JP2014031874A - Gear structure - Google Patents

Abstract

A gear structure capable of efficiently reducing gear noise generated from an idle gear is provided.
An oil supply passage 9 that passes from an oil supply passage 7 of a fixed shaft 1 through a bearing portion 6 of a slide bearing 2 to an outer peripheral surface 8 of an idle gear 3 is connected to a center 10 of the idle gear 3 and a drive gear 5 that meshes therewith. An oil sump 14 formed along a virtual center line 11 connecting to the center 11 and having a concave shape on the outer peripheral surface 13 of the fixed shaft 1 is engaged with an engagement start point 15 and an engagement end point with the drive gear 5. 17 and the first virtual mesh line 15 and the second virtual mesh line 18 that connect the center 17 of the idle gear 3 and the virtual center line 11, respectively.
[Selection] Figure 1

Description

  The present invention relates to a gear structure, and more particularly, to a gear structure that can efficiently reduce gear noise generated from an idle gear.

  When the distance between the shafts of a plurality of transmission shafts is long or when the rotation directions of the transmission shafts are matched, generally an idle gear is arranged between the transmission shafts. Such a gear structure is widely used in a transmission mechanism of a vehicle (see, for example, Patent Document 1). However, if the supply of lubricating oil to the meshing portion of the gear is not sufficient, rattle noise, meshing noise, etc. There is a drawback that gear noise is likely to occur. When gear noise is generated in a vehicle, there is a risk of causing noise damage to passengers and residents around the road.

  In order to reduce the gear noise, it is conceivable to always supply a sufficient amount of lubricating oil to the meshing portion. However, there is a problem that installation of a supply device and a large amount of lubricating oil are required. Therefore, there is a demand for a gear structure that can efficiently reduce gear noise.

JP 2001-50392 A

  An object of the present invention is to provide a gear structure capable of efficiently reducing gear noise generated from an idle gear.

  The gear structure of the present invention that achieves the above object includes an idle gear attached to a fixed shaft having an oil feed passage extending in the axial direction via a slide bearing to which lubricating oil is supplied from the oil feed passage. In the gear structure including at least one gear that meshes with the idle gear, an oil supply path that passes from the oil feeding path through the bearing portion of the slide bearing to the outer peripheral surface of the idle gear, and the idle gear and An oil sump that is formed along a virtual center line connecting the centers of the gears, and that opens to the bearing portion of the slide bearing, has an engagement start point and an engagement end point with the gear, and the center of the idle gear, respectively. The first virtual mesh line and the second virtual mesh line to be connected are provided so as to straddle the virtual center line.

  The oil supply passage formed on the idle gear side is preferably opened at a valley portion between the teeth of the idle gear in order to further reduce the meshing noise. Moreover, the number of oil supply passages and oil reservoirs can be easily increased by forming the oil reservoir concavely on the outer peripheral surface of the fixed shaft. It is desirable that the number of idler oil supply passages be one or more in the circumferential direction and less than the number of teeth of the idle gear.

  The gear that meshes with the idle gear may be a drive gear or a driven gear that transmits rotation through the idle gear.

  According to the gear structure of the present invention, the lubricating oil used for the idle gear slide bearing is forcibly supplied to the meshing portion with the other gear using the centrifugal force when meshing with the idle gear. Gear noise generated from the gear can be efficiently reduced.

It is a block diagram of the gear structure which consists of the 1st Embodiment of this invention. It is an expanded sectional view showing an example of an oil sump. It is an expanded sectional view showing another example of an oil sump. It is a conceptual diagram explaining the meshing state of the gear in FIG. It is an expanded sectional view which shows the oil supply path in the outer peripheral part of an idle gear. It is a block diagram of the gear structure which consists of another example of the 1st Embodiment of this invention. It is a block diagram of the gear structure which consists of the 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a gear structure according to a first embodiment of the present invention.

  This gear structure includes an idle gear 3 attached to a fixed shaft 1 via a slide bearing 2 and a drive gear 5 fixed to a drive shaft 4 that meshes with the idle gear 3. In this embodiment, when the drive gear 5 is driven to rotate counterclockwise, the idle gear 3 is rotated clockwise.

  The slide bearing 2 supports the idle gear 3 rotatably by an oil film of lubricating oil formed on the bearing portion 6 between the fixed shaft 1 and the idle gear 3. The lubricating oil for the bearing portion 6 is supplied by an oil pump (not shown) through an oil feed passage 7 extending in the longitudinal direction in the fixed shaft 1.

  In such a gear structure, in the fixed shaft 1 and the idle gear 3, a tunnel-like oil supply passage 9 </ b> A that passes from the oil supply passage 7 through the bearing portion 6 of the slide bearing 2 to the outer peripheral surface 8 of the idle gear 3. , 9B are formed along a virtual center line 12 connecting the center 10 of the idle gear 3 and the center 11 of the drive gear 5. Further, as shown in FIG. 2, a substantially fan-shaped concave oil sump 14 is formed on the outer peripheral surface 13 of the fixed shaft 1 facing the bearing portion 6 so as to be connected to the oil supply passage 9A on the fixed shaft 1 side. ing. The oil sump 14 includes a first virtual meshing line 16 that connects the meshing start point 15 of the idle gear 3 and the drive gear 5 and the center 10 of the idle gear 3, a meshing end point 17 of the idle gear 3 and the drive gear 5, and an idle. It extends in the circumferential direction so as to straddle the virtual center line 12 between the second virtual mesh line 18 connecting the center 10 of the gear 3.

  As shown in FIG. 3, the oil sump 14 is formed in a substantially fan-shaped concave shape on the inner peripheral surface 20 of the idle gear 3 facing the bearing portion 6 so as to be connected to the oil supply passage 9B on the idle gear 3 side. You can also. However, as will be described later, when a plurality of oil reservoirs 14 are formed, the number is limited as compared with the case where they are formed on the outer peripheral surface 13 of the fixed shaft 1.

  The volume of the oil reservoir 14 is not particularly limited, but is preferably as small as possible so that the pressure of the lubricating oil in the bearing portion 6 is not greatly reduced.

  The meshing start point 15 and meshing end point 17 of the idle gear 3 and the drive gear 5 will be described below based on the conceptual diagram of FIG. Since the idle gear 3 and the drive gear 5 are engaged with each other, the pitch circles 21 and 22 are in contact with each other. Here, a line of action 25 is set in contact with the basic circle 23 of the idle gear 3 and the basic circle 24 of the drive gear 5 at the same time. At this time, the meshing start point 15 is an intersection of the action line 25 and the tooth tip circle 27 of the idle gear 3 at the meshing start portion 26. The meshing end point 17 is an intersection of the action line 25 and the tooth tip circle 29 of the drive gear 5 at the meshing end portion 28.

  By forming the oil supply passages 9A and 9B and the oil reservoir 14 in this way, when the rotational drive of the drive gear 5 is transmitted and the idle gear 3 rotates, the oil is supplied from the oil supply passage 7 through the oil supply passage 9A on the fixed shaft 1 side. The lubricating oil staying in the reservoir 14 is forcibly sent to the outer peripheral surface 8 through the oil supply passage 9B on the idle gear 3 side by the pressure using the centrifugal force of the idle gear 3 when meshed with the drive gear 5 to drive the drive gear. 5 is supplied to the meshing part. Accordingly, since the lubricating oil is supplied to the meshing portion only when the idle gear 3 is meshed, the gear noise can be efficiently reduced.

  In addition, since the hydraulic pressure supplied by the oil pump is also added to the pressure applied to the lubricating oil flowing through the oil supply passages 9A and 9B, the lubricating oil can be reliably supplied to the meshing portion by appropriately setting the hydraulic pressure. .

  As shown in FIG. 5, the oil supply passage 9 </ b> B on the idle gear 3 side desirably opens in a valley portion 31 between adjacent teeth 30 in the idle gear 3. By doing so, the opening 32 of the outer peripheral surface 8 of the oil supply passage 9B does not come into contact with the teeth of the drive gear 5, so that the meshing noise can be further reduced.

  When the idle gear 3 rotates at a high speed, as shown in FIG. 1, the lubricating oil is diffused and supplied to the meshing portion with the drive gear 5 even when there is only one oil supply passage 9B on the idle gear 3 side. be able to. However, as shown in FIG. 6, by providing a plurality of oil supply passages 9B, even when the idle gear 3 rotates at a low speed, the lubricating oil can be quickly and reliably supplied to the meshing portion with the drive gear 5. Can do. The upper limit of the number of these oil supply passages 9B is desirably the number of teeth of the idle gear 3 from the viewpoint of the normal gear meshing rate. FIG. 6 shows an example in which four oil supply passages 9B are provided at equal intervals in the circumferential direction of the idle gear 3, but the number and the interval in the circumferential direction are not limited to this. It can be appropriately changed according to the manufacturing specifications such as the dimensions and the number of teeth of the gear 3.

  FIG. 7 shows a gear structure according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same part as FIG. 1, and description is abbreviate | omitted.

  This gear structure is obtained by adding a driven gear 34 fixed to the driven shaft 33 so as to mesh with the idle gear 3 in the first embodiment described above. In this embodiment, when the drive gear 5 is driven to rotate counterclockwise, the driven gear 34 is also rotated counterclockwise.

  In such a gear structure, second oil supply passages 35A and 35B and a second oil reservoir 36 for the driven gear 34 are formed in the driven shaft 33 and the idle gear 3, respectively. The virtual center line 37, the meshing start point 38, the meshing end point 39, and the virtual meshing lines 40 and 41 that define the second oil supply passages 35A and 35B and the second oil reservoir 36 are the same as those in the first embodiment. Is defined in the same way as

  The number of the second oil supply passages 35B on the idle gear 3 side is not particularly limited as long as it is equal to or less than the number of teeth of the idle gear 3 as in the first embodiment. Further, the magnitude relationship with the number of the oil supply passages 9 </ b> B with respect to the drive gear 5 is not particularly limited, and can be appropriately changed according to the manufacturing specifications of these three gears 3, 5, 34.

  As described above, by providing the second oil supply passages 35A and 35B and the oil reservoir 36 corresponding to the driven gear 34, the lubricating oil of the bearing portion 6 staying in the oil reservoirs 14 and 36 is supplied to the drive gear 5 or the driven gear 34. Is forced to the outer peripheral surface 8 through the oil supply passages 9B and 35B on the idle gear 3 side and supplied to the meshing portions with the respective gears 5 and 34 by the pressure using the centrifugal force of the idle gear 3 at the time of meshing with the gears 5 and 34. Therefore, gear noise can be reduced efficiently.

  The number and function of the gears meshed with the idle gear 3 are not limited to the first and second embodiments described above, and can be changed as appropriate according to the performance required for the gear structure.

DESCRIPTION OF SYMBOLS 1 Fixed shaft 2 Slide bearing 3 Idle gear 5 Drive gear 6 Bearing part 7 Oil supply path 8 Peripheral surface 9A of the idle gear (9B) Oil supply path 10 Center of the idle gear 11 Center of the drive gear 12 Virtual center line 14 Oil pool 15 Engagement start point 16 First virtual engagement line 17 Engagement end point 18 Second virtual engagement line

Claims (5)

An idle gear attached to a fixed shaft formed with an oil feed passage extending in the axial direction via a slide bearing supplied with lubricating oil from the oil feed passage, and at least one gear meshing with the idle gear In the gear structure provided,
An oil supply path that passes from the oil supply path to the outer peripheral surface of the idle gear through the bearing portion of the slide bearing is formed along a virtual center line that connects the idle gear and the center of the gear,
An oil sump that opens to the bearing portion of the slide bearing extends between a first virtual meshing line and a second virtual meshing line that respectively connect the meshing start point and meshing end point with the gear and the center of the idle gear. The gear structure is provided so as to straddle the virtual center line.   The gear structure according to claim 1, wherein an oil supply passage formed on the idle gear side opens in a valley portion between teeth of the idle gear.   The gear structure according to claim 1 or 2, wherein the oil reservoir is formed in a concave shape on an outer peripheral surface of the fixed shaft.   The gear structure according to any one of claims 1 to 3, wherein an oil supply passage formed on the idle gear side is formed with a number of one or more in the circumferential direction and the number of teeth of the idle gear or less.   The gear structure according to any one of claims 1 to 4, wherein the at least one gear is a drive gear and / or a driven gear to which rotation is transmitted via the idle gear.

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