JP2009060733A - Rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor which can eliminate the gap between a rotor core and a shaft in the direction of relative rotation and in the radial direction, and can prevent metal waste from being generated easily when the shaft is press fit. <P>SOLUTION: In the rotor X where a rotor core 10 having a fitting hole 11 formed by interconnecting through holes 1b is formed by laminating a plurality of core plates 1 each having the through hole 1b and a shaft 20 is press fit in the fitting hole 11, an engaging portion and an engaged portion interlocking to regulate relative rotation of the rotor core 10 and the shaft 20 are provided between the rotor 10 and the shaft 20, and a gap filling member 50 deforming to fill a gap when the shaft 20 is press fit is provided in the gap between the engaging portion and the engaged portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention forms a rotor core having a fitting hole formed by connecting a plurality of core plates each having a through hole, and is formed by press-fitting a shaft into the fitting hole. It relates to the rotor to be attached.

  A rotating electrical machine such as a motor forms a rotor core having a fitting hole formed by communicating a plurality of core plates formed with through holes, and press-fitting a shaft into the fitting hole. It has a rotor to be assembled. In a rotating electrical machine, it is required to realize low noise, low vibration, and the like and to have an excellent torque transmission force between the rotor core and the shaft.

Patent Document 1 describes a rotor in which a sufficient tightening allowance is ensured between the rotor core and the shaft even in a high-temperature environment to improve the torque transmission force between the two.
The rotor press-fits the shaft, the collar, the collar, and the rotor core by interposing at least a collar having a linear expansion coefficient larger than that of the rotor core between the rotor core and the shaft that is inserted through the rotor core. At this time, the rotor core and the collar are press-fitted and fastened by spline fitting.

  When the rotor is used in a high-temperature environment, the rotor core, the shaft, and the collar are all thermally expanded to increase their outer diameter. In particular, since the collar has a larger linear expansion coefficient than at least the rotor core, the degree of diameter expansion due to the linear expansion becomes significant. Since the outer peripheral surface of the collar is constrained by the rotor core, the diameter expansion force of the collar accompanying thermal expansion also acts in the direction of diameter reduction. As a result, in the thermally expanded state, the collar can maintain a press-fit fastening state with a predetermined fastening margin with respect to the rotor core and the shaft. Thereby, a large transmission torque can be secured between the rotor core and the shaft in a high temperature environment.

JP 2006-187063 A

  In the rotor of Patent Document 1, the collar maintains a press-fit fastening state with a predetermined fastening allowance with respect to the rotor core and the shaft. At this time, the rotor core and the collar are press-fitted and fastened by spline fitting, but the collar and the shaft are only press-fitted and fastened. For this reason, when the motor rotates at high torque or at high rotation, the collar and the shaft may slide relative to each other and rotate relative to each other, thereby causing a positional shift. In this case, it is difficult to ensure a transmission torque between the rotor core and the shaft.

When assembling the rotor, for example, a collar is press-fitted and fastened to the shaft in advance with a predetermined tightening allowance, and the shaft integrated with the collar is inserted into the insertion hole of the rotor core. It was press-fitted with a predetermined tightening allowance.
In this case, the angles of the rotor cores are matched with the outer shape of the collar, but the angles of the many core plates do not all match. In addition, the spline recess shape formed in the core plate includes errors during processing. Therefore, when the shaft is press-fitted into the insertion hole, the collar integrated over the entire circumference of the shaft is scraped by the rotor core, and metal scraps are easily generated. The generated metal scraps may cause noise and further contribute to a failure of the connector portion of the motor case internal sensor.

  Accordingly, an object of the present invention is to provide a rotor that can prevent displacement in the relative rotational direction and radial displacement between the rotor core and the shaft, and hardly generate metal debris when the shaft is press-fitted.

  The rotor according to the present invention for achieving the above object, by laminating a plurality of core plates in which through holes are formed, forms a rotor core having an insertion hole formed by communicating the through holes, The rotor is assembled by press-fitting a shaft into the insertion hole, and the first feature of the rotor is engagement between the rotor core and the shaft so that relative rotation between the rotor core and the shaft can be regulated. A joint portion and an engaged portion are provided, and a gap filling member that deforms to fill the gap when the shaft is press-fitted is provided in the gap between the engaging portion and the engaged portion.

  As in this configuration, by providing an engaging portion and an engaged portion that engage with each other so that the relative rotation between the rotor core and the shaft can be regulated, the rotor core and the shaft The engagement state can be maintained, and the transmission torque can be reliably ensured by preventing the displacement in the relative rotational direction and the displacement in the radial direction of the two.

  In the gap between the engaging portion and the engaged portion, a gap filling member that is deformed by being sandwiched between the rotor core and the shaft when the shaft is press-fitted is provided. When the shaft is press-fitted, a press-fitting load acts on the rotor core and the shaft. However, since the load can be absorbed by the deformation of the gap filling member, the rotor core and the shaft are not deformed. Further, since the gap filling member is press-fitted while being deformed, there is no member to be scraped when the shaft is press-fitted, and no metal scrap is generated. Therefore, it is possible to prevent the occurrence of noise, sensor malfunctions, and the like.

  The gap filling member deformed when the shaft is press-fitted can fill the gap between the engaging portion and the engaged portion. For this reason, there is no backlash between the rotor core and the shaft, and it is possible to apply a load uniformly over the entire engaging portion and engaged portion. It is possible to prevent an excessive load from being applied.

  In the second characteristic configuration of the rotor according to the present invention, the engaging portion and the engaged portion are a concave portion or a convex portion formed along the axial direction of the rotor core and the shaft, and when the shaft is press-fitted The gap filling member is in a point of being sequentially deformed along the axial direction of the rotor core and the shaft from the press-fitted portion.

According to this configuration, the inner peripheral surface shape of the rotor core and the outer peripheral surface shape of the shaft that form the engaging portion and the engaged portion can be made into a simple shape that can be engaged with each other and become a pair.
The concave portion and the convex portion are formed along the press-fitting direction of the shaft. The press-fitting direction of the shaft matches the axial direction of the fitting hole. Therefore, when the shaft is press-fitted, the gap filling member is sequentially deformed from the press-fitted portion along the axial direction of the rotor core and the shaft. The shaft can be press-fitted with.

  A third characteristic configuration of the rotor according to the present invention is that the gap filling member is a long member having a U-shaped cross-sectional shape.

  According to this configuration, the shape of the gap filling member that can be interposed between the concave portion and the convex portion forming the engaging portion can be specified with a simple shape. As a result, the gap filling member can be easily manufactured.

  A fourth characteristic configuration of the rotor according to the present invention is that the gap filling member is configured to be fitted to the concave portion or the convex portion by thermal deformation or to be fitted by plastic deformation.

  According to this configuration, the gap filling member can be configured to be deformed by applying heat or external force. Since a known method can be applied to such deformation, the gap filling member can be easily attached to the concave portion or the convex portion.

  A fifth characteristic configuration of the rotor according to the present invention is that the gap filling member is formed of a material having a larger linear expansion coefficient than materials of the rotor core and the shaft.

According to this configuration, the gap filling member can be easily attached to the rotor core or the shaft by shrink fitting.
For example, at a high temperature, the degree of contact of the gap filling member with the rotor core or the shaft increases due to the thermal expansion of the gap filling member. Since the volume of the space between the rotor core and the shaft is constant to some extent, the contact between the rotor core and the shaft is increased as a result of the expansion of the gap filling member. Thereby, a rotor core and a shaft can be reliably engaged in an engaging part. Therefore, the reliability of motor driving is improved even at high temperatures.

  A sixth characteristic configuration of the rotor according to the present invention is that the gap filling member is formed of a material selected from the group consisting of soft iron-based metal, aluminum, aluminum alloy, and zinc alloy.

  If this gap filling member is made of any material of soft iron-based metal, aluminum, aluminum alloy, and zinc alloy as in this configuration, the gap filling member can be easily formed when the shaft with the gap filling member is press-fitted. Deform. Therefore, the press-fitting resistance at the time of press-fitting becomes small, and the press-fitting operation becomes easy.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, the rotor X of the present invention includes a fitting hole 11 in which a plurality of core plates 1 each having a through hole 1 b are stacked to form the through hole 1 b in communication. The rotor core 10 is formed, and the shaft 20 is press-fitted into the fitting hole 11 and assembled.
Between the rotor core 10 and the shaft 20, there are provided an engaging portion and an engaged portion that engage with each other so that relative rotation between the rotor core 10 and the shaft 20 can be regulated. A gap filling member 50 that is deformed so as to fill the gap when the shaft is press-fitted is provided in the gap between the engaging portion and the engaged portion.

  The rotor core 10 is formed in a cylindrical shape by laminating and integrating a plurality of disk-shaped core plates 1. As the core plate 1, for example, a silicon steel plate that is a magnetic material is used. The core plate 1 is punched into a disk shape one by one from a thin plate material by a known press process. A through-hole 1b is further formed in the central portion of the punched core plate 1 by pressing.

  Two protrusions 1c are provided on the inner peripheral edge of the through hole 1b so as to protrude toward the center of the through hole 1b. A plurality of core plates 1 are stacked so that the convex portions 1c overlap each other. The rotor key portion (engagement portion) 12 is formed by the convex portion 1c being continuous in the axial direction.

  The rotor key portion 12 is projected on the inner peripheral surface of the insertion hole 11 toward the axial center side of the insertion hole 11 (inner peripheral surface convex portion). A plurality of the rotor key portions 12 are formed so as to be point-symmetric with respect to the center of the through hole 1b, for example. Thereby, engagement with the rotor core 10 and the shaft 20 is stabilized, and the balance of the rotor core 10 becomes favorable. In the present embodiment, the case where the rotor key portion 12 is formed at two locations is exemplified, but the present invention is not limited to this.

  The shape of the insertion hole 11 in the convex part 1c as viewed in the axial direction is configured to include a side part 1d parallel to the radial direction of the through hole 1b (FIG. 3). Since the side portion 1d has an end surface substantially perpendicular to the rotation direction of the shaft 20, the leg portion 52 of the gap filling member 50 abuts the side portion 1d substantially perpendicular to the rotation direction. . Therefore, the positional deviation between the side portion 1d and the gap filling member 50 is difficult to occur.

The shaft 20 is, for example, a steel columnar or cylindrical member.
A shaft key portion (engaged portion) 21 having a shape that can be engaged with the rotor key portion 12 formed on the rotor core 10 is formed on the outer surface of the shaft 20. In the present embodiment, since the rotor key portion 12 is formed in a convex shape, the shaft key portion 21 is recessed (outer peripheral surface recessed portion). The same number of shaft key portions 21 as the number of rotor key portions 12 are provided.

  The engaging portion and the engaged portion are a concave portion (shaft key portion 21) or a convex portion (rotor key portion 12) formed along the axial direction of the rotor core 10 and the shaft 20. Further, when the shaft 20 is fitted in the rotor core 10, there is a gap S between the rotor key portion (engagement portion) 12 and the shaft key portion (engaged portion) 21, and the gap S is a gap filling member 50. Filled by.

  In this embodiment, since the rotor key portion 12 is formed as an inner peripheral surface convex portion and the shaft key portion 21 is formed as an outer peripheral surface concave portion, the gap filling member 50 has a U-shaped cross-sectional shape. It is configured to be a long member. Therefore, the gap filling member 50 can be interposed between the rotor key portion 12 (inner peripheral surface convex portion) and the shaft key portion 21 (outer peripheral surface concave portion) with a simple shape.

  The gap filling member 50 includes a trunk portion 51 and opposing leg portions 52. The two leg parts 52 are connected to the body part 51 at a right angle, for example, at a corner part 53. At this time, the two leg parts 52 are parallel (FIG. 3).

  The “U-shaped cross-sectional shape” may be a shape that is not attached to the rotor key portion 12 or the shaft key portion 21 and has a substantially U-shaped cross-sectional view. For example, the leg portion 52 can be connected to the trunk portion 51 at an acute angle or an obtuse angle at the corner portion 53.

  The gap filling member 50 is fitted to the rotor key portion 12 (inner peripheral surface convex portion) or the shaft key portion 21 (outer peripheral surface concave portion) by thermal deformation or plastic deformation. Thereby, the gap filling member 50 can be configured to be deformed by applying heat or external force. Since a known method can be applied to such deformation, the gap filling member 50 can be easily attached to the rotor key portion 12 or the shaft key portion 21.

When fitting by thermal deformation, the gap filling member 50 is formed of a material having a larger linear expansion coefficient than the material of the rotor core 10 and the shaft 20. Thereby, the gap filling member 50 can be easily attached to the rotor core 10 or the shaft 20 by shrink fitting.
For example, when the gap filling member 50 is fitted into the rotor key portion 12 by shrink fitting, the gap filling member 50 is first heated to expand and engage with the rotor key portion 12. Next, when the temperature of the gap filling member 50 is lowered to room temperature, the gap filling member 50 can be contracted and fitted into the rotor key portion 12.

  Further, at the time of high temperature, due to thermal expansion of the gap filling member 50, the degree of contact of the gap filling member 50 with the rotor core 10 or the shaft 20 increases. Since the volume of the space between the rotor core 10 and the shaft 20 is constant to some extent, the contact force with respect to the rotor core 10 and the shaft 20 is eventually increased by the expansion of the gap filling member 50. Thereby, the rotor core 10 and the shaft 20 can be reliably engaged. Therefore, the reliability of motor driving is improved even at high temperatures.

  On the other hand, when fitting by plastic deformation, the gap filling member 50 can be fitted to the rotor key portion by caulking or the like, for example. At this time, the gap filling member 50 can be fitted into the rotor key portion 12 by first engaging the gap filling member 50 with the rotor key portion 12 and then caulking the gap filling member 50 with an external force to cause plastic deformation.

As described above, the gap filling member 50 is formed of a material selected from the group consisting of soft iron-based metal, aluminum, aluminum alloy, and zinc alloy as a material that has a large linear expansion coefficient and can be deformed during press-fitting.
As the soft iron-based metal, for example, pure iron, silicon iron alloy, iron / silicon / aluminum alloy, iron / nickel alloy, soft ferrite, and the like are applicable. If formed of these materials, the gap filling member 50 is easily deformed when the shaft 20 fitted with the gap filling member 50 is press-fitted. Therefore, the press-fitting resistance at the time of press-fitting becomes small, and the press-fitting operation becomes easy.
In addition, although aluminum, aluminum alloy, and zinc alloy were illustrated as a nonferrous metal, it is not restricted to this.

<Assembly method of rotor X>
First, the core plate 1 is laminated to form the rotor core 10. For example, as shown in FIGS. 4 and 5, there is a manufacturing error between the plurality of core plates 1, and when the core plates 1 are stacked, the side portions 1 d and the tip portions 1 f of the convex portions 1 c are not aligned. A step may be formed. In this case, if the shaft 20 is press-fitted in a state where the gap filling member 50 does not exist, the tip of the shaft 20 is caught at the step, and the press-fit cannot be smoothly performed. If the gap filling member 50 is provided as in the present invention, the gap filling member 50 can be deformed during press-fitting to eliminate the step.

  The gap filling member 50 is attached to the rotor key portion (inner peripheral surface convex portion) 12 by the above-described fitting. After fitting the gap filling member 50 into the rotor core 10, the shaft 20 is press-fitted into the rotor core 10 and fitted.

  The rotor core 10 and the shaft 20 are engaged at the engaging portion and the engaged portion via the gap filling member 50. In the engaging portion and the engaged portion, the relative rotation between the rotor core 10 and the shaft 20 is engaged so as to be able to be regulated, so that the rotor core 10 and the shaft 20 can be connected even during high torque rotation or high rotation of the motor. The engaged state is reliably maintained, and the shift in the relative rotation direction and the shift in the radial direction of both can be prevented. Therefore, the transmission torque between the rotor core 10 and the shaft 20 can be reliably ensured.

When the shaft 20 is press-fitted, the gap filling member 50 is easily deformed sequentially from the press-fitted portion along the axial direction of the rotor core 10 and the shaft 20. Therefore, the shaft 20 can be smoothly press-fitted. At this time, when the gap filling member 50 is deformed, a load acting on the rotor core 10 and the shaft 20 at the time of press-fitting can be absorbed. Therefore, deformation of the rotor core 10 and the shaft 20 at the time of press fitting can be prevented. Further, since the gap filling member 50 is press-fitted while being deformed, there is no member to be scraped when the shaft 20 is press-fitted.
The gap S between the rotor core 10 and the shaft 20 can be filled with the gap filling member 50 that is deformed when the shaft 20 is press-fitted. For this reason, rattling between the rotor core 10 and the shaft 20 is eliminated.

On the other hand, the fitting of the rotor core 10 and the shaft 20 excluding the engaging portion and the engaged portion is, for example, a clearance fitting. For this reason, when the shaft 20 is press-fitted, the outer surface of the shaft 20 is not scraped by the rotor core 10 and no metal scrap is generated.
Further, since only the rotor key portion 12 and the shaft key portion 21 are press-fitted, the press-fitting load required at the time of press-fitting can be reduced, and the equipment and jigs can be reduced in size, thereby facilitating manufacture.

  After the shaft 20 and the gap filling member 50 are attached to the rotor core 10, circular end plates (not shown) are attached to both ends of the rotor core 10. The end plate is formed by previously forming an insertion hole of the shaft 20 in the center of a circular silicon steel plate as in the core plate 1. In order to closely arrange the end plates on both side surfaces of the rotor core 10, the end plates are press-fitted or fixed with caulking to the shaft 20.

[Another embodiment]
(1) In the above-described embodiment, as an example of the case where the gap filling member 50 is fitted to the rotor key portion 12 (inner peripheral surface convex portion) or the shaft key portion 21 (outer peripheral surface concave portion) by thermal deformation, Although the case where the filling member 50 is heated and expanded and then fitted to the rotor key portion 12 has been described (shrink fitting), the present invention is not limited to this.
For example, when the gap filling member 50 is fitted to the rotor key portion 12 (inner peripheral surface convex portion) by cooling contraction, the gap filling member 50 may be attached after the rotor core 10 is cooled and contracted. In this case, when the rotor core 10 (rotor key part) returns to, for example, room temperature, the rotor key part 12 expands, and the gap filling member 50 can be fitted into the rotor key part 12.

(2) In the above-described embodiment, the case where the rotor key portion 12 protruding from the inner peripheral surface of the insertion hole 11 of the rotor core 10 is formed integrally with the rotor core 10 has been described. However, the present invention is not limited to this, and the rotor key portion 12 may be formed of a separate member. In this case, a long member having a rectangular cross section is fitted into the groove provided in the inner peripheral surface of the insertion hole 11 of the rotor core 10. And the part which protruded from the said internal peripheral surface becomes the rotor key part 12. FIG. In this structure, since the rotor core 10 and the rotor key part 12 are manufactured separately, the freedom degree of design of the rotor key part 12 increases.
If the long member is applied in this manner, the convex portion and the concave portion can be arranged in reverse, such as by projecting the shaft key portion 21 on the outer surface of the shaft 20.

(3) In the above-described embodiment, the shape of the insertion hole 11 in the convex portion 1c as viewed in the axial direction is described as including the side portion 1d that is parallel to the radial direction of the through hole 1b. It is not limited to this.
For example, as shown in FIG. 6, the shape of the convex portion 1 c as viewed in the axial direction has a longer side toward the distal end portion 1 f of the convex portion 1 c (center side of the through hole 1 b), and the base end portion of the convex portion 1 c. You may comprise in the trapezoid shape which 1e narrows.

  For example, it is assumed that the gap filling member 50 having the leg portion 52 connected to the trunk portion 51 at an acute angle in the corner portion 53 is attached to the rotor key portion 12 (inner peripheral surface convex portion). In this case, the gap filling member 50 is attached to the rotor key portion 12 by shrink fitting or the like. When the gap filling member 50 returns to normal temperature, the legs 52 engage with each other so as to bite into the rotor key portion 12 due to shrinkage deformation during cooling. As a result, the gap filling member 50 is reliably engaged with the rotor key portion 12.

  The present invention forms a rotor core having a fitting hole formed by connecting a plurality of core plates each having a through hole, and is formed by press-fitting a shaft into the fitting hole. It can be used for a rotating electric machine such as a motor having a rotor to be attached.

Exploded perspective schematic view of rotor of the present invention Schematic view in top view in the axial direction of the rotor of the present invention Schematic diagram of relevant parts near the engaging part Schematic view of engagement section in circumferential direction Schematic diagram of the engagement section in the radial direction Schematic diagram of the main part near the engaging part of another embodiment

Explanation of symbols

X Rotor S Clearance 1 Core plate 1b Through hole 10 Rotor core 11 Insertion hole 12 Rotor key part 20 Shaft 21 Shaft key part 50 Gap filling member

Claims (6)

By laminating a plurality of core plates having through-holes, a rotor core having a fitting hole formed by communicating the through-holes is formed, and in a rotor to be assembled by press-fitting a shaft into the fitting hole,
An engaging portion and an engaged portion are provided between the rotor core and the shaft so that relative rotation between the rotor core and the shaft can be regulated, and the engagement portion and the engaged portion A rotor provided with a gap filling member that deforms to fill the gap when the shaft is press-fitted.   The engaging portion and the engaged portion are a concave portion or a convex portion formed along the axial direction of the rotor core and the shaft, and the gap filling member is inserted into the rotor core from a portion where the gap filling member is press-fit when the shaft is press-fitted. The rotor according to claim 1, wherein the rotor is sequentially deformed along an axial direction of the shaft.   The rotor according to claim 2, wherein the gap filling member is a long member having a U-shaped cross-sectional shape.   4. The rotor according to claim 2, wherein the gap filling member is configured to be fitted to the concave portion or the convex portion by thermal deformation or fitting by plastic deformation. 5.   The rotor according to any one of claims 1 to 4, wherein the gap filling member is made of a material having a larger linear expansion coefficient than materials of the rotor core and the shaft.   The rotor according to any one of claims 1 to 5, wherein the gap filling member is formed of a material selected from the group consisting of soft iron-based metal, aluminum, aluminum alloy, and zinc alloy.

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