Abstract: An ultrasound probe according to the present disclosure includes: an ultrasound element unit 2; a tip storage portion 7 including a panel which is sealed by a holding member and in which an acoustic medium liquid 6 and the ultrasound element unit 2 are stored; a cover member 17a disposed on a surface of the holding member 10a; and an acoustic medium liquid reservoir portion 15a for retaining the acoustic medium liquid 6 in a space formed by the holding member 10a and the cover member 17a. The holding member 10a has at least one communication path that communicates with the acoustic medium liquid reservoir portion 15a and an inside of the tip storage portion 7. The cover member has at least one ventilation path that communicates with the acoustic medium liquid reservoir portion and an outside of the tip storage portion.

Abstract: With a hydrodynamic bearing device 10, a first gap G1 is formed between a shaft 12 and a sleeve 11. A second gap G2 is formed between a sleeve cap 16 and the sleeve 11, and holds a lubricant 17. A thrust bearing member 21 is disposed near the inner peripheral surface of a center hole 16a of the sleeve cap 16. A third gap G3 is formed between the thrust bearing member 21 and the sleeve cap 16, and is open to the atmosphere. A fourth gap G4 is formed between the thrust bearing member 21 and the sleeve 11. The lubricant 17 circulates along a circulation passage that includes a communicating path 11b, the first gap G1 and the second gap G2.

Abstract: A hydrodynamic bearing rotary device which can reduce rotation friction, and recording and reproducing apparatus including the same is provided. In the hydrodynamic bearing rotary device, such as hard disc devices, a rotary shaft having a hub on one end is provided in a bearing of a sleeve so as to be rotatable. Thrust hydrodynamic grooves are provided on the other end surface of the rotary shaft, to form a thrust bearing with the thrust plate. A communication path is provided in the sleeve. The second gap between the hub and the sleeve end surface is used as a flow channel and is connected to the communication path. In this way, the rotation friction torque of the thrust bearing can be made sufficiently small, and internal pressure in bonded portions of the rotary shaft or the bottom plate can be suppressed. Thus, the oil can be prevented from oozing out from a small space of the bonded surfaces. Furthermore, the hydrodynamic bearing can be made thin.

Abstract: A hydrodynamic bearing, a motor including the same, and a recording and reproducing apparatus which can improve vibration resistance property and suppress noises even in a situation where vibration is expected are provided. Radial hydrodynamic grooves formed on an inner peripheral surface of a sleeve have a shape which satisfy the relational expression L2<L1/2. L1 refers to a length of a hydrodynamic causing portion of a radial bearing portion in an axial direction; and L2 refers to a length in the axial direction from a benchmark point where an end portion of the radial bearing portion on an outward side in the axial direction and center of a predetermined radial hydrodynamic groove cross each other, to a relative rotational direction backward side end portion of a radial hydrodynamic groove adjacent to the predetermined radial hydrodynamic groove on the forward side in a relative rotational direction.

Abstract: In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Abstract: In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Abstract: With a hydrodynamic bearing device 10, a first gap G1 is formed between a shaft 12 and a sleeve 11. A second gap G2 is formed between a sleeve cap 16 and the sleeve 11, and holds a lubricant 17. A thrust bearing member 21 is disposed near the inner peripheral surface of a center hole 16a of the sleeve cap 16. A third gap G3 is formed between the thrust bearing member 21 and the sleeve cap 16, and is open to the atmosphere. A fourth gap G4 is formed between the thrust bearing member 21 and the sleeve 11. The lubricant 17 circulates along a circulation passage that includes a communicating path 11b, the first gap G1 and the second gap G2.

Abstract: In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Abstract: There are provided a thrust plate with which there is less warpage when the thrust plate has been incorporated into a hydrodynamic bearing device, which improves the reliability of the hydrodynamic bearing device, as well as a hydrodynamic bearing device, a spindle motor, and an information apparatus equipped with this thrust plate, and a method for manufacturing a thrust plate. With a thrust plate that is provided at one end of a shaft of a hydrodynamic bearing device and that closes off one end of a sleeve formed so as to surround the shaft via a lubricating fluid (oil), a laser irradiated portion is provided to the opposite side of the thrust plate from the side facing the shaft in order to reduce the warpage that is produced by the formation of a hydrodynamic groove on the side facing the shaft, and the warpage that occurs during assembly, etc.

Abstract: In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Abstract: In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Abstract: A hydrodynamic bearing, a motor including the same, and a recording and reproducing apparatus which can improve vibration resistance property and suppress noises even in a situation where vibration is expected are provided. Radial hydrodynamic grooves formed on an inner peripheral surface of a sleeve have a shape which satisfy relational expression L2<L1/2. L1 refers to a length of a hydrodynamic causing portion of a radial bearing portion in an axial direction; and L2 refers to a length in the axial direction from a benchmark point where an end portion of the radial bearing portion on an outward side in the axial direction and center of a predetermined radial hydrodynamic groove cross each other, to a relative rotational direction backward side end portion of a radial hydrodynamic groove adjacent to the predetermined radial hydrodynamic groove on the forward side in a relative rotational direction.

Abstract: A hydrodynamic bearing rotary device which can reduce rotation friction, and recording and reproducing apparatus including the same are provided. In the hydrodynamic bearing rotary device such as hard disc devices, a rotary shaft having a hub on one end is provided in a bearing of a sleeve so as to be rotatable. Thrust hydrodynamic grooves are provided on the other end surface of the rotary shaft, to form a thrust bearing with the thrust plate. A communication path is provided in the sleeve. The second gap between the hub and the sleeve end surface is used as a flow channel and is connected to the communication path. In this way, the rotation friction torque of the thrust bearing can be made sufficiently small, and internal pressure in bonded portions of the rotary shaft or the bottom plate can be suppressed. Thus, the oil can be prevented from oozing out from a small space of the bonded surfaces. Furthermore, the hydrodynamic bearing can be made thin.

Abstract: A high-accuracy, long-life hydrodynamic bearing that does not cause oil film breakage in bearing clearances and a disc rotation apparatus using the bearing is disclosed. Oil film breakage is avoided as negative pressure is prevented from generating between the shaft and sleeve of the hydrodynamic bearing. Herringbone shaped dynamic pressure generating grooves, located on the thrust bearing section and the radial bearing section of the hydrodynamic bearing, are oil filled and have optimum shapes. The optimum shapes prevent the generation negative pressure and thus prevents the coagulation of air bubbles that can cause oil film breakage. The disc rotation apparatus, that holds a reproduction/recording disc, is concentrically secured to the hydrodynamic bearing and rotated. The disc is put into contact with magnetic or optical heads while rotating in the disc rotation apparatus. Both the hydrodynamic bearing and the disc rotation apparatus experience high reliability.

Abstract: A high-accuracy, long-life hydrodynamic bearing that does not cause oil film breakage in bearing clearances and a disc rotation apparatus using the bearing is disclosed. Oil film breakage is avoided as negative pressure is prevented from generating between the shaft and sleeve of the hydrodynamic bearing. Herringbone shaped dynamic pressure generating grooves, located on the thrust bearing section and the radial bearing section of the hydrodynamic bearing, are oil filled and have optimum shapes. The optimum shapes prevent the generation negative pressure and thus prevents the coagulation of air bubbles that can cause oil film breakage. The disc rotation apparatus, that holds a reproduction/recording disc, is concentrically secured to the hydrodynamic bearing and rotated. The disc is put into contact with magnetic or optical heads while rotating in the disc rotation apparatus. Both the hydrodynamic bearing and the disc rotation apparatus experience high reliability.

Abstract: A hydrodynamic bearing device includes a sleeve having a bearing bore substantially at a center portion, a shaft inserted in the bearing bore in a rotatable manner, a thrust plate for supporting an end of the shaft in the thrust direction and an upper retaining portion that has an opening portion through which the shaft passes and covers the upper surface of the sleeve. A radial hydrodynamic bearing is formed between the bearing bore of the sleeve and the shaft, while a thrust hydrodynamic bearing is formed between the thrust plate and an end of the shaft. A first space is formed between the upper surface of the sleeve and the upper retaining portion. A second space is formed between the upper retaining portion and a step portion.

Abstract: Radial dynamic pressure grooves are provided in a first region 4A and a second region 4B on the side of a fixed shaft 2. A vent 2D is provided inside the top end 2A of the fixed shaft 2. The vent 2D connects spaces over and under a flange 3 to each other. The flange 3 in an annular shape is fixed at the top end 2A of the fixed shaft 2. Thrust dynamic pressure grooves 3A and 3B are provided on the surfaces of the flange 3. A circulation hole 3C is provided in the flange 3, and connects spaces over and under the flange 3 to each other. A sleeve 4 revolves around the fixed shaft 2. A thrust plate 6 in an annular shape is fixed at the top of the sleeve 4 and opposed to the flange 3. The first region 4A, the second region 4B, the thrust dynamic pressure grooves 3A and 3B, and the circulation hole 3C of the flange 3 are filled with a lubricant 7.

Abstract: In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Abstract: A reduced pressure or pressurizing pump is provided which can be used in a wide variety of fields of foods, pharmaceuticals, medical treatment, agriculture, healthcare equipment, room air conditioning, combustion, biotechnology, and so on. By the application of the pump of the present invention, there can be materialized, for example, an oxygen enriching apparatus or a nitrogen enriching apparatus, which have the features of an oil-free structure, a small size, compactness, low vibration, low noise, long operating life, and so on. A transport groove of a viscosity pump, which exerts a force feed action on the fluid, is formed at a relative displacement interface between a rotor and a housing, and the rotor supported by a bearing capable of coping with a high-speed rotation is rotated at a high speed.

Abstract: A sleeve 1 is fixed on a base. Radial dynamic-pressure generating grooves 1A and 1B are provided on an inner surface of the sleeve 1. A thrust plate 4 hermetically seals a lower opening end of the sleeve 1. A shaft 2 is inserted inside the sleeve 1, being allowed to revolve. A flange 3 is fixed at the bottom end of the shaft 2, and its lower surface is placed close to an upper surface of the thrust plate 4. Thrust dynamic-pressure generating grooves 3A and 3B are provided on the surfaces of the flange 3. Gaps A–H among the sleeve 1, the shaft 2, the flange 3, and the thrust plate 4 are filled with a lubricant 5. Hollows 1C–1F are provided on the inner surface of the sleeve 1. The gaps A and C over the thrust dynamic-pressure generating grooves 3A and 3B and their vicinities are narrower than the surrounding gaps B and D (A<B, A<D, C<B, and C<D), and the surrounding gaps B and D are narrower than the gap H in the upper opening end of the sleeve 1 and its vicinity (B<H and D<H).