Single piezo-actuator rotary-hammering (SPaRH) drill
A Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill includes a horn actuator having high power piezoelectric materials and a flexure pre-stress to increase the actuators effectiveness. The drill is a low mass, low power, compact coring drill measuring 20-cm high by 7-cm diameter and having a total weight of 2 kg including drive electronics. Using an average power of 50-Watts, the drill basalt is expected to cut basalt at a rate of 0.2 cm/min down to depth of 10-cm and create cuttings and an intact core. The drill is expected to operate under different environments including Martian ambient (6 Torr and down to −50° C.), and liquid nitrogen temperatures (77 K) and low pressure (<<1 Torr) to simulate lunar polar and Europa conditions. Materials expected to be sampled include Kaolinite, Saddleback Basalt, Limestone, Volcanic Breccia, Siltstone, ice, permafrost and layered rocks with different hardness.
1. A Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill, comprising:
a single piezoelectric stack actuator having an electrical signal input port and a mechanical signal output port;
a horn transducer structure comprising a plurality of slotted helical members, said horn transducer mechanically coupled to said single piezoelectric stack actuator mechanical Signal output port to receive a linear mechanical signal from said single piezoelectric stack actuator and configured to provide an output mechanical signal simultaneously having both a longitudinal mode and a twisting mode; and
a rotor/stator interface mechanically coupled to said slotted helical members of said horn transducer, said rotor/stator interface configured to receive from said horn transducer said mechanical signal simultaneously having both a longitudinal mode and a twisting mode, and configured to impart a longitudinal motion and a rotational motion simultaneously to a tool.
2. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 1 , wherein said single piezoelectric stack actuator comprises a flexurc horn.
3. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 1 , wherein said single piezoelectric stack actuator comprises a pre-stress bolt.
4. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 1 , wherein said single piezoelectric stack actuator comprises a piezoelectric single crystal.
5. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 1 , wherein said rotor stator/interface is configured to hold a removable tool by way of a ball detent holding mechanism.
6. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 1 , wherein said rotor/stator interface comprises a keyed free mass.
7. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 1 , further comprising an electronic driving circuit configured to supply an electrical signal to said electrical signal input port of said single piezoelectric stack actuator.
8. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 1 , further comprising a removable tool.
9. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 8 , wherein said removable tool is selected from the group consisting of a powder bit, a coring bit and a rock abrasion bit.
10. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 8 , wherein said removable tool comprises an auger.
11. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 8 , wherein said removable tool comprises a cuttings collection slot.
12. The Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill of claim 1 , wherein said single piezoelectric stack actuator is configured to be excited in the range of 3 KHz to 100 KHz.