JPS6155337B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a permanent magnet rotor, and at least one ferromagnetic member disposed on a stator extends in the area covered by the magnetic flux of the rotor, and the member includes:
The present invention relates to a brushless direct current motor configured to store magnetic energy during electromagnetic drive and serve to release this energy during momentary interruptions of the electromagnetic drive.

The object of the invention is to simplify conventional motors of this type and thus extend their range of use to valuable devices (tape recorders, record players, etc.).

A further object of the invention is to provide a ferromagnetic component for supplying magnetic energy during a portion of the rotational movement of the rotor, while simplifying conventional motors and reducing manufacturing costs.

This is solved as follows. In motors with a flat air gap, at least one soft magnetic element is provided in the inner region of the permanent magnet rotor;
It is formed with an edge formed point symmetrically with respect to the rotation axis, and the edge is provided with protrusions that protrude evenly over the entire circumference into the magnetic flux range of the rotor magnet, and further includes a ferromagnetic member. This is achieved by the fact that the stator is designed as a holder for a flat stator with flat coils.

Next, the present invention will be described in detail with reference to the drawings showing embodiments of the present invention.

The motor 10 according to FIG. 1 has a bearing tube 11 shown in FIGS. 4 and 5, which is welded to the tube and has three threaded holes 12 serving for fixing. A flange 13 is provided. The motor 10 is suspended from the bearing tube 11 during operation (first to
Figure 7 shows the component at about twice the enlarged size, and Figures 8 to 13 show it at its original size). A generally U-shaped notch 14 is provided on one side of the flange 13.

6 and 7 show an insulating intermediate member 15 whose inner recess 16 is slidable on the bearing tube 11 and whose outer diameter corresponds to the outer diameter of the flange 13. FIG. Member 15 which is a molded plastic body
is in the form of a ring-shaped tub, the outer wall 17 of which is lower than the inner wall 18. As a result, in the installed state (FIG. 1), a ring-shaped gap 19 is formed on the outside,
A conductor harness 20 (FIG. 1) is passed through the gap 19.
is guided laterally.

A radial web 23 divides the ring-shaped tub into three parts, of which part 2
4, 26 each have a hole 27, 28 in the bottom, which serves to pass the connecting conductor.

8 to 10 show the configuration of flat coils 32, 33, and 34 formed as circular coils, each of which is wound in two wires and connected in series. The flat coils 32, 33, 34 are formed as pasted coils, that is, their conductors are glued to each other in such a way that they are stable and rigid in shape,
Therefore, it is sufficient to support this coil on its inner periphery and to place the coil in the air gap 35 of the motor 10 (the first
It is also possible to make it protrude freely as shown in the figure. This coil is glued symmetrically into a plate 36, on the underside of which (FIG. 8) a printed circuit and (in addition to coil 32) a Hall generator 37 are provided.

Current is supplied to the coil through three conductors 38, 39,
40, but conductors 38, 39, 40
are conductors 38', 39', and 40', respectively (Fig. 8).
is familiar with Two conductors reach into the coil 33 from the conductors 39', 40'. The coil 33 reaches the inside of the coil 32 via conductors 43 and 44, and from there reaches the inside of the coil 34 via conductors 45 and 46, and is connected to conductors 38' and 40'. 1st
Figure 4 shows the circuit connections. A positive voltage is applied to point 39'. Point 38' is connected to the collector of transistor 47, and point 40' is connected to the collector of transistor 48. Transistors 47, 48
The emitter of is connected to the negative pole (OV). The output of the Hall generator 37 is the transistor 47, 48
given on the basis of. One input of Hall generator 37 leads to line 49 and the other input to resistor 5
0 to point 39'. The rotation speed control circuit for a motor according to the present invention is disclosed in, for example, Japanese Patent Application Laid-Open No. 50-52516.
It is stated in the No. During operation - controlled by a Hall generator whose output voltage is controlled by the magnetic flux of the rotor 65 - a current flows through the three coils 32 to 34 in each case alternately clockwise or counterclockwise, successive to one another. There is a momentary break between the electromagnetic drive pulses during which no electromagnetic torque is produced.

As shown in FIGS. 9 and 10, four conductive wires 54 extend outward from the Hall generator 37. In the center, the guide plate 36 has a triangular opening 53 through which the guide plate 36 is inserted into the bearing tube 11 in a centered manner.

11 to 13 show the guide plate 36 mounted on the bearing tube 11. FIG. To do this, first, the intermediate member 15 connects the conductive wires 38 to 40 to the guide plate 36 through the holes 28.
The conductive wire 54 is installed so as to pass through the hole 27. As shown in FIG. 12, the intermediate piece 15 and the guide plate 36 are placed over the bearing tube 11, with the conductors 38-40, 54 projecting laterally outwards through the annular gap 19. Intermediate member 15 defines the distance from flange 13 to coils 32-34 (FIG. 1). A thin insulating plate is passed through the lower side of the bearing tube 11, and the holder 55 is pressed against the bearing tube 11 from below.In other words, the holder 55 connects the coils 32 to above through the insulating plate. 3
It is pressed in four directions, pressing the coil in the direction of the intermediate body 15, thereby completely fixing the coil at its inner periphery. The structural parts constructed in this way (FIGS. 11 to 13) are then glued with epoxy resin to securely and permanently fix the holder 55, the coil, the guide plate 36, and the intermediate member 15 to the bearing tube 11. Once the epoxy resin has hardened, the two porous bearings 56, 57 are press-fitted into the bearing tube 11, and the lubricating oil supply ring 58 is installed between them.

The conductors 38 to 40, 54 are then passed through the transverse cutout 14 of the flange 13, so that the ferromagnetic back cover plate 59 communicates with the flange 11 via the intermediate member 15 in its central recess 60 and thus closes to the back cover. Plate 59 is coil 3
It touches the upper side of 2 to 34. The conductors are then bundled with an insulating tube (FIG. 1).

Once the required thickness of the spacing ring 63 has been determined, this ring is inserted into the shaft 64 of the rotor 65, which has a shell-like back cover plate 66 made of soft iron, which is inserted through the bush 62. A six-pole permanent magnet ring 67 having magnetism in the axial direction is aligned and fixedly bonded within the cover plate 66 (as disclosed in Japanese Patent Laid-Open No. 49-50412). Fourth
It is also advantageous to use the bent pole shape shown in the figure). The direction of rotation is indicated by arrow 68 in FIG.

The shaft 64 is inserted into the bearing tube 11 from below. The magnet 67 first pulls the back cover plate 59 and holds it against the flange 69 of the cover part 66. Furthermore, the shaft 64
A ring 70 is fitted to the upper end of the ring 7.
0 serves as a thrust bearing for the suspended rotor and abuts the upper porous bearing 56.

In order to generate the necessary reluctance torque,
A holder 55 with a dual function is useful. The holder 55 is shown in FIGS. 2 and 3 and is generally gear-shaped in plan. The reason is that the holding body 55 has six identical lens-shaped concave portions 75 (corresponding to the number of poles of the rotor) on its circular outer periphery. Three fixing ribs 77 are formed on the inner periphery 76 and are bent at right angles. The ribs 77 serve to press into the bearing tube 11 as shown in FIG.

The illustrated peripheral edges 74 and 75 of the holding body 55 generate reluctance torque by interaction with the magnetic field existing at the inner circumference of the rotor. This reluctance torque is formed in opposite phase to the alternating component of the electromagnetic torque and thus compensates for ripples in the electromagnetic torque. Therefore, effective torque is always generated on the shaft 64 during operation, and the ripple component of the torque that causes vibration in the motor-generated torque is almost canceled out.

FIG. 15 shows the motor 10 mounted on, for example, a cassette recorder. The flange 13 is screwed to the upper holding plate 80. An adjustment screw 82 is screwed into the screw hole of the lower holding plate 81, and an axial bearing 83 made of plastic containing molybdenum disulfide is attached above the adjustment screw 82. On the axial bearing 83 the spherical lower end 8 of the shaft 64
4 (Fig. 1) slides. The axial clearance of the rotor is set by the adjustment screw 82, and after it has been set, the screw 82 is glued. The ring plate 70 (FIG. 1) in this case does not act as a thrust bearing during operation.
As shown in FIG. 15, the motor has a large axial moment of inertia, thus typically eliminating the need for a special inertial flywheel.

The invention can equally be used in the case of motors with other numbers of poles or other bearings, for example ball bearings. The shape of the recess 75 is expediently determined experimentally. FIG. 11 shows the holder 5 for the coil 34.
5 shows the exact location. This position defines the relative position of the reluctance torque to the electromagnetic torque and thus also indicates the stable rest position of the rotor in the de-energized state.

It is also possible to bring the holder 55 into direct contact with the guide plate 36 instead of via the coils 32-34. However, contact via the coil is preferred. The reason for this is that arranging the magnetically active edges 74, 75 of the holder close to the rotor magnet 67 is highly favorable with regard to the magnetic moment. The object of the present invention also includes the mounting method according to this embodiment.

The flat stator body is a guide plate (with coil) 3
6. Coils 32 to 34 (Figs. 1 to 15) themselves, parts 118, 168 to coils 119, 16
9 (FIGS. 16 to 19).

According to FIG. 16, a ring-shaped magnet 105 having permanent magnetism is coaxially fixed to the rotor shaft 101 via a magnetic cover plate 104 in the axial direction. The cover plate 104 and the magnet 105 together with the boss 102 form a first rotor disk 106, which is assembled into one structural unit. The boss 102 has an insertion hole 107, the end face of which indirectly serves as a sliding surface for a bearing tube 109 inserted into the shaft 101 with an axial clearance seat. This construction style is very simple in the axial direction.
The bearing tube 109 is made of porous metal and is cast into sliding bearings 113, 114 at both ends thereof. A flange plate 116 formed according to the present invention is press-fitted into the enlarged central portion 115. A stator plate 118 is fixed to the end face 117 side of the flange plate 116 by adhesive, and is formed to have sufficient rigidity. The square ferromagnetic boss 102 is considered to be used for a rotor 105 having four polar axial magnetism, and its radial protrusion 20 is within the range of the inner magnetic flux.
0 is provided (FIG. 20). Inserted into the stator plate 118 with the printed circuit are two diametrically opposed induction coils, one of which is shown in FIG.

The second rotor disk 125 consists of a ferromagnetic cover plate, which is inserted into the shaft 101 with a gap and fitted into the groove portion 126 of the rotor shaft 101 by the axial tensile force generated by the magnets 105. The fixed plate 127 is contacted. The axial distance between the groove portion 126 and the sliding surface 108 is indicated by the arrow 110,
Together with the spacing indicated by 120 and the thickness of the steel plates 123, 124, the gap width and the upper spacing between the rotor and stator, indicated by the double arrow 129, are determined. The end face of the bearing tube 109 is freed from the tensile force generated by the magnet 105 by a fixing plate 127, which would otherwise come into contact with the upper and lower sliding surfaces.

The bearing tube body has sliding surfaces 108 to steel plates 123, 12.
4 and the fixed plate 127, leaving a small allowable gap,
Or by interposing the steel plate 128, the fixing plate 1
27 (this is not shown in the figure). The clamp ring 132 prevents the rotor disk 125 from falling off the rotor shaft.

The flange plate 116 has a large thickness in the axial direction for stability reasons. This creates a relatively wide pressing surface or bonding surface for securely fixing the bearing 114 to the bearing tube 109 even if the area of the bearing 114 is narrowed. Even in this case, the structural length in the axial direction is not increased. The reason for this is that the thick flange plate 116 protrudes into the inside of the ring-shaped magnet 105. This shape of the flange plate 116 is advantageous because the magnitude of the reluctance torque can be adjusted by changing its dimensions.

The stator plate 118 is thinned in the area between the motor coil 119 and the bearing tube 109. This is because the coil 119 reaches the bearing tube through a gap 199. In this case, the flange plate 11
6 is fixed to the stator plate 118 by adhesive.

Therefore, the flange plate 116 can be fixed to the bearing tube body 109 by press-fitting, by gluing, or by a combination of press-fitting and gluing.
In FIG. 17, if two or more coils 140 are disposed radially outwardly within stator plate 139, stator plate 139 can be secured to flange plate 136 by mounting or riveting (FIG. 17). In addition, the first
In FIG. 7, the rotor shaft 13 is attached to the bearing tube 137.
8 is inserted.

The stator plate is riveted to the flange plate 136 with two hollow rivets diametrically opposed to each other. Two hollow rivets are located in the intermediate chamber between the motor coils, displaced by two 180 degrees, with only one hollow rivet 141 being shown. The structure of the embodiment shown in FIG. 17 is the same as that shown in FIG. 16 except for the above-mentioned points. The strength and placement of the hollow rivet does not have an unacceptably negative effect on producing a given reluctance torque. Therefore, in some cases, it may be necessary to use rivets of the same number as the number of poles. For a two-pole rotor, it is advantageous to use two rivets displaced by 180 DEG as described above. 20th
The figure shows a four-pole rotor using four rivets 141. In the second embodiment shown in FIG. 18, a first rotor disk 150 and a second rotor disk 151 are shown. The two rotor plates each form a structural element. The rotor disk 150 consists of a ferromagnetic cover plate 152, which has a central recess 153, into which a boss 154 formed as a pulley for hanging a belt is inserted. The boss 154 has an insertion hole 156, the end surface of which serves as a support surface 157 for a bearing tube 158 inserted into the rotor shaft 155 with axial gap support. The bearing tube is provided with two ball bearings 159, 160 at both ends thereof, in which the rotor shaft 155 rotates. Ball bearing 159,
The inner rings 161 and 162 of the bearing tube 160 are supported by the rotor shaft 155 with a gap in the axial direction, and the outer rings 163 and 164 are supported by the inner tube 165 of the bearing tube body 158.
is supported on both sides. A rigid stator plate 168 is fixed to an end surface 167 of the flange plate 166 on the rotor disk 150 side. Two motor coils 169 and 170 are inserted into the stator plate 168 and are diametrically opposed to each other. The stator plate consists of two cases 172, 1 made of iron plates.
It is riveted between the outer edges 174 and 175 of 73. Two rivets distributed around the circumference are shown in FIG. 2 cases 172,1
73 forms a metal case for the rotor consisting of two rotor disks 150 and 151, and its boss 154
protrudes from the case by a central hole 178. Electrical circuitry for the rectifier circuit may be secured to stator plate 168. In the illustrated embodiment, the circuit elements 180, 181 protrude from the case and are fixed to the edge 182 of the stator plate and also within the case, where the elements are not shown. Another magnetic iron plate 18
3 is fixed to the case 173 by a fixing means (not shown), and can be adjusted by an adjustment screw 184 screwed to the case, thereby making it possible to adjust the overall reluctance torque. The second lower rotor disk 151 has a single structure consisting of a ferromagnetic cover plate 185, in which a metal boss 187 is molded in a central recess 186, and the cover plate 185 has a ring-shaped permanent A magnet 188 is fixed. boss 1
87 moves in contact with the inner ring 162 of the ball bearing 159 with two steel plates 190 and 191 interposed therebetween;
The boss 154 is connected to the ball bearing 15 with a steel plate 193 interposed therebetween.
9 in contact with the inner ring 161 and its moving surface 157
exercise with. In this way, both bosses 154,
187 is connected to the ball bearings 159, 160, the inner tube 165, and the bearing tube body 1 through the inner rings 161, 162.
58. It is particularly advantageous if the bearing tube is a smooth cylindrical sleeve. Other than this, the ball bearings 159 and 160 are
Provided on the turning part of. This support takes place without gaps. The reason is that both rotor discs have magnets 18
This is because the magnetic force of 8 attracts each other up to the stopper. The spacing between both rotor disks 150, 151 depends on the axial position of both ball bearings and the plates 190, 19.
The thickness is very precisely given by the thickness of 1,193 mm, and the dimensions are very easily and accurately maintained even in mass production. both rotor discs 150,
The gap width 194 between the gaps 151 and 151 is defined by the surfaces of the rotor disks 150 and 151 that define the gap 194 and the boss 154
~187, and in mass production this spacing is defined by the 16th
As shown in the figure, it can be held accurately, so
The gap width can be kept within tolerance. Adjustment of the stator plate 168 within the air gap is also simple. This is because the axial position of the flange plate 166 on the bearing tube 158 can be adjusted. The spacing between rotor disk 151 and stator plate 168, for example spacing 194, can be varied by changing the thickness of plates 190,191. Increasing this type of clearance, which is necessary to prevent contact of the rotor parts, for example, generally causes the motor to have less power.

The boss 154 is formed as an output pulley, and the outer peripheral surface of the pulley is indicated by 198. The insertion hole 156 extends up to the height of the driven surface 198, so that lateral forces are better handled. This is the first
6 has already been explained in detail with respect to FIG. If ball bearings are provided, this problem is less of a problem.

In the embodiment shown in FIGS. 18 and 19, case 1
The case formed by 72,173 is
It can also be used for the embodiment of FIG.

Figure 19, which is an enlarged view of Figure 18, shows the ball bearing system 1.
No. 21 in improving the present invention together with No. 63,164.
There are particular economic advantages in connection with those shown.
If the bearing seat requires turning in the bearing tube or is suitable for the purpose, the bearing tube 158 can be machined from a hexagonal bar of free-cutting steel integrally with the flange plate 166 in a very economical manner. It can be manufactured as a machined part, in which case turning can be carried out simultaneously. Free-cutting steel exhibits sufficient magnetic properties to generate effective reluctance torque. FIG. 21 is of course based on a six-pole rotor.

On the other hand, when using an arbitrary sliding bearing as shown in Fig. 16, the bearing tube body is directly manufactured from sintered material,
This is advantageous as it allows for smaller dimensions (particularly with a shaft diameter of 6 mm). In this case, the sinterable shape material (members 116, 118) can be economically applied integrally, but the reason is that there is not much difference in price between this type of member having the edge portion 116 compared to the tubular shape. There isn't. This configuration is advantageous for mass-produced products requiring small dimensions and minimal reluctance torque. In this case, machining that produces chips is eliminated.

Sintered materials are magnetically insufficient to generate strong reluctance torques. This can be compensated to some extent by changing the axial thickness of the flange plate 116, but this also has its limits.

FIG. 20 shows a cross section taken in the direction of the arrow - in FIG. 15. When the number of poles of the rotor matches the number of protrusions 200, there should be a minimum magnetic cross section between the protrusions 200. A spatial rivet displacement structure of 45° relative to the position shown is selected (4-pole rotor).

The dotted edges 202 of the recesses 203 between the protrusions 201 in FIG. 21 can also be adapted for adjusting the predetermined reluctance torque. This also applies to the protrusion 201. The protrusion 201 can be bent as a plate, for example by different dimensions. Further, the flange portion can also be manufactured from steel plate as a pressed and drawn member at an advantageous price.

The present invention should not be understood as being limited to the embodiments shown here.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a brushless DC motor according to the present invention, FIG. 2 is a plan view of a soft magnetic holder, and FIG. 3 shows the cross-sectional line - of FIG.
FIG. 4 is a plan view of the combination of the bearing tube and flange, FIG. 5 shows the cross-sectional line in FIG. 4, FIG. 6 is a plan view of the insulating intermediate material, and FIG. 6 is a cross-sectional line in FIG. 6, FIG. 8 is a plan view of a guide plate equipped with three flat coils, FIG. 9 is a cross-sectional line in FIG. FIG. 11 is a plan view of the guide plate bonded to the bearing tube, and FIG.
FIG. 2 shows the section line XII-XII in FIG. 11, and FIG. 13 is a plan view of the guide plate attached to the bearing tube body.
FIG. 14 shows a driving circuit for the motor shown in FIG. 1, FIG. 15 shows the motor shown in FIG. 1 installed, and FIG. 16 shows a motor according to a second embodiment of the present invention. FIG. 17 is a sectional view of an embodiment in which the flange plate and its fixing member are different from the embodiment shown in FIG. 16, FIG. 18 shows the fourth embodiment, and FIG. FIG. 20 shows the cross-sectional line of FIG. 16, and FIG. 21 shows the cross-sectional line of FIG. 18.
The arrow direction - in the figure is shown. 10...Brushless DC motor, 35...Flat gap, 55...Ferromagnetic member, holding body, 65...
Rotor, 15... intermediate body, 11, 109... bearing tube body, 116... flange plate.

Claims (1)

[Claims] 1. A permanent magnet rotor is provided, and a ferromagnetic member disposed on the stator extends in the area covered by the magnetic flux of the rotor, and the member receives magnetic energy during electromagnetic driving. In a brushless DC motor, the ferromagnetic member has a plurality of ferromagnetic members formed point-symmetrically with respect to the axis of rotation. has an edge, and the edge is
A brushless DC motor characterized in that the brushless DC motor is configured as a protrusion that protrudes uniformly over the entire circumference of the magnetic flux range of the rotor magnet, which is the radially inner range of the permanent magnet rotor. 2 Equipped with a permanent magnet rotor, a ferromagnetic member disposed on the stator extends in the area covered by the magnetic flux of the rotor, and the member stores magnetic energy during electromagnetic driving and transfers this electromagnetic energy. Serving to release this energy during momentary interruptions of the drive, the stator is constructed as a flat stator body with coils and is located between two rotor discs. In a brushless DC motor in which at least one rotor disc of the plates is provided with a magnet having a magnetic pole direction along the axial direction, the ferromagnetic member is arranged on the rotation axis of the motor with a flat air gap 35. It has a plurality of edges formed in point symmetry with respect to the permanent magnet rotor, and the edges are the radially inner range of the permanent magnet rotor and are distributed evenly over the entire circumference of the magnetic flux range of the rotor magnet. The brushless DC motor is configured as a protruding protrusion, and the coil of the stator is configured as a flat coil fixed on the flat stator and disposed in the air gap, wherein the ferromagnetic member A brushless direct current motor characterized in that an edge portion is formed as a holder for holding the flat stator around a bearing tube around a rotating shaft. 3. A permanent magnet rotor is provided, and a ferromagnetic member provided on the stator extends in the area covered by the magnetic flux of the rotor, and the member stores magnetic energy during electromagnetic drive, and the member stores magnetic energy during electromagnetic drive. The stator is configured as a flat stator body with coils and located between two rotor discs, the stator being configured as a flat stator body with coils, the stator being located between two rotor discs. In a brushless DC motor in which at least one of the rotor discs is provided with a magnet having a magnetic pole direction along the axial direction, the ferromagnetic member is arranged relative to the rotation axis of the motor with a flat air gap 35. a plurality of edges formed point symmetrically, the edges protruding evenly over the entire circumference of the magnetic flux range of the rotor magnet in the radially inner range of the permanent magnet rotor; The brushless direct current motor is configured as a protrusion that is fixed to the stator, and the coil of the stator is configured as a flat coil fixed on the flat stator and disposed in the air gap, wherein the ferromagnetic member is , is formed as a holder for holding the flat stator around the bearing tube around the rotating shaft via an insulating intermediate, and the flat stator coil 3
2, 33, and 34 are sandwiched between an insulating intermediate body 15 inserted around the bearing tube body and a holding body 55. 4. A permanent magnet rotor is provided, and a ferromagnetic member provided on the stator extends in the area covered by the magnetic flux of the rotor, and the member stores magnetic energy during electromagnetic driving and is capable of storing magnetic energy during electromagnetic driving. The stator is configured as a flat stator body with coils and located between two rotor discs, the stator being configured as a flat stator body with coils, the stator being located between two rotor discs. In a brushless DC motor in which at least one of the rotor discs is provided with a magnet having a magnetic pole direction along the axial direction, the ferromagnetic member is arranged relative to the rotation axis of the motor with a flat air gap 35. a plurality of edges formed point symmetrically, the edges protruding evenly over the entire circumference of the magnetic flux range of the rotor magnet in the radially inner range of the permanent magnet rotor; The brushless direct current motor is configured as a protrusion that is fixed to the stator, and the coil of the stator is configured as a flat coil fixed on the flat stator and disposed in the air gap, wherein the ferromagnetic member is , the flat stator is formed as a holder for holding the flat stator around a bearing tube located around the rotation axis, and the holder is formed as a flange plate fitted in the rotation axis direction within the rotor magnet. A brushless DC motor, characterized in that a flat stator surrounding the bearing tube 109 is fixed on one side by the flange plate 116 coupled to the bearing tube.