摘要:
A single piezoelectric is excited at a first frequency to cause two vibration modes in a resonator producing a first elliptical motion in a first direction at a selected contacting portion of the resonator that is placed in frictional engagement with a driven element to move the driven element in a first direction. A second frequency excites the same piezoelectric to cause two vibration modes of the resonator producing a second elliptical motion in a second direction at the selected contacting portion to move the driven element in a second direction. The piezoelectric is preloaded in compression by the resonator. Walls of the resonator are stressed past their yield point to maintain the preload. Specially shaped ends on the piezoelectric help preloading. The piezoelectric can send or receive vibratory signals through the driven element to or from sensors to determine the position of the driven element relative to the piezoelectric element or resonator. Conversely, the piezoelectric element can receive vibration or electrical signals passed through the driven element to determine the position of the driven element. The resonator is resiliently urged against the driven element, or vice versa. Plural resonators can drive common driven elements.
摘要:
The invention relates to a piezoelectric motor comprising a piezoelectric component that is connected to a resonator and a two-dimensional resonator that interacts with a movable element, the resonator having principal surfaces that are parallel to each other and that are also identical in shape and size. The invention further relates to methods for producing such piezoelectric motors, wherein the resonators are manufactured by cutting a profiled, extruded bar into lengths or by cutting, preferably by punching, from sheet metal having constant thickness. Finally, this invention relates to a method for exciting such a piezoelectric motor, wherein the excitation frequency or frequencies is/are generated by the control electronics as a function of time in response to the respective peak current and/or in response to the respective phase minimum between current and voltage and/or in response to the change in phase.
摘要:
A piezoelectric motor has a piezoelectric element that is connected to a resonator, and a driven element that interacts with the piezoelectric motor. During the service life of the motor and resonator at least one operating state variable changes, and the change in operating variable is used to help avoid failure of the piezoelectric motor.
摘要:
A single piezoelectric is excited at a first frequency to cause two vibration modes in a resonator producing a first elliptical motion in a first direction at a selected contacting portion of the resonator that is placed in frictional engagement with a driven element to move the driven element in a first direction. A second frequency excites the same piezoelectric to cause two vibration modes of the resonator producing a second elliptical motion in a second direction at the selected contacting portion to move the driven element in a second direction. The piezoelectric is preloaded in compression by the resonator. Walls of the resonator are stressed past their yield point to maintain the preload. Specially shaped ends on the piezoelectric help preloading. The piezoelectric can send or receive vibratory signals through the driven element to or from sensors to determine the position of the driven element relative to the piezoelectric element or resonator. Conversely, the piezoelectric element can receive vibration or electrical signals passed through the driven element to determine the position of the driven element. The resonator is resiliently urged against the driven element, or vice versa. Plural resonators can drive common driven elements.
摘要:
A structural support beam having a top wall joined to a side wall at an angle substantially different from a right angle. When installed in a facility or machine with the side wall parallel to a vertical reference, no surface on the support beam is parallel to a horizontal reference, thereby providing for rapid and thorough draining of water deposited on any surface of the beam. Some beam embodiments place the top wall at an angle of about twenty degrees above a horizontal reference when the beam is installed. Alternatively, the top wall may be at an angle of about twenty degrees below the horizontal reference. Some beam embodiments have an open side. Alternatively, a bottom wall may be attached to a side wall to form a tubular support beam. A support beam may include a lower beam joined to an upper beam by a connector bar.
摘要:
A structural support beam having a top wall joined to a side wall at an angle substantially different from a right angle. When installed in a facility or machine with the side wall parallel to a vertical reference, no surface on the support beam is parallel to a horizontal reference, thereby providing for rapid and thorough draining of water deposited on any surface of the beam. Some beam embodiments place the top wall at an angle of about twenty degrees above a horizontal reference when the beam is installed. Alternatively, the top wall may be at an angle of about twenty degrees below the horizontal reference. Some beam embodiments have an open side. Alternatively, a bottom wall may be attached to a side wall to form a tubular support beam. A support beam may include a lower beam joined to an upper beam by a connector bar.
摘要:
A drying apparatus for use with many kinds of objects, but is particularly suited for use in drying most kinds of produce and vegetables including leaf vegetables. In one embodiment, the dryer includes a canted drum design which provides a number of benefits and advantages over prior art designs. The canted design allows the use of a spin drying method that breaks up clumps of material in the dryer and assists in the even distribution of material, thereby improving load balance. The canted design provides ergonomic advantages to the operator when loading and unloading the dryer, and, the canted design allows easy access to the drive system for maintenance and repairs.