Parallel motion for upright engine
Parallel motion for upright engine. A, A, are radius-rods connected at one end with the framing and at the other with a vibrating piece on top of piston-rod.
Only the input is driven; every other part of this model moves by physics (MuJoCo), and its ratios are measured. Run it live, change its parameters, or switch the friction off to see the output stop.
- Modelled as
- Watt's parallel motion, set upright between the two columns of the framing. The two radius-rods A, A, are each 20 cm long. One is on a bracket on the left column, the other on a bracket on the right column, 20 cm lower. They point toward each other. Their ends are joined by the upright vibrating piece, 20 cm long. The piston-rod's cross-head is pinned to the middle of the piece, and the rod runs down through the gland into the cylinder. The left radius-rod is rocked through 0.25 radian each way. The right one is free on its pivot, and the piece's lower end is a pin in its eye. Every joint between the piece and the rods or cross-head is a pin in a ring with a few hundredths of a centimetre play. The cross-head is free to move up, down and across, and only the piece's middle pin places it. The left radius-rod is the only driven part.
- Measured
- The piston-rod rises and falls 10 cm, 0.198 m per radian of the radius-rod, in step with it. The right radius-rod swings just as far the other way. The cross-head strays across by no more than 0.1 mm. The deepest contact is 0.02 mm.
- Notes
- Brown gives no sizes. The radius-rods are made equal and the vibrating piece the same length, with the pivots set so that the rods lie level at mid-stroke. The middle of the piece then keeps very nearly to an upright line. The connecting-rod, crank and fly-wheel above are left out. No steam is simulated.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
