JP4714507B2 - motor - Google Patents

Description

  The present invention relates to a motor having a commutator, and more particularly to a construction technique of a motor for electrically connecting commutator segments.

Usually, DC motors require as many brushes as the number of stator poles. However, as the number of brushes increases, the resistance loss due to friction between the commutator and the brush when the armature rotates may increase. Moreover, the number of parts increases as the number of brushes increases. Therefore, the segments located on the diagonal among the segments provided in the commutator are equalized, and the coils connected to the two segments are connected to make them electrically equivalent. For example, the stator has four poles. However, a motor that can be driven by using two brushes is known. Japanese Patent Laid-Open No. 2000-134873 (refer to Patent Document 1) discloses a motor in which segments are connected by connecting wires by connecting wires to a neck portion between a commutator and an armature. ).
JP 2000-134873 A

A wire forming a coil disposed between the slots of the armature is further wired at the neck portion between the commutator and the armature of the motor as described in the prior art. Therefore, the number of wires in the neck portion increases, and the load when the rotor composed of the output shaft, armature, commutator and coil rotates increases, and the motor is burdened.
This invention is made | formed in view of this point, and provides the construction technique of the motor which connects between the segments of a commutator rationally electrically.

(Invention of Claim 1)
In order to achieve the above object, the invention described in each claim is configured.
According to the first aspect of the present invention, the armature, the commutator rotating together with the armature, the plurality of segments arranged in the circumferential direction around the major axis of the commutator, and the armature and the commutator A motor having a fan device that is disposed and rotates with the armature to introduce cooling air is configured.
The “motor” in the present invention broadly includes motors in which the direction of current supplied to the armature winding is commutated by a commutator and a brush. Typically, this is a DC motor or an AC commutator motor.

The motor of the present invention has a conductive region formed of a plurality of blades formed of a conductive material and arranged around the commutator . And this fan apparatus is arrange | positioned between an armature and a commutator so that it may electrically connect between segments, when the said electroconductive area | region contact | abuts a several segment .
According to the motor of the present invention, the fan device is disposed between the armature and the commutator so that the conductive regions of the fan device are in contact with the plurality of segments to electrically connect the segments. Arranged.
As a method of electrically connecting the segments, as described in the prior art, a method of connecting the wires by connecting a wire to the neck portion between the commutator and the armature, or an electrical connection between the segments. A method has been employed in which a device for connecting to the device is separately provided in the vicinity of the commutator.
According to the present invention, first, there is no need to connect segments with wires. Therefore, the number of wires of the neck portion can be reduced, and the load when the rotor composed of the output shaft, the armature, the commutator, and the coil rotates can be reduced. In addition, since it is not necessary to separately arrange a device for electrically connecting the segments, it is not necessary to consider the arrangement space and arrangement procedure, and the assembly of the motor is simplified.
In the motor of the present invention, the fan device is disposed so that the conductive region electrically connects between the segments, so that the conductive region electrically connects between the segments by disposing the fan device. It may be configured such that the segments are all connected, and the segments are electrically connected only by disposing the fan device. Alternatively, in the motor of the present invention, when the fan device is disposed, the conductive region becomes a part of a path for electrically connecting the segments, and other components of the motor also contribute, so that the fan device When arranged, the segments may be configured to be electrically connected.
The “fan device” only needs to have a configuration that introduces at least cooling air by rotating together with the armature. Typically, the fan device introduces cooling air, a blade fixing member, a fan, and the like. The device is configured as an assembly having members for assembling the device between the armature and the commutator. In the motor of the present invention, any part of the fan device configured as described above is a conductive region. The conductive region only needs to be formed of a conductive material that can be electrically connected between members, and is typically formed using a metal such as iron.

By the way, the commutator supplies current to the coil of the armature in cooperation with the brush that slides on the outer peripheral surface of the commutator. Heat is likely to be generated in the commutator segment that is a part. In the motor of the present invention, when the fan device is disposed, the conductive region and the segment are electrically connected, so that heat generated in each segment during operation of the motor is transmitted to the conductive region, and the conductive region Released through the region. That is, the conductive region plays the role of a heat radiating fin of each segment.
Therefore, in the motor of the present invention, the fan device is configured to simultaneously introduce cooling air, which is a function of the original fan device, electrical connection between the segments, and heat radiation of the segments.

(Invention of Claim 2)
According to a second aspect of the present invention, in the motor according to the first aspect, the fan device extends in a direction crossing the major axis direction of the motor, is formed of a conductive material, and is electrically insulated from each other. A plurality of blades sequentially arranged in the circumferential direction of the child, a protrusion provided on each of the blades so as to protrude in the motor long axis direction, and a protrusion formed of a conductive material, and can be fitted to each protrusion The fitting holes are sequentially arranged in the circumferential direction, and are formed of a conductive material, and have a plurality of annular connecting members arranged in an overlapping manner in a state of being insulated from each other. A plurality of conductive regions are formed in the fan device for each blade and annular connection member that are electrically connected by selectively combining the protrusion and the fitting hole.
In the motor of the present invention, the blade and the annular connection member that are electrically connected by selectively combining the protrusion provided on the blade and the fitting hole provided on the connection member. A plurality of conductive regions are formed for each time. Therefore, by disposing the fan device between the armature and the commutator, the plurality of segments can be electrically connected separately for each of the plurality of conductive regions.
The conductive region of the motor of the present invention is provided with blades. In order to perform the original function of introducing the cooling air, the blade generally has an extended portion with a large surface area in the intersecting direction of the major axis direction of the motor. Therefore, the heat generated in the segment is easily transmitted to the blade and is easily released through the blade. The blade is configured to rotate with the armature during operation of the motor. Thus, the air around the blades is constantly flowing and the transferred segment heat is quickly released.
In addition, according to the present invention, when assembling the annular connecting member, the motor assembly worker can simply and reliably assemble the annular connecting member by fitting the fitting hole into the protrusion of the blade. it can.
In addition, since the fitting hole of the annular connection member is fitted to the protrusion of the blade, the blade and the annular connection member are electrically and structurally connected. The position is restricted, the fixing force of the blade is improved, and the strength against the centrifugal force acting on the blade during rotation is improved. Note that, in the motor of the present invention, each protrusion has a long axis of the motor as a position where the centrifugal force acting on each blade and the annular connecting member disposed on the protrusion is small when the fan device is rotated. It is preferable that each blade is provided at a position near the axis of the motor in the direction crossing the direction.
The number of blades forming one conductive region and the number of conductive regions may be appropriately determined based on the specifications of the motor. Typically, these numbers are determined by the number of poles, brushes and segments of the motor. For example, in the case of a 4-pole 2-brush motor, the number of segments that should have the same potential is 2 (2 = 4 (the number of poles) / 2 (the number of brushes)), so two for each conductive region. Each segment is electrically connected. Generally, when the fan device is disposed between the commutator and the armature, each blade is configured to be electrically connected to each segment, so that the blades forming one conductive region Let the number be 2. If the number of segments is 10, five conductive regions are formed. Accordingly, each of the 10 blades in contact with the 10 segments is selectively electrically connected to each other by the five annular connecting members.

(Invention of Claim 3)
According to a third aspect of the present invention, in the motor of the second aspect, the fan device is configured to introduce cooling air from the long axis direction of the motor. Each blade is provided with an abutting portion that abuts on each segment. Each of the contact portions is configured such that a gap through which cooling air flows from the major axis direction of the motor is formed between the contact portions in a state where each contact portion is in contact with each segment. In addition, each protrusion is provided at a position closer to the outer periphery of the motor than each contact portion in the direction intersecting with the major axis direction of the motor in each blade, and the annular connecting member is larger than the outer diameter of the commutator. Has a large inner diameter. Accordingly, the fan device is configured to be fixed to the commutator in a state in which a cooling air circulation space is ensured between the outer peripheral surface of the commutator and the inner peripheral surface of the annular connecting member.
According to the present invention, each contact portion is configured such that cooling air flows between the contact portions from the long axis direction of the motor, and the annular connection member includes the inner peripheral surface and the outer periphery of the commutator. A cooling air circulation space is ensured between the surfaces, and is disposed on the blades. Therefore, it is possible to form a flow of cooling air toward the axial direction of the fan device along the outer peripheral surface of the commutator. Accordingly, it is possible to actively circulate the cooling air in the immediate vicinity of the segment that is the sliding portion and the energization portion of the brush and easily generates heat, and the cooling efficiency of the commutator by the fan device is improved.

(Invention of Claim 4)
According to a fourth aspect of the present invention, in the motor according to the second or third aspect, each protrusion is provided on each blade at a position near the motor axis in the direction crossing the major axis direction of the motor. ing. Thereby, when the fan device is rotated together with the armature, the influence of the centrifugal force acting on each blade and the annular connecting member is reduced.
When the fan device is rotating, the member provided at a position farther from the center of rotation is more susceptible to the centrifugal force. In the present invention, the motor may be configured such that the protrusion is provided at a position relatively close to the motor axis of the blade having a wide surface area extending in the direction crossing the major axis direction of the motor. it can. As a result, the plurality of annular connecting members that are fitted to the protrusions are also arranged at positions near the motor axis. Therefore, the annular connecting member is disposed at a position near the rotation center of the fan device, and the influence of the centrifugal force acting on the annular connecting member and the blade on which the annular connecting member is disposed is reduced.

  According to the present invention, a technology for constructing a motor that rationally electrically connects commutator segments is provided.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, a case where the “motor” of the present invention is applied to a drive motor provided in an electric (rechargeable) impact driver 100 will be described. Also, when the drive motor is a 4-pole 2-brush DC motor, the segments located on the diagonal of the commutator are electrically connected, and the coils located on the diagonal of the armature are connected in series Will be described. In addition, hereinafter, when the segments are electrically connected, it is referred to as equalization between the segments.
FIG. 1 is a partially broken side sectional view schematically showing the overall configuration of an impact driver 100 according to the present embodiment. FIG. 2 is a cross-sectional view illustrating a schematic configuration of a drive motor of the impact driver 100. FIG. 3 is a perspective view showing a state in which a cooling fan is attached to the rotor of the drive motor. In addition, the coil arrange | positioned at an armature is abbreviate | omitted for convenience. FIG. 4 shows an assembly diagram of the rotor and the cooling fan shown in FIG. FIG. 5 shows a cross-sectional view of the blade portion of the cooling fan.

As shown in FIG. 1, the impact driver 100 according to the present embodiment is generally attached to a main body 101 that forms an outline of the impact driver 100 and a distal end region of the main body 101 so as to be detachable. It is mainly composed of a driver bit 109 for performing screw tightening work of various screws.
The main body 101 includes a motor housing 103, a gear housing 105, and a hand grip 107. A drive motor 121 is accommodated in the motor housing 103. The drive motor 121 corresponds to the “motor” in the present invention.
The hand grip 107 is provided with a trigger 125 for turning on the power switch of the drive motor 121.
In the gear housing 105, a speed reduction mechanism 111 including a planetary gear device for appropriately reducing the rotation of the output shaft 122 of the drive motor 121, a spindle 112 rotated by the speed reduction mechanism 111, and a ball 113 is transmitted from the spindle 112. A hammer 114 that is rotationally driven as a member, and an anvil 115 that is rotationally driven by the hammer 114 are arranged. The hammer 114 is relatively movable in the longitudinal direction of the spindle 112 and is urged toward the anvil 115 side by a compression coil spring 116. The tip of the anvil 115 protrudes from the tip of the gear housing 105, and the driver bit 109 is detachably attached to the protruding tip.

  According to the impact driver 100 configured as described above, when the tightening torque by the driver bit 109 is increased and a predetermined high load state is reached, a large tightening torque is generated in the driver bit 109 by the hammering operation of the hammer 114. Can be made. Since the operating principle of the impact driver itself belongs to a well-known technical matter, a detailed description of the configuration and operation is omitted for convenience.

Next, a schematic configuration of the drive motor 121 will be described with reference to FIG. As the drive motor 121 in the present embodiment, a four-pole direct current motor using a battery 127 (also see FIG. 1 as a drive power source) is used. The drive motor 121 includes an output shaft 122, a cooling fan 151 that rotates integrally with the output shaft 122, an armature 133 that rotates integrally with the output shaft 122 and is wound with a wire that forms a coil 134, and the motor housing 103. Fixed to the stator 135 generating a field magnetic field around the armature 133, a commutator 137 provided on one end side of the output shaft 122 (opposite side of the speed reduction mechanism 111), and an outer peripheral surface of the commutator 137. It is mainly composed of two brushes 145 that slidably contact a plurality of provided segments and supply a drive current to a coil 134 disposed in the armature 133.
The output shaft 122 has one end (rear end, ie, the left end shown in FIG. 2) rotatably supported by the motor housing 103 via a bearing 123, and the other end side (the speed reduction mechanism 111 side, ie, the right side shown in FIG. 2). A gear housing 105 (also see FIG. 1) is rotatably supported via a bearing 124. The output shaft 122, the armature 133, the commutator 137, and the coil 134 constitute a rotor.

Power is supplied to the drive motor 121 configured as described above, and drive current is supplied to the coil 134 of the armature 133 in the field magnetic field of the stator 135 through the segments of the brush 145 and the commutator 137. Thus, the rotor is driven to rotate. At this time, the commutator 137 and the brush 145 appropriately switch the direction of the current flowing through the coil 134 so that the armature 133 and the output shaft 122 continuously rotate in a predetermined direction. Note that the operating principle of the direct current motor configured as described above belongs to a well-known technical matter, and therefore a detailed description of the configuration and operation is omitted for the sake of convenience.
The cooling fan 151 disposed between the armature 133 and the commutator 137 functions as a centrifugal fan. Therefore, the cooling fan 151 rotates integrally with the output shaft 122 when the drive motor 121 is driven, and from a wind window (not shown) provided in the motor housing 103 on the commutator 137 side (left side shown in FIG. 2). The introduced cooling air is caused to flow out in the radial direction of the motor (direction intersecting with the major axis direction). Thereby, the commutator 137, the brush 145, and those peripheral parts are cooled. The cooled wind is discharged to the outside from a wind window (not shown) provided in the motor radial direction of the motor housing 103. The detailed configuration of the cooling fan 151 will be described later.
Further, around the major axis of the commutator 137, ten segments 137a are arranged in the circumferential direction (refer to FIG. 4 together). Each segment 137a is provided with a groove-like connecting portion 137b. The coil 134 connected to the segment is formed by forming the coil 134 between the slots of the armature 133 by the wire embedded in the connection portion 137b. Adjacent segments are insulated from each other.

Next, a detailed configuration of the cooling fan 151 will be described with reference to FIGS.
As shown in FIG. 4, the cooling fan 151 has 10 blades 151 a made of metal, 10 blades made of resin, and the first blade ring 151 b made of resin that fixes the blades radially on the commutator 137 side. A resin-made second fan ring 151c that is fixed radially on the armature 133 side and that fixes the cooling fan 151 to a slot of the armature 133, and five pressure equalizing rings 151d for equalizing the diagonal segments are provided. It has been.
The blade 151a is provided with a connecting portion (not shown) connected to the extending portion H1, the abutting portion H2, the protruding portion H3, and the second fan ring 151c. The extending portion H1 has a relatively large surface area, extends in a direction crossing the major axis direction of the motor, and introduces wind by rotating. The abutting portion H2 is formed so as to extend from one end surface of the extending portion H1 in the major axis direction of the motor, and is disposed in contact with the segment 137a of the commutator 137 when the cooling fan 151 is disposed. Note that the abutting portion H2 is configured to have such a size that when the abutting portion H2 is abutted against the segment 137a, a gap through which cooling air can flow is formed between the abutting portions. The protrusion H3 is provided on the extended portion H1 side of the contact portion H2 (position near the outer periphery of the drive motor 121) so as to protrude in the long axis direction of the motor, and each hole of the pressure equalizing ring 151d (for details) , Which will be described later). Although the protrusion H3 is on the extending part H1 side with respect to the contact part H2, the protrusion H3 is provided at a position relatively close to the axis of the motor in terms of the radial dimension of the extending part H1.
The first fan ring 151b is provided with ten holes at equal intervals in the circumferential direction for fitting the protrusions H3 of the blades 151a.
The second fan ring 151c is provided with ten holes at equal intervals in the circumferential direction for fitting connection portions (not shown) of the blades 151a. The second fan ring 151c is formed with an outer diameter that is substantially the same as the outer diameter of the armature 133, and ten ribs that fit into the slots of the armature 133 are provided at equal intervals in the circumferential direction.
By fitting the projection H3 of each blade 151a into the blade fitting hole of the first fan ring 151b and fitting the connection portion of each blade 151a into the blade fitting hole of the second fan ring 151c Ten blades are fixed radially.

Then, five pressure equalizing rings 151d are arranged on the protrusion H3 of each blade 151a protruding from the hole of the first fan ring 151b.
The pressure equalizing ring 151d is composed of a conductive part member having the same diameter as the first fan ring 151b. The inner diameter of the pressure equalizing ring 151d is larger than the outer diameter of the commutator 137, and is set to a dimension that does not come into contact with the contact portion H2 when disposed on the protrusion H3. Further, the upper and lower surfaces are wiped with an insulating powder, and when the pressure equalizing ring 151d is disposed in a laminated form, the insulating state can be maintained. The pressure equalizing ring 151d is provided with eight insulating holes A and two connection holes B. The holes are provided at equal intervals at positions shifted by 36 degrees in the circumferential direction of the pressure equalizing ring 151d, and two of the connection holes B are provided at diagonal positions. The insulating hole A has a hole diameter larger than the diameter of the protruding portion H3 so that the inner peripheral surface of the insulating hole A does not contact the protruding portion H3 when the insulating hole A is disposed in the protruding portion H3 of the blade 151a. Is formed. Further, the same insulating powder as the upper and lower surfaces is wiped on the inner peripheral surface of the insulating hole A. On the other hand, the connection hole B is formed with such a hole diameter that the inner peripheral surface of the connection hole A contacts the protrusion H3 when the connection hole B is fitted to the protrusion H3 of the blade 151a. The insulating powder is not wiped on the inner peripheral surface of the connection hole B. Therefore, when the pressure equalizing ring 151d is disposed, the blades positioned diagonally provided with the protrusion H3 fitted in the connection hole B are electrically connected.
As shown in FIG. 4, the pressure equalizing ring 151 d is sequentially arranged in a stacked (superposed) manner on the protrusion H <b> 3 in a state where the positions of the connection holes B are shifted one by one in the circumferential direction. As a result, a pair of blades located diagonally are electrically connected to each pressure equalizing ring, and in a state where five pressure equalizing rings 151d are disposed as shown in FIG. Five pairs of located blades are electrically connected. That is, five conductive regions are formed in the cooling fan 151 for each blade and pressure equalizing ring that are electrically connected.

The cooling fan 151 configured as described above is disposed between the commutator 137 and the armature 133.
The cooling fan 151 is configured such that when the ribs provided on the second fan ring 151c are fitted into the slots of the armature 133, the contact portions H2 of the blades 151a contact the segments 137a. . Thereby, each blade | wing 151a is electrically connected to each segment 137a. Therefore, as shown in FIG. 5, one segment provided in the commutator 137, the contact portion H2 of the blade 151a connected to the segment, the projection H3 of the blade 151a, and the connection hole B in the projection. The pressure equalizing ring fitted (the pressure equalizing ring arranged at the bottom in FIG. 5), the other connection hole of the pressure equalizing ring, and the protrusion of the blade into which the connection hole is fitted The segment in contact with the contact portion (the segment located on the opposite side of the commutator 137) is electrically connected (equalized) through the contact portion of the blade. ) Similarly, pressure is equalized between five pairs of segments located at the opposite corners of the commutator 137 via each blade and each pressure equalizing member (by five conductive regions).

Further, as described above, the abutting portion H2 of each blade 151a is configured to have such a size that when the abutting portion 137a is abutted against the segment 137a, a clearance is formed between the abutting portions so that cooling air can flow. Yes. Further, in each blade 151a, the protrusion H3 is provided at a position closer to the outer periphery of the motor than the contact portion H2, and the inner diameter of the pressure equalizing ring 151d disposed in each contact portion H2 is rectified. It is set to a dimension that is larger than the outer diameter of the child 137 and does not contact each contact portion H2. Therefore, between the outer peripheral surface of the commutator 137 and the inner peripheral surface of the pressure equalizing ring 151d disposed in each protrusion H3, a space S in which cooling air flows between the contact portions (see FIG. 3). ) Is secured. As a result, when the cooling fan 151 is rotated, from the air window (not shown) provided in the motor housing 103 on the commutator 137 side (left side shown in FIG. 2), the surface of each segment 137a is moved in the axial direction of the motor. A cooling air flow is formed along the direction of the axis of the cooling fan 151. Then, the cooling air flows through the spaces S and flows out from between the extending portions H1 of the blades 151a in the radial direction of the motor. This “space S” corresponds to the “cooling air circulation space” of the present invention.
The “cooling fan 151” of the present embodiment corresponds to the “fan device” of the present invention, and the “pressure equalizing ring 151d” of the present embodiment corresponds to the “annular connecting member” of the present invention. The “blade 151a” in the form corresponds to the “blade” of the present invention. Further, “blade 151a” and “pressure equalizing ring 151d” of the present embodiment correspond to “conductive region” of the present invention. The “projection H3” in the present embodiment corresponds to the “projection” in the present invention. The “connection hole B” in the present embodiment corresponds to the “fitting hole” in the present invention.

In the drive motor 121 according to the present embodiment, five pairs of blades 151a located at the opposite corners of the cooling fan 151 are electrically connected by five pressure equalizing rings 151d. And if the cooling fan 151 is arrange | positioned between the armature 133 and the commutator 137, each blade | wing 151a and each segment 137a will be electrically connected. Thereby, the segments in which the blades located diagonally are electrically connected to each other are pressure-equalized through the blades 151a and the pressure equalizing rings 151d. Therefore, in the drive motor 121, only the cooling fan 151 is disposed, and the pressure between the five pairs of segments positioned at the diagonal of the commutator 137 is equalized.
As a method of equalizing the pressure between the segments, a wire connected to the segment is wired to the neck portion between the commutator and the armature, and connected to the segment that equalizes the pressure with the segment, or the segments are electrically connected. The method of arrange | positioning this apparatus separately in the vicinity of a commutator was employ | adopted. According to the drive motor 121 of the present embodiment, it is not necessary to connect the segments with wires. Accordingly, the number of wires in the neck portion between the commutator 137 and the armature 133 can be reduced, and the load when the rotor composed of the output shaft, the armature, the commutator, and the coil rotates is reduced. be able to. Further, since it is not necessary to separately provide a device for electrically connecting the segments, it is not necessary to consider the arrangement space and arrangement procedure, and the assembly of the drive motor 121 is simplified.

  Further, in the drive motor 121 of the present embodiment, when the cooling fan 151 is disposed, each blade 151a and each segment 137a are connected, so that heat generated in the segment 137a during operation of the drive motor 121 is generated by each blade. 151a, and heat generated in the segment 137a can be released. Each blade 151a has an extended portion H1 having a large surface area in a direction intersecting the major axis direction of the motor in order to perform its original function of introducing the cooling air. Therefore, the heat generated in each segment 137a is easily transmitted to each blade 151a, and each blade 151a plays a role of a radiation fin of each segment 137a, so that heat is easily released. Further, since each blade 151a is configured to rotate together with the armature 133 during operation of the motor, the air around each blade 151a is always flowing, and heat is quickly released.

  Further, in the drive motor 121 of the present embodiment, when the pressure equalizing ring 151d is assembled, the connection hole B may be fitted into the protrusion H3 of each blade 151a, and the motor assembly worker can 151d can be easily and reliably assembled.

  Further, in the drive motor 121 of the present embodiment, the connecting hole B of the pressure equalizing ring 151d is fitted into the protrusion H3 of each blade 151a, so that each blade 151a and the pressure equalizing ring 151d are electrically structured. Connected. Therefore, the radial position of each blade 151a is regulated by the pressure equalizing ring 151d, the fixing force of each blade 151a is improved, and the strength against the centrifugal force acting on each blade 151a during rotation is improved.

  Further, according to the drive motor 121 of the present embodiment, each contact portion H2 is configured such that cooling air flows between the contact portions from the major axis direction of the motor. Further, the pressure equalizing ring 151d is disposed on each blade 151a while ensuring a space S through which cooling air flows between the inner peripheral surface thereof and the outer peripheral surface of the commutator 137. Therefore, it is possible to form a flow of cooling air toward the axial direction of the cooling fan 151 along the outer peripheral surface of the commutator 137. This makes it possible to actively circulate the cooling air in the immediate vicinity of the segment 137a that is the sliding portion and the energization portion of the brush 145 and easily generates heat, and the cooling efficiency of the commutator 137 by the cooling fan 151 is improved. .

In the drive motor 121 of the present embodiment, the protrusion H3 is provided at a position near the motor axis of the blade having the extended portion H1 having a large surface area in the direction crossing the major axis direction of the motor. ing. As a result, the pressure equalizing ring 151d that is fitted to the protrusion H3 is also disposed at a position near the motor axis. That is, the pressure equalizing ring 151 d is disposed at a position near the rotation center of the cooling fan 151. When the cooling fan 151 is rotated, the member provided at a position farther from the center of rotation is more susceptible to the centrifugal force. Therefore, the pressure equalizing ring 151d of the drive motor 121 is connected to this. The blades 151a are not easily affected by centrifugal force.
If the drive motor 121 of this Embodiment is used, the segment of the commutator 137 will be rationally equalized.

Note that the present invention is not limited to the configuration described in the embodiment, and various changes, additions, and deletions are possible.
In the present embodiment, the case where the pressure equalizing ring 151d has the same number of holes as the protrusions H3 has been described. However, the pressure equalizing ring 151d only needs to be provided with the connection hole B. Therefore, as shown in FIG. 6, the holes other than the connection hole B connected to the protrusion H3 of the blade 151a may be continuously configured so as to avoid connection with the protrusion H3. Moreover, as shown in FIG. 7, the pressure equalizing ring 151d may be configured with an inner diameter that avoids connection with the protrusion H3 except for the portion where the connection hole B is formed.
Further, in the present embodiment, as shown in FIG. 8, the case where the powder of the insulator C is wiped on the upper surface and the lower surface of the pressure equalizing ring 151d has been described. However, as shown in FIG. The insulating member D is not subjected to insulation processing, and the insulating member D may be disposed between the pressure equalizing rings when the pressure equalizing rings are disposed in a laminated form.
Further, as shown in FIGS. 8 and 9, a structure in which pressure equalizing rings 151 d are combined in advance in a laminated form may be integrated as a pressure equalizing member and assembled to the cooling fan 151.
The drive motor 121 includes a blade 151a, a first fan ring 151b, and a second fan ring 151c assembled between the commutator 137 and the armature 133, and then a pressure equalizing ring 151d. It may be configured to be.
Further, in the present embodiment, the case where the protrusion H3 of each blade 151a is formed to protrude toward the commutator 137 has been described, but the protrusion of each blade is formed to protrude toward the armature 133. It may be. FIG. 10 shows an assembly drawing of the cooling fan 251 configured as described above. FIG. 11 is a cross-sectional view of the blade 251a portion of the cooling fan 251 in a state where the cooling fan 251 is disposed between the armature 133 and the commutator 137. In this case, as shown in FIG. 10, the cooling fan 251 includes ten metal blades 251 a and ten resin blades 251 b that fix the ten blades radially on the commutator 137 side. The second fan ring 251c made of resin that fixes the fan blades radially on the armature 133 side and fixes the cooling fan 251 to the slot of the armature 133, and five pressure equalizing rings for equalizing the pressure between the diagonal segments 251d is provided. Each blade 251a is provided with a projection H4 formed on the armature 133 side so as to protrude in the longitudinal direction of the motor. The second fan ring 251c is provided with ten holes at equal intervals in the circumferential direction for fitting with the protrusions H4 of the blades 251a and fixing the blades 251a. Ten blades are fixed radially by the first fan ring 251b and the second fan ring 251c, and the pressure equalizing ring 251b is attached to the protrusion H4 of each blade 251a protruding from the hole of the second fan ring 251b. Arrange one sheet. The pressure equalizing ring 251b is configured as a member having the same diameter as the second fan ring 251b. According to this configuration, the pressure equalizing ring 251d is disposed in a state where five pieces are sandwiched between the second fan ring 251c and the armature 133 that fix the blades 251a. Therefore, the adhering force at the arrangement location is high.
Moreover, although this embodiment demonstrated the motor, the summary of this invention is applicable also to the generator which has a commutator and a brush.
Although the case where the present invention is applied to the motor provided in the impact driver 100 has been described in the present embodiment, the motor of the present invention can be widely applied to motors provided in other devices. .

As an example of an electric tool to which the motor of the present invention is applied as a drive motor, an overall configuration of an impact driver 100 is shown. A side sectional view of a drive motor 121 provided in the impact driver 100 is shown. The appearance of a state in which a cooling fan 151 is disposed between the armature 133 and the commutator 137 is shown. The assembly drawing of the cooling fan 151 is shown. A cross-sectional view of the blade 151a portion of the cooling fan 151 in a state where the cooling fan 151 is disposed between the armature 133 and the commutator 137 is shown. Another structure of the pressure equalizing ring 151d is shown. Another structure of the pressure equalizing ring 151d is shown. A state in which the pressure equalizing rings 151d are arranged in an overlapping manner is shown. A state in which the pressure equalizing rings are arranged in an overlapping manner while the insulating member D is sandwiched is shown. The assembly drawing of the cooling fan 251 is shown. A sectional view of the blade 251a portion of the cooling fan 251 in a state where the cooling fan 251 is disposed between the armature 133 and the commutator 137 is shown.

DESCRIPTION OF SYMBOLS 100 Impact driver 101 Main body part 103 Motor housing 105 Gear housing 107 Hand grip 109 Driver bit 111 Deceleration mechanism 112 Spindle 113 Ball 114 Hammer 115 Anvil 116 Compression coil spring 121 Drive motor 122 Output shaft 123, 124 Bearing 125 Trigger 127 Battery 133 Armature 134 Coil 135 Stator 137 Commutator 137a Segment 137b Connection part 145 Brush 151 Cooling fan 151a Blade 151b First fan ring 151c Second fan ring 151d Pressure equalizing ring A Insulating hole B Connection hole H1 Extension part H2 Contact part H3 Projection Part S space

Claims (4)

An armature; a commutator that rotates together with the armature; a plurality of segments disposed in a circumferential direction around a long axis of the commutator; and the electric machine disposed between the armature and the commutator. A motor having a fan device that introduces cooling air by rotating with a child,
The fan device has a conductive region formed of a plurality of blades formed of a conductive material and arranged around the commutator , and the conductive region abuts on the plurality of segments. Arranged between the armature and the commutator so as to electrically connect the segments, whereby the fan device simultaneously introduces cooling air, electrically connects the segments, and radiates the segments. The motor is configured as described above. The motor according to claim 1,
The fan device is
A plurality of blades extending in a direction intersecting with the major axis direction of the motor and formed of a conductive material, and sequentially disposed in a circumferential direction of the armature in a state of being insulated from each other;
Protrusions provided on each of the blades so as to protrude in the motor longitudinal direction and formed of a conductive material;
A plurality of annular connecting members that are sequentially arranged in the circumferential direction and that are formed of a conductive material and are arranged in a superposed manner in a state of being insulated from each other. Have
A plurality of conductive regions are formed in the fan device for each of the blades and the annular connection member that are electrically connected by selectively combining the protrusion and the fitting hole. motor. The motor according to claim 2,
The fan device is configured to introduce cooling air from the longitudinal direction of the motor,
Each of the blades is provided with a contact portion that is in contact with each segment,
Each of the contact portions is configured such that a gap through which cooling air flows from the long axis direction of the motor is formed between the contact portions in a state where each contact portion is in contact with each segment.
The protrusions are provided at positions closer to the outer periphery of the motor than the contact portions in the direction crossing the major axis direction of the motor in the blades, and the annular connecting member is disposed outside the commutator. Has an inner diameter greater than the diameter,
Thus, the fan device is fixed to the commutator in a state in which a cooling air circulation space is secured between the outer peripheral surface of the commutator and the inner peripheral surface of the annular connecting member. motor. The motor according to claim 2 or 3,
Each of the protrusions is provided at a position near the motor axis in the direction crossing the major axis direction of the motor in each blade.
Thereby, when the fan device is rotated together with the armature, the motor is configured to reduce the influence of the centrifugal force acting on the blades and the annular connecting member.

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