Rotor of rotating electric machine

According to the invention, in a rotor of a vehicular alternating current generator motor having a Lundell type core having a field winding, a cylindrical portion wound with the field winding, a yoke portion widened from a portion in an axial direction of the cylindrical portion in an outer peripheral direction, and a plurality of claw-like magnetic pole portions constituted to incorporate the field winding, extended in the axial direction from an outer periphery of the yoke portion and folded to bend to be brought in mesh with each other alternately, and a magnet arranged between the claw-like magnetic poles, an outer peripheral face of the field winding and an inner peripheral face of the magnet are made to be proximate to each other to thereby hamper draft between the field winding and the magnet.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rotor of a rotating electric machine, particularly relates to a constitution for reducing wind sound by a flow of air at inside of a rotor core in a rotor structure of a vehicular alternating current generator or a vehicular alternating current generator motor.

2. Description of the Related Art

A core of a rotor of a rotating electric machine according to a related art includes a field winding and a cylindrical portion wound with the field winding via an insulating member, a yoke portion widened from the cylindrical portion in an outer peripheral direction, and a plurality of claw-like magnetic poles extended in an axial direction from an outer periphery of the yoke portion to surround to incorporate the field coil and fold to bend to be brought in mesh with each other alternately. As described above, the claw-like magnetic pole portion is constituted by a cantilever shape and a certain constant clearance between the magnetic poles is provided between contiguous ones of the claw-like magnetic poles such that a magnetic flux is prevented from being leaked between the two claws.

According to the rotating electric machine having above-described Lundell type rotor, the magnetic flux is generated by making current flow at the field winding, by a change in the magnetic flux generated in accordance with rotation of the rotor, alternating current is made to flow at an armature winding to provide a power generating function.

Further, in recent years, there is also a rotor constituted by arranging a magnet between the claw-like magnetic poles for increasing an output (refer to, for example, Patent Reference 1).

According to the related art, there is a space between the field winding wound around the cylindrical portion of the core and an inner peripheral face of the claw-like magnetic pole as well as between the claw-like magnetic poles, in rotating the rotor, wind sound is emitted by draft both from a front side and a rear side, particularly, a component thereof in a peripheral direction produced between the inner periphery of the claw-like magnetic pole and an outer peripheral face of the field winding to cause noise of vehicular alternating current generator. Particularly, since draft paths by a number of magnetic poles multiplied by an integer are formed, noise having a component of a number of an order of the number of magnetic poles multiplied by an integer is emitted to pose a problem of noise.

Further, in recent years, although there is a case of applying a magnet between the claw-like magnetic poles in order to increase power, even in such a case, there are spaces among the field winding wound around the cylindrical portion of the core and inner peripheral faces of the claw-like magnetic poles and an inner peripheral face of the magnet, faces of the field windings opposed thereto are constituted by recesses and projections by the magnet and therefore, wind sound is similarly emitted by draft both from the front side and the rear side to cause the noise of the vehicular alternating current generator.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a rotor of a rotating electric machine for restraining draft among a field winding and a claw-like magnetic pole portion and a magnet and capable of reducing wind sound emitted from the rotor.

According to a rotor of a rotating electric machine of the invention, in a rotor of a rotating electric machine including a Lundell type core having a cylindrical portion wound with a field winding, a yoke portion widened from a position in an axial direction of the cylindrical portion in an outer peripheral direction, a plurality of claw-like magnetic pole portions constituted to incorporate the field winding, extended in the axial direction from an outer periphery of the yoke portion and folded to bend to be brought in mesh with each other alternately and a magnet arranged between the claw-like magnetic poles, an outer peripheral face of the field winding and an inner peripheral face of the magnet are made to be proximate to each other to hamper draft between the field winding and the magnet.

According to the invention, the rotor of the rotating electric machine restraining draft among the field winding and the claw-like magnetic pole portion and the magnet and capable of reducing wind sound emitted from the rotor can be provided.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1 according to the invention will be explained in reference toFIG. 1throughFIG. 3.FIG. 1is a sectional view of a rotating electric machine according to an embodiment of the invention,FIG. 2is a perspective view of a rotor when a structure of a rotor is used in a rotor of a vehicular rotating electric machine, andFIG. 3is a sectional view of a core portion of the rotor.

The rotating electric machine is provided with a case40constituted by a front bracket1and a rear bracket2made of aluminum, a shaft6provided at inside of the case40and fixed with a pulley4at one end portion thereof, a rotor7fixed to the shaft6, fans5fixed to both side faces of the rotor7, an armature8fixed to an inner wall face at inside of the case40, a slip ring9fixed to other end portion of the shaft6for supplying current to the rotor7, a pair of brushes10sliding on the slip ring9, a brush holder11containing the brushes10, a rectifier12electrically connected the armature8for rectifying alternating current generated at the armature8into direct current, a heat sink19fitted to attach to the brush holder, and a regulator20adhered to the heat sink for regulating a magnitude of alternating current voltage generated at the armature8. The armature8is constituted by an armature core15and an armature winding16wound around the armature core15.

The rotor7is provided with a field winding13as a rotor coil in a cylindrical shape for generating a magnetic flux by making current flow therein, and a pole core14provided to cover the rotor coil13and formed with a magnetic pole by the magnetic flux.

The pole core14is constituted by a pair of a first pole core member21and a second pole core member22brought in mesh with each other alternately. The pole core member21and the pole core member22are normally made of iron and comprise cylindrical portions21e,22ewound with the rotor coil13, and yoke portions21k,22kin a circular disk shape projected with the cylindrical portions21e,22e. Outer edges of the yoke portions21k,22kare respectively provided with pluralities of claw-like magnetic poles23,24brought in mesh with each other at positions between an outer periphery of the rotor coil13and an inner periphery of the armature8.

The claw-like magnetic poles23,24are constituted by a shape in which thicknesses and widths on sides of the yoke portions21k,22kare large and the thicknesses and the widths become slender as proceeding to front end sides thereof. Thicknesses of inner peripheral faces of the claw-like magnetic poles23,24are thinned as proceeding to front ends thereof and outer peripheral faces thereof are constituted by an arcuate shape along an inner peripheral face of the stator8.

The claw-like magnetic poles23,24are provided with two side faces in a trapezoidal shape relative to a peripheral direction of the rotor7. Front ends of the respective claw-like magnetic poles23,24are alternately brought in mesh with each other to be opposed to each other and therefore, inclinations of the inner peripheral faces of the claw-like magnetic poles23,24are aligned alternately in the peripheral direction.

Further, side faces of the claw-like magnetic poles23,24are inclined to center sides of the claw-like magnetic poles23,24such that the front end sides become slender as proceeding from root sides to the front end sides.

Further, an interval between contiguous ones of the claw-like magnetic poles23,24is fixedly attached with a magnet30in a shape of a parallelepiped magnetized in a direction of reducing leakage of the magnetic flux by both of the side faces opposed to each other and the magnet30is attached thereto by using a holding member for alleviating a centrifugal force.

As shown byFIG. 1throughFIG. 3, the rotor core7of the rotating electric machine includes the field winding13and the cylindrical portions21e,22ewound with the field winding13via the insulting member, the yoke portions21k,22kconstituted by base portions in the circular disc shape widened from the positions in the axial direction of the cylindrical portions21e,22ein the outer peripheral direction, and the plurality of claw-like magnetic poles23,24extended in the axial direction from the outer peripheries of the yoke portions21k,22kto surround to incorporate the field winding13and folded to bend to be brought in mesh with each other. As described above, the claw-like magnetic pole portions23,24are constituted by the cantilever shape, and the magnet30is arranged between the claw-like magnetic poles23,24such that the outer peripheral face of the field winding13and the inner peripheral face of the magnet30become proximate to each other. According to the embodiment, the outer peripheral face of the field winding13is constituted to be equal to or smaller than a root diameter of the claw-like magnetic poles23,24.

In this way, by making the outer peripheral face of the field winding13and the inner peripheral face of the magnet30arranged between the claw-like magnetic poles23,24proximate to each other, draft in the claw-like magnetic poles23,24is restrained and wind sound is reduced.

According to Embodiment 1 of the invention, in the rotor of the vehicular alternating current generator motor including the Lundell type core having the field winding13, the cylindrical portions21e,22ewound with the field winding13, the yoke portions21k,22kwidened from the positions in the axial direction of the cylindrical portions21e,22ein the outer peripheral direction, and the plurality of claw-like magnetic pole portions23,24constituted to incorporate the field winding13by surrounding to incorporate the field winding13, extended from the outer peripheries of the yoke portions in the axial direction and folded to bend to be brought in mesh with each other alternately, and the magnet30arranged between the claw-like magnetic poles23,24, the outer peripheral face of the field winding13and the inner peripheral face of the magnet30are made to be proximate to each other, a draft path between the field winding13and the magnet30is brought into a closed state to hamper draft between the field winding13and the magnet30and therefore, the outer peripheral face of the field winding13and the inner peripheral face of the magnet30become proximate to each other to hamper draft between the field winding13and the magnet30and therefore, draft among the field winding13and the claw-like magnetic pole portions23,24and the magnet30is restrained and wind sound emitted from the rotor is reduced.

Further, according to Embodiment 1 of the invention, in the constitution of the preceding item, there is provided the field winding wound such that an outermost peripheral portion of the field winding13becomes equal to or smaller than the root diameter of the claw-like magnetic poles23,24to thereby make the inner peripheral face of the magnet30and the outermost periphery of the field winding13proximate to each other and therefore, the inner peripheral face of the magnet30is smaller than the root diameter of the magnetic claws23,24and therefore, the draft path between the magnetic poles23,24can be closed by the magnet30and draft can firmly be restrained. Further, since the magnet30is present in the space at side faces of the roots of the claw-like magnetic poles23,24and therefore, draft flowing from the front side and the rear side in the axial direction is also restrained and noise is reduced.

Embodiment 2 according to the invention will be explained in reference toFIG. 4.FIG. 4is a sectional view of a rotor core portion when a structure of a rotor according to Embodiment 2 is used in a rotor of a vehicular rotating electric machine.

According to Embodiment 2, as shown byFIG. 4, the outer peripheral face of the field winding13is made to be equal to or larger than the root diameter of the claw-like magnetic poles23,24and the magnet30is arranged between the claw-like magnetic poles23,24such that the outer peripheral face of the field winding13and the inner peripheral face of the magnet30become proximate to each other. Further, the field winding13is wound such that also the inner peripheral faces of the roots of the claw-like magnetic poles23,24and the outer peripheral face of the field winding13become proximate to each other.

In this way, by making the outer peripheral face of the field winding13and the inner peripheral faces of the roots of the claw-like magnet poles23,24as well as the outer peripheral face of the field winding13and the inner peripheral face of the magnet30proximate to each other, draft passing the inner peripheral face of the claw-like magnetic poles23,24is also restrained and wind sound is reduced. Further, by reducing the width of recesses and projections of the inner peripheral face of the claw-like magnetic poles23,24and the inner peripheral face of the magnet30, disturbance of draft is reduced and wind sound is reduced.

Further, according to Embodiment 2, a space of winding the field winding13can be increased and therefore, a magnetomotive force by the field winding13can be increased. Or, current (flowing to the field winding13) necessary for providing the same magnetomotive force is reduced and therefore, temperature rise of the field winding13can be restrained.

Further, a volume of the magnet30is reduced and therefore, cost taken by the magnet can be reduced.

According to Embodiment 2 of the invention, in the constitution of Embodiment 1, there is provided the field winding13wound such that the outermost periphery of the field winding13becomes equal to or larger than the root diameter of the claw-like magnetic poles23,24, the inner peripheral face of the magnet30and the outermost periphery of the field winding13are made to be proximate to each other and therefore, the outer peripheral face of the field winding13and the inner peripheral faces of the roots of the claw-like magnetic poles23,24as well as the outer peripheral face of the field winding13and the inner peripheral face of the magnet30become proximate to each other and therefore, draft passing the inner peripheral faces of the claw-like magnetic poles23,24is also restrained and wind sound is reduced. When the field winding13is wound such that the outermost periphery of the field winding13becomes equal to or larger than the root diameter of the claw-like magnetic poles23,24, a line of projecting the inner peripheral face of the magnet30to side faces of the claw-like magnetic poles23,24is disposed on the inner peripheral faces of the claw-like magnetic poles23,24, the recesses and projections of the inner peripheral faces of the claw-like magnetic poles23,24and the inner peripheral face of the magnet30are reduced and therefore, disturbance of draft of the component in the peripheral direction is reduced and wind sound is reduced. Further, since the space of winding the field winding13is increased and therefore, when current made to flow to the field winding13stays the same, the magnetomotive face by the field winding13can be increased. Or, in achieving the same magnetomotive face, necessary current made to flow to the field winding13is reduced and temperature rise of the field winding13can be restrained. Further, since the volume of the magnet30is reduced, cost taken by the magnet30can be reduced.

Embodiment 3 according to the invention will be explained in reference toFIG. 5.FIG. 5is a sectional view of a rotor core portion when a structure of a rotor according to Embodiment 3 is used in a rotor of a vehicular rotating electric machine.

According to Embodiment 3, as shown byFIG. 5, in the shape of the magnet30arranged between the claw-like magnetic poles23,24, the inner peripheral face of the magnet30is constituted to be substantially in parallel with at least portions of the inner peripheral faces of the magnetic poles23,24. Further, both ends of the magnet30are constituted to cover the side faces of the roots of the claws23,24.

In this way, since the inner peripheral face of the magnet30is substantially in parallel with the inner peripheral faces of the magnetic poles23,24, recesses and projections of the inner peripheral face of the magnet30and the inner peripheral faces of the magnetic poles23,24are not present, disturbance of draft is eliminated and wind sound is reduced. Further, spaces of the side faces of the roots of the claw-like magnetic poles23,24can be sealed by the magnet30, draft is restrained and noise is reduced.

According to Embodiment 3 of the invention, in the constitution of the Embodiment 2, at least a portion of the inner peripheral face of the magnet30arranged between the claw-like magnetic poles23,24is constituted to be substantially in parallel with the inner peripheral faces of the magnetic poles23,24and therefore, by making the inner peripheral face of the magnet30and the inner peripheral faces of the magnetic poles23,24substantially in parallel with each other, recesses and projections of the inner peripheral faces of the claw-like magnetic poles23,24and the inner peripheral face of the magnet30are reduced, disturbance of draft is reduced and therefore, wind sound is further reduced.

Embodiment 4 according to the invention will be explained in reference toFIG. 6.FIG. 6is a sectional view of a rotor core portion when a structure of a rotor according to Embodiment 4 is used in a rotor of a vehicular rotating electric machine.

According to Embodiment 4, as shown byFIG. 6, an insulating layer LA is formed at the outer periphery of the field winding13by using an insulating member51of a tape or the like and is brought into contact with the magnet30.

By bringing the magnet30and the insulating member51formed at the outer periphery of the field winding13into contact with each other in this way, the clearance between the inner peripheral face of the magnet30and the insulating member51is completely eliminated, and wind sound is further reduced. Further, since the magnet30and the insulating member51are brought into contact with each other, vibration of the magnet is reduced and noise is reduced.

Further, although according to Embodiment 4, the insulting layer LA is formed at the field winding13by using the insulating member51of an outer peripheral tape or the like, the insulating layer LA may be formed at the outer peripheral portion of the field winding13by extending an insulating member52for insulating the rotor core7and the field winding13.

According to Embodiment 4 of the invention, in any constitution of Embodiment 1 through Embodiment 3, the insulating layer LA is formed by arranging the insulating member51or the insulating member52at the outer periphery of the field winding13by surrounding to incorporate the outer periphery of the field winding13by the insulating member51or the insulating member52, and the insulting member51or the insulating member52arranged at the outer periphery of the field winding13is brought into contact with the inner peripheral face of the magnet30and therefore, by forming the insulating layer LA at the outer periphery of the field winding13, insulation between the magnet30and the outer periphery of the field winding13is sufficiently maintained and therefore, the magnet30and the insulating member51or the insulating member52formed at the outer periphery of the field winding13can be brought into contact with each other, the clearance between the inner peripheral face of the magnet30and the insulating member51or the insulating member52is completely eliminated and wind sound is further reduced.

Embodiment 5 according to the invention will be explained in reference toFIG. 7.FIG. 7is a sectional view of a rotor core portion when a structure of a rotor according to Embodiment 5 is used in a rotor of a vehicular rotating electric machine.

According to Embodiment 5, as shown byFIG. 7, an insulating layer LB is formed at the outer periphery of the field winding13by using an insulting member53of a tape or the like and is brought into contact with the inner peripheral faces of the claw-like magnetic poles23,24.

By bringing the inner peripheral faces of the claw-like magnetic poles23,24and the insulting member53formed at the outer periphery of the field winding13into contact with each other in this way, the clearance between the inner peripheral faces of the claw-like magnetic poles23,24and the insulating member53is completely eliminated and wind sound is further reduced.

Further, since the inner peripheral faces of the claw-like magnetic poles23,24and the insulating member53are brought into contact with each other, rigidities of the claw-like magnetic poles23,24are increased and resonance of the claw-like magnetic poles23,24by a magnetic force is restrained.

According to Embodiment 5 of the invention, in any constitution of Embodiment 1 through Embodiment 4, the insulating layer LB is formed by arranging the insulating member53at the outer periphery of the field winding13by surrounding to incorporate the outer periphery of the magnetic winding13by the insulating member53, the outer peripheral face of the field winding13is brought into contact with the inner peripheral faces of the claw magnetic poles23,24and therefore, by forming the insulating layer LB at the outer periphery of the field winding13, insulation between the claw-like magnetic pole portions23,24and the outer periphery of the field winding13is sufficiently maintained and therefore, the inner peripheral faces of the claw-like magnetic pole portions23,24and the insulating member53formed at the outer periphery of the field winding13can be brought into contact with each other, the clearance between the inner peripheral faces of the claw-like magnetic poles23,24and the insulating member53is completely eliminated and wind sound is further reduced.

Embodiment 6 according to the invention will be explained in reference toFIG. 8andFIG. 9.FIG. 8is a perspective view of a rotor when a structure of a rotor according to Embodiment 6 is used in a rotor of a vehicular rotating electric machine andFIG. 9is a sectional view of the rotor core portion.

According to Embodiment 6, as shown byFIG. 8andFIG. 9, the insulating layer LB is formed at the outer periphery of the field winding13by using the insulating member53of a tape or the like and is brought into contact with a magnet holding member31holding the magnet30such that the magnet30is not stripped off by a centrifugal force or vibration.

By bringing an inner peripheral face of the magnet holding member31and the insulating member53formed at the outer periphery of the field winding13into contact with each other in this way, a clearance between the magnet holding member31and the insulating member53is completely eliminated and wind sound is reduced.

Since the magnet holding member31and the insulating member53are brought into contact with each other, vibration of the magnet holding member31is restrained and noise is reduced.

Further, with regard to heat generation by the field winding13, heat is diffused by way of the magnet holding member31and therefore, there is also achieved an effect of reducing temperature of the field winding13.

Further, although according to the embodiment, the insulating layer LB is formed at the field winding13by using the insulating member53of an outer peripheral tape or the like, when the magnet holding member31is constituted by an insulating member of a resin or the like, it is not necessary to form the insulating layer at the outer periphery of the field winding13.

According to embodiment 6 of the invention, in any constitution of Embodiment 1 through Embodiment 5, the insulating layer LB is formed at the outer periphery of the field winding13by using the insulting member53of a tape or the like and is brought into contact with the magnet holding member31holding the magnet30such that the magnet30is not stripped off by a centrifugal force or vibration, the outer periphery of the field winding13is continuously brought into contact with the inner peripheral face of the magnet30via the insulating member53and therefore, wind sound and vibration noise can be reduced and temperature rise of the field winding13can be restrained.

Further, according to Embodiment 6 of the invention, in any constitution of Embodiment 1 through Embodiment 5, the outer periphery of the field winding13is brought into contact with the magnet holding member31comprising an insulating member of a resin or the like holding the magnet30such that the magnet30is not stripped off by a centrifugal force or vibration, the outer periphery of the field winding13is continuously brought into contact with the inner peripheral face of the magnet30via the magnet holding member31comprising the insulating member and therefore, wind sound and vibration noise can be reduced.

Embodiment 7 according to the invention will be explained in reference toFIG. 10.FIG. 10is a sectional view of a rotor core portion when a structure of a rotor according to Embodiment 7 is used in a rotor of a vehicular rotating electric machine.

According to Embodiment 7, as shown byFIG. 10, plates PA, PB are provided between the rotor core7and the fans5disposed at the both side faces of the rotor core7.

By providing the plates PA, PB between the rotor core7and the fans5in this way, draft flowing from side faces of the yoke portion21k,22kof the rotor core7is restrained and wind sound is reduced.

According to Embodiment 7 of the invention, in any constitution of Embodiment 1 through Embodiment 6, the plates PA, PB are provided between the rotor core7and the fans5disposed at the both side faces of the rotor core7and therefore, draft flowing from the side faces of the yoke portions21k,22kof the rotor core7is restrained and wind sound can be reduced.

Embodiment 8 according to the invention will be explained in reference toFIG. 11.FIG. 1is a perspective view of a rotor when a structure of a rotor according to Embodiment 8 is used in a rotor of a vehicular rotating electric machine.

According to Embodiment 8, as shown byFIG. 11, a resin sealing layer LC is constituted by sealing insides of the claw-like magnetic poles23,24by a resin member54and at least one portion of valley portions VL constituted at the yoke portions21k,22kof the rotor core7is constituted to seal.

By sealing inside of the rotor core7by the resin in this way, draft at inside of the rotor core7is completely eliminated and therefore, wind sound is reduced.

According to Embodiment 8 of the invention, in any constitution of Embodiment 1 through Embodiment 7, the resin sealing layer LC is constituted by sealing insides of the claw-like magnetic poles23,24by the resin member54, at least one portion of the valley portions VL constituted by the yoke portions21k,22kof the rotor core7is sealed and therefore, a draft path to inside of the core7is closed and therefore, wind sound is further reduced.

Further, although according to the embodiments described in the specification, the vehicular alternating current generator is shown, the invention is applicable to a vehicular alternating current generator motor having the Lundell type rotor.

Further, although according to the embodiments described in the specification, the alternating generator cooled by air by the inner fans is shown, the invention is applicable also to a vehicular alternating current generator having the Lundell type rotor of a water-cooled type or having an outer fan so far as a draft path is provided at inside of the rotor.