JP2020190314A - Transmission - Google Patents

Abstract

To provide a transmission which reduces the generation of abrasion powder with a comparatively small amount of lubrication oil, and which can suppress deterioration of the lubrication oil by the abrasion powder.SOLUTION: In a transmission 10, a carrier 28 of a planetary gear mechanism 20 includes an annular cover 32 in which an outer diameter side is closed and an inner diameter side is open, a housing 12 includes a rib 18 extending toward the inside, and a lubrication oil attached to a surface moves on the rib 18 and flows from an opening part of the cover 32 in-between the cover 32 and the carrier 28, and at a pinion shaft 27 of a pinion gear 26, an oil supply passage 25 for communicating between the opening part and the pinion gear 26 is provided. The scraped lubrication oil is collected at the rib 18, flows in-between the cover 32 and the carrier 28, and flows in-between the pinion shaft 27 and the pinion gear 26 through the oil supply passage 25. Therefore, lubrication efficiency can be enhanced, and with a relatively small amount of lubrication oil, generation of abrasion powder is reduced and deterioration of the lubrication oil due to the abrasion powder can be suppressed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a transmission using a planetary gear mechanism, and more particularly to a transmission having a lubrication structure of the planetary gear mechanism.

A planetary gear mechanism may be used as a transmission for increasing or decelerating the number of revolutions from a drive source such as a motor. The planetary gear mechanism is provided on a rotating shaft and is arranged concentrically with a sun gear having external teeth and an annular ring gear having internal teeth, and is arranged between the sun gear and the ring gear. It has external teeth that mesh with each of the external teeth of the ring gear and the internal teeth of the ring gear, and is equipped with a pinion gear that is held by a carrier so that it can revolve around the sun gear.

In order to operate the planetary gear mechanism smoothly, it is important to lubricate the planetary gear mechanism such as the meshing portion of the pinion gear, the sun gear and the ring gear, and the bearing portion of the pinion gear. However, if the amount of lubricating oil that lubricates the planetary gear mechanism is increased, the resistance due to the stirring of the lubricating oil (stirring resistance) acts on each gear of the planetary gear mechanism, causing a problem that the power transmission efficiency is lowered. .. On the other hand, if the amount of lubricating oil is reduced, the planetary gear mechanism is not sufficiently lubricated, heat generation and wear are generated, which contributes to a malfunction of the planetary gear mechanism, and wear powder accelerates the deterioration of the lubricating oil. Can also occur. An oil pump may be used to supply the lubricating oil to the planetary gear mechanism, but in this case, the weight of the reduction gear is increased and the complexity is increased. Under such circumstances, a structure for efficiently lubricating the planetary gear mechanism has been developed, and examples thereof are shown in Patent Documents 1 and 2.

Japanese Unexamined Patent Publication No. 10-267114 Japanese Unexamined Patent Publication No. 2012-117602

Patent Document 1 discloses a lubrication structure of a transmission in which a carrier of a pinion gear of a planetary gear mechanism includes an oil receiver. According to this, it is said that the lubricating oil scattered by the centrifugal force can be captured by the oil receiver and guided to the bearing of the pinion gear.

Patent Document 2 discloses a lubricating structure of a transmission having a rib for guiding lubricating oil on an inner wall of a housing. According to this, the lubricating oil scooped up by the rotating gear is guided to the rotating shaft by the lubricating oil guiding rib, and penetrates into the inside of the planetary gear mechanism through the lubricating oil entry hole provided in the rotating shaft. It is said that the planetary gear mechanism can be lubricated.

However, it is desired to develop a transmission capable of further improving the lubrication efficiency of the transmission, reducing the generation of wear debris with a relatively small amount of lubricating oil, and suppressing the deterioration of the lubricating oil due to the wear debris.

Therefore, in view of the above circumstances, an object of the present invention is to provide a transmission having a planetary gear mechanism having high lubrication efficiency.

The present invention includes a housing and
A first rotating shaft that is pivotally supported inside the housing and extends in one direction of the housing.
A sun gear having external teeth provided on the first rotating shaft, a ring gear having internal teeth arranged concentrically with the first rotating shaft inside the housing, and the sun gear. A planetary gear mechanism composed of a pinion gear having external teeth that mesh with each of the external teeth and the internal teeth of the ring gear, and a carrier that pivotally supports the pinion gear via a pinion shaft.
In a transmission having a second rotating shaft connected to the carrier, pivotally supported inside the housing, and extending in the other direction of the housing.
An annular cover attached to the unidirectional side of the carrier, with the outer diameter side of the planetary gear mechanism closed and the inner diameter side open to form an opening.
With ribs extending toward the inside of the housing
The lubricating oil that adheres to the surface of the rib and is sealed inside the housing is configured to move on the rib and flow from the opening between the cover and the carrier.
The problem is solved by a transmission provided on the pinion shaft and provided with an oil supply path that communicates between the opening and the pinion gear.

According to the present invention, in a transmission having a planetary gear mechanism inside the housing, the carrier of the planetary gear mechanism has an annular cover with the outer diameter side closed and the inner diameter side open, and the housing is directed toward the inside. It has an extending rib, and the lubricating oil adhering to the surface of the rib is configured to move on the rib and flow from the opening of the cover between the cover and the carrier, and the pinion shaft has the opening and the pinion gear. Since there is an oil supply path that communicates between them, the lubricating oil that is lifted by the operation of the planetary gear mechanism is collected by the ribs and flows between the cover and the carrier, and through the oil supply path to the pinion shaft. It flows between the pinion gears. Therefore, since the lubrication efficiency of the planetary gear mechanism can be improved, the generation of wear debris can be reduced and the deterioration of the lubricating oil due to the wear debris can be suppressed with a relatively small amount of lubricating oil.

Further, if a filter is provided between the opening of the cover and the oil supply path, the generated wear debris can be captured by the filter, so that the deterioration of the lubricating oil due to the wear debris can be further suppressed.

Further, if the filter has a magnetic structure, the wear debris trapping performance of the filter can be further improved.

Further, the second rotating shaft and the carrier are made into a columnar shape, an oil circulation path is formed between the inner wall of the housing and the second rotating shaft and the carrier, and the second rotating shaft is fitted with a bearing fitted in the oil circulation path. If the bearing is provided with an oil circulation hole that communicates from the planetary gear mechanism side to the oil circulation path and extends radially in the other direction in which the second rotation shaft extends, the second rotation shaft The lubricating oil adhering to the inner diameter side can be sent to the oil circulation path through the oil circulation hole by centrifugal force, and the bearing that supports the second rotation shaft can be lubricated.

Further, if the surface of the second rotating shaft facing the planetary gear mechanism is provided with an oil reservoir leading to the oil circulation hole, the area on the inner diameter side of the second rotating shaft to which the lubricating oil adheres can be increased. As a result, the amount of lubricating oil sent to the oil circulation path through the oil circulation hole increases, so that the bearing that supports the second rotation shaft can be further lubricated.

A cross-sectional view of the transmission according to the embodiment of the present invention along the axial direction. 2-2 sectional view of FIG. FIG. 1 is a sectional view taken along line 3-3 of FIG. Enlarged view of the main part of FIG.

Embodiments of the present invention will be described with reference to FIGS. However, the present invention is not limited to this embodiment.

FIG. 1 shows a transmission 10 according to an embodiment of the present invention. The transmission 10 is pivotally supported inside the housing 12 and extends in one direction (right direction in the figure) of the housing 12 and a second rotation shaft 14 extending in the other direction (left direction in the figure). It has a two-turn shaft 16. The first rotating shaft 14 and the second rotating shaft 16 are configured so that torque is transmitted via a planetary gear mechanism 20 arranged between the first rotating shaft 14 and the second rotating shaft 16. ..

The planetary gear mechanism 20 shown is of a single pinion type, and as is known, it is composed of a sun gear 22, a ring gear 24, and a pinion gear 26.

The sun gear 22 has external teeth and is provided on the first rotating shaft 14. The ring gear 24 has internal teeth, is inside the housing 12, and is arranged concentrically with the axial center X of the sun gear 22. The pinion gear 26 has external teeth that mesh with the external teeth of the sun gear 22 and the internal teeth of the ring gear 24, respectively. The pinion gear 26 is rotatably supported by a pinion shaft 27. A double pinion type having a plurality of pinion gears 26 in the radial direction may be used.

The pinion shaft 27 is connected to the carrier 28. Since the carrier 28 is integrally continuous with the second rotation shaft 16, these rotation speeds are equal. In the case of the transmission 10, for example, when torque from a drive device (not shown) is transmitted to the first rotating shaft 14, the sun gear 22 rotates, the pinion gear 26 revolves with respect to the sun gear 22, and the second rotating shaft 16 To rotate. Thus, the rotation speed of the first rotation shaft 14 is decelerated, the torque is amplified, and is transmitted to the second rotation shaft 16. The carrier 28 and the second rotating shaft 16 may be of an integrated type as shown in the figure, or may have a separate configuration.

The portion of the housing 12 where the planetary gear mechanism 20 is arranged is sealed by a seal member S or the like, and a lubricating oil (not shown) is sealed. The lubricating oil can be discharged from the oil hole 11 by removing the drain bolt D.

The housing 12 includes ribs 18 that extend inward. The position and range of providing the rib 18 may be determined in relation to the position of the opening 36 of the cover 32, which will be described later. As shown in FIG. 2, the rib 18 is preferably configured to be inclined in the vertical direction. This is because the planetary gear mechanism 20 is lifted by the operation, and the lubricating oil adhering to the rib 18 easily flows. Further, the rib 18 is preferably provided over a wide range of the inner wall of the housing 12 so that the lubricating oil that adheres to the inner wall of the housing 12 and drips can be collected over a wide range.

On the other hand, an annular cover 32 is attached to the carrier 28 of the planetary gear mechanism 20 on one direction side (right direction side in the drawing) of the housing 12, that is, on the side opposite to the direction in which the second rotation shaft 16 extends. (See Figures 1 and 3). The cover 32 is formed or attached so that the outer diameter side of the planetary gear mechanism 20 is closed, while the inner diameter side is open. Therefore, the cover 32 has an opening 36 formed on the inner diameter side (see FIG. 4). The position and range of the rib 18 described above are determined so that the lubricating oil flowing on the rib 18 flows into the opening 36 of the cover 32.

On the other hand, the pinion shaft 27 that pivotally supports the pinion gear 26 is provided with an oil supply path 25 that is a hole that communicates between the opening 36 of the cover 32 and the pinion gear 26. The shape and diameter of the oil supply path 25 may be appropriately determined.

Since the transmission 10 has the above configuration, the lubricating oil that is lifted by the operation of the planetary gear mechanism 20 is collected by the ribs 18 and flows from the opening 36 of the cover 32 between the cover 32 and the carrier 28. , Flows between the pinion shaft 27 and the pinion gear 26 through the oil supply path 25 of the pinion shaft 27. Therefore, since the lubrication efficiency of the planetary gear mechanism 20 can be improved, the lubricating oil can be supplied to the sun gear 22, the ring gear 24, and the pinion gear 26 with a relatively small amount of lubricating oil.

Further, as shown in FIG. 4, a filter 34 may be provided between the opening 36 of the cover 32 and the oil supply path 25 of the pinion shaft 27. The filter 34 can be made of a fibrous material having a density through which the lubricating oil can pass. As a result, even if the wear debris generated by the operation of the planetary gear mechanism 20 is mixed with the lubricating oil, the wear debris can be captured by the filter 34 when the lubricating oil passes through the filter 34. Deterioration of gears can be further suppressed. Further, the filter 34 may be made magnetic. This is because the filter 34 can capture fine abrasion powder.

The second rotating shaft 16 and the carrier 28 can be cylindrical as a whole (see FIG. 1). As a result, the oil circulation path 13 is formed between the inner wall of the housing 12 and the second rotating shaft 16 and the carrier 28. Then, the second rotating shaft 16 can be pivotally supported by the bearing B fitted in the oil circulation path 13.

In the transmission 10, an oil circulation hole 17 is provided in the second rotating shaft 16. The oil circulation hole 17 extends in the other direction of the housing 12 (left direction in the figure), that is, the second rotation shaft 16 so as to communicate from the planetary gear mechanism 20 side of the second rotation shaft 16 to the oil circulation passage 13. It is a through hole that extends radially in the direction of According to this configuration, the lubricating oil adhering to the inner diameter side of the second rotating shaft 16 can be sent to the oil circulation path 13 through the oil circulation hole 17 by centrifugal force, and the bearing B that pivotally supports the second rotating shaft 16 is provided. Can be lubricated.

Further, the second rotary shaft 16 is provided with an oil reservoir 19 communicating with the oil circulation hole 17 on the surface facing the planetary gear mechanism 20. With this configuration, the area on the inner diameter side of the second rotating shaft 16 to which the lubricating oil adheres can be increased, so that the amount of lubricating oil sent to the oil circulation path 13 through the oil circulation hole 17 increases. The bearing B that supports the two rotating shafts 16 can be further lubricated.

As shown in the figure, if the oil circulation path 13 is configured to communicate with the internal teeth of the ring gear 24, the lubricating oil can be circulated inside the housing 12 provided with the planetary gear mechanism 20. , Lubrication efficiency can be further improved.

As described above, according to the present invention, there is provided a transmission that has high lubrication efficiency, can reduce the generation of wear debris with a relatively small amount of lubricating oil, and can suppress deterioration of the lubricating oil due to wear debris. can do.

10 Transmission 12 Housing 13 Oil circulation path 14 First rotation axis 16 Second rotation axis 17 Oil circulation hole 18 Rib 19 Oil reservoir 20 Planetary gear mechanism 22 Sun gear 24 Ring gear 25 Oil supply path 26 Pinion gear 27 Pinion shaft 28 Carrier 32 Cover 34 Filter 36 Opening B Bearing

Claims (5)

With the housing
A first rotating shaft that is pivotally supported inside the housing and extends in one direction of the housing.
A sun gear having external teeth provided on the first rotating shaft, a ring gear having internal teeth arranged concentrically with the first rotating shaft inside the housing, and the sun gear. A planetary gear mechanism composed of a pinion gear having external teeth that mesh with each of the external teeth and the internal teeth of the ring gear, and a carrier that pivotally supports the pinion gear via a pinion shaft.
In a transmission having a second rotating shaft connected to the carrier, pivotally supported inside the housing, and extending in the other direction of the housing.
An annular cover attached to the unidirectional side of the carrier, with the outer diameter side of the planetary gear mechanism closed and the inner diameter side open to form an opening.
With ribs extending toward the inside of the housing
The lubricating oil that adheres to the surface of the rib and is sealed inside the housing is configured to move on the rib and flow from the opening between the cover and the carrier.
An oil supply path provided on the pinion shaft and communicating between the opening and the pinion gear is provided.
Transmission. The transmission according to claim 1, wherein a filter is provided between the opening and the oil supply path. The transmission according to claim 2, wherein the filter is magnetic. The second rotation shaft and the carrier are columnar, and an oil circulation path is formed between the inner wall of the housing and the second rotation shaft and the carrier.
The second rotating shaft is pivotally supported by a bearing fitted in the oil circulation path, communicates from the planetary gear mechanism side to the oil circulation path, and provides an oil circulation hole that extends radially in the other direction. The transmission according to any one of claims 1 to 3 provided. The transmission according to claim 4, wherein the second rotating shaft is provided with an oil reservoir portion communicating with the oil circulation hole on a surface facing the planetary gear mechanism.

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