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Boyko M., Chala K.
National University of Food Technologies (Kiev,
Ukraine)
Synthesis of cam gears of machine tools of automatic
control units for manufacturing of hardware
Increase of the requirements
to productivity, accuracy of reliability, metal and capacity of cutting
machines, the improvement of the quality of the projects have stipulated broad
usage of a computer while designing . The introduction of an automated design
engineering system presupposes the change of labour technology while designing
of new products. In the field of machine-tool construction CAD will allow to
execute:
- Complex design
calculations of clusters on the basis of the requirements to the machine tool
as a whole;
- Numerical matching of many
versions of designs and their optimization according to different yardsticks of
functionability;
- Optimization of the design
solutions in essentially new working conditions of the machine tool.
Cam gears
Cam gears are three link
mechanism with a maximum kinematic pair the input link of which is called the
cam,, and output link is - thruster (or rocker arm). Often to replace in a
maximum pair coupler by rolling friction and to reduce wearing of both cam, and
thruster, in the scheme of the gear actuate a padding link - roller and rotary
kinematic pair. The mobility in this roler pair does not change transfer
functions of the gear and is local motility.
Assigning and field of application
The cam gears are intended
for transformation (conversion) rotary or translational motion of the cam
into-rotary or reciprocal motion of the thruster. Thus in the gear with two
mobile links it is possible to realize transformation (conversion) of motion
under the composite law. The relevant advantage of cam gears is the capability
to provide precise immobility of an output link. This advantage has determined
their broad application in the elementary devices of frame automatics and in
mechanical computing devices (adding machines, calendar gears). The cam gears
can be sectioned into two groups. In The gears of 1-st the group movement of
the thruster is on a desired law of motion. The gears of the second group
provide only given maximum (movement) of an output link - course of the
thruster. Thus the law, on which one implements this (movement), is selected
from a set of the standard laws of motion depending on the operation conditions
and production process.
Classification of cam gears
The cam gears are categorized
to following tags:
• on arrangement of links in
space
Space (spatial)
Flat
• on motion of the cam
Rotary
Translational
Screw (propeller)
• on motion of an output link
Reciprocating (with the
thruster)
Into-rotary (with a rocker arm)
• on availability of a roller
With a roller
Without a roller
• by the form of a cam Disk
(flat)
Cylindrical
Conoid (composite space
(spatial)
• under the shape of a
working surface of an output link Flat
Concentrated
Cylindrical
Spherical
Evolvent
• on a way of closing of
members of a maximum pair
At power short circuit the
deleting of the thruster implements effect of a contact surface of the cam on
the thruster (leading link - cam conducted - the thruster). The motion of the
thruster at approach implements at the expense of elastic energy of a spring or
force of weight of the thruster, thus the cam is not a leading link. At
geometrical closing the motion of the thruster at deleting implements effect of
an outside working surface of the cam on the thruster, at approach - effect of
an internal working surface of the cam on the thruster. On both phases of
motion the cam is a leading link, thruster is a conductor.
Literature:
1.
Artobolevsky I.I., Theory of mechanisms. Science, 1988. - 712 pages.
2. Directory
technologist-mechanic. Ed. Kosilova A.G. and Meshcheriakova R.K.. - 4th ed.,
add. - M.: Mechanical Engineering, 1985. - 656 pages.
3.
Directory technologist-mechanic. Ed.
Kosilova A.G. and Meshcheriakova R. K.. - 4th ed., add. - M.: Mechanical
Engineering, 1985. - 496 pages.