Rotating machine and rotor thereof

A rotating machine is provided, including a rotor and a stator set. The rotor rotates around an axis, wherein the rotor includes a first permanent magnet set and a second permanent magnet set, the first permanent magnet set is magnetized in a circumference direction of the axis, and the second permanent magnet set is magnetized in an axial direction of the axis. The stator set corresponds to the rotor, wherein the stator set includes a radial stator member and an axial stator member, the axial stator member corresponds to the rotor in the axial direction of the axis, and the radial stator member corresponds to the rotor in a radial direction of the axis.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application claims priority of China Patent Application No. 201010590746.4, filed on Dec. 3, 2010, the entirety of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rotating machine, and in particular relates to a rotating machine and a rotor having increased unit volume capacity.

2. Description of the Related Art

A conventional rotating machine is composed of a stator and rotor. The stator is arranged corresponding to the rotor, and the rotating machine is rotated by magnetic force generated between the rotor and the stator.

A conventional rotating machine having distributed windings has good torque, inductance and flux weakening performance. However, the conventional rotating machine having distributed windings has grooves crossing across a large amount of silicon steel sheets, and a stator coil is coiled on an end portion of the stator. The length of the end portion of the stator is therefore increased, the length of the coil is increased, an additional radial or axial space occupies the stator, and unit volume capacity is reduced.

Recently, rotating machines having planar structure are popular due to their heat dissipation advantages over other like machines.

BRIEF SUMMARY OF THE INVENTION

In one embodiment, a rotating machine is provided, including a rotor and a stator set. The rotor rotates around an axis, wherein the rotor comprises a first permanent magnet set and a second permanent magnet set, and the first permanent magnet set is magnetized in a circumference direction of the axis, and the second permanent magnet set is magnetized in an axial direction of the axis. The stator set corresponds to the rotor, wherein the stator set comprises a radial stator member and an axial stator member, the axial stator member corresponds to the rotor in the axial direction of the axis, and the radial stator member corresponds to the rotor in a radial direction of the axis.

In another embodiment, a rotor is provided. The rotor is utilized in a rotating machine and rotated along an axis. The rotor includes a rotor core, a first permanent magnet set and a second permanent magnet set. The first permanent magnet set is magnetized in a circumference direction of the rotating machine against the axis. The second permanent magnet set is magnetized in an axial direction of the rotating machine against the axis, wherein the first permanent magnet set is embedded in the rotor core, and the second permanent magnet set is axially disposed on the rotor core.

In another embodiment, a rotor is provided. The rotor is utilized in a rotating machine and rotated along an axis. The rotor includes a rotor core, a first permanent magnet set and a second permanent magnet set. The first permanent magnet set includes a plurality of circumferentially magnetized permanent magnets which are arranged around the axis. The second permanent magnet set includes a plurality of axially magnetized permanent magnets which are arranged around the axis, wherein the circumferentially magnetized permanent magnets and the axially magnetized permanent magnets are arranged staggeredly on a periphery or the rotor, and the axially magnetized permanent magnets are arranged in pairs axially. Each two circumferentially magnetized permanent magnets which are circumferentially adjacent have a same first pole arrangement at corresponding portions thereof. A pair, of the axially facing axially magnetized permanent magnets between the two circumferentially magnetized permanent magnets which are circumferentially adjacent have the same first pole arrangement at corresponding portions thereof.

In another embodiment, a rotating machine is provided, including a rotor and a stator set, an axial air gap, a radial air gap, a first magnetic flow path and a second magnetic flow path. The axial air gap is located between the rotor and an axial stator member of the stator set. The radial air gap is located between the rotor and a radial stator member of the stator set. The first magnetic flow path extends through the rotor, the radial air gap, and the radial stator member. The second magnetic flow path extends through the rotor, the radial air gap, the radial stator member, the axial air gap and the axial stator member.

Via the arrangement of the rotor, the circumferentially magnetized permanent magnets, the axially magnetized permanent magnets, the stator set, the axial stator members and the radial stator member, the space in the axial direction of the end portion of the radial stator coil is sufficiently used, the utilization of the rotor core is increased, and the unit volume capacity is improved.

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIGS. 1,2A and2B,FIG. 1shows a rotating machine of an embodiment of the invention,FIG. 2Ais a perspective view showing a rotor member and permanent magnet arrangement (including a rotor core), andFIG. 2Bis a perspective view showing a rotor member and permanent magnet arrangement (not including a rotor core). The rotating machine1comprises a shaft2, a rotor3and a stator set4. The shaft2is disposed along an axis of the rotating machine1. The rotor3is planar, disposed on the shaft2, and rotates around the shaft2. The stator set4comprises axial stator members (planar stator member)4-1and4-2and a radial stator member4-3. The axial stator members4-1and4-2are disposed along an axial direction and face the rotor3. The radial stator member4-3is disposed along an radial direction and faces the rotor3. Following, the axial direction is an extended direction of the axis of the rotating machine1, and the radial direction is a diametric direction of the rotor3. The axial direction and the radial direction are not restricted to the directions which are overlapping the axis or the diameter of the rotor3, but are directional tendencies. A deviation in direction due to tolerance during assembly is expected. Axial air gaps5-1and5-2are respectively formed between the rotor3and the axial stator members4-1and4-2. A radial air gap5-3is formed between the radial stator member4-3and the rotor3. The axial stator members4-1and4-2are disposed in the covers6-1and6-2. The axial stator members4-1and4-2can be fixed to the covers6-1and6-2via through holes, screws or epoxy resins. The radial stator member4-3is fixed in the housing7. The radial stator member4-3can be disposed in the housing7via wedging. The covers6-1and6-2are mechanically connected to the housing7. The shaft2is rotatably connected to the covers6-1and6-2via the bearings8-1and8-2. The axial stator members4-1and4-2are respectively composed by the axial stator coils11-1and11-2, and the axial stator cores12-1and12-2. The radial stator member4-3is composed by the radial stator coil13and radial stator core14. The axial stator coils11-1and11-2and the radial stator coil13are respectively coiled on the axial stator cores12-1and12-2and the radial stator core14.

As shown inFIGS. 2A and 2B, the rotor3comprises a rotor core10, axially magnetized permanent magnets9-2and circumferentially magnetized permanent magnets9-1. The axially magnetized permanent magnets9-2are axially disposed on two sides of the rotor core10and circumferentially arranged. The pole direction of the axially magnetized permanent magnets9-2is axial; that is, axially magnetized. In this embodiment, the axially magnetized permanent magnets9-2are axially attached on two sides of the rotor core10. The circumferentially magnetized permanent magnets9-1are disposed in the rotor core10, and are circumferentially arranged. The pole direction of the circumferentially magnetized permanent magnets9-1is circumferential; that is, circumferentially magnetized. The circumferentially magnetized permanent magnets9-1and the axially magnetized permanent magnets9-2are staggeredly arranged. The axially magnetized permanent magnets9-2are arranged in pairs which face to each other. In this invention, the circumferential direction extends along the periphery of the rotor3which is rotated against the shaft2. The circumferential direction is not restricted to the directions which overlap the periphery of the rotor3, but is a directional tendency. For example, in this embodiment, the magnetizing directions of the circumferentially magnetized permanent magnets9-1do not overlap with the periphery of the rotor3, but are close to the periphery of the rotor3. Therefore, the magnetizing directions of the circumferentially magnetized permanent magnets9-1are defined as being circumferentially magnetized. The circumferentially magnetized permanent magnets9-1and the axially magnetized permanent magnets9-2are arranged with spaces. Two circumferentially adjacent circumferentially magnetized permanent magnets9-1and two axially adjacent axially magnetized permanent magnets9-2form a chamber (an open chamber with a rectangular opening). The rotor core10is partially in the chamber.FIG. 2Bshows poles of the circumferentially magnetized permanent magnets9-1and the axially magnetized permanent magnets9-2. Each two circumferentially magnetized permanent magnets which are circumferentially adjacent have a same pole arrangement (same N poles or same S poles) at corresponding portions thereof, and each two circumferentially magnetized permanent magnets which are circumferentially adjacent have a pair of the axially facing axially magnetized permanent magnets between the two circumferentially magnetized permanent magnets which are circumferentially adjacent having the same pole arrangement (same N poles or same S poles) at corresponding portions thereof. In a preferred embodiment, the circumferentially magnetized permanent magnets9-1and the axially magnetized permanent magnets9-2are equidistantly arranged on a circumferential direction.

FIGS. 3A and 3Bshows magnetic flow paths of the circumferentially magnetized permanent magnets9-1and the axially magnetized permanent magnets9-2of the rotating machine. With reference toFIGS. 1,2B,3A and3B, inFIG. 3A, a first magnetic flow path (magnetic flow path of the circumferentially magnetized permanent magnet9-1) travels from an N pole of the circumferentially magnetized permanent magnet, to pass through the rotor core10received in the chamber. Following, the first magnetic flow path flows to the radial air gap5-3, to the tooth16, and then to the yoke17of the radial stator core14, and then travels from the tooth16of the radial stator core14adjacent S pole, to pass through the radial air gap5-3and the rotor core10received in the chamber to the S pole of the circumferentially magnetized permanent magnet9-1. The arrangement of circumferentially magnetized permanent magnet9-1in the rotor core10increases the saliency ratio (Lq/Ld) of quadrature-axis inductance and d-axis inductance, increases reluctance torque, and improves unit volume capacity. As shown inFIG. 3B, a second magnetic flow path (magnetic flow path of the axially magnetized permanent magnets9-2) travels from an N pole of one of the axially magnetized permanent magnets9-2, to pass through the rotor core10received in the chamber, and the radial air gap5-3to the tooth16and the yoke17of the radial stator core14corresponding to the axially magnetized permanent magnets9-2(real line inFIG. 3B). Following, the second magnetic flow path then travels from the tooth16of the radial stator core14corresponding to the circumferentially adjacent axially magnetized permanent magnets9-2(another axially magnetized permanent magnets9-2), to pass through the radial air gap5-3, the rotor core10received in the chamber corresponding to the adjacent axially magnetized permanent magnet9-2, the adjacent axially magnetized permanent magnet9-2(S pole to N pole), and the axial air gaps5-1and5-2, to the teeth and the yokes (not shown) of the axial stator cores12-1and12-2facing the adjacent axially magnetized permanent magnet9-2(dotted line inFIG. 3B), and then travels from the teeth of the axial stator cores12-1and12-2, through the axial air gaps5-1and5-2to an S pole of the axially magnetized permanent magnet9-2where the second magnetic flow path starts from (real line inFIG. 3B). For the radial air gap magnetic flow path, each pole surface is parallel connected by the circumferentially magnetized permanent magnet9-1and the axially magnetized permanent magnet9-2, providing magnetic effect of focusing on the rotating machine, increasing the magnetic current density of the radial air gap, and increasing the power of the rotating machine.

FIG. 3Cshows an equivalent magnetic circuit of the rotating machine of the embodiment of the invention. In the embodiment of the invention, the two circumferentially adjacent axially magnetized permanent magnets9-2are defined respectively by having magnetic flux Φa and reluctances Rm_a1and Rm_a2. However, the equivalent magnetic circuit inFIG. 3Cis equivalent to half of the two circumferentially adjacent axially magnetized permanent magnets9-2. Therefore, inFIG. 3C, the axially magnetized permanent magnets9-2equivalently have magnetic flux Φa/2and reluctances2×Rm_a1and2×Rm_a2. A part of the reluctances mentioned are equivalent to two times that of the original reluctances. Similarly, the two axially magnetized permanent magnets9-2which axially corresponding to the two circumferentially adjacent axially magnetized permanent magnets9-2respectively have magnetic flux Φa/2and reluctances2×Rm_all and2×Rm_a22. The magnetic flux Φa/2of one of the magnetized permanent magnets9-2(with reluctance2×Rm_al) travels from an N pole thereof, to pass through axial air gaps5-1and5-2(with reluctance2×Rg_al), axial stator cores12-1(with reluctance Rs_a), and axial air gaps5-1and5-2(with reluctance2×Rg_a2), to the circumferentially adjacent axially magnetized permanent magnet9-2(with reluctance2×Rm_a2), and then travels from the rotor core10(with reluctance Rr2) received in the chamber corresponding to the adjacent axially magnetized permanent magnet9-2, to pass through the air gap (with reluctance2×Rg_r1), the radial stator core14(with reluctance Rs_r), the air gap (with reluctance2×Rg_r1), the rotor core10(with reluctance Rr1) received in the chamber corresponding to the axially magnetized permanent magnet9-2, and to the S pole of the axially magnetized permanent magnet9-2where the second magnetic flow path starts from. The magnetic flow path of the two axially magnetized permanent magnets9-2on a side of the rotor core10is the same as the magnetic flow path of the two axially magnetized permanent magnets9-2on the other side of the rotor core10. The N pole of one of the axially magnetized permanent magnets9-2corresponds to the axial air gap, and the N pole of the other axially magnetized permanent magnet9-2adjacent thereto corresponds to the rotor core. The magnetic flow path is a close-loop path, which can also be described as starting from the axially magnetized permanent magnet9-2corresponding to the rotor core (with reference toFIG. 3B). The circumferentially magnetized permanent magnets9-1between the circumferentially adjacent axially magnetized permanent magnets9-2have magnetic flux Φt and reluctance Rm_t. The magnetic flux Φt travels from the N pole of the circumferentially magnetized permanent magnet9-1, and passes through the rotor core10(with reluctance Rr2) received in the chamber corresponding to the N pole of the circumferentially magnetized permanent magnet9-1, the radial air gap (with reluctance2×Rg_r2), and the radial stator core14(with reluctance Rs_r), and then passes through the radial air gap (with reluctance2×Rg_r1), and the rotor core10(with reluctance Rr1) received in the chamber corresponding to the S pole of the circumferentially magnetized permanent magnet9-1, and the flows back to the S pole of the circumferentially magnetized permanent magnet9-1.

As mentioned above, via the arrangement of the rotor3, the circumferentially magnetized permanent magnets9-1, the axially magnetized permanent magnets9-2, the stator set4, the axial stator members4-1and4-2and the radial stator member4-3, the space in the axial direction of the end portion of the radial stator coil13is sufficiently used, the utilization of the rotor core10is increased, and unit volume capacity is improved. The rotor core10does not face the axial air gap, thus preventing core loss caused by armature reactions. Additionally, when rotating, the axially magnetized permanent magnets9-2generate air flow which removes heat from the rotating machine.

InFIGS. 1,2A,2B,3A,3B and3C, the radial stator member4-3corresponds to the outer periphery of the rotor3. However, the invention is not limited thereby.

FIG. 4shows a rotating machine of another embodiment of the invention. Compared to the embodiment ofFIG. 1, in the embodiment ofFIG. 4, the rotor3is fixed on the housing7, and the radial stator member4-3corresponds to the inner periphery of the rotor3and is fixed on the shaft2. The axial stator members4-1and4-2are axially and symmetrically disposed on the rotor3, and are fixed on braces15-1and15-2. When the rotating machine operates, the axial stator members4-1and4-2and the radial stator member4-3are static, and the housing7and covers6-1and6-2of the rotor3are rotated around the axis. In a modified embodiment, the axial stator members can corresponds to outer and inner peripheries of the rotor3simultaneously.

FIG. 5shows a rotating machine of another embodiment of the invention. In the embodiments ofFIGS. 1,2A,2B,3A,3B,3C and4, the end portions of the radial stator coil13are longer in length to sufficiently utilize axial space. However, the invention is not limited thereby. In the embodiment ofFIG. 5, the end portions of the axial stator coils11-1and11-2have a longer length to sufficiently utilize radial space.