Abstract: A method of producing a light water reactor fuel assembly may include: setting conditions at least concerning an operation cycle period and burnup; setting an initial enrichment of enriched uranium; calculating excess reactivity of a light water reactor core where light water reactor fuel assemblies including the enriched uranium are burned until an end stage of a final operation cycle; determining whether a condition where excess reactivity at an end of a first operation cycle in the burnup calculation step is close to a predetermined positive value is true or not; and returning to the setting of the initial enrichment, when it is determined at the determining that the situation is not true, or deciding an enrichment of the enriched uranium when it is determined that the situation is true.

Abstract: To maintain the functionality as a compact and inexpensive motor-mounted internal gear pump and also offer further inexpensiveness and reliability. The motor-mounted internal gear pump 80 has a pump part 81 including: an inner rotor 1, an outer rotor 2, a pump casing and an internal shaft 5. The pump casing has flat inner surfaces facing both end faces of the inner rotor 1 and the outer rotor 2. The internal shaft 5 includes a bearing 51 which is inserted into an axial hole of the inner rotor 1 and a fitting part 53 extending from both its ends in both axial directions. The pump casing includes two pump casing members 3, 4 as separate members with flat inner surfaces 25, 26 respectively.

Abstract: A motor-mounted internal gear pump 80 includes: a pump part 81 which sucks and discharges hydraulic fluid; and a motor part 82 which drives the pump 81. The pump part 81 includes: an inner rotor 1 with teeth on its outer surface; an outer rotor 2 with teeth on its inner surface to mesh with the teeth of the inner rotor; and pump casings 3, 4 which house the inner rotor 1 and the outer rotor 2. The motor part 82 includes a rotator 11 and a stator 12 which rotates the rotator 11. A common member 112 of permanent magnet material as resin containing magnetic powder serves as the rotator 11 and the outer rotor 2. This structure assures further inexpensiveness and reliability while maintaining compactness and inexpensiveness in functions.

Abstract: A motor-integrated internal gear pump that is inexpensive and highly reliable while maintaining characteristics of small size and inexpensive functions. The motor-integrated internal gear pump (80) has a pump section (81) with an inner rotor (1), an outer rotor (2), a pump casing, and an inner shaft (5). The pump casing has flat inner surfaces facing both end surfaces of each of the inner rotor (1) and the outer rotor (2). The inner shaft (5) has a bearing section (51) inserted into a shaft hole of the inner rotor (1) and fitting sections extending axially outward from both end surfaces of the inner shaft (51). The pump casing is constructed from two pump casing members (3, 4) where the flat inner surfaces (25, 26) are formed as separate members.

Abstract: A drainage pump has a pump part in which blades mounted on a rotary shaft are arranged in a pump casing and an underwater bearing unit which uses pumped water mixed with hard particles as a lubricant and has a sliding bearing for journaling the rotary shaft. A portion of the rotary shaft journaled by the sliding bearing is formed of a cemented carbide material and a shaft journaling surface of the sliding bearing is formed of a thermoplastic resin material to be embedded with hard particles.

Abstract: The invention relates to a pump which assures high reliability while maintaining the functionality as a compact, inexpensive motor-mounted internal gear pump. The pump includes an inner rotor with teeth on its outer surface, an outer rotor with teeth on its inner surface to engage with the inner rotor teeth, a pump casing housing both the rotors, and an inner rotor support shaft which pivotally supports the inner rotor. The motor includes a rotator located inside the pump casing, and a stator located outside the pump casing. The pump casing includes two casing members which face both side faces of the outer rotor and the inner rotor and have an outer rotor bearing which pivotally supports both sides of the outer rotor. The inner rotor support shaft has an inner rotor bearing eccentric to the outer rotor to support the inner rotor pivotally in a rotatable manner and connects the two casing members virtually concentrically with the outer rotor bearing.

Abstract: A drainage pump has a pump part in which blades mounted on a rotary shaft are arranged in a pump casing and an underwater bearing unit which uses pumped water mixed with hard particles as a lubricant and has a sliding bearing for journaling the rotary shaft. A portion of the rotary shaft journaled by the sliding bearing is formed of a cemented carbide material and a shaft journaling surface of the sliding bearing is formed of a thermoplastic resin material to be embedded with hard particles.