| 摘要 |
FIELD: mechanical engineering; stepless transmissions; devices requiring steady rotation of driven link with possibility of changing direction and speed. SUBSTANCE: articulated lever mechanism has base 1, driving and driven cranks of equal length, 2 and 3, respectively, mounted on base, connecting rod 4 whose length is equal to distance between axles of cranks 2 and 3 and device intended to exclude uncertain movement of driven cranks made in form of lever 5 with roller 6 loaded by spring 7 and controlled by handle 8 hinge-connected with lever 5. Roller 6 is installed on lever 5 to constantly thrust against cam 9 rigidly connected with crank 3 at one side of axis of symmetry of cam for the moment when crank 3 passes through rotation uncertainty position. Axle of driven crank 3 has torsion (flexible tie) at its output, torsion being connected with driven link (flywheel). With crank 2 rotating, rotary motion of the same direction is transmitted to crank 3 through connecting rod 4. When roller 6 is installed at one side of axis of symmetry of cam 9 for the moment when crank 3 passes through rotation uncertainty position, roller 6 acts onto cam 9 either in direction coinciding with direction of rotation of crank 3, or in opposite direction. As direction of rotation and speed of driven cranks are determined by resultant of vector sums of torques acting in position of static uncertainly (torque caused by acting of roller 6 on cam 9, torsion twisting torque and inertia moment of crank 3 - cam 9 system) the mechanisms turns into controlled transmission. Ratio between driving and driven cranks varies within +1 to 0 and -1 in half-a-revolution steps. A particular case is mechanisms in which length of connecting rod 4 equal to distance between axles of cranks 2 and 3 is equal to length of crank. In this case crank 3 can rotate at angular velocity of driving crank 2 or stay standstill until crank 2 makes a full revolution, i. e. provide ratio from +1 to 0 with steo equal to 1 revolution. Articulated lever mechanism provides reversing and features variable transmission function at constant coupling between driving and driven links (no reversing is provided in the above indicated particular case). EFFECT: enlarged operating capabilities, steady rotation in different directions and change of speed of driven crank. 4 cl, 3 dwg |
