JP2008089078A - Pinion shaft and automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pinion shaft and an automatic transmission with improved durability. <P>SOLUTION: Second delivery ports 4h and 4k confronting washers 4g, 4g arranged between carriers 4d 4d and a needle bearing 10, and an oil supply passage 4f for supplying lubricating oil supplied from the outside to the second delivery ports 4h and 4k are provided, and a suitable amount of the lubricant can be supplied from the second delivery ports 4h and 4k to the washers 4g 4g by supplying the lubricating oil from the outside through the oil supply passage 4f, and thereby, early abrasion of the washers 4g, the pinion shaft 4e and the carriers 4d, 4d can be reduced, and malfunction such as seizure or the like can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pinion shaft suitable for use in, for example, a planetary gear mechanism for an automatic transmission, a continuously variable transmission, and the like, and an automatic transmission using the pinion shaft.

For example, in an automatic transmission mounted on a vehicle or the like, a planetary gear mechanism is generally used. Here, since the radial needle bearing uses small-diameter rollers, it can fit in a space where the difference between the inner ring outer diameter and the outer ring inner diameter is small, so that the planetary gear of the planetary gear mechanism can be supported rotatably. This is preferable because it contributes to the compactness of an automatic transmission equipped with the automatic transmission (see Patent Document 1).
JP 2005-256857 A

  Here, in the planetary gear mechanism, the planetary gear is rotatably supported by a radial needle bearing with respect to the pinion shaft. However, planetary gears of planetary gear mechanisms often use helical gears to improve transmission efficiency, but due to their characteristics, thrust force is generated during power transmission. When such a thrust force is generated, the planetary gear is pressed toward the carrier, and the end face of the planetary gear and the carrier slide with each other. Therefore, a washer is generally inserted between the planetary gear and the carrier. However, in recent years, with the improvement in performance, the number of rotations and transmission torque of gears have increased, so the thrust force and the sliding speed have increased, and there is a risk of premature wear and seizure of carriers, washers, and planetary gears. There is.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a pinion shaft and an automatic transmission with improved durability.

The pinion shaft of the present invention is a pinion shaft that is attached to a carrier of a planetary gear mechanism and supports a rolling bearing.
A discharge port facing a washer disposed between the carrier and the rolling bearing, and an oil supply passage for supplying lubricant supplied from the outside to the discharge port are provided.

  According to the present invention, since the discharge port facing the washer disposed between the carrier and the rolling bearing and the oil supply passage for feeding the lubricant supplied from the outside to the discharge port are provided. By supplying the lubricant from the outside through the oil supply passage, an appropriate amount of lubricant can be supplied from the discharge port to the washer, thereby reducing the early wear of the washer, pinion shaft and carrier, baking, etc. Can be prevented in advance. In addition, when the oil supply passage is shared with a lubricant supply passage for lubricating the rolling bearing, the lubricant is discharged toward the rolling bearing with a cross-sectional area of the discharge port in order to achieve a lubrication balance. It is desirable to make it smaller than the cross-sectional area of the opening.

  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 planetary gear mechanism 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. The gear 4c is rotatably supported, and has a carrier 4d that can also rotate.

  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 to the drive side, the planetary gear 4c (carrier) to 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 set to the driven side, and the ring gear 4a is set to the drive side. A ratio is obtained. Further, in the case of the third speed, as shown in FIG. 3 (c), the sun gear 4b is fixed, the planetary gear 4c (carrier) is set to the drive side, and the ring gear 4a is set to the driven side, thereby obtaining a small reduction ratio. It is done. 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 output is output with respect to the input. Can be reversed. 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 view showing a state in which a needle bearing is incorporated in the planetary gear mechanism including the pinion shaft of the present embodiment. As shown in FIG. 4, the needle bearing 10 which is a rolling bearing is disposed between a pinion shaft (inner ring) 4e and a planetary gear (outer ring) 4c, and rotatably supports the planetary gear 4c with respect to the pinion shaft 4e. is doing. The needle bearing 10 includes a plurality of rollers 11 and a cage 12 that holds them. Between the carriers 4d and 4d supporting both ends of the pinion shaft 4e and the retainer 12, doughnut-shaped washers 4g and 4g are arranged. As the planetary gear 4c rotates, the washers 4g and 4g slide with respect to the cage 12 and the carriers 4d and 4d. The cage 12 is used for outer ring guidance.

  In the pinion shaft 4e, an oil supply passage 4f extending in a bag hole shape along the axis from the right side in FIG. 4, and extending radially from the oil supply passage 4f and opening toward the center of the roller 11 respectively. A first discharge port 4i and second discharge ports 4h and 4k extending in the radial direction from the oil supply passage 4f and opening toward the inner diameter surfaces of the washers 4g and 4g are formed. The inner diameter B of the first discharge port 4i is larger than the inner diameters A and C of the second discharge ports 4h and 4k (B> A, B> C). The open end of the oil supply passage 4f is connected to a lubricating oil piping system (not shown) so that the lubricating oil is supplied from the outside.

  According to the present embodiment, the second discharge ports 4h and 4k opposed to the washers 4g and 4g disposed between the carriers 4d and 4d and the needle bearing 10 and the lubricating oil supplied from the outside are discharged to the second discharge port. Since the oil supply passage 4f for feeding to the outlets 4h and 4k is provided, an appropriate amount of oil is supplied from the second discharge ports 4h and 4k to the washers 4g and 4g by supplying lubricating oil from the outside through the oil supply passage 4f. Lubricating oil can be supplied, whereby the sliding portions of the washers 4g and 4g, the pinion shaft 4e, and the carriers 4d and 4d can be lubricated to reduce early wear and prevent problems such as seizing. Further, since the inner diameter B of the first discharge port 4i is larger than the inner diameters A and C of the second discharge ports 4h and 4k, the amount of lubricating oil on the raceway surface of the roller 12 with more severe lubrication conditions is not reduced. Thus, a good lubrication balance can be ensured.

  Here, the inner diameters of the second discharge ports 4h and 4k are equal (A = C), but the inner diameter A of the second discharge port 4h on the back side is larger than the inner diameter C of the second discharge port 4k on the inlet side. You may enlarge (A> C). Accordingly, it is possible to achieve a lubricant supply balance between the second discharge ports 4h and 4k.

  FIG. 5 is a view showing a state in which a needle bearing is incorporated in a planetary gear mechanism including a pinion shaft according to the second embodiment. In the present embodiment, the pinion shaft 4e extends in a bag hole shape in parallel with the first oil supply passage 4f extending in the bag hole shape along the axis from the right in FIG. The second oil supply passage 4f ′ is formed. The second discharge ports 4h and 4k extend in the radial direction from the second oil supply passage 4f 'and open toward the inner diameter surfaces of the washers 4g and 4g. The open ends of the oil supply passages 4f and 4f 'are connected to a lubricating oil piping system (not shown) so that the lubricating oil is supplied from the outside.

  In the above-described embodiment, the lubrication supplied to the needle bearing 10 and the washers 4g and 4g is performed using the lubricating oil supplied via the common oil supply path 4f. In this form, the washers 4g and 4g are refueled via an independent oil supply path 4f '. According to the present embodiment, the amount of oil supplied to the needle bearing 10 and the amount of oil supplied to the washers 4g and 4g can be adjusted independently. For example, by making the inner diameter of the oil supply passage 4f larger than the inner diameter of the oil supply passage 4f ′, a large amount of lubricating oil is supplied to the needle bearing 10 and a small amount of lubricating oil is supplied to the washers 4g and 4g. The balance can be optimized.

  The present invention has been described above with reference to the embodiments. However, the present invention is not limited to the above-described embodiments, and can of course be changed or improved within the scope of the invention. For example, the needle bearing can be applied not only to a transmission for an automobile but also to various machines such as a car cooler compressor.

It is sectional drawing of the automatic transmission of the vehicle containing the planetary gear mechanism concerning this Embodiment. 4 is an exploded view of the planetary gear mechanism 4. FIG. It is a figure which shows the operating principle of a planetary gear mechanism. It is a figure shown in the state which incorporated the needle bearing in the planetary gear mechanism containing the pinion shaft of this Embodiment. It is a figure shown in the state which incorporated the needle bearing in the planetary gear mechanism containing the pinion shaft of another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic transmission 4-6 Planetary gear mechanism 4f Pinion shaft 10 Needle roller bearing 11 Roller 12 Cage

Claims (2)

In the pinion shaft attached to the carrier of the planetary gear mechanism and supporting the rolling bearing,
A pinion shaft comprising: a discharge port facing a washer disposed between the carrier and the rolling bearing; and an oil supply passage for supplying lubricant supplied from the outside to the discharge port.   An automatic transmission comprising a planetary gear mechanism including the pinion shaft according to claim 1.

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