b) Cellular: used to take care of rigidity for block base by decrease concrete mass
c) Block: for reciprocate machine. Need to tighter machine structure through opening, recesses, channels by using bolt.
5.0 IMPORTANCE OF SAND PITS AT MACHINE BASE
a) To reduce/ prevent vibration to the minimum level due to heavy machine at the machine base from transfer from heavy machine to the base structure
b) To provide space for machine base tolerance due to temperature, bending etc.
6.0 BASIC CONDITION FOR MACHINE BASE
a) Ensure machine can operate effectively without having excessive wear
b) Ensure base does not experience settlement, which can cause machine become malfunction and thus need to realignment
c) Soil propagation under machine base does destruct machine base, sensitive machine and machine handler
d) Base type is chosen from economy base
e) Machine base design must follow at least machine maker minimum requirement
7.0 PROCEDURE TO INSTALL MACHINE AT CONCRETE BLOCK BASE
a) Ensure bolts that placed at their own hole have space at least 75mm. Hole shape should smaller dimension at the top.
b) Bolts should have enough length. Position of bolts in the block base can make machine reposition during aligning and leveling.
c) Use 100mm² square leveling packing or shims when leveling. All shims need to be placed near to the base hole.
8.0 OTHER FACTORS TO BE CONSIDERED ( INSTALLATION MACHINE AT THE CONCRETE BLOCK BASE)
a) Machine base must follow machine maker requirement. Refer to structure engineer if necessary.
b) Casting must be reinforced with enough or suitable reinforcement rod.
c) Before install machine at the base, make sure time for setting is given to prevent bolt at base collapse.
d) Whenever information regarding base dimension does not complete, refer to empirical rules for concrete base dimension.
9.0 THINGS THAT ALWAYS INTERFERE MACHINE BASE STABILITY
a) External force
b) External primary couples
c) External secondary couples
d) Harmonic torque
These are due to the following:
i. Loads due to dynamic conditions
ii. Loads due to faulty synchronizing condition
iii. Loads due to hydraulic, thermal of surge effects from pumps or compressor
iv. Loads due to out of step running between the machine and other machine
v. Loads due to an abnormal sudden stoppage
10.0 TEST TOWARDS NEW INSTALLATION MACHINE
a) Make sure machine can provide good output by referring the machine specification.
b) Alignment checks on the relationship of the various elements of machine it is idle and unloaded.
c) Practical test- to check accuracy of the work done by the machine.
11.0 MACHINE TESTING PURPOSE
a) Ensure the machine can operate
b) Determine either the machine operates by following specification or not.
c) Machine is safe and suitable to use.
12.0 COMMISIONING OBJECTIVES
a) To review machine test result and problem that occurred during test.
b) To make decision either re-test need to do or not.
c) To repair malfunction machine.
d) To deliver machine to buyer after commissioning.
MARA UNIVERSITY OF TECHNOLOGY (UiTM)
FACULTY OF MECHANICAL ENGINEERING