JP2005147285A - Planetary gearing mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planetary gearing mechanism which can appropriately fix a pinion shaft onto a carrier without any labor. <P>SOLUTION: The planetary gearing mechanism is configured so that a pinion shaft 4e is fixed onto a carrier 4d by caulking an edge part of a hole 4g after the pinion shaft 4e is inserted into the hole 4g of the carrier 4d. This does not require any large force in a caulking C and also does not any large-scale manufacturing facility. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a planetary gear mechanism, and more particularly to a planetary gear mechanism that is easy to manufacture.

In an automatic transmission mounted on a vehicle or the like, a planetary gear mechanism is generally used (see Patent Document 1). In such a planetary gear mechanism, the planetary gear is rotatably supported by a radial needle bearing with respect to a pinion shaft implanted in the carrier.
JP 2002-349647 A

  Here, it is necessary to fix the pinion shaft appropriately so that it does not come out of the carrier. One fixing method is to plastically deform the end of the pinion shaft that has been inserted into the hole of the carrier with a tool so that the end expands, thereby fixing it to the hole of the carrier. There is. However, in recent years, there is a demand for common parts from the viewpoint of cost reduction, and there is a tendency to install the same automatic transmission on a vehicle that outputs different torque. Therefore, the planetary gear mechanism used in the automatic transmission needs to be able to transmit a larger torque, and therefore a bearing having a longer life is required. This is no exception for the pinion shaft, and for the purpose of extending the life, ordinary carbon tool steel is not subjected to high-frequency heat treatment, but bearing steel is treated as a special heat treatment to cope with a longer life.

  However, since the above-mentioned special heat treatment includes a complete quenching and tempering treatment, the pinion shaft cannot be fixed to the carrier because of high hardness. Therefore, when using a pinion shaft that has been subjected to special heat treatment, the end of the pinion shaft is usually pinned to the carrier. However, in the method of pinning the end of the pinion shaft to the carrier, the number of parts is increased, and processing for inserting the pin through the pinion shaft and the carrier must be performed in advance. There is a problem that increases.

In Patent Document 2 below, a technique for deforming the carrier and fixing the pinion shaft is described. However, since a portion of the carrier away from the pinion shaft is hit, a large force is required to give plastic deformation. Therefore, there is a problem that a large-scale manufacturing facility is required.
JP 2002-195358 A

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a planetary gear mechanism that can appropriately fix a pinion shaft to a carrier without taking time and effort.

The planetary gear mechanism of the present invention is
A carrier,
A pinion shaft implanted in the carrier;
Planetary gears arranged around the pinion shaft;
A bearing that rotatably supports the planetary gear with respect to the pinion shaft;
After the pinion shaft is inserted into the hole of the carrier, the pinion shaft is fixed to the carrier by caulking the edge of the hole.

  According to the planetary gear mechanism of the present invention, the pinion shaft is fixed to the carrier by caulking the edge of the hole after the pinion shaft is inserted into the hole of the carrier. Power is not required, and large manufacturing facilities are not required.

  It is preferable that the pinion shaft has a rotationally asymmetric portion because it can prevent rotation of the pinion shaft during use. In this case, a rotationally asymmetric part corresponding to the carrier may be provided, and the rotationally asymmetric part of the pinion shaft may be engaged therewith, and the edge of the carrier is caulked to the rotationally asymmetric part of the pinion shaft. Even so, the rotation of the pinion shaft is prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an automatic transmission 1 for a vehicle including a needle bearing according to the present embodiment. In FIG. 1, torque output from the crankshaft 2 of the engine is transmitted through a torque converter 3 and further decelerated to a plurality of stages through a plurality of planetary gear mechanisms 4, 5, 6, etc. The power is output to a wheel (not shown) via the differential gear 7 and the drive shaft 8.

  FIG. 2 is an exploded view of the planetary gear mechanism 4 (5 and 6 are basically the same). In FIG. 2, the planetary gear mechanism 4 includes a ring gear 4a having internal teeth, a sun gear 4b having external teeth, three planetary gears 4c meshing with the ring gear 4a and the sun gear 4b, and three pinion shafts 4e. And a carrier 4d that can also rotate itself.

  The operating principle of the planetary gear mechanism 4 is shown in FIG. First, in the case of the first speed, as shown in FIG. 3A, a large reduction ratio can be obtained by setting the sun gear 4b on the drive side, the planetary gear 4c (carrier) on the driven side, and fixing the ring gear 4a. Next, in the case of the second speed, as shown in FIG. 3 (b), the sun gear 4b is fixed, the planetary gear 4c (carrier) is driven, and the ring gear 4a is driven. Is obtained. Further, in the case of the third speed, as shown in FIG. 3 (c), a small reduction ratio can be obtained by fixing the sun gear 4b, the planetary gear 4c (carrier) on the drive side, and the ring gear 4a on the driven side. . In the case of reverse, as shown in FIG. 3 (d), the sun gear 4b is driven, the planetary gear 4c (carrier) is fixed, and the ring gear 4a is driven, so that the output is reversed with respect to the input. Can be made. In addition, the above shows an example of the operation of the planetary gear mechanism 4, and the operation is not necessarily limited to this operation.

  FIG. 4 is a diagram showing the needle bearing incorporated in the planetary gear mechanism of the present embodiment. FIG. 5 is a diagram showing the periphery of the end of the pinion shaft 4e in the present embodiment. As shown in FIG. 4, both ends of the pinion shaft 4e are inserted into the holes 4g of the carrier 4d facing each other. In this state, the edge of the hole 4g of the carrier 4d is plastically deformed by hitting the entire circumference in the axial direction, thereby forming a crimp C for fixing the end of the pinion shaft 4e.

  The radial needle bearing 10 is a so-called full-roller type bearing without a cage, and is disposed between a pinion shaft (inner ring) 4e and a planetary gear (outer ring) 4c, and rotatably supports the planetary gear 4c. It consists of the rollers 11 and 11 of a row | line | column, and the spacer 12 arrange | positioned between the row | line | columns of the rollers 11 and 11. FIG. A sliding bearing 4h is inserted between the bearing 10 and the carrier 4d. In the pinion shaft 4e, it is preferable that an oil passage extending from the end portion thereof along the axis and extending to the outer peripheral surface of the pinion shaft 4e at a position facing the spacer 12 is formed.

  According to the present embodiment, the pinion shaft 4e is fixed to the carrier 4d by caulking (C) the edge of the hole 4g over the entire circumference, thereby improving manufacturability.

  FIG. 6 is a view similar to FIG. 4 showing the planetary gear mechanism according to the second embodiment. FIG. 7 is a view showing the periphery of the end of the pinion shaft 4e in the second embodiment. In the present embodiment, the caulking C is formed by inserting the end of the pinion shaft 4e into the hole 4g of the carrier 4d and then hitting the edge of the hole 4g in the axial direction at intervals of 90 degrees. Thus, the caulking C may not be the entire circumference of the hole 4g. Since other configurations are the same as those of the above-described embodiment, the same reference numerals are given and description thereof is omitted.

  FIG. 8 is a view similar to FIG. 4 showing the planetary gear mechanism according to the third embodiment. FIG. 9 is a diagram showing an end portion of the pinion shaft 104e in the third embodiment. In the case of the embodiment shown in FIGS. 4 to 7, the inner peripheral surface of the hole 4g of the carrier 4d and the outer peripheral surface of the pinion shaft 4e are cylindrical surfaces. The amount of plastic deformation must be increased.

  On the other hand, in the present embodiment, the pinion shaft 104e has a stepped portion 114e as a rotationally asymmetric portion on the outer periphery of the right end portion in the drawing. The step 114e is formed of a plane perpendicular to the axis of the pinion shaft 104e and a plane parallel to the axis. Therefore, the end of the pinion shaft 104e is rotationally asymmetric when the axis is the rotation axis. It has a shape (D shape when viewed from the axial direction). After such an end of the pinion shaft 104e is inserted into the hole 4g of the carrier 4d, the edge of the hole 4g is caulked (C) over the entire circumference. In this case, since the stepped portion 114e is formed, the rotation of the pinion shaft 104e with respect to the carrier 4d can also be realized. Since other configurations are the same as those of the above-described embodiment, the same reference numerals are given and description thereof is omitted.

  FIG. 10 is a view similar to FIG. 4 showing the planetary gear mechanism according to the fourth embodiment. FIG. 11 is a diagram illustrating an end portion of the pinion shaft 104e 'in the fourth embodiment. The present embodiment is different only in that two step portions 114e as rotationally asymmetric portions are formed in parallel to each other at the end of the pinion shaft 104e '. Since other configurations are the same as those of the above-described embodiment, the same reference numerals are given and description thereof is omitted.

  The present invention has been described with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. The rollers are not limited to double rows but may be single rows.

It is sectional drawing of the automatic transmission 1 of the vehicle containing the needle bearing concerning this Embodiment. 4 is an exploded view of the planetary gear mechanism 4. FIG. FIG. 3 is a diagram illustrating an operation principle of the planetary gear mechanism 4. It is a figure which shows the planetary gear mechanism concerning 1st Embodiment. It is a figure which shows the edge part periphery of the pinion shaft 4e in 1st Embodiment. It is a figure which shows the planetary gear mechanism concerning 2nd Embodiment. It is a figure which shows the edge part periphery of the pinion shaft 4e in 2nd Embodiment. It is a figure which shows the planetary gear mechanism concerning 3rd Embodiment. It is a figure which shows the edge part of the pinion shaft 104e in 3rd Embodiment. It is a figure which shows the planetary gear mechanism concerning 4th Embodiment. It is a figure which shows the edge part of pinion shaft 104e 'in 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic transmission 4 Planetary gear mechanism 4c Planetary gear 4d, 104d Carrier 4e, 104e, 104e 'Pinion shaft 10 Radial needle bearing

Claims (2)

A carrier,
A pinion shaft implanted in the carrier;
Planetary gears arranged around the pinion shaft;
A bearing that rotatably supports the planetary gear with respect to the pinion shaft;
After the pinion shaft is inserted into the hole of the carrier, the pinion shaft is fixed to the carrier by crimping the edge of the hole. The planetary gear mechanism according to claim 1, wherein the pinion shaft has a rotationally asymmetric portion.

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