Creation of the plan of accelerations is one of ways of the solution of tasks on the provision of links of the mechanism. For similar construction the kinematic scheme of the mechanism and function of movement its initial (initial – for the mechanism with one degree of freedom) links has to be set.
Instruction
1. In the chosen scale construct the kinematic scheme. Then apply motionless axes and links which provisions are defined on the drawing. At the same time it is supposed that the initial link moves with a constant speed. Construct provisions of other links by the known sizes of rather already certain links.
2. Further describe the provision of links of external kinematic pairs of mechanism the vector equations of speed and acceleration. For this purpose use method of decomposition of their movement on forward and rotary. Acceleration of any link of the mechanism geometrically consists of acceleration of other link taken for a pole and acceleration which the first link receives at rotation around a pole.
3. At the solution of a task represent the mechanism in that situation for which it is required to define acceleration of the necessary link. First of all according to a task define the link (point) taken for a pole.
4. After that on free space about the kinematic scheme of the mechanism note a point - a pole of the plan of acceleration, being the beginning of vectors of all full accelerations. Then set construction scale, define motionless axes, the directions.
5. Afterwards construct vectors which accelerations are known (usually vectors of an initial link). Further work out the vector equations for unknown accelerations. At the solution of the equations determine unknown sizes and the directions, and then apply these decisions on the plan. If acceleration size is unknown, then the straight line characterizing the direction of a vector of acceleration is applied on the plan.
6. At the solution of the vector equation find the size of acceleration and in scale postpone the received value on put earlier direct. Further work out the vector equations for the following link of the mechanism, determine their speeds and accelerations from proportions according to properties of plans of speeds and accelerations.