Structure Design And Mechanical Analysis Of Multifunctional Nursing Bed

With the arrival of the worldwide aging population, our country has already entered the ageing society. According to the statistics, the population in our country aged over 60 years old reached about 160 million at the end of 2008, which accounted for 12% of the total population. It is predicted that the aging rate of our country will reach 17.17% in 2020. Moreover, it will be more than 30% in 2050.According to information available, about 79.1% of the old man has at least one chronic disease. People with chronic diseases can get bedsore or other complications after a long-term bed rest, which will increase the body motility disorders significantly. Helping the patient to turn around from the back regularly can prevent or reduce the occurrence of bedsore. Patients with regular limb rehabilitation trainings will enhance the activity of their bodies and improve their own immunity.In this paper, multi-functional nursing bed is designed for elderly patients and disabled people who lose lower limb motor ability. The patients can get up, curve legs and rollover with the help of the nursing bed. By using it, patients can also get limb rehabilitation trainings, which will speed up the functional recovery of lower limb. The main research results of this dissertation are as follows:1) According to the proposed design requirements, the dimensions of the bed and the angle of each bedplates are determined. The spatial position of individual functional modular mechanism is figured out and the type of each mechanism is determined depending on the design principles.2) Kinematic models of the mechanisms are established and the kinematic analysis is also carried out. The sizes and the rotation angle ranges of all the rods in the nursing bed are set. The function formulas of displacement, velocity and acceleration of individual rod are established by using analytical method of vector equation.3) The paper also investigates the whole frame structural design and material selection. All functional modular parts of the bed is determined. The type of the driver motor is selected according to the analysis of each mechanism. At last, the three-dimensional drawings are shown under each functional status.4) Stress and strain analysis of the bedstead and the fluctuation beam is developed based on the ANSYS software. The stress distribution and the displacement deformation getting from stress and strain analysis indicates the rationality of the two parts.