A smooth impact rotation motor using a multi-layered torsional piezoelectric actuator

Abstract

A smooth impact rotation motor was fabricated and successfully operated using a torsional piezo actuator. Yoshida et al. reported a linear type smooth impact motor in 1997. This linear motor demonstrated a high output force and a long stroke. A superior feature of the smooth impact drive is a high positioning resolution compared with an impact drive. The positioning resolution of SIDM (smooth impact drive mechanism) is equal to the piezo displacement. The reported positioning resolution of the linear type was 5 nm. Our rotation motor utilized a torsional actuator containing multi-layered piezoelectric material. The torsional actuator was cylindrical in shape with an outer diameter of 15 mm, an inner diameter of 10 mm, and a length of 11 mm. Torsional vibration performance was measured with a laser Doppler vibrometer. The obtained torsional displacement agreed with the calculated values and was sufficient to drive a rotor. The rotor was operated with a saw-shaped input voltage (180 V; 8 kHz). The revolution direction was reversible. The maximum revolution speed was 27 rpm, and the maximum output torque was 56 gfcm. In general, smooth-impact drives do not show high efficiency; however, the level of efficiency of our results (max., 0.045%) could be increased by improving the contact surface material. In addition, we are studying quantitative consideration, for example, about the optimum pre-load or frictional force.

Piezoelectric Inertia Motors—A Critical Review of History, Concepts, Design, Applications, and Perspectives

“…The use of the different terms rather seems to have historical reasons: "impact drive (mechanism)" is used for moving actuator motors, and mostly by authors whose works are to different extents based on the early works of Higuchi et al [35,110] on this type of motor; e.g., in [64,70,[113][114][115][116]. The derived term "smooth impact drive mechanism" is used for fixed actuator motors by authors who directly or indirectly refer to the works of Okamoto, Yoshida et al [26,117,118] (e.g., in [25,95,119,120]). On the other hand, "stick-slip drive" or similar has been used for inertia motors of any design, even if they clearly have a moving actuator; e.g., the motors of Niedermann et al [41] and Smith et al [51].…”

“…Combinations of one of these hard materials and metals are also common, mostly with steel [30,44,51,52,78,96,139,160,161] or bronze [49,162,163], sometimes also with other metals [49,[164][165][166]. A steel-steel couple is also used sometimes [34,47,50,62,84,157], while couples of steel with other metals [167], of two relatively soft partners like bronze [168], or with a very soft partner like polytetrafluorethylene (PTFE) [169,170] or other plastics [84,118,138,171,172] are rare.…”

“…[110][111][112][113][114][115][116][117][118][119][120][121][122][123][124][125][126][127][128][129] and on the mechanical boundary conditions, especially on the prestress of the actuator ( [212] (pp. 110-129); [213] (pp.…”

Nonlinear Dynamics of an Electrically Driven Impact Microactuator

“…Although harmful in many mechanical systems, such as rattling in a gear box, recurrent impacts are utilized for the operation of devices in macro-, micro-, and even nanoscale devices. In this paper, we study the impacting dynamics in an electrically driven microactuator, which has applications in microscopes, assembly of micromachines, nanoscale data storage, and microsurgery [1][2][3][4][5][6][7][8][9][10][11][12][13] . When the characteristic size is less than a millimeter, manual assembly of microcomponents faces difficulty of sticking due to surface adhesion forces, such as electrostatic forces, van der Waals forces, and surface tension [13,14].…”

A Millimetre-Sized Robot Realized by a Piezoelectric Impact-Type Rotary Actuator and a Hardware Neuron Model

“…Some specially designed actuators have been reported; for example, those that directly use the vibration of the piezoelectric device [13]. The impactdriven linear actuator operates by friction and inertia [14]. These actuator structures are both simple and suitable for miniaturization, but their displacement is smaller than that of conventional SMA.…”