JP2004108451A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a lubrication pathway excellent in oil supply efficiency in a planetary shaft of a power transmission device at low cost. <P>SOLUTION: In the power transmission device provided with a fixed wheel 1, a sun shaft 2, a plurality of planetary rolling elements 3, planetary shafts 4 of same numbers as the planetary rolling elements 3, a needle roller bearing 5, and a carrier 6, each planetary shaft 4 is composed of a hollow metal shaft, an oil introduction hole 12 passing through each planetary shaft 4 in a radial direction is provided in an area supported by the carrier 6, an oil supply hole 13 passing through each planetary shaft 4 in a radial direction is provided in an area to be a raceway surface of the needle roller bearing 5, and the oil introduction hole 12 and the oil supply hole 13 are connected by a flexible tube 14. Since the planetary shaft 4 has a through hole instead of a bottomed hole, chip will not remain in the planetary shaft 4. Lubrication oil can be quickly supplied from the oil introduction hole 12 to the oil supply hole 13 via the flexible tube 14. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power transmission device using a planetary rolling element as a gear or a roller.
[0002]
[Prior art]
In a conventional planetary gear type power transmission device, a lubricating path for supplying lubricating oil to a needle roller bearing interposed between the planetary gear and the planetary shaft is provided on the planetary shaft ( Patent Document 1). The lubricating oil is introduced from a portion of the planetary shaft that is attached to the carrier.
[0003]
In this case, the lubrication path has a bottomed hole formed at the center of the solid planetary shaft, an oil introduction hole formed radially through a region supported by the carrier on the planetary shaft, and It is formed by an oil supply passage formed in a radial direction in a region serving as a raceway surface of the needle roller bearing. These bottomed holes, oil introduction holes, and oil supply holes are formed by drilling, and plugs are attached to the openings of the bottomed holes.
[0004]
[Patent Document 1]
JP-A-9-303495 [0005]
[Problems to be solved by the invention]
In the above-described conventional example, a solid planetary shaft is drilled in order to provide a lubrication path for the planetary shaft, but chips generated by the drilling are provided at the center of the planetary shaft. It tends to remain in the holes and requires post-processing to remove the chips and the like, leading to an increase in manufacturing costs.
[0006]
[Means for Solving the Problems]
On the other hand, the applicant of the present application is studying earnestly that a hollow shaft made of metal is used as a planet shaft, and plugs are attached to openings at both axial ends of the center hole. In addition, an oil supply hole penetrating in the radial direction is provided in a region supported by the carrier on the planetary shaft, and an oil supply passage penetrating in the radial direction is provided in a region serving as the raceway surface of the roller bearing on the planetary shaft. I have. In this case, if the lubricating oil does not accumulate in the entire area of the center hole closed by the plug on the planetary shaft, the lubricating oil cannot flow from the oil introduction hole to the oil supply hole, and the lubricating oil supply efficiency is poor. Here, there is room for further improvement, and the present invention has been proposed.
[0007]
The present invention relates to a fixed wheel, a sun shaft inserted concentrically around the inner periphery of the fixed wheel, a plurality of planetary rolling elements interposed between the sun axis and the fixed wheel, and each planetary rolling element. Each having a planetary shaft inserted through a radial type roller bearing, and a carrier for supporting each of the planetary shafts, wherein each of the planetary shafts is formed of a hollow metal shaft, and each of the planetary shafts An oil supply hole penetrating in the radial direction is provided in a region supported by the oil introduction hole, and an oil supply hole penetrating in the radial direction is provided in a region serving as a raceway surface of the roller bearing in each of the planetary shafts. The hole and the oil supply hole are communicatively connected by a flexible tube.
[0008]
In this case, since the planetary shaft is a hollow shaft made of metal, it is advantageous in reducing the manufacturing cost. In addition, since the oil introduction hole and the oil supply hole are directly connected to each other by the flexible tube, the lubricating oil introduced from the oil introduction hole can easily reach the oil supply hole quickly.
[0009]
The present invention relates to a fixed wheel, a sun shaft inserted concentrically around the inner periphery of the fixed wheel, a plurality of planetary rolling elements interposed between the sun axis and the fixed wheel, and each planetary rolling element. Each having a planetary shaft inserted through a radial type roller bearing, and a carrier for supporting each of the planetary shafts, wherein each of the planetary shafts is formed of a hollow metal shaft, and each of the planetary shafts An oil supply hole penetrating in a radial direction is provided in a region supported and supported, and an oil supply hole penetrating in a radial direction is provided in a region serving as a raceway surface of a roller bearing in each of the planetary shafts. In the center hole of the shaft, plugs are respectively attached to a position near the oil introduction hole outside the oil introduction hole and a position near the oil supply hole outside the oil supply hole. The inside of the center hole is a closed space.
[0010]
In this case, since the range from the oil introduction hole to the oil supply hole in the center hole of each planet shaft is a sealed space, the sealed space is reduced to the minimum necessary, and the lubricating oil introduced from the oil introduction hole is supplied to the oil supply hole. It is easier to reach the holes quickly.
[0011]
The two stoppers may be fixed to both ends of a shaft having a smaller diameter than the center hole of each planet shaft. In this case, the number of parts and the number of assembly steps are reduced. Moreover, the volume of the sealed space secured in the center hole of each planet shaft can be reduced as much as possible by the presence of the shaft body to which the two stoppers are fixed. More quickly.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
1 and 2 show an embodiment of the present invention. In this embodiment, a well-known planetary gear type is exemplified as a power transmission device. In the figure, 1 is a fixed wheel, 2 is a sun wheel, 3 is a plurality of planetary gears, 4 is a plurality of planetary shafts, 5 is a needle roller bearing, and 6 is a carrier.
[0013]
The fixed wheel 1 is attached to a case (not shown) in a non-rotating state, and has a helical gear formed on an inner peripheral surface.
[0014]
The sun wheel 2 has a spline formed on its inner peripheral surface and a helical gear formed on its outer peripheral surface, and the first rotating shaft 7 is spline-fitted to this inner peripheral surface.
[0015]
The planetary gear 3 has a circular inner peripheral surface and a helical gear formed on the outer peripheral surface. Each of the planetary gears 3 is meshed with the fixed wheel 1 and the sun wheel 2.
[0016]
The planetary shaft 4 is inserted into the inner peripheral surface of the planetary gear 3 via a needle roller bearing 5.
[0017]
The needle roller bearing 5 is what is called a cage and roller, and includes a needle roller and a retainer. The needle roller bearing 5 uses the planetary gear 3 as an outer ring and the planetary shaft 4 as an inner ring.
[0018]
The carrier 6 has a shape in which several circumferential portions on the outer diameter side of two opposed annular plates 8 and 9 are connected by a bridge wall 10. Through holes 8a and 9a are respectively provided at several (three) circumferential positions corresponding to the first and second annular plates 8 and 9 of the carrier 6, and the through holes 8a of the first annular plate 8 are formed in the through holes 8a. On the other hand, one end of the planetary shaft 4 and the other end of the planetary shaft 4 are fitted into the through-hole 9a of the second annular plate 9, respectively. Although not shown, the planetary shaft 4 may be axially positioned and detented with respect to the carrier 6 using a stopper pin or the like. A spline is formed in the center hole of the first annular plate 8 of the carrier 6, and the second rotating shaft 11 is spline-fitted to the center hole.
[0019]
Next, the operation will be described. First, when the first rotating shaft 7 is driven, the sun shaft 2 rotates integrally, so that the planetary gear 3 rotates and revolves, and the carrier 6 and the second rotating shaft 11 are driven by the revolving. At this time, the rotational power of the first rotating shaft 7 is reduced and transmitted to the second rotating shaft 11.
[0020]
On the other hand, when driving the second rotating shaft 11, the carrier 6 rotates integrally, so that the planetary gear 3 rotates and revolves, and the sun wheel 2 and the first rotating shaft 7 are driven by the revolving. At this time, the rotational power of the second rotating shaft 11 is increased and transmitted to the first rotating shaft 7.
[0021]
In this embodiment, a lubricating path for supplying lubricating oil to the needle roller bearings 5 is provided in the planetary shaft 4, and thus will be described in detail.
[0022]
Each of the planetary shafts 4 is a hollow shaft made of metal. As the material of the planet shaft 4, for example, a chrome molybdenum steel (JIS G 4105) hardened (carburized and tempered) or a high carbon chromium bearing steel (JIS G 4805) is hardened (sub quenched). , Tempered). An oil introduction hole 12 penetrating in the radial direction is provided in a region of each of the planet shafts 4 supported by the second annular plate 9 of the carrier 6, and a track surface of the needle roller bearing 5 in each of the planet shafts 4. Are provided with oil supply holes 13 penetrating in the radial direction.
[0023]
Both ends of the flexible tube 14 are attached to the oil introduction hole 12 and the oil supply hole 13, and the oil introduction hole 12 and the oil supply hole 13 are directly connected to each other by the flexible tube 14. The flexible tube 14 is disposed in the center hole of each planet shaft 4, and is formed of a flexible material such as rubber or synthetic resin.
[0024]
The second annular plate 9 of the carrier 6 is provided with three oil introduction passages 15 penetrating radially from the inner peripheral surface of the three through holes 9 a toward the center hole of the second annular plate 9. Have been. The oil introduction passages 15 communicate with the oil introduction holes 12 of the three planetary shafts 4. The first rotary shaft 7 is provided with an oil passage 7a, and the lubricating oil supplied from the oil passage 7a is supplied to the oil introduction passage 15 of the carrier 6. .
[0025]
Thus, a lubrication path is formed by the oil introduction hole 12, the oil supply hole 13, and the flexible tube 14.
[0026]
Next, the operation of supplying the lubricating oil to the needle roller bearing 5 will be described. That is, lubricating oil is supplied from an oil passage 7 a provided in the first rotating shaft 7, and the lubricating oil is introduced into the oil introduction hole 12 through the oil introduction passage 15 of the carrier 6 by a rotational centrifugal force or the like. The lubricating oil that has entered the oil introduction hole 12 is supplied to the needle roller bearing 5 between the planetary gear 3 and the planetary shaft 4 from the oil supply hole 13 through the flexible tube 14.
[0027]
In the embodiment described above, since the hollow shaft made of metal is used as the planetary shaft 4, it is advantageous in reducing the manufacturing cost. Moreover, since the oil introduction hole 12 and the oil supply hole 13 are directly connected to each other by the flexible tube 14, the lubricating oil introduced from the oil introduction hole 12 can easily reach the oil supply hole 13 quickly. Become. Therefore, even when the amount of lubricating oil introduced into oil introduction hole 12 is small, lubricating oil can be stably supplied to the arrangement portion of needle roller bearing 5.
[0028]
Note that the present invention is not limited to only the above-described embodiment, and various applications and modifications are conceivable.
[0029]
(1) FIGS. 3 and 4 show another embodiment of the present invention. In this embodiment, a lubrication path is created by attaching a stopper plug member 20 to the center hole of the planetary shaft 4 instead of the flexible tube 14. More specifically, the stopper member 20 has a shape in which large-diameter portions 22 and 23 are provided at both ends in the axial direction of a round shaft portion 21 and is made of, for example, a synthetic resin. The diameter of the shaft portion 21 of the stopper member 20 is set smaller than the inner diameter of the center hole of the planetary shaft 4, but the outer diameters of the large diameter portions 22 and 23 are larger than the inner diameter of the center hole of the planetary shaft 4. Is also set slightly larger. The interval between the inner ends of the large-diameter portions 22 and 23 at both ends of the stopper member 20 is the same as the length from the outer position of the oil introduction hole 12 to the outer position of the oil supply hole 13 of the planetary shaft 4. Is set to That is, when this stopper plug member 20 is inserted into the center hole of the planetary shaft 4, one large-diameter portion 22 is press-fitted to a position close to the outside of the oil supply hole 13 of the planetary shaft 4, The other large-diameter portion 23 is press-fitted to a position near the outside of the oil introduction hole 12 of the planetary shaft 4. When the stopper member 20 is attached to the center hole of the planetary shaft 4 in this manner, the large-diameter portions 22 and 23 at both ends thereof become walls, and a closed space 25 is created in the center hole of the planetary shaft 4. . The volume of the sealed space 25 is made as small as possible due to the presence of the shaft portion 21 of the stopper member 20, and the axial length of the sealed space 25 is not limited to a region over the entire length of the center hole of the planetary shaft 4. In addition, since the length is set from the oil introduction hole 12 to the oil supply hole 13, the size is minimum. As a result, the lubricating oil introduced from the oil introduction hole 12 easily reaches the oil supply hole 13 quickly. Therefore, even when the amount of the lubricating oil introduced into the oil introduction hole 12 is small, the lubricating oil can be stably supplied to the arrangement portion of the needle roller bearing 5.
[0030]
(2) In each of the above embodiments, the oil introduction hole 12 and the oil supply hole 13 of the planetary shaft 4 may not be formed in the radial direction but may be formed obliquely with respect to the rotation axis of the planetary shaft 4. Good. In this case, the oil introduction hole 12 and the oil supply hole 13 can be formed by one drilling.
[0031]
(3) In the above embodiments, the carrier 6 may be formed integrally with the second rotating shaft 11. In addition, in the above embodiment, the planetary gear type power transmission device has been described as an example, but a planetary roller type power transmission device can be used.
[0032]
【The invention's effect】
According to the present invention, compared to the conventional example, the manufacturing cost of the planetary shaft can be reduced, and lubricating oil can be quickly sent from the oil introduction hole provided in the planetary shaft to the oil supply hole. Lubrication path can be secured. Therefore, according to the present invention, a highly reliable power transmission device having excellent operation stability can be provided.
[Brief description of the drawings]
FIG. 1 is a sectional view of an upper half of a planetary gear type power transmission device according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line (2)-(2) of FIG. FIG. 4 is a sectional view of an upper half of a planetary gear type power transmission device according to another embodiment of the present invention. FIG. 4 is a perspective view showing a stopper member shown in FIG.
DESCRIPTION OF SYMBOLS 1 Fixed wheel 2 Sun shaft 3 Planetary gear 4 Planetary shaft 5 Needle roller bearing 6 Carrier 12 Planetary shaft oil introduction hole 13 Planetary shaft oil supply hole 14 Flexible tube 15 Carrier oil introduction passage

Claims (3)

A fixed wheel, a sun shaft inserted concentrically around the inner periphery of the fixed wheel, a plurality of planetary rolling elements interposed between the sun shaft and the fixed wheel, and a radial type for each planetary rolling element. A planetary shaft that is inserted through a roller bearing, and a carrier that supports each planetary shaft,
Each of the planetary shafts is formed of a metal hollow shaft, and an oil introduction hole penetrating in a radial direction in a region supported by the carrier in each of the planetary shafts, and a raceway surface of a roller bearing in each of the planetary shafts. Oil supply holes penetrating in the radial direction are provided in the area
A power transmission device, wherein the oil introduction hole and the oil supply hole are communicatively connected by a flexible tube. A fixed wheel, a sun shaft inserted concentrically around the inner periphery of the fixed wheel, a plurality of planetary rolling elements interposed between the sun shaft and the fixed wheel, and a radial type for each planetary rolling element. A planetary shaft that is inserted through a roller bearing, and a carrier that supports each planetary shaft,
Each of the planetary shafts is formed of a metal hollow shaft, and an oil introduction hole penetrating in a radial direction in a region supported by the carrier in each of the planetary shafts, and a raceway surface of a roller bearing in each of the planetary shafts. Oil supply holes penetrating in the radial direction are provided in the area
In the center hole of each of the planetary shafts, a plug is attached to a position near the oil introduction hole outside the oil introduction hole and a position near the oil supply hole outside the oil supply hole. A power transmission device wherein the inside of the center hole is a closed space. The power transmission device according to claim 2, wherein the two stoppers are fixed to both ends of a shaft having a smaller diameter than a center hole of each of the planetary shafts. 4.

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