摘要:
A piezoelectric resonator includes a piezoelectric resonator element having a resonating arm and a metal film that is formed on the resonating arm; a package including a bottom part on which the piezoelectric resonator element is fixed and a frame wall that surrounds the bottom part, and having an opening above the bottom part; and a lid including a frame in which a through hole is provided and an optically transparent part that has an upper face and a lower face of the frame and is disposed at the through hole, the through hole penetrating a front face and a back face, the lower face of the optically transparent part being disposed so as to oppose the metal film, and the lid closing the opening of the package such that the lid overlaps with the bottom part and the frame wall, the through hole having a curved inner wall face whose curved face is coupled with at least one of the front face and the back face at least one opening edge of the front face and the back face and a vertical inner wall face that is provided vertical to the front face and the back face and in a part of a thickness direction of the frame, and the optically transparent part being provided so as to contact closely with at least a part of the vertical inner wall face and at least a part of the curved inner wall face.
摘要:
A piezoelectric resonator includes a piezoelectric resonator element having a resonating arm and a metal film that is formed on the resonating arm; a package including a bottom part on which the piezoelectric resonator element is fixed and a frame wall that surrounds the bottom part, and having an opening above the bottom part; and a lid including a frame in which a through hole is provided and an optically transparent part that has an upper face and a lower face of the frame and is disposed at the through hole, the through hole penetrating a front face and a back face, the lower face of the optically transparent part being disposed so as to oppose the metal film, and the lid closing the opening of the package such that the lid overlaps with the bottom part and the frame wall, the through hole having a curved inner wall face whose curved face is coupled with at least one of the front face and the back face at least one opening edge of the front face and the back face and a vertical inner wall face that is provided vertical to the front face and the back face and in a part of a thickness direction of the frame, and the optically transparent part being provided so as to contact closely with at least a part of the vertical inner wall face and at least a part of the curved inner wall face.
摘要:
A piezoelectric resonator includes a piezoelectric resonator element having a base portion and a resonating arm extending from the base portion, a package including a bottom to which the piezoelectric resonator element is fixed and a frame wall that surrounds the bottom and having an opening above the bottom, and a lid for closing the opening of the package. In this piezoelectric resonator, the lid includes a main body having a through-hole formed therein, a flange formed to surround a periphery of the main body and to be thinner than the main body, and an optically transparent member located in the through-hole. The flange has a joining portion with an upper end surface of the frame wall, and the main body projects in a direction from the flange to the bottom in a thickness direction. Also, the through-hole is at a position displaced in a first direction approaching a first end of the main body from a center of the main body. Also, the flange is joined with the frame wall such that a clearance between the first end and the joining portion of the flange nearest to the first end is larger than a clearance between a second end in a second direction opposite to the first direction of the main body and the joining portion of the flange nearest to the second end.
摘要:
A piezoelectric device includes: a piezoelectric vibrating reed; and a package, wherein the piezoelectric vibrating reed has a vibrating part and first and second supporting arms extending from a base end part, the package has a base, a lid, a cavity defined by the base and the lid, a convex part projecting from the base or the lid into the cavity, a length of the first supporting arm is shorter than a length of the second supporting arm, and the convex part is provided in a range ahead of a leading end of the first vibrating arm in an extension direction of the first supporting arm and at least partially overlapping with the second supporting arm in a length direction of the piezoelectric vibrating reed so as not to overlap with the piezoelectric vibrating reed in a plan view.
摘要:
The hydrodynamic bearing device has a sleeve composed of a sintered material and having a compression-absorbing space inside the sleeve, the sleeve having a bearing hole in the center thereof; a shaft rotatably inserted into the bearing hole; a bearing portion formed between the bearing hole and the shaft; a hydrodynamic groove formed on at least one of the internal peripheral surface of the bearing hole and the external peripheral surface of the shaft; a concavity having one or more steps and formed to one end of the sleeve in the axial direction; a convexity formed to the other end of the sleeve in the axial direction, the convexity having a shape similar to the concavity; and a lubricating fluid filled in the gap of the bearing portion. The hydrodynamic bearing device has a readily obtainable predetermined shape precision, the internal density of the sintered material is made uniform, and lubricating fluid therein does not leak from the surface.
摘要:
A hydrodynamic bearing having a high performance and a long life and a manufacturing method for the same are provided by forming hydrodynamic grooves to have a sufficient depth with a high accuracy, and sealing remaining pores on a bearing surface. A shaft is inserted into a bearing hole of a sleeve so as to be relatively rotatable. The bearing hole has a bearing surface having hydrodynamic grooves. The sleeve is formed by: forming metal powder to have a hollow cylindrical shape, sintering the metal powder; inserting a core rod in a pattern having a tapered surface into a bore of the sintered metal material; forming an inner surface having hydrodynamic grooves by pressing the sintered metal material from upper, lower and outer peripheral direction; inserting a core rod having a wide diameter portion and a narrow diameter portion into the bore of the sintered metal material to form the bearing bore surface of a hydrodynamic groove with the small diameter portion and to form the sleeve inner surface with the wide diameter portion at the same time; and removing the core rod from bore of the sintered metal material to have the inner periphery formed as such as the bearing inner surface and a large diameter portion as a lubricating fluid reservoir. Thus, grooves can be processed with a high accuracy.
摘要:
To generate the desired dynamic pressure with an inexpensive structure. A hydrodynamic bearing device comprises a sleeve 1, a shaft 2, and oil 100. With the sleeve 1, a stepped portion 1b provided at one end and an inner peripheral face 1e extending linearly in the axial direction and continuously with the stepped portion 1b are formed by a working method that involves the use of a metal mold. The shaft 2 is inserted so as to be capable of relative rotation in the inner peripheral face 1e of the sleeve 1. The oil 100 fills the space formed between the inner peripheral face 1e of the sleeve 1 and the outer peripheral face 2a of the shaft 2. Dynamic pressure generation grooves 9a and 9b, which open in the axial direction at at least one end in the axial direction of the inner peripheral face 1e and are continuous in the axial direction from one end, are formed in the inner peripheral face 1e.
摘要:
A spindle motor including a rotor hub which is rotationally driven by a magnetic action of a rotational magnetic field generated when a current is applied to a wire wound around teeth of a stator core and a magnetic field of a magnet provided on a rotor. Herein, the stator core formed by laminating magnetic steel plates is mounted to an outer periphery of a supporting part of a rotation support shaft of the rotor hub, and the supporting part is made of sintered metal containing a ferromagnetic material. This spindle motor can suppress generation of vibration and noise even when it is reduced in size.