JP6448433B2 - Career - Google Patents

Description

  The present invention relates to a carrier that supports a gear shaft of a planetary gear in a planetary gear mechanism.

One of the speed change mechanisms is a planetary gear mechanism in which a planetary gear is disposed between a sun gear disposed in the center and a ring gear disposed on the outer periphery. The planetary gear mechanism is provided with a carrier that supports the gear shaft of the planetary gear.
The carrier supports one end and the other end of the gear shaft in the planetary gear. Therefore, it has been proposed to manufacture a carrier by joining one member in the axial direction and the other member in the axial direction to the planetary gear. For example, the carrier is manufactured by bending one plate in the axial direction and welding it while being in contact with the surface of the other plate.

In such a structure, it is difficult to weld from the inner peripheral side due to interference of the plates, and the plates are welded from the outer peripheral side. However, if the plates are welded together from the outer peripheral side, there is a risk that spatter will scatter to the inner peripheral side. In this case, since the spatter may interfere with the planetary gear (so-called impurities), the spatter has to be removed, which increases the number of work steps and increases the manufacturing cost.
Therefore, it has been proposed to weld the plates from the axial direction. Specifically, by inserting the end part where the other plate in the axial direction is bent into the slit arranged in the circumferential direction in one plate in the axial direction, irradiating an electron beam from one axial direction, and welding the plates together, Manufacturing a carrier has been studied (see Patent Document 1).

JP 58-61982

  However, in the carrier in which the plates are joined along the circumferential direction as shown in Patent Document 1, the plates are joined only on the outer peripheral side or the inner peripheral side with respect to the gear shaft. As a result, the joint strength between the plates on the inner peripheral side or the outer peripheral side is insufficient, and the support rigidity of the planetary gear may not be ensured.

  The present invention has been devised in view of the above problems, and an object of the present invention is to ensure the support rigidity of the planetary gear in the carrier. It is to be noted that the present invention is not limited to the purpose herein, and is an operational effect derived from each configuration shown in [Mode for Carrying Out the Invention] to be described later, and also exhibits an operational effect that cannot be obtained by conventional techniques. It can be positioned as another purpose.

(1) In order to achieve the above object, the carrier of the present invention supports the gear shaft of the planetary gear in the planetary gear mechanism.
The carrier includes a main body portion that supports one axial direction of the gear shaft and a cover portion that supports the other axial direction of the gear shaft.
The cover portion is joined to the main body portion at a circumferential edge that connects a radial position on the inner peripheral side of the gear shaft and a radial position on the outer peripheral side of the gear shaft.
In addition, since the said circumferential edge part of the said cover part is joined with respect to a main-body part, the said cover part is the site | part divided | segmented into the circumferential direction in the said carrier.

(2) It is preferable that the said cover part is shape | molded so that the dimension between the said circumferential direction edge parts may become short as it goes to an inner periphery from an outer periphery. In this case, it is preferable that the circumferential edge and the main body are joined in the same plane orthogonal to the axial direction.
(3) It is preferable that a plurality of the cover portions are provided at intervals in the circumferential direction. In this case, it is preferable that the circumferential edge portions of the facing cover portions are arranged in a straight line when viewed in the axial direction. That is, it is preferable that the two circumferential edge portions are set on a straight line when viewed in the axial direction.
(4) It is preferable that the main body is formed by forging, casting or sintering.

(5) Leg portions are erected on both sides of the planetary gear in the main body portion, and a stepped portion is formed on the other axial side of the leg portion according to the thickness of the cover portion. preferable. In this case, it is preferable that the circumferential edge portion of the cover is joined to the stepped portion.
(6) It is preferable that the said circumferential direction edge part of the said cover part is welded to the said main-body part from the axial direction other side.

  According to the carrier of the present invention, in the cover portion that supports the other axial direction of the gear shaft, the circumferential edge connecting the radial position on the inner peripheral side with respect to the gear shaft and the radial position on the outer peripheral side with respect to the gear shaft. The portion is joined to the main body portion that supports one axial direction of the gear shaft. Accordingly, it is possible to increase the bonding strength between the cover portion and the main body portion that are bonded to the gear shaft of the planetary gear on the inner peripheral side and the outer peripheral side, and it is possible to ensure the support rigidity of the planetary gear.

FIG. 1 is an exploded perspective view showing a carrier in an embodiment of the present invention. FIG. 2 is a front view showing a carrier in one embodiment of the present invention. FIG. 3 is an enlarged perspective view showing a main part of the carrier in one embodiment of the present invention. FIG. 4 is a plan view for explaining the manufacturing process of the carrier cover in the embodiment of the present invention.

Hereinafter, embodiments of the carrier of the present invention will be described with reference to the drawings.
This carrier supports the gear shaft of the planetary gear in the planetary gear mechanism.
In the present embodiment, the axis of the planetary gear mechanism (revolution axis of the planetary gear) is “C ₁ ”, and the axis of the planetary gear itself (the rotation axis of the planetary gear) is “C ₂ ”. In the drawings, one of the directions along the axial centers C ₁ and C ₂ provided in parallel to each other (hereinafter referred to as “one axial direction”) is referred to as “I” and the other (hereinafter referred to as “the other axial direction”). ) Is “O”.

In addition, viewing along the axial centers C ₁ and C ₂ is referred to as “axial viewing”, and a position in the direction along the axial centers C ₁ and C ₂ is referred to as “axial position”. Furthermore, a “circumferential direction” and a “radial direction” are determined with reference to the axis C ₁ . Therefore, means a side on which "inner circumferential side" is close to the axis C _1, "the outer circumferential side" is meant the side away from the axis C _1, "the radial position" is the distance to the axis C ₁ means.

[I. One Embodiment]
[1. Constitution]
As shown by a two-dot chain line in FIG. 2, the planetary gear mechanism is provided with a sun gear 2 disposed at the center and a ring gear 4 disposed on the outer periphery, concentrically with the axis C _1, and the sun gear 2 and the ring gear 4. The planetary gear 3 is disposed between the two. The planetary gear 3 meshes with each of the sun gear 2 and the ring gear 4 and rotates (rotates) around its own axis C ₂ and rotates (revolves) around the axis C ₁ of the planetary gear mechanism. Here, four planetary gears 3 are arranged at equal intervals along the circumferential direction centered on the axis C ₁ .

Each of these planetary gears 3 is provided with a gear shaft 3a extending therethrough so that both ends protrude in both the axial direction and the other. Each end of the gear shaft 3 a protruding in this way is supported by the carrier 1.
Hereinafter, the configuration of the carrier 1 will be described in detail with reference to FIGS.
The carrier 1 is roughly divided into two types of members: a main body 10 that supports one of the gear shafts 3a in the axial direction and a cover 20 that supports the other of the gear shafts 3a in the axial direction.

[1-1. Main unit]
The main body 10 is a member that supports one of the four gear shafts 3a in the axial direction. The main body 10 has a disk-like shape centered on the axis C ₁ and a surface 11 that is perpendicular to the axis C ₁ , and four legs that protrude from the surface 11 in the other axial direction. It is divided roughly into two types of sites.
As for the main-body part 10, the surface part 11 and the leg part 12 are shape | molded integrally. The main body 10 is formed by any one of manufacturing methods 1 to 3 exemplified below.
Manufacturing method 1: Cutting after forging a lump of metal Manufacturing method 2: Cutting after casting a molten metal Manufacturing method 3: Sintering and forming a powdered metal

In manufacturing method 1, since the shape accuracy after forging is not sufficient, the shape accuracy is ensured by cutting. Similarly, in the manufacturing method 2, since the shape accuracy after casting is not sufficient, the shape accuracy is ensured by cutting. Moreover, in the manufacturing method 3, although the shape accuracy of the metal after sintering is ensured more than the shape accuracy after casting or after forging, about the site | part which requires shape accuracy and position accuracy, such as the shaft hole 11a mentioned later, is mentioned. The accuracy is ensured by cutting.
Hereinafter, the surface portion 11 and the leg portion 12 will be described in this order.

<Surface part>
The surface portion 11 has a plane (hereinafter referred to as “inner surface”) 111 extending in the other axial direction and a plane (hereinafter referred to as “outer surface”) 112 extending in the axial direction. The surface portion 11 is provided at an axial position corresponding to a portion (hereinafter referred to as “one end portion”) that protrudes in one axial direction of the gear shaft 3a.
Further, the surface portion 11 protrudes in a flange shape to the inner peripheral side than the inner peripheral surface 12a of the leg portion 12, and an inner peripheral surface portion 11A that overlaps the outer peripheral portion of the sun gear 2 in the axial direction, and a main body portion between the leg portions 12. 10, and a dimension along the radial direction (hereinafter referred to as “radial width”) is roughly divided into an outer peripheral surface portion 11 </ b> B having a slightly smaller diameter than the planetary gear 3 and the same radial width as the leg portion 12.

  The outer peripheral surface portion 11B is provided with four shaft holes 11a that support one end portions of the inserted gear shaft 3a corresponding to the gear shafts 3a. Further, each shaft hole 11a is formed at the center in the radial direction of the outer peripheral surface portion 11B so that the outer peripheral portion of the planetary gear 3 protrudes from both radial edges of the outer peripheral surface portion 11B described above.

<leg>
The four legs 12 are arranged so as to sandwich the planetary gears 3 in the circumferential direction. Legs 12 are erected on both sides of the planetary gear 3 in the circumferential direction. Each of these legs 12 is provided in the four times of rotation symmetrical shape relative to the axis C _1. For this reason, the leg portions 12 are formed in the same shape except for the arrangement location. Therefore, in the following description, the description will be given focusing on one leg 12.
The leg portion 12 is provided so as to protrude from the outer peripheral surface portion 11B to an axial position corresponding to a portion (hereinafter referred to as “the other end portion”) of the gear shaft 3a protruding in the other axial direction. That is, the leg portion 12 is provided at an axial position corresponding to a portion of the gear shaft 3a excluding one end portion.

Here, the cross-section orthogonal to the axis C ₁ illustrates the leg portion 12 having a fan shape. Here, the sector shape is a shape formed by two arcs (radius r ₁ and r ₂ ) centered on the axis C ₁ and a radial straight line connecting them.
The leg portion 12 is formed with a step portion 13 that is notched in accordance with the thickness of the cover portion 20, which will be described in detail later, at each circumferential end portion (straight edge portion) at the end portion on the other side in the axial direction. ing. The step portion 13 is formed of a surface portion (hereinafter referred to as “axial surface”) 13 a along the axial direction and a circumferential surface portion (hereinafter referred to as “circumferential surface”) 13 b along the circumferential direction.

[1-2. Cover part]
The cover part 20 is a member provided in accordance with each planetary gear 3. These cover portions 20 are provided at intervals in the circumferential direction, and are attached so as to be bridged between the step portions 13 of the leg portions 12 adjacent to each other in the circumferential direction. Therefore, it can be said that the cover 20 is divided in the circumferential direction in the carrier 1. For example, the circumferential end 21 of the cover 20 is provided every 45 ° when viewed in the axial direction.
These cover portions 20 are formed in a four-fold rotationally symmetric shape with respect to the axis C ₁ . For this reason, the cover portions 20 are formed in the same shape except for the arrangement location. Therefore, in the following description, the description will be given focusing on one cover portion 20.

The cover part 20 is a plate-like member along the circumferential direction. The cover portion 20 has a surface (hereinafter referred to as “inner surface”) 201 extending in one axial direction and a surface (hereinafter referred to as “outer surface”) 202 extending in the other axial direction.
The cover portion 20 is provided with a shaft hole 20 a corresponding to the shaft hole 11 a of the main body portion 10. The other end portion of the corresponding gear shaft 3a is inserted into and supported by the shaft hole 20a. That is, the circumferential end 21 of the cover 20 connects the radial position on the inner peripheral side with respect to the gear shaft 3a and the radial position on the outer peripheral side with respect to the gear shaft 3a.

  Moreover, the cover part 20 is fan-shaped similarly to the leg part 12, and the dimension (henceforth "the circumferential direction width") along the circumferential direction is from the circumferential direction width | variety of the outer peripheral surface part 11B between the leg parts 12. FIG. Is also formed widely by two peripheral surfaces 13b. Further, the radial width of the cover portion 20 is the same as the radial width of the leg portion 12.

In other words, the dimension between the circumferential edge portions 21 of the cover portion 20 is shortened from the outer periphery toward the inner periphery. The circumferential dimension between the axial surfaces 13a in the stepped portion 13 is also formed to be shorter from the outer periphery toward the inner periphery corresponding to the circumferential edge 21.
Furthermore, viewed in the axial direction, the two cover portions 20 and 20 'each circumferential edge 21, 21' of the opposite sides of the axis C ₁ is disposed on the straight line L _1. That is, two circumferential edges 21, 21 'are disposed on the same straight line L _1. In the present embodiment, the straight line _{L 1} passes through the axis _{C 1.} Therefore, there is a diameter of the body portion 10 on the straight line L _1.

As shown in FIG. 4, the cover portion 20 is formed by being punched from a rectangular or strip-shaped metal plate 9. For example, the cover portion 20 is punched from the plate material 9 by a fine blanking press.
A feed hole 9a is formed in the plate material 9 at a location other than the cover portion 20 to be punched for transfer (so-called longitudinal running) in the punching process. When the shaft hole 20a is also punched and molded, the shaft hole 20a can have the function of the feed hole 9a. That is, the feed hole 9a can be omitted. However, it is necessary to first punch the cover 20 after punching the shaft hole 20a.

Thus, since the cover part 20 is shape | molded by punching the board | plate material 9, the circumferential direction edge part 21 is shape | molded by the planar shape along an axial direction. Therefore, in the following description, the circumferential edge 21 is referred to as a circumferential end surface 21.
The carrier 1 is manufactured by attaching the cover part 20 to the main body part 10 by joining the circumferential end face 21 to the shaft surface 13 a of the step part 13.

[2. Carrier production]
Next, the manufacture of the carrier 1 will be described in detail.
First, positioning of the cover part 20 with respect to the main body part 10 will be described.
As shown in FIG. 1, the cover portion 20 is pushed into the stepped portion 13 of the leg portion 12 in the main body portion 10 from the outer periphery toward the inner periphery, and the cover portion 20 is pressed from the other axial direction to the other. Therefore, the circumferential end surface 21 of the cover part 20 and the axial surface 13a of the step part 13 are abutted, and the inner surface 201 of the cover part 20 in the vicinity of the circumferential end surface 21 and the peripheral surface 13b of the step part 13 are abutted. In this way, the cover part 20 is positioned with respect to the main body part 10.

Then, joining of the cover part 20 with respect to the main-body part 10 is demonstrated.
In a state where the cover portion 20 is positioned with respect to the main body portion 10, as shown in FIG. 3, the circumferential end surface 21 of the cover portion 20 and the shaft surface 13 a of the step portion 13 are abutted and in close contact with each other. That is, the circumferential end surface 21 and the axial surface 13a are joined in the same plane orthogonal to the axial direction.

Here, the circumferential end surface 21 and the shaft surface 13a are joined by welding from the other axial side (outer surface 202 side). For the welding used here, it is preferable to use electron beam welding or laser welding from the viewpoint of securing the joining depth (the dimension in the axial direction that melts during welding).
Further, the two circumferential end faces 21, 21 ′ are moved by moving an electron beam or a laser irradiated at the time of welding along a straight line L ₁ arranged with the axis C ₁ interposed therebetween. 21 'is welded in one step.

The surfaces 21 and 13a may be brazed. However, brazing is preferably performed together with welding because the bonding strength is lower than welding and the bonding strength can be reduced by tempering.
After the main body portion 10 and the cover portion 20 are joined, if the shaft holes 11a and 20a are not provided, the shaft holes 11a and 20a are formed. In this way, the carrier 1 is assembled.

[3. Action and effect]
Since the carrier 1 in the present embodiment is configured as described above, the following operations and effects can be obtained.
(1) The cover portion 20 that supports the other axial direction of the gear shaft 3a is located between the inner peripheral side and the outer peripheral side of the circumferential end surface 21 with respect to the main body portion 10 that supports one axial direction of the gear shaft 3a. Are joined. Therefore, the bonding strength of the cover part 20 to the main body part 10 can be increased. Therefore, the support rigidity of the planetary gear 3 assembled to the carrier 1 can be ensured.

For example, as compared with a structure in which the main body portion and the cover portion are joined only on the outer peripheral side or the inner peripheral side with respect to the gear shaft 3a, the inner peripheral side or the outer peripheral side not joined in this structure is joined in the present carrier 1. Therefore, the support rigidity of the planetary gear 3 can be increased.
Moreover, since the cover part 20 is divided | segmented into the circumferential direction in the carrier 1, compared with punching and shape | molding the annular plate like the surface part 11 of the main-body part 10, the magnitude | size (width | variety) of the board | plate material 9 is sufficient. Can be suppressed. In other words, the material yield can be suppressed. Therefore, material cost can be suppressed.

  (2) The dimension between the end faces 21 in the circumferential direction of the cover part 20 is shortened from the outer periphery toward the inner periphery (that is, formed in a fan shape), and correspondingly, the dimension between the shaft surfaces 13a in the step part 13 Is also shortened from the outer periphery toward the inner periphery. Therefore, the cover 20 can be easily and accurately positioned by simply pushing the cover 20 into the step 13 from the outer periphery toward the inner periphery.

(3) Since the two cover portions 20 and 20 'each circumferential end faces 21, 21' facing each other across the axis C ₁ is disposed on the straight line L _1, during welding along the straight line L ₁ By moving the irradiated electron beam or laser, the two circumferential end faces 21, 21 'can be welded in one step. Therefore, productivity can be improved and manufacturing cost can be reduced.

(4) Temporarily, when the main body is bent and formed by press working, it is necessary to provide a recess (so-called “relief”) in order to avoid stress concentration at the bent portion. However, there is a possibility that the strength or rigidity of the main body portion is lowered by the concave portion.
On the other hand, since the main body 10 of the carrier 1 is formed by forging, casting or sintering, it is possible to ensure strength or rigidity without providing a recess necessary for press working.

  (5) In the leg portion 12 of the main body portion 10, the circumferential end face 21 of the cover portion 20 is joined to the step portion 13 that is cut out according to the thickness of the cover portion 20, so the other axial direction of the leg portion 12 The surface (that is, the plane of the top of the leg portion 12) and the outer surface 202 of the cover portion 20 can be arranged on the same plane (so-called flush). Therefore, similarly to the outer surface 112 of the surface portion 11, a flat surface can be formed on the other axial direction of the carrier 1.

(6) By the way, in the structure in which two members such as the main body, the cover, and the two plates are joined by welding from the outer periphery of the carrier 1, there is a risk that spatter will be scattered to the inner periphery, particularly at the joint end. This spatter must be removed because it interferes with the planetary gear (so-called impurities). Therefore, there is a possibility that the work process increases and the manufacturing cost increases.
On the other hand, in the carrier 1, the circumferential end surface 21 of the cover portion 20 and the axial surface 13 a of the step portion 13 are welded from the other axial side. Therefore, the scattering of the sputter | spatter to the inner surface 111 of the outer peripheral surface part 11B can be suppressed, and manufacturing cost can be reduced.

[II. (Modification)
Although one embodiment has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Each structure of one Embodiment mentioned above can be selected as needed, and may be combined suitably.
The number of planetary gears 3 is not limited to four, but may be three or less, or may be five or more. In this case, as many leg portions 12 and cover portions 20 as the number of planet gears 3 are provided. For example, in the case where three planetary gears 3 are provided, if the circumferential end edges 21 are provided every 60 ° when viewed in the axial direction, the circumferential end faces 21 of the facing cover parts 20 are arranged on a straight line. Can do. With such an arrangement, even if an odd number of covers 20 is provided, the manufacturing cost can be reduced by improving the joining efficiency.
The end surface 21 in the circumferential direction of the cover portion 20 is not limited to the one along the axial direction, and may be formed in a shape that is inclined so as to face one side in the axial direction, as indicated by a two-dot chain line in FIG. In this case, the stepped portion 13 is formed into a shape that is inclined so as to face the other axial direction corresponding to the circumferential end surface 21.

Moreover, the cover part 20 is not restricted to the fan shape mentioned above, It can take various shapes. For example, as shown by a two-dot chain line in FIG. 2, even the cover portion 20 </ b> A having a circumferential end surface 21 </ b> A that forms a sector having a greater degree of reduction in the circumferential dimension from the outer periphery toward the inner periphery than the sector described above. On the contrary, a sector shape having a smaller degree of reduction in the circumferential dimension from the outer periphery toward the inner periphery than the sector shape described above may be used. Further, as shown by a three-dot chain line, the cover portion 20B may have a circumferential end surface 21B having a constant circumferential dimension between circumferential end edges regardless of the radial position. In these cases, it is preferable that the circumferential end surfaces 21, 21 </ b> A, 21 </ b> B of the facing cover portions 20, 20 </ b> A, 20 </ b> B are arranged on a straight line.
In addition, the main-body part 10 may be shape | molded not only by forging, casting, and sintering but by other manufacturing methods, such as press work.

DESCRIPTION OF SYMBOLS 1 Carrier 2 Sun gear 3 Planetary gear 3a Gear shaft 4 Ring gear 10 Main body part 11 Face part 111 Inner face 112 Outer face 11A Inner peripheral face part 11B Outer peripheral face part 11a Shaft hole 12 Leg part 13 Step part 13a Shaft face 13b Perimeter face 20 Cover part 20a Shaft hole 201 Inner surface 202 Outer surface 21 Circumferential end surface (circumferential end edge)
9 plate 9a feed holes r ₁ radial position L ₁ straight outer peripheral side of the radial position r ₂ gear shaft 3a of the inner circumferential side of the gear shaft 3a

Claims (6)

A carrier for supporting the gear shaft of the planetary gear in the planetary gear mechanism,
A main body portion supporting one axial direction of the gear shaft, and supporting the other axial direction of the gear shaft, and a radial position on the inner peripheral side with respect to the gear shaft and a radial position on the outer peripheral side with respect to the gear shaft. A cover portion in which a circumferential edge portion to be joined is joined to the main body portion;
A carrier characterized by comprising. The cover part is formed with a short dimension between the circumferential edge portions as it goes from the outer periphery to the inner periphery,
The carrier according to claim 1, wherein the circumferential edge and the main body are joined in the same plane orthogonal to the axial direction. A plurality of the cover portions are provided at intervals in the circumferential direction,
3. The carrier according to claim 1, wherein the circumferential edge portions of the facing cover portions are arranged on a straight line when viewed in the axial direction. The carrier according to claim 1, wherein the main body is formed by forging, casting, or sintering. Legs are erected on both sides of the planetary gear in the main body,
On the other side in the axial direction of the leg part, a stepped part is formed according to the thickness of the cover part,
The carrier according to any one of claims 1 to 4, wherein the circumferential edge of the cover is joined to the stepped portion. The carrier according to any one of claims 1 to 5, wherein the edge portion in the circumferential direction of the cover portion is welded to the main body portion from the other side in the axial direction.

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