39results about How to "Reduce fatigue wear" patented technology

A method for producing a wear resistant polyethylene medical implant includes forming a medical implant, such as an orthopedic implant, made at least partially of ultra high molecular weight polyethylene (UHMWPE). The polyethylene may be irradiated with gamma ray or e-beam radiation to form free radicals and then crosslinked to eliminate free radicals prior to exposure to oxygen. The so treated bearing surface of the crosslinked polyethylene is then coated with a photoinitiator. Thereafter the bearing material is photocrosslinked with ultra-violet (UV) radiation. The photocrosslinking process can also be applied to non-crosslink UHMWPE.

The invention discloses a walking energy collection system, which comprises a piezoelectric power generation device and an electric energy collection device connected with the piezoelectric power generation device. The piezoelectric power generation device comprises a pressure bearing component, a support component, a two-stage pressure amplification component, an elastic component and a piezoelectric component, wherein the pressure bearing component bears walking pressure; the support component supports the pressure bearing component; the two-stage pressure amplification component adopts a wedge block, and amplifies pressure in a combined way; the elastic component resets the pressure amplification component and the pressure bearing component; and the piezoelectric component converts mechanical energy into electric energy. The electric energy collection device comprises a rectification circuit, an energy storage capacitor, a control circuit and a voltage stabilizing circuit, which are sequentially cascaded. According to the walking energy collection system, the mechanical energy in a walking process is converted into the electric energy which is easily collected and utilized, so that the collection efficiency of the electric energy collection device is improved; the walking energy collection system is suitable for the low-frequency excitation of walking; and fatigue wear to the components in the system at work can be effectively reduced.

The invention relates to a two-freedom-degree limit anisotropic flexible biomimetic ankle which comprises a connector for being connected with a prosthetic socket, a connecting rod connected to the lower end of the connector, a spring mounting bracket connected to the middle of the connecting rod, a central sphere pin pair connected to the lower end of the connecting rod, an ankle limit end cover arranged on the upper portion of the central sphere pin pair and a sphere pin pair base arranged below the central sphere pin pair. A limit cambered surface with four spring guide holes is arranged at the upper end of the ankle limit end cover, and an inner spherical surface is arranged at the lower end of the ankle limit end cover. The spring mounting bracket is supported in the limit cambered surface through four spiral compression springs installed in the four spring guide holes. An inner spherical surface is arranged at the upper end of the sphere pin pair base. The central sphere pin pair is in clearance fit with the inner spherical surface of the ankle limit end cover and the inner spherical surface of the sphere pin pair base, and a bolt pin on the side face of the central sphere pin pair is in clearance fit with a bolt pin guide groove in the ankle limit end cover and a bolt pin guide groove in the sphere pin pair base. The two-freedom-degree limit anisotropic flexible biomimetic ankle has two degrees of freedom, can perform plantar flexion, dorsal flexion, introversion and extroversion, has different angle ranges and flexibility in each direction, and enables an amputee to walk on a more complicated pavement.

The invention belongs to the field of ice-breaking ships, in particular to an adaptive ice-breaking device for ships. The device comprises a base, a reserve box, a crankshaft, an electric motor, a controller, a conveyor belt, a speed reducer, an electromagnetic clutch, a connecting rod, a slider vibration exciting rod, small and large electromagnets, a return spring, a stop pin, an electric motorcontroller and the like; One end of the crankshaft is connected with the output shaft of the speed reducer through an electromagnetic clutch to transmit torque, and the other end is connected with theconnecting rod through a rotating pair; The slider vibration exciting rod and the connecting rod are connected through a ball hinge, and the slider vibration exciting rod and the slider rail are connected through a ball to realize the guidance and reduce the friction; The slide rail has four arc-shaped grooves, the ball is located in the arc-shaped groove, and the slide rail is fixed on the base.The controller selects the rotational speed of the motor according to the natural frequency fn of the sea ice, so that the frequency f1 of the exciting force exerted by the vibration hammer on the ice is equal to the natural frequency fn of the ice, so as to realize the resonant ice breaking. The invention is based on the resonance principle, and has the advantages of low cost-effectiveness ratio, strong adaptability and high ice breaking efficiency.

The invention relates to a control system and method for flexible docking of a movable beam of a hydraulic machine and a leveling system. Input the command signal with the same difference to the proportional servo valve of the leveling cylinder to control the circular fall of the leveling cylinder and collect the displacement of the leveling cylinder and the pressure of the rodless chamber, and record the corresponding command signal; use the neural network algorithm to carry out model identification on the collected data , get the flow model of the valve port of the leveling cylinder control valve, and calculate the feedforward value of the speed valve port of each leveling cylinder; then, collect the position information of the movable beam and the four leveling cylinders in real time, and calculate the position information of each leveling cylinder according to the displacement difference Control the opening of the valve port, and at the same time, the displacement deviation compensation module of the four leveling cylinders adjusts and compensates the valve ports of the control valves of each cylinder; after docking, use the sliding mode controller to perform pressure tracking control on the rodless cavity of the four leveling cylinders . The invention adopts the coordinated control of the main cylinder and the leveling system and the coordinated control method of four cylinders, can realize the flexible docking of the movable beam and the hydraulic leveling system, and has strong engineering adaptability.