Abstract: The object of the present invention is to provide an eddy current retarder capable of ensuring brake capacity and preventing magnetic leak. In one preferred embodiment of the invention, an eddy current retarder (1) comprises a first magnet ring (18) disposed opposite a brake rotor (3) and comprising a plurality of permanent magnets (16) disposed with a spacing in the circumferential direction, and a second magnet ring (7) disposed opposite the first magnet ring (18) and comprising a plurality of permanent magnets (10) disposed with a spacing in the circumferential direction, wherein the magnetic force of each permanent magnet (10) of the second magnet ring (7) is set larger than the total magnetic force of one or a plurality of permanent magnets (16) of the first magnet ring (18) serving as a partner in forming a magnetic circuit in a brake OFF state. As a result, the magnetic flux leaking to the brake rotor (3) during the brake OFF can be almost zeroed.

Abstract: An eddy current deceleration device comprises: a rotor mounted on a rotary shaft; a first magnet ring arranged facing this rotor and including permanent magnets that are arranged at prescribed intervals in the circumferential direction and such that the poles thereof facing each other in the circumferential direction are of a same polarity, and magnetic members interposed between these permanent magnets; and a second magnet ring arranged between this first magnet ring and the rotor and including permanent magnets and magnetic members which are similar to those of the first magnet ring; at least one of the first and second magnet rings being freely rotatable. The permanent magnets of the first and second magnet rings can be magnetized separately between the first and second magnet rings.

Abstract: An eddy current deceleration device comprises: a rotor mounted on a rotary shaft; a first magnet ring arranged facing this rotor and including permanent magnets that are arranged at prescribed intervals in the circumferential direction and such that the poles thereof facing each other in the circumferential direction are of a same polarity, and magnetic members interposed between these permanent magnets; and a second magnet ring arranged between this first magnet ring and the rotor and including permanent magnets and magnetic members which are similar to those of the first magnet ring; at least one of the first and second magnet rings being freely rotatable. The permanent magnets of the first and second magnet rings can be magnetized separately between the first and second magnet rings.

Abstract: An eddy current deceleration device includes a rotor mounted on a rotary shaft; a first magnet ring arranged facing this rotor and including permanent magnets that are arranged at prescribed intervals in the circumferential direction and such that the poles thereof facing each other in the circumferential direction are of a same polarity, and magnetic members interposed between these permanent magnets; and a second magnet ring arranged between this first magnet ring and the rotor and including permanent magnets and magnetic members which are similar to those of the first magnet ring; at least one of the first and second magnet rings being freely rotatable. The permanent magnets of the first and second magnet rings can be magnetized separately between the first and second magnet rings.

Abstract: A composite magnet has an iron core, a coil around the iron core, and a permanent magnet in the iron core. A first eddy current retarder includes a brake drum with a rotatable shaft, and a stationary magnet unit inside the inner peripheral surface of the brake drum and having an annular base portion, iron core portions, a support member having magnetic pole pieces at the ends of the iron core portions and opposed to the brake drum, electromagnets, and a permanent magnet in each of the iron core portions with its magnetic pole surface directed in the radial direction. A second eddy current retarder includes a stationary brake drum, an annular magnet support member coupled to a rotatable shaft and inside the inner peripheral surface of the brake drum, and magnets outside the magnet support member and opposed to the surface of the brake drum.

Abstract: An eddy current deceleration device comprises: a rotor mounted on a rotary shaft; a first magnet ring arranged facing this rotor and including permanent magnets that are arranged at prescribed intervals in the circumferential direction and such that the poles thereof facing each other in the circumferential direction are of a same polarity, and magnetic members interposed between these permanent magnets; and a second magnet ring arranged between this first magnet ring and the rotor and including permanent magnets and magnetic members which are similar to those of the first magnet ring; at least one of the first and second magnet rings being freely rotatable. The permanent magnets of the first and second magnet rings can be magnetized separately between the first and second magnet rings.

Abstract: A rotor of a rotating machine includes: a shaft having an axis of rotation and a cylindrical body portion disposed substantially integrally therein; permanent magnets and magnetic members provided integrally within the body portion and arranged radially and circumferentially alternating and in intimate contact with each other, each of the permanent magnets being completely embedded in the body portion and each of the magnetic members having only a radially outward end surface thereof being exposed and having all other surfaces thereof being in embedded in the body portion. The shaft and permanent magnets and magnetic members and body portion are integrated upon the body portion being cast.

Abstract: A rotor of a rotating machine includes a body portion having a rotating shaft mounted therein substantially integrally, having a circular outer peripheral surface and opposite side surfaces, and formed of a nonmagnetic material; and permanent magnets and magnetic members provided integrally with the body portion and arranged radially and circumferentially alternately in intimate contact with each other. Each of the permanent magnets is completely embedded in the body portion, and each of the magnetic members has only a radially outward end surface thereof exposed, and has other surfaces thereof embedded in the body portion The rotor can be produced by die casting.

Abstract: A composite magnet of electromagnet and permanent magnet comprises an iron core, a coil arranged to surround the outer peripheral surface of the iron core, and a permanent magnet mounted in the iron core in a manner that the magnetic pole is in agreement with the direction of magnetization of the iron core. The permanent magnet is mounted in a number of one or in a plural number in the iron core in a manner that at least the outer peripheral surfaces thereof are surrounded by the iron core.

Abstract: The present invention is directed to an alloy for a high-performance rare earth permanent magnet. This alloy has a metallographic structure of approximately two phases that comprises a Nd2Fe14B phase (1) consisting of hard magnetic crystal grains and an &agr;-Fe phase (2) consisting of soft magnetic crystal grains. The metallographic structure has an ultra-thin film (3) that contains a large amount of nonmagnetic metallic elements that have an atomic radius of between the atomic radius of Fe and the atomic radius of Nd at each of the crystal grain boundaries between the phases (1, 2) and that will not form solid solutions with either Fe or Nd. The nonmagnetic metallic elements consist of one or two or more elements selected from among Nb, Zr, Ta and Hf, the thickness of each ultra-thin film is 10 to 20 angstroms, and the sizes of the crystal grains in each of the phases (1, 2) are in the range 5 to 100 nm, preferably 10 to 40 nm.

Abstract: An eddy-current apparatus including a movable magnet support tube (25) disposed internally of a brake drum (8), and supporting an array of magnets (15) operable to generate a braking force in the brake drum (8). An outer guide tube (22) covers the magnet support tube (25) and consists of alternating magnetic first sections (41) and non-magnetic or weak magnetic second sections (41a). The outer guide tube (22) is formed of magnetic stainless steel, and the second sections (41a) are formed by being rapidly cooled from a high temperature state (partial solution state) into a non-magnetic or weak magnetic austenite phase.

Abstract: An eddy current reduction braking system in which with high speed rotation of a brake drum, magnetic flux produced by magnets is concentrated to increase magnetic flux density and thereby enhance braking force. According to the invention, there is provided a guide tube formed of a non-magnetic material and having a hollow portion in the shape of a rectangle in section disposed interiorly of a brake drum. A number of ferromagnetic pole pieces are disposed at annularly equal intervals on an outer surface of the guide tube and at least one magnet support tube is movably mounted in the hollow portion of the guide tube. Magnets are mounted on the magnet support tube such that their polarities with respect to the ferromagnetic pole pieces are alternately different.

Abstract: A floor structure (1) for a load-carrying platform of a truck. The truck has a pair of parallel side rails (3) extending in a longitudinal direction of the truck. The floor structure (1) includes a floor panel part (2) made from a fiber reinforced plastic (5) and a pair of longitudinal sills (4) extending along the pair of side rails (3) under the floor panel part (2) and made from the fiber reinforced plastic (5). The floor panel part (2) is thicker in a first area (11, T1) (111, T3) between the longitudinal sills (4) than in second and third areas (12, T2) (112, T4) outside the first area.

Abstract: Magnets (20) are separated by ferromagnetic plates (21) from an inner surface of a brake drum (13) made of steel and secured to a rotational shaft (4). When the rotating brake drum (13) crosses magnetic flux generated by the magnets (20), a braking force caused by eddy currents is produced in the brake drum (13). An annular body (41) formed of a good conductor such as copper is fastened adjacent to at least one side surface of the brake drum (13) in a position axially spaced from the plates (21).

Abstract: A vehicle braking system including a brake drum connected to a rotational shaft; an annular member formed of a ferromagnetic material; a guide frame for supporting the annular member in a position within said spaced from an inner surface of the brake drum; and a cylindrical body defining an uninterrupted wall between the inner surface of the brake drum and the annular member; at least portions of the cylindrical body disposed directly between the inner surface of the brake drum and outer surfaces of the permanent magnets being formed from a magnetically permeable material.

Abstract: A guide tube formed from non-magnetic material defines a cavity of rectangular section arranged within a brake drum, and a plurality of ferromagnetic plates are retained at equal circumferential intervals by an outer portion of the guide tube. Magnet support tubes formed out of magnetic material and axially spaced and rotatably supported in the cavity of the guide tube and magnets twice in number of the ferromagnetic plates are mounted to outer surfaces of the magnet support tubes with pairs of the magnets having common and alternating polarities. The magnet support tubes are reciprocatively rotated by actuators to produce non-braking, braking and partial braking conditions.

Abstract: A guide frame for an eddy current type braking system includes a brake drum connected to a rotary shaft; a stationary pole piece frame formed of a non-magnetic material, disposed within the brake drum and retaining a plurality of ferromagnetic plates opposed to an inner surface of the brake drum; and magnet support rings formed of a magnetic material and retaining permanent magnets opposed to the ferromagnetic plates. An outer surface and an inner peripheral surface of each ferromagnetic plate is displaced in a direction parallel to the axis of the brake drum, and an axial center of the outer peripheral surface of the ferromagnetic plates is substantially radially aligned with an axial center of the brake drum.

Abstract: Projecting into a brake drum is an annular guide frame defining an annular inner chamber of rectangular shape in section, having an outer wall portion formed by a thin cylindrical body of nonmagnetic material, and an inner annular wall of ferromagnetic material. An annular magnet support member is axially movable within the inner chamber of the guide frame, and supports a plurality of permanent magnets disposed closely adjacent to the cylindrical body and in circumferentially spaced apart positions of uniform pitch, the polarities of the permanent magnets alternating circumferentially.

Abstract: An eddy current retarder for an automotive vehicle braking system including an annular fixed frame defining a hollow chamber is disposed internally of a brake drum, a pair of transversely adjacent parallel support rings disposed in the chamber of the fixed frame, one of the support rings being fixed to the frame and the other being rotatable to permit relative angular movement therebetween. Each support ring supports a plurality of permanent magnets circumferentially spaced apart at a given pitch and having outwardly facing alternating polarities. Ferromagnetic plates circumferentially spaced apart at the given pitch are embedded in an outer wall of the fixed frame between the magnets and the brake drum. The ferromagnetic plates have central portions thicker than transversely projecting end portions.

Abstract: A vehicle braking system including a brake structure defining an annular surface; an annular magnet support disposed adjacent to the annular surface; a plurality of permanent magnets mounted on the magnet support and circumferentially spaced apart thereon, the polarities of the plurality of permanent magnets alternating circumferentially and each permanent magnet having circumferentially spaced apart end portions of substantially equal cross-sectional area joined by a middle portion of substantially smaller cross-sectional area; an annular pole piece support; and a plurality of ferromagnetic pole pieces mounted on the pole piece support and circumferentially spaced apart in positions between the annular surface and the permanent magnets, each pole piece having a circumferential length substantially equal to the circumferential length of a radially adjacent permanent magnet.