Patent ID: 12218554

DESCRIPTION OF EMBODIMENTS

An example of a motor disclosed in the present application will be described below in detail with reference to the drawings. Note that the dimensional relationships, the proportions, and the like between elements in the drawings may differ from those in reality. Among the drawings, the dimensional relationships and proportions may not necessarily be the same. In each of the drawings, a coordinate system including at least any one of an axial direction (rotation axis direction of a motor1), a radial direction, or a circumferential direction of the motor1, which will be described later, may be illustrated for the purpose of facilitating explanation. In addition, the rotation axis direction of the motor1may be simply referred to as an “axial direction” below.

FIG.1is a perspective view illustrating one example of a motor according to a first embodiment.FIG.2is a cross-sectional view illustrating one example of the motor according to the first embodiment.FIG.3is a perspective view of the motor according to the first embodiment. InFIG.3, a housing of the motor is removed.FIG.2illustrates a cross section taken along the line A-A inFIG.1. As illustrated inFIGS.1to3, the motor1according to the present embodiment includes a stator2, a rotor40, a first substrate50, a second substrate60, a housing70, a shaft80, and a bearing housing90. The stator2includes an insulator10, a stator core20, and a coil30.

In the present embodiment, the insulator10is formed with an insulating member such as resin. The stator core20is configured, for example, by stacking, in the axial direction, a predetermined number of steel sheets formed of a magnetic substance such as a silicon steel sheet. The stator core20includes a teeth part21protruding in the radial direction, and a core back22extending in the circumferential direction. The coil30is wound around the stator core20via the insulator10.

The coil30includes, for example, a winding line such as a copper line. For example, the rotor40includes a magnet41such as a neodymium magnet, and a yoke42serving as a magnetic body.

In the present embodiment, the first substrate50is, for example, a driver circuit configured to control operation of the motor1. The second substrate60receives alternating current (AC) power supplied from the outside, and supplies direct current (DC) power to the motor1.

The housing70is formed of metal such as steel, and accommodates the stator2. The shaft80includes an end part81opposing to the first substrate50in the axial direction and disposed at an upper direction side in the drawing, and an output-side end part82disposed at a lower direction side in the drawing. The shaft80is inserted into the bearing housing90.

FIG.4is a perspective view illustrating one example of the insulator according to the first embodiment. As illustrated inFIG.4, the insulator10includes an outer circumference part11, a connecting part12, an internal circumference part13, and coupling parts14. In addition, at an upper side in the axial direction, the insulator10further includes a fixing part15, a first conductive member16, and a second conductive member17, as illustrated inFIG.4.

For example, the insulator10is mounted at the stator core20from above in the axial direction, as illustrated inFIG.2. Note that the insulator10may be configured by, for example, being combined with a lower insulator18mounted at the stator core20from below in the axial direction, as illustrated inFIG.2.

As illustrated inFIGS.2to4, the outer circumference part11of the insulator10opposes to the core back22of the stator core20in the axial direction. In addition, the connecting part12of the insulator10opposes to the teeth part21of the stator core20in the axial direction. The coil30is wound around the teeth part21via the connecting part12.

The internal circumference part13of the insulator10has an outer side surface in the radial direction opposing to the coil30. In addition, the inner side surface of the internal circumference part13in the radial direction opposes to the bearing housing90.

Each coupling part14of the insulator10extends outwards in the radial direction from the outer circumference part11of the insulator10. The coupling parts14are coupled to a casing3not illustrated inFIGS.1to4, and the motor1is mounted at the casing3. Note that the casing3serves as one example of the external device.

As illustrated inFIG.1, the insulator10includes the two coupling parts14opposing to each other in the radial direction. Note that the present embodiment describes the insulator10including the two coupling parts14. However, the number of the coupling parts14is not limited to this number. For example, the insulator10may include only one coupling part14, or may include three or more coupling parts14.

In the present embodiment, as illustrated inFIG.1, the motor1and the casing3are coupled to each other by the coupling parts14provided at the insulator10formed of a resin material, not by an attachment part formed at the housing70.FIG.5is a bottom view illustrating one example of the motor according to the first embodiment. As illustrated inFIG.5, a gap G0is formed between a tubular part79of the housing70and each coupling part14of the insulator10. This makes it possible to reduce the size of the housing70formed of metal. Thus, it is possible to reduce the weight of the motor1. In addition, the coupling parts14are formed at the insulator10formed of resin having higher elasticity than a metal. Thus, the vibration generated from the motor1can be reduced due to an internal loss of the resin material when the vibration transfers to the casing3. In addition, the amplitude of the vibration generated from the motor1is reduced due to the internal loss of the resin material. Thus, the vibration can be attenuated in a shorter time. Furthermore, with the insulator10, the noise generated from the motor1is less likely to be transferred. This makes it possible to achieve noise reduction of the motor1.

In addition, the fixing part15illustrated inFIGS.1and4is, for example, a protruding part formed of resin. The first substrate50is fixed to the fixing part15in the axial direction.

The first conductive member16and the second conductive member17illustrated inFIGS.1and4are terminal pins used to handle the winding line that forms the coil30. In the present embodiment, the motor1includes, for example, three first conductive members16and one second conductive member17.

For example, winding starts of winding lines of COM, a U phase, a V phase, and a W phase are wound around the first conductive members16, and the first conductive members16are fixed to the first substrate50through soldering. This enables the coil30and the first substrate50to be electrically connected.

Furthermore, a winding end of a wiring line of COM is wound around the second conductive member17, and the second conductive member17includes a resin coating. The second conductive member17is fixed to the first substrate50through soldering. In addition, the first substrate50and the second substrate60are electrically connected through pins (conductive members)51aof coupling members51. Furthermore, the pins51aof the plurality of coupling members51are electrically connected to the GND, Vdc, Vcc, and the like, and signals are transferred from an external device. This enables the coil30, the first substrate50, and the second substrate60to be electrically connected to each other.

In the present example, the first substrate50and the second substrate60are disposed so as to oppose to each other in the axial direction with a gap G1being provided between the first substrate50and the second substrate60, as illustrated inFIGS.1and2. That is, the first substrate50and the second substrate60are spaced apart from each other in the axial direction.

As illustrated inFIGS.1and2, the first substrate50includes the coupling members51, and a first wire line52. For example, each coupling member51is a member obtained by covering, with resin, the pin51a(conductive member) electrically connecting the first substrate50and the second substrate60. In the present embodiment, the first substrate50includes the five coupling members51. The first wire line52is connected to a Hall sensor (not illustrated) provided at the rotor40side of the first substrate50. In this manner, the first conductive member16, the second conductive member17, and the coupling members51including the pins51aare used to fix the first substrate50and the second substrate60, and to fix the insulator10to the first substrate50and the second substrate60. This makes it possible to reduce structural elements of the motor1.

A plurality of electronic components61are mounted at the second substrate60. The electronic components61include, for example, a capacitor and an AC-DC converter but are not limited to these components. In addition, a second wire line62configured to supply power is connected to the second substrate60.

As illustrated inFIG.1, the electronic components61have a relatively large size, as compared with the size of the motor1. In the present embodiment, the electronic components61are disposed at an upper side surface of the second substrate60in the axial direction, that is, at a surface disposed at an opposite side in the axial direction from a surface opposing to the first substrate50and the insulator10. In other words, the electronic components61are disposed at a surface opposite in the axial direction from the output-side end part82of the shaft80. This makes it possible to reduce the size or the diameter of the motor1.

Furthermore, the sizes, in the radial direction, of the first substrate50and the second substrate60are formed so as to be smaller than the size, in the radial direction, of the outer circumference part11of the insulator10.FIG.6is an enlarged cross-sectional view illustrating one example of the motor according to the first embodiment.FIG.6is an enlarged view of a part indicated by the area F inFIG.2. As illustrated inFIG.6, a gap G2is formed between the outer circumference part11of the insulator10and the outer circumference part59of the first substrate50and between the outer circumference part11of the insulator10and the outer circumference part69of the second substrate60. The gap G2forms an annular space C1surrounding the outer circumference part59of the first substrate50and the outer circumference part69of the second substrate60. This makes it possible to prevent the casing3from being brought into contact with the first substrate50or the second substrate60, thereby suppressing transfer of the vibration to the casing3. Note that, an example has been described with reference toFIG.6, and, in this example, the size, in the radial direction, of the first substrate50is substantially the same as the size, in the radial direction, of the second substrate60. However, a configuration is not limited to this configuration, and it is only necessary that, in the radial direction, the outer circumference part59of the first substrate50and the outer circumference part69of the second substrate60be disposed at the inner side than the outer circumference part11of the insulator10. In addition, a gap G4between the inner surface of the casing3and the outer circumference part59of the first substrate50or the outer circumference part69of the second substrate60may be increased to increase the size of the annular space C1. Furthermore, it may be possible to provide a gap G5between the inner surface of the casing3and the outer circumference part11of the insulator10, provide a space C2surrounding the outer circumference part11of the insulator10and including the gap G5, and form the space C2largely. With these spaces being provided, air passing through the inside of the motor1including the coil30more easily flows. This makes it possible to suppress an increase in temperature of the motor1.

In addition, as illustrated inFIG.6, a gap G3is formed between the first substrate50and other members of the motor1. For example, the outer circumference part59of the first substrate50and the tubular part79of the metal housing70are spaced apart from each other with a gap G6being provided between the outer circumference part59and the tubular part79. This makes it possible to suppress transfer of the vibration of the motor1to the first substrate50or the second substrate60.

The bearing housing90includes a pair of bearings91and92. Each of the bearings91and92opposes to the shaft80in the radial direction. In the present embodiment, an end part93of the bearing housing90at the first substrate50side in the axial direction opposes to the yoke42of the rotor40in the axial direction. In addition, the bearing housing90integrally holds the bearing91at the lower side in the axial direction and the bearing92at the upper side in the axial direction. This makes it possible to improve the accuracy of coaxiality of the bearing91at the lower side and the bearing92at the upper side, thereby achieving the increased service life of the motor1.

FIG.7is a perspective view illustrating one example of the housing according to the first embodiment. As illustrated inFIGS.5and7, the housing70includes the tubular part79and a bottom surface71. The bottom surface71constitutes an end surface of the housing70at the lower side in the axial direction. An insertion hole74to allow the shaft80to be inserted is formed in the bottom surface71. In addition, a plurality of hole parts72and a plurality of hole parts73are also formed in the bottom surface71. In the present embodiment, the hole parts72are formed to have diameters larger than diameters of the hole parts73. Note that the insertion hole74serves as one example of a first hole part. In addition, the hole parts72serve as one example of a second hole part, and the hole parts73serve as one example of a third hole part.

As illustrated inFIG.5, the hole parts72are formed, for example, at positions opposing to the coil30in the axial direction. That is, the hole parts72are formed so that air flows inside the motor1including the coil30. With the hole parts72being formed in the bottom surface71of the housing70, it is possible to reduce the weight of the housing70and to suppress an increase in temperature of the motor1, for example, due to self-heating of the coil30or heat transferred from the coil30to the stator core20or the rotor40. That is, with the hole parts72, it is possible to suppress demagnetization of the motor1at high temperatures, deterioration of a resin material of the insulator10due to heat generation, or the like, and it is also possible to achieve the weight reduction and the increased service life.

Furthermore, the hole parts73illustrated inFIG.7may be used, for example, as a positioning hole or screw hole used to attach the housing70to the insulator10or the first substrate50. In this case, the hole parts73may be formed, for example, at positions opposing to the first substrate50in the axial direction. This makes it possible to improve an assembling accuracy of the motor1, and also makes it possible to reduce assembling cost of the motor1. Note that the housing70illustrated inFIG.7includes the seven hole parts72and the five hole parts73. However, the numbers of the hole parts included in the housing70are not limited to these numbers.

As described above, the motor1according to the present embodiment includes the rotor40, the stator2, the first substrate50, the second substrate60, and the electronic components61arranged at the second substrate. The stator2includes the stator core20, the insulator10, and the coil30wound around the stator core via the insulator. The insulator10includes the coupling part14coupled to an external device. The first substrate50is fixed to the insulator10. The second substrate60is fixed to the first substrate50, and the first substrate50and the second substrate60are spaced apart from each other in the rotation axis direction of the rotor40. With such a configuration, it is possible to achieve the weight reduction and the noise reduction.

The embodiment according to the present invention has been described above. However, the present invention is not limited by the embodiment described above. A configuration obtained by appropriately combining the above-mentioned constituent elements is also included in the present invention. In addition, a skilled person can further derive modification examples in an easy manner. Thus, a wide range of aspects of the present invention is not limited to the embodiment described above, and may be modified variously.

REFERENCE SIGNS LIST

1motor,2stator,3body,10insulator,11outer circumference part,12connecting part,13internal circumference part,14coupling part,15fixing part,16first conductive member,17second conductive member,18lower insulator,20stator core,21teeth part,22core back,30coil,40rotor,41magnet,42yoke,50first substrate,51coupling member,52first wire line,59outer circumference part,60second substrate,61electronic component,62second wire line,69outer circumference part,70housing,71bottom surface,72,73hole part,74insertion hole,79tubular part,80shaft,90bearing housing,91,92bearing