摘要:
A Six-Degree-of-Freedom Parallel-Manipulator having three inextensible limbs for manipulating a platform is described in which the three inextensible limbs are attached via universal joints to the platform at non-collinear points. Each of the inextensible limbs is also attached via universal joints to a two-degree-of-freedom parallel driver such as a five-bar lineage, a pantograph, or a bidirectional linear stepper motor. The drivers move the lower ends of the limbs parallel to a fixed base and thereby provide manipulation of the platform. The actuators are mounted on the fixed base without using any power transmission devices such as gears or belts.
摘要:
A new and innovative concept for the control of backlash in gear-coupled transmission mechanisms. The concept utilizes redundant unidirectional drives to assure positive coupling of gear meshes at all times. Based on this concept, a methodology for the enumeration of admissible redundant-drive backlash-free robotic mechanisms has been established. Some typical two- and three-DOF mechanisms are disclosed. Furthermore, actuator torques have been derived as functions of either joint torques or end-effector dynamic performance requirements. A redundantly driven gear coupled transmission mechanism manipulator has a fail-safe advantage in that, except of the loss of backlash control, it can continue to function when one of its actuators fails. A two-DOF backlash-free arm has been reduced to practice to demonstrate the principle.
摘要:
A motor-integrated transmission mechanism for use in parallel hybrid electric vehicles. The transmission can provide five basic modes of operation that can be further classified into sixteen sub-modes: one electric motor mode, four engine modes, four engine/charge modes, three power modes and four regenerative braking modes. Each of these sub-modes can be grouped into like clutching conditions, providing the functional appearance of a conventional 4-speed automatic transmission, with electric launch, engine-only, engine/charge, power-assist, and regeneration capability. CVT capability is provided with one of the engine/charge modes. The transmission can be incorporated in front-wheel drive and in rear-wheel drive vehicles.
摘要:
This invention provides a fabrication process for manufacturing of truly 3-dimensional micromechanisms which takes advantages of SOI (silicon-on-insulator) wafers each of which is processed to create a respective structural element of the 3-dimensional micromechanisms by DRIE (deep reactive ion etching) of the wafer and thermal oxidation of the trenches opened during the DRIE etching. The wafers are sequentially bonded into a multistack structure from which the 3-D micromechanism. is released by XeF2 etching. Thermally grown SiO2 is used as structural material for the 3-D micromechanism.
摘要:
Disclosed is a novel parallel hybrid transmission that transmits torque from two power sources to the drive wheels of a vehicle. The transmission functions with a single heat engine and a single electric motor/generator. Through the use of a compound planetary gear train and four automatically controlled clutches, the transmission is able to (i) sum torque from the two power sources to drive the vehicle; (ii) split torque from the heat engine to drive the vehicle and charge the batteries; (iii) transmit torque individually from either of the two power sources; and (iv) operate as a one- or two-degree-of-freedom mechanism. The configuration of clutches and the compound planetary gear train enable thirteen modes of operation, namely, one motor-only mode, three combined motor and engine modes, one continuous variable transmission/charging mode, four engine-only modes, and four regenerative braking modes. Because the design is based on conventional automatic transmission components, the design is simple, compact, efficient, and reliable.
摘要:
A new generation of hybrid form multi-axis machine tools is described. The hybrid machine tools comprise a position mechanism and an orientation mechanism. Both mechanisms are three-DOF parallel mechanisms that can be connected either in series to form a hybrid parallel-serial manipulator, or in parallel to form a cooperating machine. The position mechanism is used for manipulating the position and the orientation mechanism is used for manipulating the orientation of an object. Six-axes machining of a workpiece is achieved by coordinating the motions of the position and orientation mechanisms. This approach has several important advantages. First of all, a high stiffness, low inertia, and high speed machine tool is realized by using the parallel construction. Secondly, its direct and inverse kinematic solutions could be solved in closed forms which would greatly simplify the control and path planning problems. Thirdly, it has a relatively large workspace in comparison to fully parallel platform manipulators. Fourthly, its position and orientation are completely decoupled. Lastly, it utilizes mostly revolute joints which can be precisely made at low cost.
摘要:
A crankshaft mounted secondary shaking force balancer for multicylinder engines and the like in which eccentrically rotating balance weights carried on the crankshaft and arranged for substantial primary balance are combined in oppositely rotating groups of weights driven by stationary ring or sun gears and associated planetary gears to provide coacting rotating forces that combine to apply directly to the crankshaft a secondary shaking force reciprocating at twice crankshaft speed and available to balance equivalent oppositely directed shaking forces developed by the crankshaft connected moving components of the engine.
摘要:
An even firing 90.degree. V6 four stroke cycle engine is provided with a single line balancer having a combination of primary balance weights and secondary Oldham coupling balancers rotating opposite crankshaft rotation which, combined with crankshaft counterweights, provide complete offsetting of the engine primary rotating unbalance couple together with offsetting of a large portion of the engine secondary rotating unbalance couple and leaving a small residual secondary unbalance couple for absorption by the engine mounting system.
摘要:
A half speed balancer for unbalanced mechanisms such as internal combustion engines comprises an Oldham coupling device with a central coupler that orbits in a curved (usually circular) path at a frequency twice the speed of the coupling rotation. The balancer substitutes for an equivalent rotating eccentric weight when driven at only half the rotational speed thus causing reduced bearing friction and noise and may be used in multiples like eccentric weights to offset various unbalance conditions.
摘要:
A Six-Degree-of-Freedom Parallel-Manipulator having three inextensible limbs for manipulating a platform is described in which the three inextensible limbs are attached via universal joints to the platform at non-collinear points. Each of the inextensible limbs is also attached via universal joints to a two-degree-of-freedom parallel driver such as a five-bar lineage, a pantograph, or a bidirectional linear stepper motor. The drivers move the lower ends of the limbs parallel to a fixed base and thereby provide manipulation of the platform. The actuators are mounted on the fixed base without using any power transmission devices such as gears or belts.