JPH07190176A - Power transmission device - Google Patents

Abstract

(57) [Summary] [Purpose] Sufficient lubricating oil is supplied to the spline joint of the driven shaft to prevent wear and seizure from occurring at the spline joint. [Structure] A boss-side oil passage 34 is formed in the first driven-side boss portion 32, and a cap that closes the fitting hole 32A of the first driven-side boss portion 32 is connected to the boss-side oil passage 34. The side oil passage 36 is formed and the spline coupling portion 25 is formed.
A lubricating oil guide 37 is provided extending toward. As a result, the lubricating oil G in the casing 31 can be transferred to the boss side oil passage 34,
It is surely supplied to the spline coupling portion 25 through the cap side oil passage 36, the lubricating oil guide 37 and the shaft insertion hole 18A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device suitable for use in an engine-driven pump device used as a hydraulic power source for a construction machine, and more particularly to input of a driven object such as a pump to a driven gear. The present invention relates to a power transmission device in which a shaft is spline-coupled.

[0002]

2. Description of the Related Art FIGS. 3 and 4 will be described as an example of an engine-driven pump device for a construction machine as a conventional power transmission device.

In the figure, reference numeral 1 denotes a disc-shaped flywheel which constitutes a part of an output shaft of an engine (not shown) serving as a drive source, and between the flywheel 1 and a power transmission device 2 described later. The intermediate cover 3 is disposed on the flywheel 1. The intermediate cover 3 covers the flywheel 1 from the outside in the radial direction. The power transmission device 2 is generally composed of a casing 4, a drive shaft 9, a drive gear 14, a driven gear 17, a driven shaft 24B, etc., which will be described later.

Reference numeral 4 denotes a casing forming the outer shape of the power transmission device. The casing 4 is a hydraulic pump 23 described later.
And a front side wall portion 4A to which the gear pump 24 is attached,
A rear side wall portion 4B provided to face the front side wall portion 4A,
An end surface of the intermediate cover 3 is formed in a box shape from a peripheral wall portion 4C that covers the outer periphery between the wall portions 4A and 4B, and a bracket portion 4D extending from the rear side wall portion 4B to the outside of the peripheral wall portion 4C. Is fixed.

Reference numeral 5 denotes a first drive side boss portion integrally formed with the rear side wall portion 4B of the casing 4 at a position facing the hydraulic pump 23, and the mounting hole 5 is provided on the inner peripheral side of the drive side boss portion 5.
A is formed. Reference numeral 6 denotes a first driven-side boss portion integrally formed with the rear side wall portion 4B at a position facing the gear pump 24, and a large-diameter fitting hole 6 is provided on the inner peripheral side of the driven-side boss portion 6.
A and a small diameter bearing hole 6B are formed.

[0006] 7 is opposed to the driving side boss portion 5 in the axial direction,
A second drive side boss portion integrally formed on the front side wall portion 4A of the casing 4 is shown, and a large diameter hole 7A and a small diameter bearing hole 7B are formed on the inner peripheral side of the drive side boss portion 7. Reference numeral 8 denotes a second driven-side boss portion that is formed integrally with the front side wall portion 4A of the casing 4 so as to face the driven-side boss portion 6 in the axial direction, and has a mounting hole on the inner peripheral side of the driven-side boss portion 8. 8A is formed.

Reference numeral 9 denotes a drive shaft having a spline formed on its outer peripheral surface, 10 denotes a flange joint provided between the flywheel 1 and the drive shaft 9, and the flange joint 10 is a hollow cylinder extending in the axial direction. Portion 10A and the cylindrical portion 10A
Is provided with a spline hole 10B formed on the inner peripheral side of the drive shaft 9 for spline coupling to one end side of the drive shaft 9, and a flange portion 10C extending outward in the radial direction. The flange portion 10C is fixed to the flywheel 1 via a plate 11. Has been done. The drive shaft 9 has one end connected to the flywheel 1 via the flange joint 10 and the plate 11 and the other end spline-coupled to a large-diameter spline hole 14A of the drive gear 14, which will be described later. The rotation is transmitted to the drive gear 14.

Reference numeral 12 denotes a mounting ring fitted and fixed to the drive side boss portion 5 of the casing 4. The mounting ring 12 is fitted in the axially extending stepped cylindrical portion 12A and the mounting hole 5A. And an abutting portion 12B fixed to the end surface of the driving side boss portion 5. Then, the outer ring of the bearing 13 having a seal on the inner peripheral surface thereof is inserted into the cylindrical portion 12A of the mounting ring 12,
The outer circumference of the cylindrical portion 10A of the flange joint 10 is fitted into the inner ring of the bearing 13.

Reference numeral 14 denotes a drive gear arranged in the casing 4, and a large diameter spline hole 14A and a small diameter spline hole 14B extending in the axial direction are provided on the inner peripheral side of the drive gear 14.
Is formed, and a tooth portion 14C that meshes with a driven gear 17, which will be described later, is formed on the outer peripheral side of the large diameter spline hole 14A.
Are splined to the other end of the drive shaft 9. The driving gear 14 is rotatably supported at one end in the mounting hole 5A of the driving boss portion 5 through the bearing 15 and at the other end in the bearing hole 7B of the driving side boss portion 7 through the bearing 16. Has been done.

Reference numeral 17 denotes a driven gear (only one is shown) arranged in the casing 4, and the driven gear 17 is a cylinder extending in the axial direction and having a shaft insertion hole 18A formed in the inner peripheral side thereof. A sleeve 18 and a gear body 20 that is spline-coupled to the axially intermediate portion of the sleeve 18 and is axially positioned by each stop ring 19,
The gear body 20 is formed with a tooth portion 20A that meshes with a tooth portion 14C of the drive gear 14. In addition, the shaft insertion hole 18A of the sleeve 18 has a spline hole 1 on the gear pump 24 side.
8B is formed, and the spline hole 18B is splined to a driven shaft 24B described later. The sleeve 18 is rotatably supported in the mounting hole 8A of the driven side boss portion 8 via a bearing 21 and rotatably supported in the bearing hole 6B of the driven side boss portion 6 via a bearing 22 such as a bush. Has been done.

Reference numeral 23 denotes a hydraulic pump, and the hydraulic pump 2
3 includes a pump main body 23A that accommodates a piston (not shown) and the like inside, and an input shaft 23B that is formed as a spline shaft and projects outward from one end side of the pump main body 23A. On the side, a fitting convex portion 23C that fits into the large diameter hole 7A of the driving side boss portion 7 is formed. Here, the hydraulic pump 23 spline-connects the input shaft 23B to the small-diameter spline hole 14B of the drive gear 14, while making the fitting convex portion 23C the large-diameter hole 7A of the drive-side boss portion 7.
And is fixed by a bolt (not shown) or the like. The hydraulic pump 23 discharges pressure oil from inside the pump body 23A when the input shaft 23B is rotationally driven by the driving force from the engine.

Reference numeral 24 denotes a gear pump, and the gear pump 2
The pump body 24A includes a pump body 24A that houses gears (not shown) that mesh with each other, and a driven shaft 24B that projects outward from one end of the pump body 24A and is formed as a spline shaft. A fitting convex portion 24C that fits into the mounting hole 8A of the driven side boss portion 8 is formed on the outer peripheral side of the. Here, the gear pump 24 has a driven shaft 24B.
Is spline-coupled to the spline hole 18B of the sleeve 18 (hereinafter, this coupling portion is referred to as "spline coupling portion 25"), and the fitting convex portion 24C is fitted into the mounting hole 8A of the driven side boss portion 8 via the spacer 26. It is fixed by a bolt (not shown) or the like in the state of being made. The driven shaft 24B of the gear pump 24 is rotationally driven by the driving force from the engine via the drive gear 14 and the driven gear 17, so that the pressure oil is discharged from the pump body 24A.

Reference numeral 27 denotes a cap which is fitted and fixed in the fitting hole 6A of the driven side boss portion 6 and closes the fitting hole 6A. The outer periphery of the cap 27 is the fitting hole 6A of the driven side boss portion 6.
It has a cylindrical insertion fitting portion 27A that is inserted into and a solid flange portion 27B that extends radially from the insertion fitting portion 27A. The cap 27 constitutes a part of the casing 4, is fixed by a bolt (not shown) or the like in a state where the flange portion 27B is in close contact with the end surface of the driven side boss portion 6, and is inserted into the fitting hole 6A. The bearing 22 is axially positioned on the front end side of the inserted insertion portion 27A. The space between the driven boss 6 and the cap 27 is sealed by an O-ring 28 as shown in FIG. 4 to prevent the lubricating oil G contained in the casing 4 from leaking to the outside of the casing 4.

In the power transmission device configured as described above, when the engine operates and the flywheel 1 rotates, the flange joint 10 connected to the flywheel 1 via the plate 11 rotates, and this rotation causes the drive shaft to rotate. It is transmitted to the drive gear 14 via 9. As a result, the drive gear 14
The input shaft 23B of the hydraulic pump 23 splined to the small diameter spline hole 14B of the
The hydraulic pump 23 operates to discharge the pressure oil from the inside.

The rotation transmitted to the drive gear 14 is
It is transmitted to the sleeve 18 of the driven gear 17 via the tooth portion 20A meshed with the tooth portion 14C of the drive gear 14. And
By the rotation of the sleeve 18, the spline coupling portion 25
The driven shaft 24B is rotationally driven through the pump main body 24A.
The gear pump 24 operates to discharge the pressure oil from the inside.

Thus, when the engine is operating,
When the rotational force of the flywheel 1 is transmitted to the hydraulic pump 23, the gear pump 24, or the like via the power transmission device 2, the lubricating oil G contained in the casing 4 is the tooth portion 14C of the drive gear 14 and the driven gear 17. While being scooped up by the tooth portions 20A of the casing and scattered into the casing 4, or while flowing down along the inner wall of the casing 4, the spline coupling portion of the drive shaft 9 and the input shaft 23B of the hydraulic pump 23 are Spline coupling part and drive gear 14
The tooth surface of the tooth portion 14C and the tooth portion 20A of the driven gear 17,
Further, it is supplied to the friction surfaces of the bearings 13, 15, 16, 21, 22 for lubrication to compensate for smooth operation of the power transmission device 2.

[0017]

By the way, in the above-described conventional power transmission device 2, the one end side of the sleeve 18 constituting the driven gear 17 and the bearing hole 6 of the driven side boss portion 6 are formed.
Since a bearing 22 such as a bush is interposed between B and B, the lubricating oil G that flows down the inner wall of the casing 4 and flows downward as shown by an arrow A in FIG.
It is supplied to the spline coupling part 25 from one end side of the sleeve 18 through the inner wall of the bearing 21 and the inner ring and the outer ring of the bearing 21. Therefore, the spline coupling unit 25
Cannot supply a sufficient amount of lubricating oil G, and it is difficult to form an oil film on the spline coupling portion 25 when the power transmission device 2 operates, and the spline hole 18B formed in the shaft insertion hole 18A of the sleeve 18 and the driven shaft 24B has a problem that abrasion and seizure are likely to occur due to oil film breakage.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to reliably supply the lubricating oil toward the spline joint portion between the shaft insertion hole of the driven gear and the driven shaft, and to the spline joint portion. It is an object of the present invention to provide a power transmission device capable of preventing wear, seizure, and the like from occurring over a long period of time.

[0019]

In order to solve the above-mentioned problems, a power transmission device according to the present invention includes a casing having a driving side boss portion and a driven side boss portion, in which lubricating oil is contained. A rotatably provided on a drive side boss portion of the casing and rotatably provided on a driven gear boss portion of the casing so as to mesh with the drive gear driven by a drive source. The driven gear has a shaft insertion hole and a driven shaft that is spline-coupled to the shaft insertion hole of the driven gear and transmits the rotation of the drive shaft via the drive gear and the driven gear.

The features of the configuration adopted by the present invention are:
In the casing, an oil passage for guiding the lubricating oil in the casing into the driven side boss portion and the driven passage for guiding the lubricating oil from the oil passage toward the spline coupling portion between the driven gear and the driven shaft are provided. There is provided a lubricating oil guide which is located so as to face the shaft in the axial direction and whose tip side projects toward the shaft insertion hole of the driven gear.

Further, it is desirable that the shaft insertion hole of the driven gear be provided with a tapered surface whose diameter gradually increases from the lubricating oil guide side toward the spline coupling portion side.

[0022]

With the above construction, the lubricating oil in the casing is introduced into the driven side boss through the oil passage and then supplied to the spline joint between the shaft fitting insertion hole of the driven gear and the driven shaft by the lubricating oil guide. It

Further, if a tapered surface is provided in the shaft insertion hole of the driven gear, the diameter of which gradually increases toward the spline coupling portion.
The lubricating oil guided to the shaft insertion hole is forcibly supplied to the spline coupling portion along the tapered surface by the centrifugal force generated when the driven gear rotates.

[0024]

Embodiments of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the conventional technique shown in FIG. 4 described above are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows a first embodiment of the present invention.

In the figure, reference numeral 31 denotes a casing of the power transmission device according to this embodiment, which has a front side wall portion 31A and a rear side wall portion 31B, which is similar to the casing 4 described in the prior art. The rear side wall portion 31B is integrally provided with a first driven side boss portion 32 in which a large diameter fitting hole 32A and a small diameter bearing hole 32B are formed. Also,
A second driven-side boss portion 33 having a mounting hole 33A is integrally provided on the front side wall portion 31A of the casing 31. However, the casing 31 according to the present embodiment is different in that a boss side oil passage 34, which will be described later, is formed in the driven side boss portion 32.

Reference numeral 34 denotes a groove-shaped boss-side oil passage formed in the driven-side boss portion 32. The boss-side oil passage 34 is located above the peripheral portion of the driven-side boss portion 32 protruding into the casing 31. Is formed by notching downward from the wall surface 34A, and the wall surface portion 34A extends to an intermediate portion between the fitting hole 32A and the bearing hole 32B. Further, the boss side oil passage 34 constantly communicates the inside of the casing 31 with the boss space B via a cap side oil passage 36 described later.

Reference numeral 35 denotes a cap that closes the fitting hole 32A of the driven side boss portion 32 and constitutes a part of the casing 31, and the cap 35 is substantially the same as the cap insertion portion 35A described in the prior art. And a cap 35 having a flange portion 35B, the lubricating oil guide 3 to be described later is attached to the cap 35.
7 are integrally formed. Further, the fitting insertion portion 35A of the cap 35 is formed to be relatively thick and forms an annular boss space B having a small volume with the bearing 22.

Reference numeral 36 denotes a cap side oil passage formed by partially notching the tip end side of the fitting insertion portion 35A of the cap 35. The cap side oil passage 36 fits the cap 35 to the driven side boss portion 32. When fitted in the dowel hole 32A, it matches the boss side oil passage 34 and allows the boss space B to communicate with the casing 31.

Reference numeral 37 denotes a lubricating oil guide which axially projects from the insertion fitting portion 35A of the cap 35.
7, the base end side has a large diameter and is integrally formed with the insertion fitting portion 35A, and the tip end portion is formed in a tapered shape so that the diameter gradually decreases. Then, the tip end portion of the lubricating oil guide 37 projects toward the shaft insertion hole 18A of the sleeve 18, and the lubricating oil G flowing into the boss space B is axially inserted as shown by an arrow C in FIG. Guide it into the hole 18A.

The power transmission device according to the present embodiment has the structure as described above, and the basic operation thereof is not different from that of the prior art.

However, in this embodiment, the first driven-side boss portion 32 is provided with the boss-side oil passage 34 and the cap 35 is provided with the cap-side oil passage 36 so that they communicate with each other. Since the lubricating oil guide 37 extending toward the shaft insertion hole 18A of the sleeve 18 is integrally formed with the cap 35, the following operational effects can be obtained.

That is, the lubricating oil G stored in the casing 31 during the operation of the power transmission device is scraped up by the tooth portion 14C of the drive gear 14 or the tooth portion 20A of the driven gear 17, and then the casing 31 Walls 31A, 31
It flows down along the inner wall surface of B, etc. The lubricating oil flowing along the rear side wall portion 31B of the casing 31 at this time is boss side oil passage 34 as shown by an arrow C in FIG.
To the wall surface portion 34A of the sleeve 18, and is further guided into the shaft insertion hole 18A of the sleeve 18 along the tapered outer peripheral surface of the cap side oil passage 36, the boss space B and the lubricating oil guide 37. Therefore, the spline hole 18 formed in the shaft insertion hole 18A
A sufficient amount of lubricating oil G for forming an oil film can be supplied from the direction of arrow D to the spline coupling portion 25 between B and the driven shaft 24B of the gear pump 24.

Therefore, according to this embodiment, the casing 3
While guiding the lubricating oil G in the casing 31 through the boss side oil passage 34 and the cap side oil passage 36 into the driven side boss portion 32 and the boss space B of No. 1, the lubricating oil G is surely supplied to the spline coupling portion 25. Can be supplied, spline 18 of sleeve 18
It is possible to prevent wear, seizure or the like from occurring between B and the driven shaft 24B for a long period of time.

Next, FIG. 2 shows a second embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 2, the feature of this embodiment is that a shaft insertion hole 41A extending in the axial direction of the sleeve 41 is a tapered surface 41C whose inner peripheral side gradually expands toward the spline hole 41B side. Especially.

Here, the sleeve 41 has a tapered surface 41C.
Except for the above, the sleeve 18 has the same configuration as the sleeve 18 described in the related art, and the driven gear 17 is configured with the gear body 20.
When the power transmission device operates, the boss side oil passage 34,
Cap side oil passage 36, boss space B and lubricating oil guide 3
7 along the tapered outer peripheral surface of the sleeve 41.
The lubricating oil G introduced into 1A is a tapered surface 41C of the shaft insertion hole 41A due to the centrifugal force generated by the rotation of the driven gear 17.
Is forcibly supplied to the spline coupling portion 25 along.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same operation and effect as in the first embodiment, but particularly in this embodiment, the spline connection is made by the taper surface 41C of the sleeve 41. The lubricating oil G can be supplied to the portion 25 more effectively.

In the second embodiment, the sleeve 4
41C on the inner peripheral side of the shaft insertion hole 41A drilled in
However, instead of this, for example, like the sleeve 18 shown in FIG. 1, another cylindrical member having an inner peripheral surface that is a tapered surface may be arranged in the shaft insertion hole 18A having the same diameter. You may

In each of the above embodiments, the casing 31
Although the cap 35 is described as being fitted and fixed in the fitting hole 32A formed in the driven side boss portion 32, the present invention is not limited to this, and for example, a portion corresponding to the cap 35 is integrally formed with the casing 31. At the same time, the lubricating oil guide 37 may be integrally formed in this portion.

[0041]

As described above in detail, according to the present invention, in the casing of the power transmission device, an oil passage for communicating the inside of the driven side boss portion that rotatably supports the driven gear with the casing,
Since the lubricating oil guide that axially opposes the driven shaft and projects toward the shaft fitting hole of the driven gear is provided, the lubricating oil in the casing during the operation of the power transmission device is driven by the oil passage to the driven boss. After being guided into the portion, the lubricating oil guide guides it to the shaft fitting insertion hole of the driven gear and supplies it to the spline coupling portion. Therefore, it is possible to supply sufficient lubricating oil to form an oil film at the spline joint portion, and it is possible to reliably prevent wear, seizure, or the like from occurring at the spline joint portion.

Further, if the tapered surface portion of the driven gear in which the shaft insertion hole is gradually expanded toward the spline coupling portion is provided, the lubricating oil guided by the lubricating oil guide to the shaft insertion hole is rotated by the driven gear. By the centrifugal force, the spline joint can be forcibly supplied along the tapered surface portion, and the lubricating oil can be more effectively supplied to the spline joint.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional view of a main part of a power transmission device according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view similar to FIG. 1, showing a power transmission device according to a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view showing a power transmission device according to a conventional technique.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

[Explanation of symbols]

 1 Flywheel (Drive Source) 5, 7 Drive Side Boss 9 Drive Shaft 14 Drive Gear 17 Driven Gear 18, 41 Sleeve 18A, 41A Shaft Insertion Hole 18B, 41B Spline Hole 24B Driven Shaft 25 Spline Joint 31 Casing 32, 33 Driven side boss portion 34 Boss side oil passage 36 Cap side oil passage 37 Lubricating oil guide 41C Tapered surface

Claims (2)

[Claims] 1. A drive-side boss portion and a driven-side boss portion,
A casing in which lubricating oil is housed, a drive gear rotatably provided on a drive boss of the casing, and a drive gear driven by a drive source, and a driven boss of the casing so as to mesh with the drive gear. And a driven gear that is rotatably provided on the inner peripheral side and has a shaft insertion hole, and is splined to the shaft insertion hole of the driven gear, and the rotation of the drive shaft is transmitted through the drive gear and the driven gear. In the power transmission device including a driven shaft, the casing has an oil passage for guiding the lubricating oil in the casing into the driven side boss portion, and the lubricating oil from the oil passage is splined between the driven gear and the driven shaft. In order to guide toward the coupling portion, a lubricating oil guide is provided that is axially opposed to the driven shaft and has a tip end side that projects toward the shaft insertion hole of the driven gear. Transmission device. 2. The power transmission device according to claim 1, wherein the driven gear has a shaft insertion hole provided with a tapered surface portion that gradually increases in diameter from the lubricating oil guide side toward the spline coupling portion side.