JP4768246B2 - Inner magnet motor with brush - Google Patents

Description

  The present invention relates to an inner magnet motor with a brush.

  Conventionally used brushed inner magnet motors have a rotating shaft of a rotor, a magnet portion composed of a plurality of permanent magnets arranged at equal intervals in an arc shape on the outer periphery of the rotor, and an outer peripheral surface of the magnet portion. A plurality of magnetic pole teeth formed radially with respect to the rotating shaft, a coil wound around each magnetic pole tooth, and an annular shape with a certain gap adjacent to one end in the axial direction of the magnetic pole teeth And a commutator comprising a plurality of segments to which winding ends of the respective coils are connected, and a plurality of brushes slidably contacting the segments.

  As described above, an inner magnet motor with a brush having a magnet portion inside a coil is usually an outer rotor type, and as an advantage, (i) a large moment of inertia, and (ii) a coil is located outside. It has features such that it is easy to dissipate heat and the coil can be easily cooled, and (iii) it is compatible with high performance magnets such as neodymium magnets.

  However, since the inner magnet motor has conventionally formed a plurality of coils by distributed winding with one winding, a crossover is generated between the coils, and the coil end becomes large. As a result, the overall size of the motor becomes large and it is difficult to reduce the size.

  On the other hand, in a DC motor with a brush, it is necessary to increase the withstand voltage between the brushes and suppress energy loss due to a phase shift of the coil. The phase shift appears as a loss of electromagnetic energy when the windings of adjacent coils are energized in opposite directions. Therefore, in order to prevent a phase shift, it is necessary to energize adjacent coils in opposite directions so that currents in the same direction flow in adjacent windings.

  Such a motor is described in Patent Document 1, for example. In the motor described in Patent Document 1, the winding ends and segments of each coil element are connected so that the coils wound around the magnetic pole teeth are continuous in a single stroke.

However, also in this case, since the coils are formed by distributed winding, crossovers are generated between the coils. For this reason, the connecting work such as connecting the connecting wires between the segments becomes complicated, and the connecting wire increases the coil end, thereby increasing the size of the entire motor. In addition, this motor is an outer magnet type motor in which a magnet is arranged on the outer peripheral side of the coil, and an inner magnet motor having the advantages as described above must be small and capable of obtaining high torque. It is said that.
JP 2001-275327 A

  The present invention has been made in consideration of the above prior art, and has an object to provide a brushed inner magnet motor that can make the coil end compact, prevent a phase shift of the coil, and achieve a small size and high output. .

According to the first aspect of the present invention, there is provided a rotating shaft, a magnet portion composed of a plurality of permanent magnets arranged in a circular arc shape at substantially equal intervals with respect to the rotating shaft, and an outer peripheral surface of the magnet portion opposed to the rotating shaft. A plurality of magnetic pole teeth arranged radially, a coil element wound around each magnetic pole tooth, and an annular arrangement at a fixed position with respect to the coil element via a certain gap, the winding of each coil element In an inner magnet motor with a brush having a commutator comprising a plurality of segments to which line ends are connected and a plurality of brushes slidably contacting the segments, the coil element is wound by a separate winding for each magnetic pole tooth together with the said segments to form a series of coils continuously connected to the coil element skipping between every two by two, each Koiruere Both ends of the winding of the current coil are connected to two mutually intersecting and opposing segments and intersect one winding end of each neighboring coil element so that one winding of each neighboring coil element An end magnet is provided with an inner magnet motor with a brush, characterized in that each end is connected to the farther segment of the two opposing segments .

According to a second aspect of the present invention, in the first aspect of the invention, a double annular slip ring is provided closer to the center of rotation than the magnetic pole teeth, and power is supplied to the coil element via the slip ring and the commutator. Thus, an inner rotor system in which the magnet portion rotates is employed .

According to a third aspect of the present invention, in the invention of the second aspect , the slip rings are provided on an inner peripheral side and an outer peripheral side of the commutator, and brush contact surfaces of the slip ring and the commutator are on the same plane, The brush is characterized by being in sliding contact with both of the slip ring and the commutator at the same time .

  According to the first aspect of the present invention, since a plurality of coil elements are wound by separate windings, a crossover is not generated, so that the coil end is reduced and the size of the entire motor can be reduced. . In addition, since there are few crossover portions that do not contribute to torque generation, electrical resistance is low and high output is possible.

  Furthermore, when the adjacent coil elements are energized in opposite directions, currents in the same direction flow in the adjacent windings. Thereby, loss of electromagnetic energy due to phase shift can be suppressed, and high torque can be obtained efficiently.

Further, when the coil is assembled, in the connecting operation between the winding end and the commutator, the adjacent coil elements are energized in the opposite directions, thereby preventing phase shift. For this reason, when winding around the magnetic pole teeth, it is sufficient to wind the winding in the same direction, which is easy to automate.

According to the invention of claim 2 , even if the core on the inner magnet portion side is rotated by supplying power from the brush with one of the slip rings of the double ring as the “+” side and the other as the “−” side. The coil elements can be supplied with electric power while switching the energization order and direction through the slip ring and the commutator as the magnet portion rotates without causing twisting of the electrical wiring. For this reason, it can be set as the inner rotor system of an inner magnet. As a result, the range of application as a product is expanded, as are many brushless motors that are commonly used in recent years.

According to the invention of claim 3 , since the number of parts is reduced and the structure becomes simple, the motor can be further reduced in size.

  1 and 2 show a configuration example of an inner magnet motor according to the present invention, FIG. 1 is a plan view, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

  The motor 1 includes a rotor 2 and a stator 3. The rotor 2 includes a rotating shaft 21, a rotor side core 22 fixed to the rotating shaft 21, a magnet portion 4 including a plurality of permanent magnets 4 a attached along the outer periphery of the rotor side core 22, and a brush holder And a brush 5 fixed to 51. The permanent magnets 4a are arranged on the outer periphery of the rotor-side core 22 so as to be divided into arcs at substantially equal intervals. As shown in FIG. 2, the brush 5 comes into contact with a commutator 7 and a slip ring 8 to be described later via a spring 52 attached in the brush holder 51.

  The stator 3 includes a case 31 that covers the entire motor 1, a stator side core 32 that is fixed to the inside of the case 31, a plurality of magnetic pole teeth 6 that are integral with the stator side core 32, and that protrude radially inward, a commutator 7, And a slip ring 8. 6 ′ is a slot formed between adjacent magnetic pole teeth 6, 6. A winding is wound around each pole tooth 6 through the slot 6 ′.

  A plurality of magnetic pole teeth 6 are provided, for example, twelve as shown in FIG. 1, and a bobbin 9 made of an insulating material such as a synthetic resin is attached to each magnetic pole tooth 6. A separate winding is wound around each bobbin 9 and is hardened with resin to form the coil element 10. The commutator 7 is composed of two segments 7a for connecting both terminals of the winding for each coil element 10, so that the total number of coil elements is twice the number of coil elements, that is, 24 segments in the example of FIG. These are arranged in an annular shape concentric with the rotating shaft 21. The slip ring 8 is provided concentrically with the rotation shaft 21 and on the inner side and the outer side with the commutator 7 interposed therebetween. Electricity on the positive electrode side is supplied to one side, and electricity on the negative electrode side is supplied to the other side.

  The surfaces of the commutator 7 and the slip ring 8 are arranged in the same plane as shown in FIG. 2, and both the commutator 7 (segment 7 a) and the inner peripheral side or the outer peripheral side slip ring 8 are formed by one brush 5. Can be contacted at the same time. For example, the battery is connected to the battery so that the inner peripheral slip ring 8a is on the positive electrode side and the outer peripheral slip ring 8b is on the negative electrode side. Since the brush 5 shown on the upper side in FIG. 2 is in contact with the outer peripheral side slip ring 8b and the commutator 7, "-" electricity is supplied to the contacting segment 7a. Therefore, the brush 5 is a “−” brush. On the other hand, the brush shown on the lower side is in contact with the inner peripheral side slip ring 8 a and the commutator 7, so that “+” electricity is supplied to the segment 7 a and becomes the “+” side brush 5.

  FIG. 3 is a development view of a coil connection example of the motor 1 of FIG. That is, this is an example of connection when there are 12 magnetic pole teeth 6 (coil elements 10) and 24 segments 7a of the commutator 7. Both ends of the windings of each coil element 10 are connected to the segments 7a of the commutator 7. The predetermined segments 7a are connected to each other.

  Corresponding to the positions of the twelve coil elements 10, two segments 7a are provided directly below each. As shown in FIG. 3, both ends of the windings of each coil element 10 intersect with each other and intersect with one winding end of the adjacent coil element 10 to be connected to the segment 7a. The winding end of the coil element 10 is connected to the far segment of the two segments 7a directly below, or to the distant segment 7a of the two segments 7a directly below the adjacent coil element 10. The coil element 10 connected to the segment 7a directly below each coil element 10 and the coil element connected to the segment 7a directly below the adjacent coil element 10 are alternately arranged. Therefore, two segments 7a are skipped from each other and connected to the coil element 10 every two to form a series of coils. As a result, as shown in FIG. 3, among the 24 segments 7a, # 3, # 4, # 7, # 8, # 11, # 12, # 15, # 16, # 19, # 20, # 23 , # 24, and 12 coil elements 10 are connected to form a series of coils. By performing such connection, a series of coils can be formed so that the energization directions of the adjacent coil elements 10 are arranged in the forward and reverse order. Thereby, the direction of the current flowing through the windings of adjacent coil elements 10 becomes the same direction, energy loss is suppressed, and phase shift can be prevented.

  For example, as shown in the figure, 24 segments 7a are connected to each other by # 1, # 7, # 13, # 19, # 2, # 8, # 14, # 20, # 3, # 9, and # 9 of segment 7a. Four segments, such as 15, # 21, # 4, # 10, # 16, # 22, # 5, # 11, # 17, # 23, # 6, # 12, # 18, and # 24 Connect 7a. By connecting the segments 7a to each other, a single brush 5 can supply power to the plurality of segments 7a at the same time, so the number of brushes 5 can be reduced.

  4A to 4C show the operation of the coils connected as shown in FIG. 3, and show the state where the brush 5 has moved to the right by half of the segment 7a from the state of FIG. 4A. .

  In the present embodiment, there are eight permanent magnets 4a constituting the magnet unit 4, two brushes 5 each on the "+" side and "-" side, and the magnet unit 4 and the brush 5 are on the rotor side. The coil element 10 and the segment 7a do not rotate, and the brush 5 sequentially contacts the segment 7a while rotating to supply power to each coil element 10.

  When the brush 5 is powered by contact with the slip ring 8, the rotor 2 is energized and the rotor 2 rotates. The brush 5 rotates together with the rotor 2 and sequentially contacts the segment 7a, and “+” or “−” power is distributed from each brush 5. The coil element 10 indicated by a dotted line in the drawing is not energized depending on the position of the brush 5. By connecting as shown in the figure, in each coil element 10, current flows in the opposite direction between the adjacent coil elements 10 as shown by the arrows in the figure, and the adjacent windings have the same direction. Current flows through Therefore, energy loss is reduced, phase shift can be prevented, and high torque can be obtained. Moreover, the space | interval between adjacent brushes 5 is an area including the clearance gap between the two segments 7a. As described above, by including two or more gaps between the segments 7a serving as the insulating regions, the insulation is improved and the withstand voltage is improved.

  The connection between the segments 7a is not limited to the above example, and the number and arrangement of the brushes 5 are appropriately determined according to the segment 7a to be connected.

  FIG. 5 is an explanatory diagram of different coil connection examples in the motor 1 of FIG. 1, and is formed by stacking another series of coils using 12 unused segments 7a in the connection example of FIG. It is.

  First, as shown in FIG. 5A, the same connection as in FIG. 3 is performed. That is, a series of coils are formed using 12 segments # 3, # 4, # 7, # 8, # 11, # 12, # 15, # 16, # 19, # 20, # 23, and # 24. Form. After that, as shown in FIG. 5B, the remaining 12 segments 7a (# 1, # 2, # 5, # 6, # 9, # 10, # 13, # 14, # 17, # 18, Using # 21, # 22), another series of coils is formed by the same method as in (A). By superimposing FIG. 5 (A) and FIG. 5 (B), as shown in FIG. 5 (C), a coil in which all the segments 7a are equally used is formed. Thereby, the use efficiency of the segment 7a is improved, and a stable high output is obtained. Further, since the sliding frictional resistance with respect to the brush 5 becomes substantially constant during rotation, the durability of the brush 5 is increased. In FIG. 5C, the series of coils formed in FIG. 5B are indicated by broken lines. In FIGS. 5B and 5C, the connection diagram of the segments 7a is omitted.

  FIG. 6 is an explanatory diagram of an embodiment of a different coil, and is an example of connection when the number of coil elements 10 is 6, 12 segments 7a, and 4 permanent magnets 4a. The number of brushes 5 is four as in the above-described embodiment, and the width of the brushes 5 is larger than in the above-described case. 6A to 6C show a state in which the brush 5 is relatively moved to the right in the figure by half of the segment 7 a by the rotation of the rotor 2. In this case, the segments 7a are not connected to each other.

  By increasing the width of the brush 5, the interval between the brushes 5 is narrower than in the above-described embodiment. In this example, there is only one gap between the segments 7a at the position of FIG. 6 (B), and the withstand voltage is lowered, but at the positions of FIG. 6 (A) and FIG. A gap between the segments 7a is included. Thus, by setting the interval between the brushes 5 so as to include two or more gaps between the segments 7a at least at one location during rotation, the average interval between the brushes 5 increases and is sufficiently large. Withstand voltage can be obtained. Therefore, it is not necessary to make the width of the brush 5 too small in order to increase the withstand voltage, and the restriction on the width of the brush 5 is reduced, and the degree of freedom in design is widened.

  FIG. 7 and FIG. 8 are development views of further different coil embodiments, in which the number of brushes 5 is increased. FIG. 7 shows the case where the number of coil elements 10 is 8, the number of segments 7a is 16, the number of permanent magnets 4a is 6, and the number of brushes 5 is 3 each on the “+” side and the “−” side. In this connection example, the number of coil elements 10 is 10, the number of segments 7a is 20, the number of permanent magnets 4a is 8, and the number of brushes 5 is 4 on each of the “+” side and the “−” side. Increasing the number of brushes 5 eliminates the need for connecting the segments 7a.

  The connection method of the coil element 10 and the segment 7a is the same as that of the above-mentioned connection shown in FIG. 3, and the energizing directions of the adjacent coil elements 10 are opposite to each other as shown by arrows in the figure. A series of coils can be formed.

  FIG. 9 is a development view of still another embodiment, in which only three magnetic pole teeth 6 are used by skipping one of the six magnetic pole teeth 6. That is, two coil elements 10a and 10b are overlapped and formed on the three magnetic pole teeth 6 to be used, and they are connected using six segments 7a out of twelve segments 7a. A coil is formed.

  As illustrated, one of the two coil elements 10a and 10b formed in an overlapping manner is connected to two segments 7a adjacent to each other with their winding ends intersecting each other. The other coil element 10b is connected to a segment 7a at a position where both winding ends are spaced apart from each other. Similarly to the above-described embodiment, the segments 7a are connected to the coil element 10 at intervals of two.

  FIG. 10 shows a configuration in which another series of coils having the same shape as in FIG. 9 is formed and superposed using three magnetic pole teeth 6 and six segments 7a not used in the embodiment of FIG. FIG. 10A is the same as FIG. 9, and two coil elements 10 a and 10 b are formed on each magnetic pole tooth 6. FIG. 10 (B) shows another series of coils with the same shape as FIG. 10 (A) but with pole teeth 6 and segments 7a not used in FIG. 10 (A), with two pole teeth for each pole tooth. Coil elements 10c and 10d are formed and connected to form a series of coils. FIG. 10C is a superposition of FIG. 10A and FIG. In FIG. 10C, a series of coils formed in FIG. 10B are indicated by broken lines.

  In all the coil embodiments described above, the number of magnetic pole teeth 6 and brushes 5 is not limited to the above example.

  11 to 13 show different embodiments of the brushed inner magnet motor according to the present invention. In this embodiment, the commutator 7 and the slip ring 8 are not arranged on the same plane. 11 is a plan view of the commutator 6 side viewed from the PP direction of FIG. 13 with the magnet portion 4 removed, and FIG. 12 is a plan view of the slip ring 8 side viewed from the QQ direction of FIG. . 13 is a cross-sectional view taken along line BB in FIG. Parts having the same application as in FIGS. 1 and 2 are denoted by the same reference numerals.

  The motor 1 includes a rotor 2 (FIG. 13) and a stator 3, and the rotor 2 is attached along a rotating shaft 21, a rotor side core 22 fixed to the rotating shaft 21, and an outer periphery of the rotor side core 22. The magnet portion 4 is composed of a plurality of, for example, twelve permanent magnets, and the commutator brush 5 a and the slip ring 8 fixed to the brush holder 51. The commutator brush 5 a comes into contact with the commutator 7 through a spring 52 attached in the brush holder 51. The slip ring 8 includes an inner peripheral side slip ring 8 a and an outer peripheral side slip ring 8 b, and is attached to a slip ring support plate 55 fixed to the rotary shaft 21. Therefore, the slip ring 8 rotates together with the magnet unit 4 as the rotating shaft 21 rotates.

  The stator 3 includes a case 31 covering the entire motor 1, a stator side core 32 fixed to the inside of the case 31, a plurality of magnetic pole teeth 6 integrally provided with the stator side core 32 and projecting radially inward, and a commutator 7.

  For example, 18 magnetic pole teeth 6 are provided, and a bobbin 9 made of an insulating material such as synthetic resin is attached to each magnetic pole tooth 6. A separate winding is wound around each bobbin 9 and is hardened with resin to form the coil element 10. The commutator 7 is composed of two segments 7a for connecting both terminals of the windings wound for each individual coil element 10, and as a whole, twice the number of coil elements 10, that is, 36 segments 7a, It is arranged in an annular shape concentric with the rotating shaft 21. Two annular slip rings 8 are provided concentrically with the rotating shaft 21, and one is used for power feeding on the positive electrode side and the other on the negative electrode side.

  In the present embodiment, since the commutator 7 and the slip ring 8 are not arranged on the same plane, the commutator brush 5a and the slip ring brush 5b are provided separately. The slip ring brush 5 b is urged toward the slip ring 8 by a leaf spring 53 attached to the case 31 and comes into contact therewith.

  As shown in FIG. 12, for example, four slip ring brushes 5b are provided. For example, the upper and lower brushes of FIG. 12 are connected to the battery “+”, and the left and right brushes are connected to “−”. . As a result, the outer peripheral side slip ring 8b in contact with the upper and lower brushes becomes “+”, and the inner peripheral side slip ring 8a in contact with the left and right brushes becomes “−”. These slip rings 8a and 8b are connected to the commutator brush 5a via internal wiring (not shown). The brush connected to the inner peripheral side slip ring 8a becomes the "-" side commutator brush 5a, and the brush connected to the outer peripheral side slip ring 8b becomes the "+" side commutator brush 5a. Thus, when the commutator brush 5a rotates with the rotation of the rotor 2, the "+" and "-" commutator brushes 5a sequentially come into sliding contact with the segment 7a of the commutator 7 on the stator 3 side, and the energization order and direction are changed. Power is supplied to each coil element 10 while switching.

  For such a motor 1 as well, a series of coils can be formed by various methods, as in the above-described embodiments relating to coil connection shown in FIGS.

  The two types of inner magnet motors shown in FIGS. 1 and 2 and FIGS. 11 to 13 both have an inner rotor system in which the inner core provided with the magnet portion 4 rotates. Even an outer rotor system in which the core rotates can be similarly implemented.

  The present invention can be applied to an inner magnet motor with a brush installed in a narrow space.

The top view which shows the internal structure of the inner magnet motor which concerns on this invention. Sectional drawing cut | disconnected by the AA line of FIG. The expanded view which shows embodiment of the coil of this invention. Operation | movement explanatory drawing of embodiment of FIG. Explanatory drawing of different embodiment of the coil of this invention. Operation | movement explanatory drawing of further different embodiment of the coil of this invention. The expanded view of further different embodiment of the coil of this invention. The expanded view of further different embodiment of the coil of this invention. The expanded view of further different embodiment of the coil of this invention. Explanatory drawing of further different embodiment of the coil of this invention. The top view which shows the internal structure of the different inner magnet motor which concerns on this invention. The top view seen from the surface from which the motor of FIG. 11 differs. Sectional drawing cut | disconnected by the BB line of FIG.

Explanation of symbols

1: motor, 2: rotor, 3: stator, 4: magnet part, 4a: permanent magnet, 5: brush, 5a: brush for commutator, 5b: brush for slip ring, 6: magnetic pole teeth, 6 ′: slot, 7 : Commutator, 7a: Segment, 8: Slip ring, 8a: Inner peripheral side slip ring, 8b: Outer slip ring, 9: Bobbin, 10, 10a, 10b: Coil element, 21: Rotating shaft, 22: Rotor side core , 31: case, 32: stator side core, 51: brush holder, 52: spring, 53: leaf spring, 54: contact, 55: slip ring support plate.

Claims (3)

A rotating shaft, a magnet portion made up of a plurality of permanent magnets arranged in a circular arc shape at substantially equal intervals with respect to the rotating shaft, and an outer peripheral surface of the magnet portion facing the outer peripheral surface and arranged radially about the rotating shaft A plurality of magnetic pole teeth, a coil element wound around each magnetic pole tooth, and a winding end of each coil element disposed in a ring shape at a fixed position with respect to the coil element via a certain gap In an inner magnet motor with a brush having a commutator composed of a plurality of segments to which a portion is connected and a plurality of brushes slidably contacting the segments,
The coil element is wound by a separate winding for each of the magnetic pole teeth, and the segments are separated from each other by two pieces and connected to the coil element every two pieces to form a continuous series of coils. The two coil ends of each coil element are connected to two segments that cross each other and face each other, and intersect with one winding end of each coil element adjacent to each other. An inner magnet motor with a brush is characterized in that one end of each of the windings is connected to the distant segment of the two opposing segments . A double annular slip ring is provided closer to the center of rotation than the magnetic pole teeth, and the magnet portion rotates by supplying power to the coil element via the slip ring and the commutator. The brushed inner magnet motor according to claim 1. The slip ring is provided on the inner peripheral side and the outer peripheral side of the commutator, and the brush contact surfaces of the slip ring and the commutator are on the same plane, and each brush is attached to both the slip ring and the commutator. 3. The brushed inner magnet motor according to claim 2 , wherein the inner magnet motor is slidable simultaneously .

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