JP2007192309A - Lubricating structure of power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the introduced amount of a lubricating oil from being reduced by the blow-off of the lubricating oil collected by a rib during the high-speed rotation in a splash lubricating structure. <P>SOLUTION: A rotating shaft 20 is supported on the vertical wall part 10a of a casing 10 through a bearing 21. The rib 15 tilted downward toward the vertical wall part and having a band-like lower surface 17 is formed at the inner surface corner part of the casing positioned above the rotating shaft. At least one side-face guide grooves 18a to 18d tilted downward toward the vertical wall part are formed in the side face 16 of the rib 15. A considerable amount of the lubricating oil spattered from a rotating member 22 installed on the rotating shaft and adhered to the side face of the rib enters the side-face guide grooves, flows to the vertical wall part by gravity, and is supplied to from introducing passages 13, 13a to the bearing. At least one lower guide groove 19 may be formed also in the tilted band-like lower surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a splash-type lubrication structure in a power transmission device such as a transmission.

  As a lubricating structure of this type of power transmission device, there is a structure as shown in FIGS. 4 and 5, for example. In this lubricating structure, a rotating shaft 20 is rotatably supported via a ball bearing 21 on a boss portion 11 formed on an inner surface of a vertical wall portion 10a of a casing 10 such as a transmission, and is positioned above the rotating shaft 20. A rib 1 having a belt-like lower surface 3 which is inclined so as to gradually become lower at the corner portion of the inner surface between the upper wall portion 10b and the vertical wall portion 10a of the casing 10 toward the vertical wall portion 10a side. The ribs 1 are formed substantially parallel to each other, and the cross-sectional shape of the rib 1 is a substantially rectangular shape whose height gradually decreases as the distance from the vertical wall portion 10a increases. Lubricating oil in the casing 10 is scraped up by each gear (not shown), and is scattered by a transmission gear 22 provided on the rotary shaft 20 as shown by a solid arrow 25 from the inner surface of the upper wall portion 10b of the casing 10. Lubricating oil that adheres to the side surface 2 of the rib 1 that is the front side with respect to the direction of rotation of the transmission gear 22, flows down along the front side surface 2 of the rib 1 due to gravity, and moves around the lower surface 3 as indicated by a solid arrow 5. Flows through the inclined lower surface 3 to the vertical wall portion 10a side and enters the back side of the ball bearing 21 through the introduction passages 13 and 13a opened in the vertical wall portion 10a that is the upper base portion of the boss portion 11. Lubricate this. The object of lubrication is not limited to the ball bearing 21 but may be other lubrication parts. Examples of such a lubrication structure include, for example, Patent Document 1 and Patent Document 2 which are displayed next.

In the lubricating structure shown in FIGS. 4 and 5, a window hole 12 reaching from the outside to the middle of the boss portion 11 is formed in the vertical wall portion 10 a corresponding to the upper portion of the boss portion 11, and the mouth side thereof is liquid-tight by a screw plug 14. The inlet 13 is closed and opened to the vertical wall portion 10a, and an introduction groove 13a is formed on the bottom surface of the storage hole of the ball bearing 21. The inlet 13 and the introduction groove 13a are used for lubricating oil. The introduction paths 13 and 13a are configured.
JP 2002-221273 A (paragraphs [0029] to [0034], FIGS. 1 to 3) Japanese Utility Model Publication No. 1-105561 (the scope of claims for utility model registration, FIGS. 1 to 4)

  In the prior art shown in FIGS. 4 and 5, while the rotational speed of the rotary shaft 20 is relatively low, the lubricating oil scattered from the transmission gear 22 and adhering to the front side surface 2 of the rib 1 wraps around the lower surface 3 and is inclined. It flows along the lower surface 3 to the vertical wall portion 10a side, and a part of it drops down in the middle, but a corresponding portion reaches the vicinity of the vertical wall portion 10a and is introduced into the introduction port 13, and passes through the introduction groove 13a to pass through the ball bearing 21. Lubricate the lubrication part. However, if the rotational speed becomes higher than a certain level, the air flow generated around the transmission gear 22 by the rotation of the rotary shaft 20 becomes stronger, so that the lubricating oil flowing along the lower surface 3 of the rib 1 is indicated by the broken arrow 6 (see FIG. 5). In this way, the amount of lubricating oil that is blown back and introduced into the inlet 13 is reduced, and therefore the amount of lubricating oil supplied to the lubricating portion is also reduced, which may cause problems such as seizure and wear of the lubricating portion. . The present invention aims to solve such problems.

  For this purpose, the lubrication structure of the power transmission device according to the present invention supports the rotating shaft rotatably on the vertical wall portion of the casing via a bearing, and the upper wall portion and the vertical wall of the casing located above the rotating shaft. A rib having a belt-like lower surface inclined so as to gradually become lower at the corner portion of the inner surface of the portion toward the vertical wall portion side is formed substantially parallel to the rotation shaft, and is provided on the rotation shaft and larger than that. The lubricating oil in the casing scattered from the rotating member having a diameter and adhering to the rib flows along the surface of the rib to the vertical wall portion side and is supplied to the lubricating portion such as a bearing from the introduction path formed in the vertical wall portion. In the lubrication structure of the power transmission device thus configured, at least one side guide groove that is inclined so as to gradually become downward as it proceeds to the vertical wall portion side is formed on the side surface of the rib.

  In the lubricating structure for a power transmission device according to the preceding item, it is preferable that at least one lower guide groove extending in the longitudinal direction is also formed on the lower surface of the rib.

  According to the first aspect of the present invention, while the rotational speed of the rotating shaft is relatively low, the lubricating oil scattered from the rotating member and adhering to the front side surface of the rib and entering the side guide groove Since it is difficult to get out of the side guide groove due to tension, the corresponding part of the lubricating oil flows to the vertical wall side by gravity in the side guide groove, and the lubricating oil that overflows from the side guide groove and goes around the lower surface of the rib Flows to the vertical wall portion side along the inclined lower surface of the belt, and both are introduced into the introduction path formed in the vertical wall portion to lubricate the lubricating portion such as the bearing. If the rotational speed increases and the air flow generated around the rotating member by the rotation of the rotating shaft becomes stronger, the lubricating oil scattered from the rotating member and adhering to the ribs is strongly pressed against the front side surface, so the side guide groove The amount of lubricating oil that overflows from the rib and flows around the lower surface of the rib and is blown off by the air flow generated by the rotation of the rotating member decreases, and the amount of lubricating oil that flows into the vertical wall portion side through the side guide groove increases. . Accordingly, the amount of lubricating oil supplied from the introduction path to the lubrication part such as the bearing does not decrease so much even when the rotational speed is increased, so that the possibility of causing problems such as seizure and wear of the lubrication part is reduced.

  According to the second aspect of the present invention, the lubricating oil that overflows from the side guide groove and wraps around from the front side surface of the rib to the lower surface and enters the lower guide groove is difficult to come out of the lower guide groove due to surface tension. Therefore, even when the rotational speed increases and the air flow generated by the rotation of the rotating member becomes stronger, the air flow is less likely to be blown away by the air flow, and the corresponding part flows to the vertical wall side and enters the introduction path. be introduced. Accordingly, the decrease in the amount of lubricating oil when the rotational speed increases is further reduced. Accordingly, the risk of causing problems such as seizure and wear of the lubrication part is further reduced.

  1 to 3 show an embodiment in which a lubricating structure for a power transmission device according to the present invention is applied to a gear transmission. The lubricating structure of this embodiment is the prior art described above except for the structure of the rib 15 formed at the corner of the inner wall of the upper wall 10b and the vertical wall 10a of the casing 10 located above the rotary shaft 20. Therefore, only the rib 15 will be described below, and the other description will be omitted.

  As shown in FIGS. 1 and 2, the rib 15 is located directly above the rotation shaft 20 and is substantially parallel to the rib 15, and is a belt-like bottom surface that is inclined so as to gradually become lower toward the vertical wall portion 10 a side. 17, the shape seen from the front side (left side in FIG. 2) is a substantially triangular shape, and the shape seen from the lower side is an elongated trapezoid whose width gradually decreases as the distance from the vertical wall portion 10a increases. The front and back side surfaces 16 of the rib 15 have a front-rear symmetrical shape that is inclined so that the lower side is narrower with respect to the vertical plane P including the rotating shaft 20, and the inclination angle and the lower half of the upper half portion 16 a of the side surface 16 with respect to the plane P The inclination angle of the portion 16b is larger in the latter than in the former. A considerable portion of the tip portion of the rib 15 away from the vertical wall portion 10a is located within the axial width of the transmission gear (rotating member) 22 provided on the rotating shaft 20 and having a larger diameter than that.

  As shown in detail in FIG. 3, four side guide grooves 18 a to 18 d are formed in parallel with each other on the front and rear side surfaces 16 of the rib 15 so as to be gradually lowered toward the vertical wall portion 10 a side. The inclination angle of each side guide groove 18 a to 18 d is slightly smaller than the inclination angle of the lower surface 17. The lower surface 17 is a portion where the width is constant and the thickness of the rib 15 in the front-rear direction is minimum, and one lower guide groove 19 is formed along the longitudinal direction. The number of the side guide grooves 18a to 18d and the lower guide groove 19 is arbitrary, and the width and depth of the side guide grooves 18a to 18d may be dimensions that prevent the lubricant contained therein from coming out due to surface tension, and the cross-sectional shape is also illustrated. The shape is not limited to the semicircular shape as described above.

  Next, the operation of the above-described embodiment will be described. As shown in FIG. 2, when the rotary shaft 20 rotates in the clockwise direction, if the gear transmission is operated, the lubricating oil in the casing 10 is scraped up by the rotating transmission gears, and the transmission gear 22 is shown by a solid line. As shown by the arrow 25, it is scattered and adheres to the inner surface of the upper wall portion 10 b of the casing 10 and the left side surface 16 of the rib 15 which is the front side with respect to the direction of rotation of the transmission gear 22. Since the lubricating oil adhering to the front side surface 16 of the rib 15 enters the side guide grooves 18a to 18d and hardly comes out of the side guide grooves 18a to 18d due to surface tension, the corresponding portion of the lubricating oil is the side guide grooves 18a to 18d. It flows through the inside to the vertical wall 10a side by gravity. Also, the lubricating oil that overflows from the side guide grooves 18a to 18d and moves around to the lower surface 17 of the rib 15 due to gravity passes through the lower surface 17 of the belt-like shape in which the corresponding portion is inclined or passes through the lower guide groove 19 formed therein. And flows to the vertical wall 10a side. The lubricating oil that has flowed to the vertical wall portion 10a in this way either drops down from the vertical wall portion 10a or from the vicinity of the vertical wall portion 10a, and becomes the vertical wall portion 10a that becomes the base portion on the upper side of the boss portion 11. And then introduced into the back side of the ball bearing 21 through the introduction groove 13a to lubricate it. Thus, the quantity of the lubricating oil introduced from the introduction paths 13 and 13a can be adjusted by changing the width, depth, and number of the side guide grooves 18a to 18d.

  If the rotational speed of the rotating shaft 20 increases and the air flow generated around the rotating member 22 becomes stronger due to the rotation of the rotating member 22, the lubricating oil scattered from the rotating member 22 and attached to the ribs 15 is caused by the air flow. Therefore, the amount of lubricating oil that overflows from the side guide grooves 18a to 18d and flows around the lower surface 17 of the rib 15 is reduced, so that the amount of lubricating oil blown off from the belt-like lower surface 17 by the air flow generated by the rotation of the rotating member 22 is reduced. Decrease. Accordingly, the amount of lubricating oil flowing in the side guide grooves 18a to 18d toward the vertical wall portion 10a and introduced into the introduction passages 13 and 13a increases, so that the ball bearings from the introduction passages 13 and 13a even when the rotational speed is increased. The amount of lubricating oil supplied to 21 does not decrease so much, and the possibility of causing problems such as seizure and wear of the lubricating portion is reduced.

  In the above-described embodiment, the lower guide groove 19 is also provided on the lower surface 17 of the rib 15, and in this way, a substantial portion of the lubricating oil that has entered the lower surface 17 passes through the lower guide groove 19. Since the lubricating oil flowing to the groove 13a side and passing through the lower guide groove 19 is not blown off by the air flow generated by the rotation of the rotating member 22 even when the rotation speed of the rotating shaft 20 is increased, the ball bearing 21 The decrease in the amount of lubricating oil supplied to is reduced. However, the present invention is not limited to this, and the lower guide groove 19 formed on the lower surface 17 may be omitted, and a considerable amount of lubricating oil adhering to the side surface 16 of the rib 15 may be included in the side guide groove 18a. Since the amount of lubricating oil flowing to the side of the vertical wall portion 10a by -18d and wrapping around the lower surface 17 is smaller than that of the prior art shown in FIGS. 4 and 5, it is considerable even if the lower guide groove 19 is omitted. The effect is obtained.

  In the above-described embodiment, the example in which the ball bearing 21 supporting the rotating shaft 20 is lubricated by the lubricating oil introduced into the introduction paths 13 and 13a has been described. However, the present invention is not limited to this and the ball bearing is not limited thereto. Instead of this, other bearings may be lubricated, or a lubrication part other than the bearing that supports the rotating shaft 20 may be lubricated. In the above-described embodiment, the example in which the rib 15 is provided directly above the rotation shaft 20 has been described. However, the rib 15 may be provided at a position off the rotation shaft 20 as long as it is above the rotation shaft 20. .

  Further, in the above-described embodiment, the side guide grooves 18a to 18d are formed on the front and rear side surfaces 16 of the rib 15, and in this way, the above-described high speed can be achieved regardless of whether the rotating shaft 20 rotates in the forward or reverse direction. It is possible to prevent a decrease in the amount of lubricating oil supplied to the lubricating part during rotation. However, the present invention is not limited to this, and when the rotating shaft 20 rotates only in one direction, the side guide groove 18a is formed only on the side surface 16 of the rib 15 which is the front side with respect to the direction of rotation of the rotating shaft 20. ˜18d may be formed.

  Further, in the above-described embodiment, the rib 15 has a shape in which the front and rear side surfaces 16 are inclined so that the lower side is narrower with respect to the plane P, and the width gradually decreases as the distance from the vertical wall portion 10a increases when viewed from the lower side. In this manner, the ribs 15 having the side guide grooves 18a to 18d are die-casted so that the cross-sectional shape of the side guide grooves 18a to 18d inclined as described above does not cause an undercut when viewed from the mold release direction of the casing 10. Etc., and can be formed integrally with the casing 10. However, the present invention is not limited to this, and the cross-sectional shape of the rib 15 is a substantially rectangular shape in which the horizontal width is the same as in the prior art shown in FIGS. 4 and 5 and the height gradually decreases as the distance from the vertical wall portion 10a increases. Other shapes may be used. In this case, the number of side guide grooves formed on the front and rear side faces is approximately the same as that of the above-described embodiment, but since the width of the lower face becomes wider, it is preferable to have a plurality of lower guide grooves.

It is a fragmentary sectional view which shows the structure of the principal part of one Embodiment of the lubrication structure of the power transmission device by this invention. It is 2-2 sectional drawing of FIG. It is a partial expanded sectional view which shows the detailed structure of the rib of embodiment shown in FIG. It is a fragmentary sectional view equivalent to FIG. 1 of the lubrication structure of the power transmission device by a prior art. FIG. 5 is a sectional view taken along line 5-5 in FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Casing, 10a ... Vertical wall part, 10b ... Upper wall part, 13, 13a ... Introduction path (introduction port, introduction groove), 15 ... Rib, 16 ... Side surface, 17 ... Lower surface, 18a-18d ... Side surface guide groove, DESCRIPTION OF SYMBOLS 19 ... Lower side guide groove, 20 ... Rotating shaft, 21 ... Bearing (ball bearing), 22 ... Rotating member (rotating member).

Claims (2)

  A rotary shaft is rotatably supported by a vertical wall portion of the casing via a bearing, and the vertical wall portion side is provided at the corner portion of the upper wall portion of the casing and the inner surface of the vertical wall portion located above the rotary shaft. A rib having a belt-like lower surface inclined so as to gradually become lower as the process proceeds to the rotary shaft is formed substantially parallel to the rotary shaft, and is scattered from a rotary member having a larger diameter than that provided on the rotary shaft. The lubricating oil in the casing adhering to the gas flows along the surface of the rib to the vertical wall portion side and is supplied to the lubricating portion such as the bearing from the introduction path formed in the vertical wall portion. In the lubricating structure of the apparatus, the lubricating structure of the power transmission apparatus is characterized in that at least one side guide groove is formed on the side surface of the rib so as to be gradually lowered toward the vertical wall portion side. 2. The lubrication structure for a power transmission device according to claim 1, wherein at least one lower guide groove extending along a longitudinal direction is also formed on a lower surface of the rib.

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