# No. 171 (Brown 1868): "Valve motion and reversing gear used in oscillating marine engines. The two eccentric rods give an oscillating motion to the slotted link which works the curved slide over the trunnion. Within the slot in the curved slide is a pin attached to the arm of a rock-shaft which gives motion to the valve. The curve of the slot in the slide is an arc of a circle described from the center of the trunnion, and as it moves with the cylinder it does not interfere with the stroke of the valve. The two eccentrics and link are like those of the link motion used in locomotives."
#
# Model (cm, no gravity; a plan): the shaft (the one driven joint, 20 turns a minute) carries two eccentrics (throw 1.4 cm, 110 deg ahead of and behind the crank), whose 12 cm rods are pinned to the ends of the slotted link.
# The link (6.8 cm between the rod pins, its slot an arc of radius 12 cm) is held by a radius rod and swings 24 deg each way. The valve rod's pin runs in the link's slot (real contact), 2.8 cm from its middle, and the valve rod, on a vertical guide, carries the curved slide
# over the trunnion; the pin of the rock-shaft arm runs in that slide's slot, so the valve rod goes 2.6 cm and the rock-shaft rocks 22 deg. Generator: opencode-runs/batch11/gen171.py. Cylinder oscillation is left out.
number: 171
slug: oscillating-engine-link-motion
name: Valve motion used in oscillating marine engines
brown: "Valve motion and reversing gear used in oscillating marine engines. The two eccentric rods give an oscillating motion to the slotted link which works the curved slide over the trunnion. Within the slot in the curved slide is a pin attached to the arm of a rock-shaft which gives motion to the valve. The curve of the slot in the slide is an arc of a circle described from the center of the trunnion, and as it moves with the cylinder it does not interfere with the stroke of the valve. The two eccentrics and link are like those of the link motion used in locomotives."
units: cm
sim:
  timestep: 0.0002
  integrator: implicitfast
  iterations: 100
  solver: PGS
  multiccd: true
  duration_s: 9.0
  floor: false
  gravity: 0
bodies:
  - id: shaft
    shape: part
    pos: [0, 0, 0]
    mass: 0.3
    color: "#cfc6b4"
    pieces:
      - {kind: rod, from: [0, -4.2, 0], to: [0, 1.6, 0], radius: 1.0, collide: 0, color: "#8f8a80"}
      - {kind: disc, center: [1.3156, -0.4788], radius: 2.2, y: [-4.2, -3.3], collide: 0, color: "#d9cfb6"}
      - {kind: disc, center: [-1.3156, -0.4788], radius: 2.2, y: [-2.7, -1.9], collide: 0, color: "#d9cfb6"}
  - id: rod_a
    shape: part
    pos: [1.3156, 0, -0.4788]
    mount: shaft
    mass: 0.3
    color: "#a89a7e"
    pieces:
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      - {kind: rod, from: [-3.4, -4.1, -11.5135], to: [-3.4, -0.2, -11.5135], radius: 0.55, collide: 0, color: "#8f8a80"}
  - id: link
    shape: part
    pos: [-3.4, 0, -11.5135]
    mount: rod_a
    mass: 0.4
    friction: 0.02
    color: "#d9cfb6"
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    shape: part
    pos: [-1.3156, 0, -0.4788]
    mount: shaft
    mass: 0.3
    color: "#a89a7e"
    pieces:
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  - id: hanger
    shape: part
    pos: [-9.0, 0, -12.0]
    mass: 0.2
    color: "#a89a7e"
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  - id: valve
    shape: part
    pos: [-2.8, 0, -11.674]
    mass: 0.3
    friction: 0.02
    color: "#cfc6b4"
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      - {kind: poly, points: [[-8.3, -14.674], [2.7, -14.674], [2.7, -14.074], [-8.3, -14.074]], y: [-1.0, -0.2], collide: 0, color: "#cfc6b4"}
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      - {kind: poly, points: [[-5.6112, -16.7573], [-5.4601, -16.5526], [-5.0689, -16.8646], [-5.1978, -17.0392]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-5.4601, -16.5526], [-5.2941, -16.3598], [-4.9273, -16.7001], [-5.0689, -16.8646]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-5.2941, -16.3598], [-5.1142, -16.1799], [-4.7739, -16.5466], [-4.9273, -16.7001]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-5.1142, -16.1799], [-4.9213, -16.0139], [-4.6094, -16.4051], [-4.7739, -16.5466]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-4.9213, -16.0139], [-4.7166, -15.8628], [-4.4348, -16.2762], [-4.6094, -16.4051]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-4.7166, -15.8628], [-4.5012, -15.7274], [-4.251, -16.1607], [-4.4348, -16.2762]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-4.5012, -15.7274], [-4.2762, -15.6085], [-4.0591, -16.0593], [-4.251, -16.1607]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-4.2762, -15.6085], [-4.043, -15.5068], [-3.8602, -15.9726], [-4.0591, -16.0593]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-4.043, -15.5068], [-3.8029, -15.4228], [-3.6554, -15.9009], [-3.8602, -15.9726]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-3.8029, -15.4228], [-3.5571, -15.3569], [-3.4458, -15.8447], [-3.6554, -15.9009]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-3.5571, -15.3569], [-3.3071, -15.3096], [-3.2325, -15.8044], [-3.4458, -15.8447]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-3.3071, -15.3096], [-3.0543, -15.2811], [-3.0169, -15.7801], [-3.2325, -15.8044]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-3.0543, -15.2811], [-2.8, -15.2716], [-2.8, -15.7719], [-3.0169, -15.7801]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-2.8, -15.2716], [-2.5457, -15.2811], [-2.5831, -15.7801], [-2.8, -15.7719]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-2.5457, -15.2811], [-2.2929, -15.3096], [-2.3675, -15.8044], [-2.5831, -15.7801]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-2.2929, -15.3096], [-2.0429, -15.3569], [-2.1542, -15.8447], [-2.3675, -15.8044]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-2.0429, -15.3569], [-1.7971, -15.4228], [-1.9446, -15.9009], [-2.1542, -15.8447]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-1.7971, -15.4228], [-1.557, -15.5068], [-1.7398, -15.9726], [-1.9446, -15.9009]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-1.557, -15.5068], [-1.3238, -15.6085], [-1.5409, -16.0593], [-1.7398, -15.9726]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-1.3238, -15.6085], [-1.0988, -15.7274], [-1.349, -16.1607], [-1.5409, -16.0593]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-1.0988, -15.7274], [-0.8834, -15.8628], [-1.1652, -16.2762], [-1.349, -16.1607]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-0.8834, -15.8628], [-0.6787, -16.0139], [-0.9906, -16.4051], [-1.1652, -16.2762]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-0.6787, -16.0139], [-0.4858, -16.1799], [-0.8261, -16.5466], [-0.9906, -16.4051]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-0.4858, -16.1799], [-0.3059, -16.3598], [-0.6727, -16.7001], [-0.8261, -16.5466]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-0.3059, -16.3598], [-0.1399, -16.5526], [-0.5311, -16.8646], [-0.6727, -16.7001]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-0.1399, -16.5526], [0.0112, -16.7573], [-0.4022, -17.0392], [-0.5311, -16.8646]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[0.0112, -16.7573], [0.1465, -16.9728], [-0.2868, -17.223], [-0.4022, -17.0392]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-6.7865, -16.3724], [-6.6034, -16.0809], [-7.0168, -15.799], [-7.2198, -16.1222]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-6.6034, -16.0809], [-6.3989, -15.8039], [-6.7901, -15.492], [-7.0168, -15.799]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-6.3989, -15.8039], [-6.1744, -15.543], [-6.5412, -15.2027], [-6.7901, -15.492]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-6.1744, -15.543], [-5.931, -15.2996], [-6.2713, -14.9328], [-6.5412, -15.2027]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-5.931, -15.2996], [-5.6701, -15.075], [-5.982, -14.6838], [-6.2713, -14.9328]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-5.6701, -15.075], [-5.3931, -14.8706], [-5.6749, -14.4572], [-5.982, -14.6838]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-5.3931, -14.8706], [-5.1016, -14.6875], [-5.3518, -14.2542], [-5.6749, -14.4572]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-5.1016, -14.6875], [-4.7973, -14.5266], [-5.0144, -14.0758], [-5.3518, -14.2542]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-4.7973, -14.5266], [-4.4817, -14.389], [-4.6645, -13.9232], [-5.0144, -14.0758]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-4.4817, -14.389], [-4.1568, -14.2753], [-4.3043, -13.7971], [-4.6645, -13.9232]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-4.1568, -14.2753], [-3.8243, -14.1862], [-3.9357, -13.6984], [-4.3043, -13.7971]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-3.8243, -14.1862], [-3.4861, -14.1222], [-3.5606, -13.6274], [-3.9357, -13.6984]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-3.4861, -14.1222], [-3.144, -14.0836], [-3.1814, -13.5847], [-3.5606, -13.6274]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-3.144, -14.0836], [-2.8, -14.0708], [-2.8, -13.5704], [-3.1814, -13.5847]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-2.8, -14.0708], [-2.456, -14.0836], [-2.4186, -13.5847], [-2.8, -13.5704]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-2.456, -14.0836], [-2.1139, -14.1222], [-2.0394, -13.6274], [-2.4186, -13.5847]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-2.1139, -14.1222], [-1.7757, -14.1862], [-1.6643, -13.6984], [-2.0394, -13.6274]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-1.7757, -14.1862], [-1.4432, -14.2753], [-1.2957, -13.7971], [-1.6643, -13.6984]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-1.4432, -14.2753], [-1.1183, -14.389], [-0.9355, -13.9232], [-1.2957, -13.7971]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-1.1183, -14.389], [-0.8027, -14.5266], [-0.5856, -14.0758], [-0.9355, -13.9232]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-0.8027, -14.5266], [-0.4984, -14.6875], [-0.2482, -14.2542], [-0.5856, -14.0758]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-0.4984, -14.6875], [-0.2069, -14.8706], [0.0749, -14.4572], [-0.2482, -14.2542]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[-0.2069, -14.8706], [0.0701, -15.075], [0.382, -14.6838], [0.0749, -14.4572]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[0.0701, -15.075], [0.331, -15.2996], [0.6713, -14.9328], [0.382, -14.6838]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[0.331, -15.2996], [0.5744, -15.543], [0.9412, -15.2027], [0.6713, -14.9328]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[0.5744, -15.543], [0.7989, -15.8039], [1.1901, -15.492], [0.9412, -15.2027]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[0.7989, -15.8039], [1.0034, -16.0809], [1.4168, -15.799], [1.1901, -15.492]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
      - {kind: poly, points: [[1.0034, -16.0809], [1.1865, -16.3724], [1.6198, -16.1222], [1.4168, -15.799]], y: [-1.0, -0.2], collide: 2, color: "#d9cfb6"}
  - id: rock
    shape: part
    pos: [5.8905, 0, -15.0487]
    mass: 0.2
    friction: 0.02
    color: "#a89a7e"
    pieces:
      - {kind: poly, points: [[5.8905, -15.4987], [-1.1095, -15.4987], [-1.1095, -14.5987], [5.8905, -14.5987]], y: [-1.8, -1.2], collide: 0, color: "#a89a7e"}
      - {kind: rod, from: [-1.1095, -1.8, -15.0487], to: [-1.1095, 0.0, -15.0487], radius: 0.5, collide: 1, capsule: true, color: "#8f8a80"}
      - {kind: rod, from: [5.8905, -2.4, -15.0487], to: [5.8905, 0.6, -15.0487], radius: 0.9, collide: 0, color: "#8f8a80"}
  - id: frame
    shape: part
    pos: [0, 0, 0]
    fixed: true
    color: "#cfc6b4"
    pieces:
      - {kind: poly, points: [[-0.8, -23.6], [0.8, -23.6], [0.6, -1.0], [-0.6, -1.0]], y: [1.8, 2.8], collide: 0}
      - {kind: poly, points: [[-3.7, -6.474], [-1.9, -6.474], [-1.9, -5.674], [-3.7, -5.674]], y: [0.2, 2.0], collide: 0, color: "#b9b09c"}   # the valve rod's guide
      - {kind: poly, points: [[5.0905, -23.6], [6.6905, -23.6], [6.3905, -15.0487], [5.3905, -15.0487]], y: [0.8, 1.8], collide: 0}   # the rock-shaft's standard
      - {kind: poly, points: [[-9.6, -23.6], [-8.4, -23.6], [-8.6, -12.0], [-9.4, -12.0]], y: [2.8, 3.4], collide: 0}
      - {kind: disc, center: [-2.8, -18.674], radius: 2.0, y: [-0.9, -0.3], collide: 0, color: "#8f8a80"}   # the trunnion
      - {kind: poly, points: [[-14, -24.6], [14, -24.6], [14, -23.6], [-14, -23.6]], y: [-3, 3], collide: 0, color: "#b9b09c"}
joints:
  - {id: j_s, type: hinge, body: shaft, axis: [0, 1, 0], damping: 0.002}   # the one driven joint: the shaft with its two eccentrics; + : clockwise
  - {id: j_ra, type: hinge, body: rod_a, axis: [0, -1, 0], damping: 0.002}
  - {id: j_l, type: hinge, body: link, axis: [0, -1, 0], damping: 0.002}
  - {id: j_rb, type: hinge, body: rod_b, axis: [0, -1, 0], damping: 0.002}
  - {id: j_h, type: hinge, body: hanger, axis: [0, -1, 0], damping: 0.002}   # the radius rod that holds the link
  - {id: j_v, type: slide, body: valve, axis: [0, 0, 1], damping: 0.05}   # the valve rod on its guide; + : up
  - {id: j_r, type: hinge, body: rock, axis: [0, -1, 0], damping: 0.002}   # the rock-shaft arm
pins:
  - {"id": "pin_b", "a": "rod_b", "b": "link", "at": [3.4, 0, -11.5135]}
  - {"id": "pin_k", "a": "hanger", "b": "link", "at": [-0.0, 0, -12.0052]}
contact: {solref: [0.002, 1.0], solimp: [0.95, 0.99, 0.0005], margin: 0}
driver: {joint: j_s, kind: velocity, rpm: 20, kv: 2.0, max_torque: 20}
checks:
  - {type: follow, out: j_v, in: j_s, expect: -0.0099, tol: 0.0008, min_r2: 0.99, settle_s: 0.2083, window_s: 0.25}
  - {type: follow, out: j_v, in: j_s, expect: 0.0116, tol: 0.0009, min_r2: 0.99, settle_s: 1.2917, window_s: 0.25}
  - {type: follow, out: j_v, in: j_s, expect: -0.0116, tol: 0.0009, min_r2: 0.99, settle_s: 2.7083, window_s: 0.25}
  - {type: follow, out: j_r, in: j_s, expect: 0.1654, tol: 0.0132, min_r2: 0.99, settle_s: 0.125, window_s: 0.25}
  - {type: follow, out: j_r, in: j_s, expect: -0.1665, tol: 0.0133, min_r2: 0.99, settle_s: 1.2083, window_s: 0.25}
  - {type: follow, out: j_r, in: j_s, expect: 0.1532, tol: 0.0123, min_r2: 0.99, settle_s: 2.625, window_s: 0.25}
  - {type: position, joint: j_v, min: -1.5336, max: 1.6914, settle_s: 0.0, window_s: 8.5}
  - {type: penetration, max: 0.003, settle_s: 0.5}
camera: {target: [-3.0, 0, -16.3], position: [-3.0, -72.0, -16.3], fov: 34}
display:
  output: j_v
  labels: {j_s: "Shaft (driver)", j_v: "Valve rod", j_r: "Rock-shaft arm", j_l: "Link"}