search: Tilt-a-Whirl
Can you explain me how does it work?
Circular into rectilinear motion. The waved-wheel or cam on the upright shaft communicates a rectilinear motion to the upright bar through the oscillating rod.
i've not understood
Cattura.JPG
search: Tilt-a-Whirl
A slider-crank mechanism is a typical design which converts rotary motion into linear motion. It is achieved by connecting a slider and a crank with a rod.
Design Requirement
(Refer to Table 1 for variables and values)
- A mechanism is to be driven by an electric motor turning at constant speed and direction. The speed of the motor must be a multiple of 10 rpm.
- Two motion outputs are required from the mechanism. The motions are all on a single plane. Their descriptions are as follows:
- A linear reciprocating motion of a slider along the horizontal axis with a stroke of S. The expected tolerance is ± 0.5 mm.
- A rocking motion with a throw angle of θ degrees. The expected tolerance is ± 1°. One of the angular position limits of the rocker must be vertical.
- To reduce the forces in the joints,
- The coupler ratio of the sliding mechanism must be made greater than 4.
- The transmission angle of the rocking mechanism should be between 35° and 145°.
- The space occupied by the moving parts of the mechanism should be minimized. The coupler ratio of the sliding mechanism should be less than 6.
- The time ratio of the sliding mechanism must be at least 1.07.
- The highest speed attained by the sliding mechanism must be between VMIN and VMAX mm/s.
- Each project group must use the assigned values S, θ , VMIN and VMAX as shown in TABLE 1
TABLE 1:
The dimensional and motion constraints of the mechanism for each group.
Group Stroke
SThrow Angle θ Maximum Slider Speed VMIN VMAX No mm degree mm/s mm/s 1 170 75 800 1000 2 190 85 900 1100 3 210 95 1000 1200
Design Tasks
The output of the design project is in the form of a brief report (50%) and a presentation (50%).
- REPORT
The report should have the following contents:
- Introduction
A brief description of the mechanism, the aim of the project and the design requirement (~2 pages)
- Methodology
The design approach. (~2 pages). Should show and justify how the design parameters were finalized.
- Results
Sample design calculations (2-3 pages)
Diagrams (To be plotted based on calculations performed using MS Excel, not ADAMS)
- The kinematic diagram of the mechanism showing the slider at mid-stroke position.
- The slider displacement curve for 2 cycles.
- The slider velocity curve for 2 cycles.
- The slider acceleration curve for 2 cycles.
- The rocker angular displacement curve for 2 cycles.
- The rocker angular velocity curve for 2 cycles.
- The rocker angular acceleration curve for 2 cycles.
- Conclusion
Design Specifications
- The lengths of all links, the slider offset.
- The strokes of the slider and the rocker.
- The crankshaft speed in rpm
- The time ratios of the slider and the rockers.
- The coupler ratio of the slider.
- The range of transmission angles of the rocker.
- The working area required by the mechanism (in terms of L x W).
- The maximum speed of the slider and the rocker