Abstract: In a method for manufacturing a stacked iron core, a stacked iron core body is manufactured by stacking so as to be phase-offset with respect to each other in the circumferential direction plural ring-shaped iron core pieces respectively configured by plural circular arc-shaped iron core pieces arranged into ring shapes. Next, each layer of the circular arc-shaped iron core pieces, which are phase-offset with respect to each other in the circumferential direction, is welded together along a stacking direction at plural locations (plural weld portions) arranged around the circumferential direction of an inner circumferential portion or an outer circumferential portion of the stacked iron core body. A pair of key protrusions is formed on inner circumferential portions of the stacked iron core at positions opposing each other, and so key components are rendered unnecessary when assembling a rotor of a vehicle drive motor.

Abstract: In a method for manufacturing a stacked iron core, a stacked iron core body is manufactured by stacking so as to be phase-offset with respect to each other in the circumferential direction plural ring-shaped iron core pieces respectively configured by plural circular arc-shaped iron core pieces arranged into ring shapes. Next, each layer of the circular arc-shaped iron core pieces, which are phase-offset with respect to each other in the circumferential direction, is welded together along a stacking direction at plural locations (plural weld portions) arranged around the circumferential direction of an inner circumferential portion or an outer circumferential portion of the stacked iron core body. A pair of key protrusions is formed on inner circumferential portions of the stacked iron core at positions opposing each other, and so key components are rendered unnecessary when assembling a rotor of a vehicle drive motor.

Abstract: A clutch apparatus is equipped with two clutch structures having a clutch drum therein. A driven plate and a piston are provided in the clutch drum of each clutch structure, and a primary coned disc spring and a secondary coned disc spring, which are ring-shaped, are provided between the driven plate and the piston. A flat portion is formed on an inner peripheral portion of a convex surface of the primary coned disc spring, and the flat portion can come into contact with a counter member first when a load is applied. A load in a flat condition due to elastic deformation is adjusted by the flat portion so as to be a desirable value. Blanks and of the primary coned disc spring and the secondary coned disc spring can be obtained from one sheet of material having the same thickness. In this case, the flat portion is formed by press forming on an inner peripheral portion of the blank in view of the shape thereof after bending forming is performed.

Abstract: A clutch apparatus is equipped with two clutch structures having a clutch drum therein. A driven plate and a piston are provided in the clutch drum of each clutch structure, and a primary coned disc spring and a secondary coned disc spring, which are ring-shaped, are provided between the driven plate and the piston. A flat portion 12 is formed on an inner peripheral portion of a convex surface of the primary coned disc spring 1, and the flat portion 12 can come into contact with a counter member first when a load is applied. A load in a flat condition due to elastic deformation is adjusted by the flat portion so as to be a desirable value. Blanks 1A and 2A of the primary coned disc spring and the secondary coned disc spring can be obtained from one sheet of material having the same thickness. In this case, the flat portion 12A is formed by press forming on an inner peripheral portion of the blank 1A in view of the shape thereof after bending forming is performed.

Abstract: A clutch apparatus is equipped with two clutch structures having a clutch drum therein. A driven plate and a piston are provided in the clutch drum of each clutch structure, and a primary coned disc spring and a secondary coned disc spring, which are ring-shaped, are provided between the driven plate and the piston. A flat portion is formed on an inner peripheral portion of a convex surface of the primary coned disc spring, and the flat portion can come into contact with a counter member first when a load is applied. A load in a flat condition due to elastic deformation is adjusted by the flat portion so as to be a desirable value. Blanks and of the primary coned disc spring and the secondary coned disc spring can be obtained from one sheet of material having the same thickness. In this case, the flat portion is formed by press forming on an inner peripheral portion of the blank in view of the shape thereof after bending forming is performed.

Abstract: A production method for coned disk springs includes: preparing a plate member; punching plural annular blanks from the plate member by pressing; and forming the blanks into coned disk springs. In the pressing, plural slits are formed at one of a peripheral portion and an inner peripheral portion of at least one of the blanks, and a smaller outer diameter blank among the blanks is punched from an inner region of a larger outer diameter blank among the blanks.

Abstract: A clutch apparatus is equipped with two clutch structures having a clutch drum therein. A driven plate and a piston are provided in the clutch drum of each clutch structure, and a primary coned disc spring and a secondary coned disc spring, which are ring-shaped, are provided between the driven plate and the piston. A flat portion 12 is formed on an inner peripheral portion of a convex surface of the primary coned disc spring 1, and the flat portion 12 can come into contact with a counter member first when a load is applied. A load in a flat condition due to elastic deformation is adjusted by the flat portion so as to be a desirable value. Blanks 1A and 2A of the primary coned disc spring and the secondary coned disc spring can be obtained from one sheet of material having the same thickness. In this case, the flat portion 12A is formed by press forming on an inner peripheral portion of the blank 1A in view of the shape thereof after bending forming is performed.

Abstract: A production method for coned disk springs includes: preparing a plate member; punching plural annular blanks from the plate member by pressing; and forming the blanks into coned disk springs. In the pressing, plural slits are formed at one of a peripheral portion and an inner peripheral portion of at least one of the blanks, and a smaller outer diameter blank among the blanks is punched from an inner region of a larger outer diameter blank among the blanks.

Abstract: This invention is concerned with a radial tire, particularly a heavy duty radial tire aiming at the improvement of durability, and is characterized by rendering a ratio W2/W1 of width W1 of a belt layer located side a carcass to width W2 of the remaining belt layer in small slant belt layers arranged at a width corresponding to 0.25–0.50 times a tread width in a widthwise direction of the tire, whereby growth and progress of cracks in the vicinity of cord ends of cords used in the belt resulting in separation failure at widthwise ends of the belt are effectively prevented to overcome a weak point in the tread reinforcement of the radial tire.

Abstract: This invention is concerned with a radial tire, particularly a heavy duty radial tire aiming at the improvement of durability, and is characterized by rendering a ratio W2/W1 of width W1 of a belt layer located side a carcass to width W2 of the remaining belt layer in small slant belt layers arranged at a width corresponding to 0.25-0.50 times a tread width in a widthwise direction of the tire, whereby growth and progress of cracks in the vicinity of cord ends of cords used in the belt resulting in separation failure at widthwise ends of the belt are effectively prevented to overcome a weak point in the tread reinforcement of the radial tire.

Abstract: A heavy duty pneumatic radial tire comprises a pair of bead portions each containing a bead core, a radial carcass, a belt comprised of at least one belt layer, and a tread, in which (1) a tapering angle &thgr;C of an inner side of the bead core in the radial direction is within ±2° of a tapering angle &thgr;R of a bead seat part in an approved rim, and (2) a compression ratio Ca at a widthwise inner end of the inner side of the bead core is within a range of 102-115% of a compression ratio Cb at a widthwise outer end thereof.

Abstract: An object of the present invention is to obtain a superconductive magnet, the size of which can be reduced by shortening the radial length of a magnetic device thereof and the refrigerating performance of which can be improved. A cylinder for fastening a refrigerator has an end facing an ambience of helium gas evaporating in a helium chamber and another end which is substantially horizontally fastened to a vacuum chamber. Further, the three-stage regenerative refrigerator is inserted and fastened to the cylinder for fastening the refrigerator. A heat insulator, such as a convection prevention tube, made of a hollow Teflon tube is wound around the outer surface of each stage of the cylinder of the three-stage regenerative refrigerator. The convection prevention tube is enclosed into a gap between the cylinder for fastening the refrigerator and the three-stage regenerative refrigerator without no undesirable gap so that heat convection of the helium gas is prevented.

Abstract: A heavy duty pneumatic radial tire has an outer profile of a tread portion in radial section of the tire having a given composite arc shape as a function of the internal structure of the tire, particularly a belt structure including at least two belt layers inclusive of main cross belt layers of steel cords.

Abstract: A cold accumulation type refrigerating machine having a high refrigeration efficiency. Rotation output of a stepping motor is converted to a reciprocative motion of a displacement member carrying a cold accumulator and disposed within a cylinder in which first and second closed chambers are defined above and below the displacement member, respectively. A compressed gas discharged from a compressor is introduced into the second closed chamber through the cold accumulator upon opening of a suction valve and undergoes expansion within the second closed chamber, the gas being then fed back to the compressor through the cold accumulator upon opening of an discharge valve, whereupon one cycle of refrigerating operation is completed.