Motor and strapping machine

Abstract

The invention relates to a motor and a binding machine, and provides a surface magnet type motor capable of inhibiting stripping of a magnet and a reinforcing steel bar binding machine provided with the motor. The motor (80) has a rotor (82) and a stator (83). The rotor (82) has: a rotating shaft (82a); a rotor core (82b); a magnet (82c) that is adhered to the outer periphery of the rotor core (82b) and has a protruding portion (82i) that protrudes in the direction of extension of the rotating shaft (82a) with respect to an end surface (82j) of the rotor core (82b); and a sealing member (82d) filled between the protruding portion (82i) and the rotating shaft (82a) and bonding the protruding portion (82i) and the rotating shaft (82a). The rebar binding machine is provided with a motor (80).

Description

Technical Field

[0001] The present invention relates to an electric motor and a bundling machine which is driven by the electric motor and uses a wire to bundle bundles such as steel bars. Background Art

[0002] In concrete structures, steel bars are used to increase strength, and they are tied together with wires to prevent them from shifting from a predetermined position during concrete pouring.

[0003] Conventionally, a so-called reinforcing bar tying machine has been proposed, which winds a wire around two or more reinforcing bars and twists the wire wound around the reinforcing bars to tie the two or more reinforcing bars with the wire (for example, see Patent Document 1).

[0004] In such a strapping machine, the motor used in the twisting action requires high-speed repetitive forward and reverse action and accurate angle control. In addition, in order to shorten the time spent on each strapping action and increase the strapping speed, it is considered to reduce the inertia of the rotor, that is, reduce the weight of the rotor.

[0005] Therefore, it is considered to apply a motor with a structure called a surface magnet type (SPM) in which magnets are attached to the outer periphery of the rotor core. In an SPM motor, the rotor core is not provided outside the magnet, so the volume of the rotor core is reduced, and thus the weight of the rotor can be reduced. This can help to increase the bundling speed.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 6791141 Summary of the invention

[0009] Problems to be solved by the invention

[0010] In the SPM motor, since the magnets are attached to the outer circumference of the rotor core, there is a problem that the magnets may be separated from the rotor core due to the centrifugal force applied to the magnets when the rotor rotates.

[0011] An object of the present invention is to provide a motor of a surface magnet type capable of suppressing separation of magnets, and a strapping machine including the motor.

[0012] Technical solutions to solve problems

[0013] In order to solve the above-mentioned problems, the present invention relates to an electric motor having a rotor and a stator, wherein the rotor has: a rotating shaft; a rotor core; a magnet adhered to the outer periphery of the rotor core and having a protrusion protruding along the extension direction of the rotating shaft relative to the end face of the rotor core; and a sealing component filled between the protrusion and the rotating shaft to bond the protrusion and the rotating shaft.

[0014] In addition, the present invention relates to an electric motor, comprising a rotor and a stator, wherein the rotor comprises: a rotating shaft; a rotor core; a plurality of magnets adhered to the outer periphery of the rotor core and having a protrusion protruding along the extension direction of the rotating shaft relative to the end surface of the rotor core; and a sealing component filled between the plurality of protrusions to bond the plurality of protrusions.

[0015] Furthermore, the present invention relates to a strapping machine comprising: a wire conveying section that conveys wire; a curling forming section that forms a ring-shaped conveying path for winding the wire conveyed by the wire conveying section around a bundle; a strapping section that twists the wire wound around the bundle; and a motor that drives the strapping section, the motor comprising a rotor and a stator, the rotor comprising: a rotating shaft; a rotor core; a magnet that is adhered to the outer periphery of the rotor core and has a protrusion that protrudes relative to the end surface of the rotor core in the extending direction of the rotating shaft; and a sealing component that is filled between the protrusion and the rotating shaft and bonds the protrusion to the rotating shaft.

[0016] In addition, the present invention relates to a strapping machine, comprising: a wire conveying section that conveys wire; a curling forming section that forms a ring-shaped conveying path for winding the wire conveyed by the wire conveying section around a bundle; a strapping section that twists the wire wound around the bundle; and a motor that drives the strapping section, the motor comprising a rotor and a stator, the rotor comprising: a rotating shaft; a rotor core; a plurality of magnets adhered to the outer periphery of the rotor core and having a protrusion that protrudes relative to the end surface of the rotor core in the extending direction of the rotating shaft; and a sealing member that is filled between the plurality of protrusions and bonds the plurality of protrusions.

[0017] In the present invention, a sealing member is filled between the protrusion of the magnet protruding from the end surface of the rotor core and the rotating shaft. In addition, in the present invention, a sealing member is filled between the protrusions of the magnet protruding from the end surface of the rotor core and adjacent to each other in the circumferential direction of the rotor core.

[0018] Effects of the Invention

[0019] In the present invention, the sealing member bonds the rotating shaft to the protruding portion of the magnet. In addition, in the present invention, the sealing member bonds the protruding portions adjacent to each other along the circumferential direction of the rotor core. Thus, even if the rotor rotates, the generation of an eccentric load that causes the magnet to roll outward due to its own inertia force can be suppressed, and the magnet can be suppressed from peeling off from the rotor core. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an internal structure diagram seen from the side showing an example of the overall structure of the reinforcing bar tying machine according to the present embodiment.

[0021] Figure 2 It is a side cross-sectional view showing an example of the electric motor according to the present embodiment.

[0022] Figure 3A It is a perspective view showing an example of a rotor according to the present embodiment.

[0023] Figure 3B It is a side view showing an example of the rotor according to the present embodiment.

[0024] Figure 3C It is a rear view showing an example of the rotor according to the present embodiment.

[0025] Figure 4A It is a side cross-sectional view showing an example of the rotor according to the present embodiment.

[0026] Figure 4B It is a rear cross-sectional view showing an example of the rotor according to the present embodiment.

[0027] Figure 5A It is an exploded perspective view showing an example of a rotor according to the present embodiment.

[0028] Figure 5B This is a perspective view showing an example of a rotor according to the present embodiment before the rotor is filled with a sealing member.

[0029] Fig. 6A It is a perspective view showing an example of another embodiment of the rotor of the present embodiment.

[0030] Figure 6B It is a rear cross-sectional view showing an example of another embodiment of the rotor of the present embodiment.

[0031] Fig. 7A It is a perspective view showing an example of another embodiment of the rotor of the present embodiment.

[0032] Figure 7B It is a rear cross-sectional view showing an example of another embodiment of the rotor of the present embodiment.

[0033] Fig. 8A It is a perspective view showing an example of another embodiment of the rotor of the present embodiment.

[0034] Figure 8B It is a rear cross-sectional view showing an example of another embodiment of the rotor of the present embodiment. DETAILED DESCRIPTION

[0035] Hereinafter, an embodiment of the electric motor of the present invention and an example of a reinforcing bar tying machine as an embodiment of the tying machine of the present invention will be described with reference to the drawings.

[0036] <Configuration Example of the Rebar Binding Machine of the Present Embodiment>

[0037] Figure 1 It is an internal structure diagram seen from the side showing an example of the overall structure of the reinforcing bar tying machine according to the present embodiment.

[0038] The reinforcing bar tying machine 1A is a type of machine that is hand-held by an operator, and includes a main body 10 and a handle 11. The reinforcing bar tying machine 1A feeds the wire W in the forward direction indicated by the arrow F, winds the wire W around the reinforcing bar S as a bundle, feeds the wire W wound around the reinforcing bar S in the reverse direction indicated by the arrow R, winds the wire W around the reinforcing bar S, twists the wire W, and ties the reinforcing bar S with the wire W. The reinforcing bar tying machine 1A ties the reinforcing bar S with a plurality of wires W, in this example, two wires W.

[0039] In order to realize the above functions, the reinforcing bar tying machine 1A includes a silo 2 for storing the wires W, a wire conveying unit 3 for conveying the two wires W arranged in a radial direction of the wires W, and a wire guide 4 for guiding the two wires W conveyed by the wire conveying unit 3. In addition, the reinforcing bar tying machine 1A includes a curling unit 5 for forming a ring-shaped conveying path for winding the two wires W conveyed by the wire conveying unit 3 around the reinforcing bar S, and a cutting unit 6 for cutting the two wires W wound around the reinforcing bar S. Furthermore, the reinforcing bar tying machine 1A includes a tying unit 7 for twisting the two wires W wound around the reinforcing bar S, and a driving unit 8 for driving the tying unit 7.

[0040] The silo 2 is rotatably and unloadably stored with a reel 20 on which a long wire W is wound so as to be released. The wire W is made of a plastically deformable metal wire, a resin-coated metal wire, or a twisted wire. The reel 20 is wound with two wires W, and the two wires W are pulled out from the reel 20 at the same time.

[0041] The wire conveying unit 3 includes a pair of conveying gears 30 for clamping and conveying two parallel wires W. The wire conveying unit 3 transmits the rotation of a conveying motor (not shown) to one of the pair of conveying gears 30. In addition, the pair of conveying gears 30 transmits the rotation of one conveying gear 30 to the other conveying gear 30 through the meshing of the gear parts.

[0042] The wire feeding unit 3 arranges two wires W in parallel along the direction in which the pair of feeding gears 30 are arranged. The wire feeding unit 3 switches the feeding direction of the wires W by switching the rotation direction of the feeding motor (not shown) to the forward and reverse directions to switch the rotation direction of the feeding gears 30.

[0043] The wire guide 4 is disposed upstream and downstream (not shown) of the conveying gear 30 with respect to the conveying direction of the wire W conveyed in the forward direction. The wire guide 4 aligns the two wires W entering the conveying gear 30 in the arrangement direction of the pair of conveying gears 30 and guides them between the pair of conveying gears 30 .

[0044] The curl forming section 5 includes: a curl guide 50 for curling the two wires W fed by the wire feeding section 3 and restricting the direction in which the two wires W are arranged side by side; and an induction guide 51 for guiding the two wires W curled by the curl guide 50 to the bundling section 7. The curl forming section 5 curls the two wires W fed by the wire feeding section 3 and passing through the curl guide 50, thereby forming a bundle from the curl guide 50 through the induction guide 51 and reaching the bundling section 7. Figure 1 The circular conveying path Ru is shown as a two-dot chain line.

[0045] The cutting section 6 includes a fixed blade section 60, a movable blade section 61 that cuts the thread W by cooperating with the fixed blade section 60, and a transmission mechanism 62 that transmits the action of the bundling section 7 to the movable blade section 61. The cutting section 6 cuts the thread W by the rotation of the movable blade section 61 with the fixed blade section 60 as a fulcrum axis.

[0046] The binding unit 7 includes a wire locking body 70 for locking the wire W and a sleeve 71 for moving the wire locking body 70. The driving unit 8 includes a motor 80 and a speed reducer 81 for reducing speed and amplifying torque.

[0047] The reinforcing bar tying machine 1A includes a conveying restriction portion 90 against which the front end of the wire W abuts at the terminal end of the conveying path of the wire W that passes through the annular conveying path Ru and is locked by the wire locking body 70. In addition, the curling guide 50 and the induction guide 51 of the curl forming portion 5 of the reinforcing bar tying machine 1A are provided at the front end of the main body 10. Furthermore, in the reinforcing bar tying machine 1A, the abutment portion 91 against which the reinforcing bar S abuts is provided between the curling guide 50 and the induction guide 51 at the front end of the main body 10.

[0048] The handle 11 of the reinforcing bar tying machine 1A extends downward from the main body 10. Furthermore, a battery 15 is detachably mounted at the lower portion of the handle 11. In addition, the hopper 2 of the reinforcing bar tying machine 1A is provided in front of the handle 11. The reinforcing bar tying machine 1A accommodates the wire feeding unit 3, the cutting unit 6, the tying unit 7, the driving unit 8 for driving the tying unit 7, and the like in the main body 10.

[0049] The reinforcing bar binding machine 1A has a trigger 12 on the front side of a handle 11 and a switch 13 inside the handle 11. In the reinforcing bar binding machine 1A, a control unit (not shown) controls the conveying motor and the motor 80 according to the state of the switch 13 pressed by the operation of the trigger 12.

[0050] <Configuration Example of the Motor of the Present Embodiment>

[0051] Figure 2 : is a side sectional view showing an example of the electric motor of this embodiment. Figure 3A is a perspective view showing an example of a rotor according to the present embodiment, Figure 3B is a side view showing an example of a rotor according to the present embodiment, Figure 3C 1 is a rear view showing an example of a rotor according to the present embodiment. Figure 4A is a side sectional view showing an example of a rotor according to the present embodiment, Figure 4B : is a rear cross-sectional view showing an example of a rotor according to the present embodiment. Figure 5A 1 is an exploded perspective view showing an example of a rotor according to the present embodiment. Figure 5B This is a perspective view showing an example of a rotor according to the present embodiment before the rotor is filled with a sealing member.

[0052] The motor 80 includes a rotor 82, a stator 83, a sensor 84, and a housing 85. The motor 80 has a structure called a surface magnet type (SPM: Surface Permanent Magnet).

[0053] The rotor 82 includes a rotating shaft 82a, a rotor core 82b, a magnet 82c, a sealing member 82d, and a covering member 82e.

[0054] The rotating shaft 82 a is rotatably supported by a bearing portion 85 a constituted by a bearing or the like provided in the housing 85 .

[0055] The rotor core 82b is made of metal and has a predetermined shape, and the rotating shaft 82a is mounted at the center. In addition, the rotor core 82b has a mounting portion 82f for the magnet 82c formed on the outer periphery. The mounting portion 82f has a concave-convex shape in which the magnet 82c is embedded.

[0056] The magnet 82c is a permanent magnet and is attached to the outer periphery of the rotor core 82b. The magnet 82c is shaped to fit into the mounting portion 82f of the rotor core 82b and is attached to the mounting portion 82f by an adhesive 82g. The adhesive 82g is, for example, epoxy resin.

[0057] In this example, the rotor 82 has four magnets 82c mounted at equal intervals along the circumferential direction of the rotor core 82b. When the magnets 82c are mounted on the mounting portion 82f of the rotor core 82b, gaps 82h are formed between adjacent magnets 82c along the circumferential direction of the rotor core 82b.

[0058] The magnet 82c includes a protrusion 82i. The protrusion 82i protrudes in the direction in which the rotation axis 82a extends relative to one end surface 82j of the rotor core 82b. Thus, a gap 82k is formed between the protrusion 82i, the rotation axis 82a, and one end surface 82j of the rotor core 82b. In addition, a gap 82h2 is formed between the protrusions 82i adjacent to each other in the circumferential direction of the rotor core 82b.

[0059] The sealing member 82d is a resin having adhesiveness to the rotating shaft 82a, the rotor core 82b, the magnet 82c and the like, and fills the gap 82k. The sealing member 82d is, for example, epoxy resin.

[0060] The sealing member 82d is filled in the gap 82k and solidified to be bonded to the rotating shaft 82a and the protrusion 82i of the magnet 82c. The sealing member 82d is filled in the gap 82k and solidified to be bonded to the rotating shaft 82a, the end face 82j of the rotor core 82b, and the protrusion 82i of the magnet 82c. Thus, at least the rotating shaft 82a and the protrusion 82i of the magnet 82c are bonded by the sealing member 82d. Preferably, the rotating shaft 82a, the end face 82j of the rotor core 82b, and the protrusion 82i of the magnet 82c are joined to each other through the sealing member 82d. In addition, the sealing member 82d is filled in the gap 82h. The sealing member 82d is filled in the gap 82h and solidified to be bonded to the rotor core 82b and the magnet 82c. Thus, the magnets 82c adjacent to each other along the circumferential direction of the rotor core 82b are bonded by the sealing member 82d. The sealing member 82d is filled in the gap 82h2 between the protrusions 82i adjacent to each other in the circumferential direction of the rotor core 82b. The sealing member 82d is filled in the gap 82h2 and solidified to be bonded to the protrusion 82i of the magnet 82c. Thus, the protrusions 82i adjacent to each other in the circumferential direction of the rotor core 82b are bonded by the sealing member 82d.

[0061] In addition, the surface of the magnet 82c is coated to improve adhesion with the adhesive 82g and the sealing member 82d and prevent rust. For example, epoxy resin is coated on the surface of the magnet 82c. In addition, the coating applied to the surface of the magnet 82c preferably has affinity for the adhesive 82g and the sealing member 82d.

[0062] The covering member 82e covers the outer periphery of the magnet 82c attached to the mounting portion 82f of the rotor core 82b. The covering member 82e is formed of a tube of a resin that is shrinkable by heat. The covering member 82e shrinks by heat, thereby covering the outer periphery of the magnet 82c while applying a force toward the radial inner side of the rotor core 82b. In the rotor 82, after the outer periphery of the magnet 82c is covered by the covering member 82e, the sealing member 82d is filled into the gaps 82k and 82h, thereby limiting the range in which the sealing member 82d is filled. In addition, the covering member 82e does not cover the rotating shaft 82a.

[0063] The stator 83 includes a stator core 83 a and a coil 83 b. The motor 80 rotates the rotor 82 by generating a rotating magnetic field through the stator 83 .

[0064] The sensor 84 includes a Hall IC and the like, and is provided at a position facing the protrusion 82i of the magnet 82c. The sensor 84 can detect the rotation direction, rotation angle, rotation speed, etc. of the rotor 82 by detecting magnetic flux.

[0065] <Operation Example of the Rebar Binding Machine of the Present Embodiment>

[0066] Next, the operation of tying the reinforcing bars S with the wires W by the reinforcing bar tying machine 1A according to the present embodiment will be described with reference to the drawings.

[0067] When the reinforcing bar S enters between the curl guide 50 and the induction guide 51 of the curl forming portion 5 and the trigger 12 is operated, the conveying motor (not shown) is driven in the forward direction, and the two wires W held by the pair of conveying gears 30 are conveyed in the forward direction indicated by the arrow F.

[0068] The wire W fed in the forward direction is fed to the crimp guide 50 of the crimp forming section 5. The wire W passes through the crimp guide 50, thereby forming a crimp trace wound around the reinforcing bar S along the loop-shaped feeding path Ru.

[0069] The wire W having a curling trace formed by the curling guide 50 is guided by the guide guide 51 and further fed in the forward direction by the wire feeding unit 3, thereby being guided to the wire locking body 70. When the front end of the wire W is fed to a position where it hits the feeding restriction unit 90, the feeding motor (not shown) stops driving.

[0070] After the conveyance of the wire W in the positive direction is stopped, the motor 80 is driven in the positive direction. The sleeve 71 is restricted from rotating in the action domain where the wire W is locked by the wire locking body 70. Thus, the rotation of the motor 80 is converted into linear movement, and the sleeve 71 moves forward, i.e., in the direction of arrow A1. When the sleeve 71 moves forward, the wire W is locked by the prescribed action of the wire locking body 70.

[0071] After the sleeve 71 is advanced to a position where the wire W is locked by the wire locking body 70, the rotation of the motor 80 is temporarily stopped and the feeding motor is driven in the reverse direction.

[0072] As a result, the pair of conveying gears 30 rotate in reverse, and the wire W sandwiched between the pair of conveying gears 30 is conveyed in the reverse direction indicated by arrow R. The wire W is wound around the reinforcing bar S by the action of conveying the wire W in the reverse direction.

[0073] After the wire W is wound around the steel bar S and the reverse driving of the conveying motor is stopped, the motor 80 is driven in the forward direction, whereby the sleeve 71 further moves in the forward direction indicated by the arrow A1. The forward movement of the sleeve 71 is transmitted to the cutting section 6 by the transmission mechanism 62, whereby the movable blade section 61 rotates, and the predetermined position of the wire W is cut by the action of the fixed blade section 60 and the movable blade section 61.

[0074] By driving the motor 80 in the forward rotation direction and moving the sleeve 71 in the forward direction indicated by the arrow A1 to cut the two wires W, the wire locking body 70 presses the wire W in the forward direction, and the front end and terminal end of the wire W are bent toward the steel bar S side.

[0075] After the front end and the terminal end of the wire W are bent toward the reinforcing bar S, the motor 80 is further driven in the forward rotation direction, thereby further moving the sleeve 71 forward. When the sleeve 71 moves to a predetermined position, the restriction on the rotation of the sleeve 71 is released.

[0076] Thus, the sleeve 71 is rotated by further driving the motor 80 in the forward rotation direction, and the action of twisting the wire W held by the wire holding body 70 begins. When it is detected that the load applied to the motor 80 becomes maximum by twisting the wire W, the forward rotation of the motor 80 is stopped. Next, when the motor 80 is driven in the reverse direction, the sleeve 71 moves backward, that is, in the direction of arrow A2, while the rotation is restricted.

[0077] When the sleeve 71 moves in the rearward direction, the locking of the wire W by the wire locking body 70 is released, and the wire W bundled with the reinforcing bars S falls off from the wire locking body 70 .

[0078] <Example of the effect of the motor>

[0079] In a reinforcing bar tying machine, a motor used for the operation of twisting a wire is required to repeat forward and reverse rotation at high speed and to perform angle control with high precision.

[0080] In the past, a so-called interior permanent magnet (IPM) motor was used in a steel bar binding machine. In an IPM motor, a magnet that is longer in the axial direction relative to the rotor core is used, and the end of the magnet is configured to be close to a sensor composed of a Hall IC, etc., thereby ensuring control accuracy. In an IPM motor, the magnet is embedded in the rotor core, so even if the rotor rotates and a centrifugal force is applied to the magnet, it is possible to prevent the magnet from peeling off from the rotor core.

[0081] In contrast, in a steel bar bundling machine, in order to shorten the time taken for each bundling operation and increase the bundling speed, it is considered to reduce the inertia of the rotor, that is, to reduce the weight of the rotor. In order to reduce the weight of the rotor, it is considered to miniaturize the rotor core and magnets. However, if the rotor core and magnets are miniaturized, the magnetic flux decreases and the output of the motor decreases.

[0082] Therefore, it is considered to apply an SPM motor having a structure in which magnets are attached to the outer periphery of the rotor core. In the SPM motor, the rotor core is not provided outside the magnet, so the volume of the rotor core is reduced, thereby reducing the weight of the rotor. This can help improve the bundling speed.

[0083] On the other hand, in order to ensure the same control accuracy as that of the IPM motor, it is still necessary to use a magnet that is longer in the axial direction relative to the rotor core, and the end of the magnet is close to the Hall IC. In the SPM motor, when such a structure is set, the following form is obtained: on the outside of the rotor core, the magnet protrudes axially from the end surface of the rotor core.

[0084] As a result, when the rotor rotates, the magnets generate an eccentric load that rolls outward due to their own inertial force, and stress is concentrated on the ends of the bonding surfaces between the magnets and the rotor core, which may reduce the firmness.

[0085] Therefore, the rotor 82 is configured to fill the gap 82k between the rotating shaft 82a, the protrusion 82i of the magnet 82c and one end face 82j of the rotor core 82b with a sealing member 82d. The sealing member 82d filled in the gap 82k at least bonds the rotating shaft 82a and the protrusion 82i of the magnet 82c. In addition, the sealing member 82d filled in the gap 82k preferably bonds the rotating shaft 82a and the protrusion 82i of the magnet 82c to the end face 82j of the rotor core 82b. Thus, even if the rotor 82 rotates, the generation of the eccentric load that the magnet 82c rolls outward due to its own inertia force can be suppressed, and the stress will not be concentrated on the end of the bonding surface between the magnet 82c and the rotor core 82b, and the same firmness as the IPM motor can be ensured.

[0086] In addition, the rotor 82 is configured such that the gap 82h between the magnets 82c adjacent to each other along the circumferential direction of the rotor core 82b is also filled with the sealing member 82d. Thus, the magnets 82c adjacent to each other along the circumferential direction of the rotor core 82b are bonded by the sealing member 82d, thereby preventing the magnets 82c from peeling off from the outer periphery of the rotor core 82b. In addition, the rotor 82 is configured such that the gap 82h2 between the protrusions 82i adjacent to each other along the circumferential direction of the rotor core 82b is also filled with the sealing member 82d. Thus, the protrusions 82i adjacent to each other along the circumferential direction of the rotor core 82b are bonded by the sealing member 82d, thereby preventing the magnets 82c from peeling off from the outer periphery of the rotor core 82b. In addition, the sealing member 82d may be the same component as the adhesive 82g.

[0087] Fig. 6A is a perspective view showing an example of another embodiment of the rotor of this embodiment. Figure 6B : is a rear cross-sectional view showing an example of another embodiment of the rotor of the present embodiment. The protrusions 82i adjacent to each other along the circumferential direction of the rotor core 82b of the rotor 82L are bonded by the sealing member 82d filled in the gap 82h2 and the gap 82k between the rotating shaft 82a and the protrusion 82i on the protrusion 82i side. On the other hand, the rotor 82L does not fill the sealing member 82d on the rotating shaft 82a side in the gap 82k. In this way, the protrusions 82i adjacent to each other along the circumferential direction of the rotor core 82b and the opposing protrusions 82i are bonded by the sealing member 82d, thereby, even if the rotating shaft 82a and the protrusion 82i of the magnet 82c are not bonded by the sealing member 82d, it is possible to suppress the magnet 82c from peeling off from the outer periphery of the rotor core 82b. In addition, it is preferable that the sealing member 82d on the protrusion 82i side filled in the gap 82k is bonded to the end face 82j of the rotor core 82b.

[0088] Fig. 7A is a perspective view showing an example of another embodiment of the rotor of this embodiment. Figure 7B : is a rear cross-sectional view showing an example of another embodiment of the rotor of the present embodiment. The protrusion 82i of each magnet 82c of the rotor 82M is bonded to the rotating shaft 82a through the sealing member 82d filled in the gap 82k. The sealing member 82d filled in the gap 82k preferably bonds the rotating shaft 82a and the protrusion 82i of the magnet 82c to the end face 82j of the rotor core 82b. In contrast, in the rotor 82M, the sealing member 82d is not filled in the gap 82h2 between the protrusions 82i adjacent in the circumferential direction of the rotor core 82b. In this way, even if the sealing member 82d is not filled in the gap 82h2, the protrusions 82i adjacent in the circumferential direction of the rotor core 82b and the opposing protrusions 82i are bonded by the sealing member 82d filled in the gap 82k, thereby suppressing the magnet 82c from peeling off from the outer periphery of the rotor core 82b.

[0089] Fig. 8A is a perspective view showing an example of another embodiment of the rotor of this embodiment. Figure 8B : is a rear cross-sectional view showing an example of another embodiment of the rotor of the present embodiment. The protrusions 82i adjacent to each other along the circumferential direction of the rotor core 82b of the rotor 82N ​​are bonded by the sealing member 82d filled in the gap 82k between the rotating shaft 82a and the protrusion 82i on the protrusion 82i side. On the other hand, the rotor 82N ​​does not have the sealing member 82d filled in the gap 82h2 and the gap 82k on the rotating shaft 82a side. In this way, the protrusions 82i adjacent to each other and the opposing protrusions 82i along the circumferential direction of the rotor core 82b are bonded by the sealing member 82d filled in the gap 82k on the protrusion 82i side, thereby, even if the rotating shaft 82a and the protrusion 82i of the magnet 82c are not bonded by the sealing member 82d, it is possible to suppress the magnet 82c from peeling off from the outer periphery of the rotor core 82b.

[0090] The rotor 82 is configured such that the outer periphery of the magnet 82c is covered by a covering member 82e. The covering member 82e is formed of a tube of a shrinkable resin, and covers the outer periphery of the magnet 82c while applying a force inward in the radial direction of the rotor core 82b. Thus, when the rotor 82 rotates, the covering member 82e can also suppress the generation of an eccentric load that causes the magnet 82c to roll outward due to its own inertial force.

[0091] Description of Reference Numerals

[0092] 1A···rebar bundling machine, 2···bin, 20···reel, 3···wire conveying unit, 30···conveying gear, 5···curl forming unit, 50···curl guide, 51···induction guide, 6···cutting unit, 7···binding unit, 70···wire fixing body, 71···sleeve, 8···driving unit, 80···motor, 81···reducer, 82, 82L, 82M, 82N···rotor, 82a·· ·rotating shaft, 82b···rotor core, 82c···magnet, 82d···sealing part, 82e···covering part, 82f···mounting part, 82g···adhesive, 82h···gap, 82i···protrusion, 82j···end face, 82k···gap, 83···stator, 83a···stator core, 83b···coil, 84···sensor, 85···housing, 85a···bearing part, W···wire.

Claims

1. An electric motor having a rotor and a stator, wherein: The rotor has: Axis of rotation; Rotor core; a magnet attached to the outer periphery of the rotor core and having a protrusion protruding along the extending direction of the rotating shaft relative to the end surface of the rotor core; and The sealing member is disposed between the protruding portion and the rotating shaft.

2. An electric motor having a rotor and a stator, wherein: The rotor has: Axis of rotation; Rotor core; A plurality of magnets attached to the outer periphery of the rotor core and having a protrusion protruding along the extending direction of the rotating shaft relative to the end surface of the rotor core; as well as The sealing member is arranged between the plurality of protrusions.

3. The electric motor according to claim 1 or 2, wherein: The sealing member is made of a resin having adhesiveness with respect to the magnet and the rotating shaft.

4. The electric motor according to claim 3, wherein: The rotor core has a plurality of the magnets mounted along the circumferential direction, and the sealing member is provided between the magnets adjacent to each other along the circumferential direction of the rotor core.

5. The electric motor according to claim 1 or 2, wherein: A covering member covering the outer circumference of the magnet is provided.

6. The electric motor according to claim 5, wherein: The covering member has shrinkage properties.

7. The electric motor according to claim 5, wherein: The sealing member is filled between the protruding portion whose outer circumference is covered by the covering member and the rotating shaft.

8. The electric motor according to claim 3, wherein: The magnet has a coating layer on the surface.

9. A strapping machine comprising: A silk thread conveying unit, for conveying silk threads; a curl forming section constituting a ring-shaped conveying path for winding the thread conveyed by the thread conveying section around the bundle; The bundling part twists the wire wound around the bundle; and The motor according to claim 1 drives the bundling portion.

10. A strapping machine comprising: A silk thread conveying unit, for conveying silk threads; a curl forming section constituting a ring-shaped conveying path for winding the thread conveyed by the thread conveying section around the bundle; The bundling part twists the wire wound around the bundle; and The electric motor according to claim 2 drives the bundling portion.

11. The strapping machine according to claim 9 or 10, wherein: The rotating shaft of the rotor protrudes from the rotor core toward the bundling portion in an extending direction of the rotating shaft.

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