JP4900780B2 - Electric motor - Google Patents

Description

  The present invention relates to an electric motor, and more particularly to an improvement in a structure for attaching a wiring such as a lead wire connected to a coil of the electric motor.

  Conventionally, an electric motor (motor) that directly supports a load rotatably without using a spindle or a gear and directly applies a rotational driving force to the load is a work rotation holding portion of a machine tool, It is used for driving joints of robots.

  As this type of electric motor, for example, an abduction type electric motor in which a stator is disposed on the inner periphery and a rotor is disposed on the outer periphery is known. An abduction motor may have a hollow hole through which wiring, piping, auxiliary shafts, etc. pass. In such a case, the hollow hole should be as large as possible due to the characteristics of the device that directly drives the load. In contrast to this, the outer shape of the device is required to be as small as possible, and the axial height of the device is required to be low.

  On the other hand, in order to make the motor output (motor output) as large as possible within a limited volume, it is necessary to make the outer circumference of the stator as large as possible and make the inner circumference as small as possible. Therefore, the outer shape of the housing that does not directly contribute to the motor output needs to be as small as possible. Furthermore, it is necessary to make the lead-out portion of the wiring that does not directly contribute to the motor output as small as possible.

Therefore, when fixing the lead wire connected to the stator coil, etc. to the motor housing, a silicon glass tube or the like can be used for each lead wire to protect the lead wire for power supply and the lead wire for the sensor. A method has been adopted in which a flexible tube is covered and these are fixed to the motor housing by pressing them with a wiring fixing bracket having a semicircular arc-shaped mounting portion. Also, when pulling out the lead wire from the motor case, a knot having a larger outer diameter than the rubber bush inserted in the lead wire lead-out hole of the motor case is formed on the lead wire, and the lead wire is pulled outside the motor case. In addition, there has been proposed one in which the knot of the lead wire hits the rubber bush and the ceiling surface of the motor case (see Patent Document 1). As a flexible body fixed to the stator-side housing, there are, for example, a tube for supplying cooling air in addition to a lead wire (cable wire) covered with a tube such as an upper portion.
JP-A-10-32956

  For example, when the flexible body is a cable wire as described above, when attaching the wiring to the housing using a wiring fixing bracket having a semicircular arc-shaped attachment portion, the outer peripheral surface of the tube inserted into the recess of the housing is used. It is necessary to insert the bolts into the bolt insertion holes formed at both ends of the wiring fixing bracket while holding the wiring fixing bracket, and tighten the bolt while crushing the wiring. For this reason, in a limited space, it is very difficult to turn the wrench with the other hand while holding the bolt and the wiring fixture with one hand.

  Further, since the wiring fixing metal fittings are arranged in a limited space, the holding width of the wiring fixing metal fittings is inevitably narrowed, and excessive pressure is applied to the wire. This is because the lead wires and other lead wires cannot be bent, which may impair the convenience of the motor. In addition, the wire may be cut or broken, and the reliability of the product may be reduced.

  Further, since the wiring is fixed by the tightening force of the bolt, there is a risk that the bolt will loosen when the lead wire is moved. This may lead to accidents such as disconnection of wiring and dropping (mixing) of metal fittings and bolts to the motor rotating part.

Furthermore, in order to secure a space for fixing the wiring fixing bracket, when a notch is provided in the mounting bottom portion of the motor housing, the outer circumference of the fitting circle is reduced, and the mounting rigidity of the motor is deteriorated. is there.
There is a similar problem when attaching another flexible body.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to increase the efficiency of attaching a flexible body such as a wiring and to improve the reliability of an electric motor.

  In order to achieve the above object, the present invention includes a housing inner disposed on the inner peripheral side of an annularly formed stator, and a long flexible body to which the housing inner is fixed and has flexibility. The electric motor includes a recess formed on an outer peripheral surface of the housing inner and a flexible body fixing member formed so as to be attachable to the recess, and the flexible body fixing member is formed so as to be attachable to the recess. A curved portion, a pair of fixing member support portions formed on one end side of the bending portion with the bending portion interposed therebetween, and an arc shape with the bending portion interposed on the other end side of the bending portion The flexible body fixing member is fixed to the housing inner with the bending portion mounted in the recess, and the flexible body is the pair of flexible body support members. A motor that is supported by the body support part It is.

  When the electric motor is configured, it is desirable that a part of the outer periphery of the flexible body be formed with a step that is prevented from moving by contact with the pair of flexible body support portions.

According to the above-described means, when the flexible body is inserted into the bending portion of the flexible body fixing member, the outer peripheral side of the flexible body is supported by the flexible body support portion, and the flexible body is inserted into the flexible body fixing member. Since it is worn, the efficiency of the work of attaching the flexible body can be increased. In addition, when the flexible body is fixed to the housing inner, the flexible body can be fixed without applying mechanical pressure, such as crushing the flexible body, so that the flexible body is prevented from being damaged. Can contribute to the improvement of the reliability of the electric motor. Further, when a step is formed on a part of the outer periphery of the flexible body so that the movement is prevented by contact with the pair of flexible body support portions, the flexible body is pulled away from the flexible body fixing member. However, since the step of the flexible body is caught by the flexible body support portion and further movement of the flexible body is prevented, the flexible body can be firmly held against the tensile force.
In another embodiment of the present invention, the step is formed by a heat-shrinkable tube that covers the outer periphery of the end of the flexible body, and in another embodiment, the concave portion is attached to the curved portion. It has 1 recessed part and 2nd recessed part which cross | intersects this 1st recessed part and the said fixing member support part fits.

  ADVANTAGE OF THE INVENTION According to this invention, while improving the efficiency of attachment work of flexible bodies, such as wiring, the reliability of an electric motor can be improved.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a main part of an abduction motor showing one embodiment of the present invention. In FIG. 1, an outer rotation type electric motor (hereinafter referred to as a motor) 10 includes an annular stator 12 (however, a coil wire wound around a core of the stator is not shown), A cylindrical housing inner 14 is provided on the circumferential side, and a cylindrical rotor (not shown) is arranged on the outer circumferential side of the stator 12.

  On the outer peripheral surface of the housing inner 14, an arc-shaped recess 16 is formed along the axial direction of the housing inner 14, and a plurality of mounting holes (tap holes) 18 are formed with the recess 16 in between. . A wiring fixture 20 as a flexible member fixing member shown in FIG. 2 is inserted into the recess 16. In FIG. 1, 14 a is a motor mounting surface of the housing inner 14.

  A plurality of mounting holes (tap holes) 14b are provided in the motor mounting surface 14a. On the other hand, the motor mounting base (not shown) to which the abduction motor 10 is fixed is provided with bolt insertion holes corresponding to the mounting holes 14b. The abduction motor 10 is fixed to the motor mounting base by bolts using these mounting holes 14b and bolt insertion holes. The motor mounting base is provided with a through hole communicating with the hollow hole of the housing inner 14 and a concave portion or through hole communicating with the concave portion 16 for guiding the cable fixed to the housing inner 14 as necessary.

  As shown in FIG. 2, the wiring fixing bracket 20 includes a curved portion 22 that can be inserted into the concave portion 16, and a pair of fixing members that are formed on one end side of the curved portion 22 with the curved portion 22 therebetween. Fastening member support portions 24 and 26 (hereinafter also referred to as fixed portion support portions) as support portions, and a pair of flexible body supports formed in an arc shape on the other end side of the bending portion 22 with the bending portion 22 therebetween. Wiring support portions 28 and 30 (hereinafter, also referred to as flexible body support portions) as parts, and bolt insertion holes 32 and 34 as fastening member insertion holes are provided in the fastening member support portions 24 and 26, respectively. Is formed. The curved portion 22 is formed in an arc shape as an arc-shaped portion, and the flexible tube 36 shown in FIG. 3 is attached to the curved portion 22.

  The tube 36 is comprised so that the outer peripheral side of the some lead wire 38 connected to the coil of the stator 12 may be covered using polyvinyl chloride (PVC), for example. Further, the end portion in the axial direction of the tube 36 is covered with a heat shrinkable tube 40 having a length of 2 mm to 6 mm. The heat shrinkable tube 40 is heat shrunk with hot air of 110 ° C. or higher so that a step of about 0.5 mm is formed between the heat-shrinkable tube 40 and the uncovered portion. In this case, since the outer diameter of the tube 36 is formed to be substantially the same as the inner diameter of the wiring support portions 28 and 30, when the tube 36 is inserted into the bending portion 22 and attached, the tube 36 extends in the axial direction. With the movement, when the step formed by the heat shrinkable tube 40 comes into contact with the wiring support portions 28 and 30, further movement of the tube 36 is prevented. For this reason, when the tube 36 into which the lead wire 38 is inserted is inserted into the bending portion 22 of the wiring fixture 20, the flexible body support portions 28, 30 and the thermal support portions 28, 30 are heated together with the movement of the tube 36 in the axial direction. When the contraction tube 40 comes into contact, the step 40 </ b> A formed by the heat contraction tube 40 is caught by the wiring fixture 20, thereby preventing the tube 36 from coming off.

  The heat-shrinkable tube 40 is fixed to the PVC tube 36 due to the shrinkage of the heat-shrinkable tube 40. It is preferable to use a material coated with an adhesive having excellent adhesiveness. Further, as shown in FIG. 3B and the like, the heat-shrinkable tube 40 covers only the tube 36 and the remaining portion surrounds the plurality of lead wires 38. In this state, the heat-shrinkable tube 40 is heat-shrinkable. By doing so, it is preferable to fix the plurality of lead wires 38 together with the tube 36.

  The cable wire composed of the tube 36, the plurality of lead wires 38 and the heat shrinkable tube 40 obtained as described above corresponds to a flexible body fixed to the housing inner 14 in the present embodiment.

  Next, when the lead wire 38 is pulled out from the stator 12, as shown in FIG. 4, the wiring fixture 20 is inserted into the recess 16 of the housing inner 14, and the bolts 42 (this embodiment) are respectively inserted into the bolt insertion holes 32 and 34. In this embodiment, a hexagon socket head cap screw is used, but it may be replaced with other various screws.) Insert and insert the front end side of each bolt 42 into the mounting hole 18 to connect the bolt 42 and the mounting hole 18 to each other. By fastening, the wiring fixture 20 is fixed to the outer peripheral surface of the housing inner 14. At this time, the fastening member support portions 24 and 26 are elastically deformed according to the arc shape of the housing inner 14.

  At this time, since only the wiring fixing bracket 20 is fixed, it is not necessary to tighten the fixing bracket with the bolt while pressing the tube or the lead wire and the fixing bracket as in the conventional case, and the bolt 42 can be easily tightened. . Further, there is no risk of damaging the lead wires 38 and the like.

  Next, as shown in FIG. 5, when the portion of the tube 36 into which the lead wire 38 is inserted is removed from the step due to the heat-shrinkable tube 40 and is inserted into the curved portion 22 of the wiring fixture 20, the outer peripheral side of the tube 36 is The tube 36 is inserted into and attached to the wiring fixture 20 by being supported by the flexible body support portions 28 and 30. Thereafter, even if the tube 36 is pulled away from the wiring fixture 20, that is, upward, the heat-shrinkable tube 40 is caught on the wiring support portions 28 and 30, and further movement of the tube 36 is prevented. The wire 36 can be held firmly. In this case, the tensile strength due to the step can be secured at 25 N or more.

  In addition, after the tube 36 is inserted into the wiring fixture 20, the flexible body support portions 28 and 30 are crimped to the tube 36 side (the annular radial direction formed by the flexible body support portions 28 and 30). The tube 36 can also be fixed more firmly.

  This caulking process can be easily performed because the tube 36 is already fixed to the housing inner 14 via the wiring fixture 20. In the above procedure, first, after fixing the wiring fixture 20 to the recess 16, the tube 36 (cable wire) in a state where the plurality of lead wires 38 are inserted and the heat shrinkable tube 40 is fixed to the end portion is fixed. However, instead of this, the wiring fixing metal fitting 20 is first attached to the tube 36 in a state in which the plurality of lead wires 38 are inserted and the heat shrinkable tube 40 is fixed to the end (here, the heat The shrinkable tube 40 may be fixed to the tube 36 after the wiring fixture 20 is attached to the tube 36), or the wiring fixture 20 may be fixed to the recess 36. Also in this case, when the tube 36 is attached to the wiring fixing metal 20, the wiring fixing tool 20 is in a free state, and there is no fear that an excessive force is applied to the tube 36 or the lead wire 38 or damage is caused. Further, when the wiring fixing metal fitting 20 attached to the tube 36 is fixed to the recess 16, it is not necessary to press the wiring fixing metal fitting 20 against the tube 36. There is no danger of adding mosquitoes or scratching. The tightening operation of the bolt 42 can be easily performed as compared with the conventional case in which the bolt 42 is pressed. Further, the tube support portions 28 and 30 may be crimped to the tube 36 side, but this crimping operation is easy to perform safely.

  According to the present embodiment, when the portion of the tube 36 into which the lead wire 38 is inserted is removed from the stepped portion with respect to the heat shrinkable tube 40, the outer peripheral side of the tube 36 is allowed. Since the tube 36 is inserted into and attached to the wiring fixing bracket 20 by being supported by the flexible body supporting portions 28 and 30, the efficiency of wiring attachment work can be increased.

  Further, according to the present embodiment, when the lead wire 38 is fixed to the housing inner 14, the lead wire 38 can be fixed without applying mechanical pressure, such as crushing the lead wire 38. Can be prevented, and can contribute to the improvement of the reliability of the motor 10.

  Furthermore, according to the present embodiment, even when the tube 36 is pulled away from the wiring fixing bracket 20, the step due to the heat shrinkable tube 40 of the tube 36 is caught on the wiring support portions 28 and 30, and the tube 36 is moved further than that. Therefore, the heat-shrinkable tube 36 and the lead wire 38 can be firmly held against a pulling force.

  Next, a second embodiment in which the shape of the recess provided in the housing inner is different from the first embodiment will be described. FIG. 6 is a view showing a main part in a state in which a stator (coil winding is not shown) and a wiring fixing bracket are attached to a housing inner of an abduction type electric motor according to a second embodiment. (B) shows the main part when the concave part is viewed from the front side.

  In the first embodiment, the recess 16 is a groove having an arcuate cross section provided at a predetermined depth along the axial direction from the outer peripheral end surface of the motor mounting surface of the housing inner 14. The case where the curved portion 22 is attached to the recess 16 is shown. On the other hand, in the second embodiment, the first concave portion 116 has a substantially U-shaped cross section provided at a predetermined depth along the axial direction from the end surface on the motor mounting surface side of the housing inner 14. 116a and a pair of second recesses 116b and 116c provided at a position away from the end surface on the motor mounting surface side of the housing inner 14 by a predetermined distance and provided to intersect the first recess 116a. Since other configurations are the same as those in the first embodiment, only different parts will be described below.

  The cross-sectional shape in the cross section orthogonal to the axial direction of the first recess 116a is such that the radius of the arc-shaped portion is substantially equal to the outer diameter of the curved portion of the wiring fixing bracket 20 and the tube support portion, and the depth to the groove bottom is When the wiring fixing metal fitting 20 is mounted, the depth is as shallow as possible within a range in which the wiring fixing metal fitting 20 does not protrude from the outer peripheral surface of the housing inner 14.

  The pair of second recesses 116b and 116c are provided symmetrically with the first recess 116a interposed therebetween. As shown in FIG. 6A, the bottoms of the pair of second recesses 116b and 116c are formed to be planar and on the same plane. As shown in FIG. 6A, the depth of the bottom of the pair of second recesses 116b and 116c is determined between the outer peripheral surface of the curved portion 22 and the recess 116a when the wiring fixing bracket 20 is attached to the recess 116. The depth at which the gap between the mounting surface of the fixing member support portion 24 and the second recess 116b and the mounting surface of the fixing member support portion 26 and the second recess 116c are substantially free of clearance. It is. Further, the distance from the end surface on the motor mounting surface side of the housing inner 14 to the end portion on the motor mounting surface side of the pair of second recesses 116b and 116c is as shown in FIG. This distance is set to be approximately equal to the distance from the tube support portion side end surface to the end portions of the fixing member support portions 24 and 26 near the tube support portion side end surface.

  Since the recess 116 is configured as described above, the wiring fixture 20 and the mounting bolt 42 do not protrude from the outer peripheral surface of the housing inner 14 as shown in FIG. Contributes to downsizing. Instead of making the second recesses 116b and 116c planar, for example, a groove having a certain depth along the circumferential direction may be used. In this case, the fixing member support portions 24 and 26 may have an arc shape corresponding to the groove bottom.

  Also in this case, it is preferable that the wiring fixing metal fittings do not protrude from the outer peripheral surface of the housing inner 14. In each of the above embodiments, a fixing screw such as a pole is used to fix the wiring fixture 20 to the housing inner 14. However, the present invention is not limited to this. For example, an adhesive (for example, epoxy) that can bond metals together. The fixing member support portions 24 and 26 may be fixed to the housing inner 14 by a system adhesive). Further, in the case of having the second recess as in the case of the second embodiment, if the wiring fixing metal fitting 20 can be prevented from moving in the radial direction by appropriate means, the fixing member support portion 24, 26 may not be fixed to the housing inner 14. That is, in this case, even if a force that pulls the cable wire in the axial direction acts, the fixing member support portions 24 and 26 are pulled out by the step formed in the housing inner 14 due to the second recess. Is prevented. In each of the above embodiments, the case where the flexible body fixed to the housing inner 14 is a cable wire in which a feeding lead wire or a sensor lead wire is covered with a tube has been described. The present invention can also be applied to the case where another flexible body such as a tube for supplying air is fixed to the housing inner 14.

  In each of the above embodiments, a step is provided at the end of the tube 36 by covering the heat-shrinkable tube. However, the present invention is not limited to this. For example, another tube may be stacked and fixed, or You may make it provide a level | step difference by using the resin molded product by which the edge part was shape | molded by the level | step difference shape. In addition, providing a step in the cable line as in each of the above embodiments means that the step part of the cable line is caught by the flexible material support portion even if the cable wire is pulled out. Thus, it is preferable because the cable wire is surely prevented from being pulled out by a simple configuration, but the step may not necessarily be provided if there is no fear of such a force acting.

  In addition, a wiring fixing structure including the concave portion 16 (116) and the wiring fixing metal fitting 20 shown in the above embodiments may be provided at a plurality of locations of the housing inner. For example, two locations are provided on the diagonal of the motor mounting surface 14a of the housing inner 14, and one is used for power feeding, that is, for a group of lead wires connected to the coil winding of the stator 12, and the other is used for a sensor, for example, a resolver. Alternatively, it may be used for a group of lead wires connected to a rotational position detection sensor such as an optical encoder. FIG. 7 shows an outline of an example of the mounting state of the abduction motor of the present invention showing such an example, and FIG. 8 shows an outline of the motor mounting base used. The motor mounting base 700 is fastened to the motor mounting surface 14a of the housing inner from the lower side of the motor mounting base 700 with bolts 704 in FIG. In FIG. 7, reference numeral 702 denotes a rotor housing disposed on the outer peripheral side of the stator 12. Further, as shown in FIG. 8, the recess 716 of the motor mounting base 700 is provided at two positions on the diagonal line so as to correspond to the position of the recess 16 (or 116) of the housing inner 14, and one of the power supply lead wire group The other is used for a lead wire group connected to a sensor, for example, a rotational position detection sensor such as a resolver or an optical encoder. The through holes 714b for the bolts 704 are equally arranged at 60 ° so as to correspond to the mounting holes 14b of the housing inner 14.

The principal part disassembled perspective view of the electric motor which shows the 1st Embodiment of this invention. It is a figure for demonstrating the structure of a wiring fixing metal, Comprising: (a) is a top view, (b) is a front view, (c) is sectional drawing which follows the AA line of (b), (d) is Side view. It is a figure for demonstrating the cable wire which consists of the tube which covers a lead wire, a heat contraction tube, and a lead wire, Comprising: (a) is a perspective view of the state which covered the heat contraction tube on the edge part of a tube, (b) ) Is a perspective view of a state in which a lead wire is inserted into the tube and further heat-shrinked with a heat-shrinkable tube, and FIG. The exploded perspective view of the electric motor which shows the state which attached the wiring fixing metal fitting to the housing inner. The perspective view which shows a state when fixing a wiring fixing metal fitting and a cable wire to a housing inner. It is a figure which shows the principal part of the electric motor which shows the 2nd Embodiment of this invention, (a) is a top view, (b) is a front view. The side view which shows the outline of the state which attached the electric motor of this invention to the motor attachment base. The bottom view of the motor attachment base shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Motor 12 Stator 14 Housing inner 16 Recessed part 18 Mounting hole 20 Wiring fixing bracket 22 Bending part 24, 26 Fixing material support part 28, 30 Flexible body support part 32, 34 Bolt insertion hole 36 Tube 38 Lead wire 40 Heat shrinkable tube

Claims (2)

A housing inner disposed on the inner peripheral side of the annularly formed stator, and a long flexible body fixed to the housing inner and having flexibility , and directly supports the load rotatably, In an electric motor that directly gives a rotational driving force to a load ,
A concave portion formed on the outer peripheral surface of the housing inner, and a flexible body fixing member formed so as to be attachable to the concave portion,
The flexible body fixing member includes a bending portion formed so as to be attachable to the recess, a pair of fixing member support portions formed on one end side of the bending portion with the bending portion interposed therebetween, and the bending portion. The other end side is composed of a pair of flexible body support portions formed in an arc shape with the curved portion in between,
The flexible body fixing member is fixed to the housing inner with the curved portion mounted in the concave portion,
The flexible body Ri Na is supported by the pair of flexible body supporting portion,
In a part of the outer periphery of the flexible body, a step is formed that is prevented from moving by contact with the pair of flexible body support portions,
The electric motor characterized in that the step is formed by a heat-shrinkable tube with an adhesive that covers the outer periphery of the end of the flexible body . 2. The electric motor according to claim 1 , wherein the concave portion includes a first concave portion in which the curved portion is mounted, and a second concave portion that intersects the first concave portion and that accommodates the fixing member support portion.

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