Pendular unit with a monolithic inertial mass mounted on a piezoelectric beam, in particular for an energy harvester in a leadless autonomous cardiac capsule
AssigneeCairdac
InventorsWilly Regnier, An Nguyen-Dinh
Life of this patent
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Abstract
The pendular unit comprises a piezoelectric transducer beam (22), and an inertial mass mounted at the free distal end of the beam (22). The inertial mass (26) is a monolithic part including a cavity in the form of an axial slit (64), with two opposite longitudinal surfaces (74) extending along a central axis of the inertial mass (26). The axial slit (64) opens out on the proximal side of the inertial mass (26), and receives the free distal end of the beam (22), secured between the two opposite longitudinal surfaces (74) of the axial slit (64).
Claims15
A pendular unit for a piezoelectric energy harvesting (PEH) module, the pendular unit comprising:
- a lead zirconate titanate (PZT) transducer beam that is elastically deformable in bending and that extends in an axial direction between a clamped proximal end and a free distal end;
- and
- an inertial mass mounted at the free distal end of the PZT transducer beam and mobile in a transverse direction,
- the pendular unit being adapted to convert a mechanical energy produced by oscillations of the pendular unit under an effect of external stresses undergone by the PEH module into an oscillating electrical signal collected by surface electrodes of the PZT transducer beam,
- wherein the inertial mass is a monolithic part including an axial slit forming a cavity, with two opposite longitudinal surfaces extending along a central axis of the inertial mass, the axial slit opening out on a proximal side of the inertial mass and receiving the free distal end of the PZT transducer beam,
- and wherein the axial slit forming said cavity comprises:
- on a proximal side, a clamping area in which the PZT transducer beam is secured between the two opposite longitudinal surfaces of the axial slit;
- and
- on a distal side, a non-clamping area.
A method for assembling a pendular unit for a piezoelectric energy harvesting (PEH) module, the pendular unit comprising a lead zirconate titanate (PZT) transducer beam that is elastically deformable in bending and an inertial mass mounted at a free distal end of the PZT transducer beam and mobile in a transverse direction,
- the method comprising the following steps:
- a) obtaining an inertial mass by forming an axial slit in a mass of a monolithic part, the axial slit extending along a central axis of the inertial mass from a proximal end, thus forming two opposite longitudinal surfaces,
- the axial slit comprising successive cavities with different geometries, comprising:
- on a proximal side, a clamping area in which the PZT transducer beam is secured between the two opposite longitudinal surfaces of the axial slit;
- and on a distal side, a non-clamping area;
- b) inserting into the axial slit the free distal end of the PZT transducer beam;
- and
- c) securing the free distal end of the PZT transducer beam to the monolithic part between the two opposite longitudinal surfaces of the axial slit in the non-clamping area.
Dependencies are inferred from the claim text.