JPH0474522B2 - - Google Patents

Abstract

PURPOSE:To prevent specific-area wear on the spiral locally-contacting surface by preventing oil from leaking outside through the larger clearance part between turning engagement faces to permit sufficient lubrication for the spiral locally-contacting surface of an idle gear. CONSTITUTION:There is a system in which the circumferential surface 9 of the bearing of an idle gear 8 mounted in the timing helical gear transmission of an engine has the oil supply port 11 of a force feed type lubricating device and this lubricating device forces lubricating oil to be fed from an oil supply port 11 into the clearance 12 between the turning engagement faces of both the bearing circumferential face 9 of an idle gear shaft 8 and the boss hole 7 of the idle gear 4. Of the bearing circumferential face 9 of the idle gear shaft 8, a spiral locally contacting face part 13 which is a circumferential part and in parallel with the axis of said gear 8 is pressed by the internal peripheral face of the boss hole 7 of the idle gear 4 while the gear 4 is turned to transmit power. Additionally, of the bearing circumferential face 9 of the idle gear shaft 8, a part in the slightly supper position that the spiral locally- contacting face part 13 with respect to the turning direction of the idle gear 4 has an oil supply port 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pressure-feed lubricating device for an idle gear bearing of a timing helical gear transmission for an engine.

[Background of the invention]

As is well known, a timing helical gear transmission for an engine transmits the timing of an intake/exhaust camshaft of a valve train or a fuel injection camshaft of a fuel injection device to a crankshaft. The basic structure of a diesel engine, for example, is as shown in FIG.

That is, the timing helical gear transmission 2 of the engine 1
The timing transmission gears 5 and 6 are meshed with the crank gear 3 of the engine via the idle gear 4, and each of these gears 3
- 6 are helical gears, the boss hole 7 of the idle gear 4 is rotatably supported on the bearing peripheral surface 9 of the idle gear shaft 8, and the idle gear shaft 8 is fixed to the fixed wall 10 of the engine 1. be.

There are two timing transmission gears 5 and 6, one of which is the valve gear 5 and the other is the fuel injection gear 6. In the case of a gasoline engine, there is no fuel injection gear 5.

In the transmission device 2 described above, the device for lubricating the bearing portion of the idle gear 4 by force feeding it is basically as follows.

For example, as shown in FIG. 2, FIG. 7, or FIG. 9, an oil supply port 11 of a pressure-feeding type lubrication device is opened on the bearing peripheral surface 9 of the idle gear shaft 8, and lubricating oil is supplied by the pressure-feeding type lubrication device. It is configured such that it is fed under pressure from the opening 11 to the space 12 between the rotational fitting surfaces between the bearing circumferential surface 9 of the idle gear shaft 8 and the boss hole 7 of the idle gear 4.

[Conventional technology]

The pressure feed type lubrication device for the idle gear bearing section is as follows:
Conventionally, the configuration is generally as shown in FIG. 9.

That is, the oil supply port 11 is opened at the center of the bearing peripheral surface 9 of the idle gear shaft 8 in the axial direction. A circumferential oil groove 14 is formed in the axial center of the inner peripheral surface of the boss hole 7 of the idle gear 4.

[Problem to be solved by the invention]

In the prior art shown in FIG. 9, although the oil is sufficiently pumped and supplied, a part of the bearing peripheral surface 9 of the idle gear shaft 8 in the circumferential direction has a spiral shape along the axial direction. The uneven contact surface portion 13 actually suffers uneven wear.

The present invention aims to clarify the cause of uneven wear described above, and
The challenge is to eliminate this uneven wear.

[Means to solve the problem]

First, we will clarify the cause of uneven wear.

As shown in FIG. 6, the idle gear 4 receives a circumferential component force f ₁ in the right direction due to the driving force at the input portion 15 in helical mesh with the crank gear 3, and the The output portions 16 and 17 of each helical mesh receive circumferential component forces f ₂ and f ₃ due to the drive resistance in a rightward direction. These circumferential component forces f ₁ , f ₂ , f ₃
The resultant force F forces the idle gear 4 to the right.

Also, as shown in Fig. 5, the idle gear 4
The helical mesh input section 15 receives the axial component force f ₁₁ due to the driving force backwards, and the helical mesh input sections 16 and 17 receive the axial component force due to the driving resistance.
Receive f ₁₂ and f ₁₃ forward.

The idle gear 4 is tilted forward and downward by the force couple M generated from these axial component forces f ₁₁ , f ₁₂ , and f ₁₃ .

As the idle gear 4 is pushed to the right side by the resultant force F as described above and tilted forward by the force couple M, the left side surface portion of the bearing circumferential surface 9 of the idle gear shaft 8 is pushed in the axial direction. The inner circumferential surface of the boss hole 7 of the idle gear 4 is pressed against the front downward spiral piece contact portion 13 along the front downward spiral piece.

Boss hole 7 of idle gear 4 and idle gear shaft 8
A gap 12 between the rotational fitting surface 9 and the bearing circumferential surface 9 is closed by the spiral piece abutting surface portion 13, and increases as the distance from this portion in the circumferential direction increases.

Oil flows from the oil supply port 11 to the circumferential oil groove 14
through the rotary mating surfaces 12.
The oil easily leaks to the outside through a large gap between the rotating fitting surfaces 12 on the side opposite to the spiral piece abutting portion 13. For this reason, the spiral piece abutting surface portion 13 whose gap is closed is hardly supplied with oil, resulting in uneven wear.

The present invention solves the above causes of uneven wear.
By preventing oil from easily leaking to the outside through the part with a large gap between the rotating fitting surfaces 12, a sufficient amount of oil can be supplied to the helical piece abutting surface part 13. .

For this purpose, as shown in FIGS. 1 to 4 or 7 and 8, for example, the idle gear shaft 8
The inner circumferential surface of the boss hole 7 of the idle gear 4 during rotation transmission is pressed against the spiral piece abutting surface portion 13 of the bearing circumferential surface 9 along the axial direction in a part of the circumferential direction of the bearing circumferential surface 9, and the idle gear Of the bearing peripheral surface 9 of the shaft 8,
It is characterized in that the oil supply port 11 is opened along the length direction of the spiral piece contact surface portion 13 in a peripheral surface portion slightly above the spiral piece contact surface portion 13 in the rotational direction of the idle gear 4. That is.

As a specific structure of the portion where the oil supply port 11 is opened along the length direction of the spiral piece contact surface portion 13, as shown in FIGS. 1 to 4, a plurality of oil supply ports 11 are formed. It is conceivable to open the oil supply ports 11 in parallel, or to form the oil supply ports 11 in the form of long grooves as shown in FIG.

[Effect]

The effects of the present invention are illustrated in FIGS. 3 and 4 or 8.
This will be explained based on the diagram.

The oil is fed under pressure from the oil supply port 11 to a part of the rotary fitting surface 12 where the gap is slightly narrower on the upper side of the rotation than the helical piece abutting surface portion 13.

First, at the point where the oil comes out from the oil supply port 11, the oil tends to be forced out radially as shown in the imaginary diagram 18.

Next, among the oil that has been pushed out radially, the oil in the front end region 19 tries to leak forward, and the oil in the rear end region 20 tries to leak backward, as shown in the broken line diagram, but there is a gap. It's narrow and doesn't leak easily. For this reason, the intermediate region portion 21 is pressed from both the front and back and tends to be held there.

The oil in the intermediate region 21 adheres to the inner circumferential surface of the boss hole 9 of the rotating idle gear 8 and is strongly applied to the helical piece contact surface 13 as shown in the solid line diagram 22. go.

〔Effect of the invention〕

The present invention has the following effects.

B. As described above, the oil in the intermediate region portion 21 illustrated in FIG. 4 or FIG.
As shown in FIG.
It can strongly prevent uneven wear.

Moreover, the new structure required for this purpose is simple and can be implemented at low cost since it only requires a plurality of oil supply ports or a long groove shape.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

◎Embodiment 1 (See Figs. 1 to 5) Fig. 5 shows a timing helical gear device 2 of a vertical multi-cylinder diesel engine 1.

A valve gear 5 and a fuel injection gear 6 are meshed with the crank gear 3 via an idle gear 4. Busbar gears are used for each of these gears 3-6.

As shown in FIGS. 1 and 2, the boss hole 7 of the idle gear 4 is rotatably supported on the bearing peripheral surface 9 of the idle gear shaft 8. As shown in FIGS. The idle gear 4 is secured to the idle gear shaft 8 by a washer 31 and a C-shaped retaining ring 32. The idle gear shaft 8 is fixed to the front wall of the crankcase 10 of the engine 1 with bolts 33.

1 to 4 show a pressure feed type lubrication device for the bearing portion of the idle gear 4 of the transmission device 2. As shown in FIG.

An oil supply port 11 at the end of an oil pumping path of a pumping type lubrication device (not shown) is opened in the bearing circumferential surface 9 of the idle gear shaft 8 . As a result, lubricating oil is supplied from the oil supply port 11 to the rotating fitting surface 12 between the bearing circumferential surface 9 of the idle gear shaft 8 and the boss hole 7 of the idle gear 4 by the lubricating pump (not shown) of the pressure-feeding lubrication device. It is configured to be pumped.

The crank gear 3 rotates to the right, and the idle gear 4 rotates to the left. The valve train gear 5 and the fuel injection gear 6 rotate to the right. The inner circumferential surface of the boss hole 7 of the idle gear 4 during rotational transmission is pressed against the spiral piece abutting surface portion 13 of the bearing circumferential surface 9 of the idle gear shaft 8, which extends along the axial direction on the left side surface portion thereof.

Of the bearing circumferential surface 9 of the idle gear shaft 8, a portion of the circumferential surface slightly above the helical piece abutting surface portion 13 in the rotational direction of the idle gear 4, along the length direction of the helical piece abutting surface portion 13. Thus, three oil supply ports 11 are opened in parallel.

Two, four, or five or more oil supply ports 11 may be arranged in parallel.

In addition, in FIG. 5, as shown in a virtual diagram, work equipment 34 such as a hydraulic pump for hydraulic work is
may be attached to the engine 1 and used by meshing the input work gear 35 of the work equipment 34 with the fuel injection gear 6.

In this case, the driving reaction force of the working equipment 34 is applied to the helical mesh output portion 17 of the idle gear 4 on the fuel injection gear 6 side. For this reason, the circumferential component forces f ₃ , f ₁ and the axial components f ₁₃ , f ₁₁ that the output portion 17 and input portion 15 of the helical mesh receive become extremely large, and the helical piece contact surface portion 13 , surface pressure becomes extremely high, and uneven wear is likely to occur due to oil leakage.

Even in such a case, according to the present invention, as explained in the above [Operation] and [Advantageous Effects] sections, the intermediate region portion 2 illustrated in FIG. 4 or FIG.
Since the oil of No. 1 is strongly applied to the helical piece abutment surface portion 13 as shown in the solid line diagram 22, uneven wear of the helical piece abutment surface portion 13 can be strongly prevented.

◎Embodiment 2 (see FIGS. 7 and 8) In this embodiment 2, a part of the structure of the above embodiment 1 (FIGS. 1 to 6) is changed as follows.

As shown in FIGS. 7 and 8, the oil supply port 11 is formed in the shape of one long groove. As in the case of the first embodiment, this long groove-shaped oil supply port 11 is located on the side of the bearing peripheral surface 9 of the idle gear shaft 8 that is slightly above the spiral piece contact surface portion 13 in the rotational direction of the idle gear 4. The spiral piece runs along the length of the contact surface portion 13 on the circumferential surface portion of the spiral piece.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the present invention.
Fig. 1 is an exploded perspective view of the idle gear portion, Fig. 2 is an assembled longitudinal sectional side view of Fig. 1, Fig. 3 is an assembled longitudinal sectional front view of Fig. 1 with important parts exaggerated for explanation of operation, and Fig. 4 5 is a perspective view of a timing helical gear transmission for a vertical multi-cylinder diesel engine, and FIG. 6 is an exploded front view of the main parts of FIG. 5. Embodiment 2 of the present invention is shown in FIGS. 7 and 8, in which FIG. 7 is a longitudinal cross-sectional side view of the idle gear portion, and FIG. 8 is a developed view of the portion shown in FIG. FIG. 9 is a vertical sectional side view of a conventional idle gear portion. 1... Engine, 2... Timing helical gear transmission, 3... Crank gear, 4... Idle gear,
5, 6... Timing transmission gear, 7... Boss hole, 8...
Idle gear shaft, 9... Bearing peripheral surface, 10... Fixed wall, 11... Oil supply port, 12... Between rotating fitting surfaces, 13... Spiral piece contact surface portion.

Claims (1)

[Scope of Claims] 1 Timing transmission gears 5 and 6 are meshed with the crank gear 3 of the timing helical gear transmission 2 of the engine 1 via the idle gear 4, and each of these gears 3 to 6
Using a helical gear, the boss hole 7 of the idle gear 4 is rotatably supported on the bearing circumferential surface 9 of the idle gear shaft 8, the idle gear shaft 8 is fixed to the fixed wall 10 of the engine 1, and the idle gear shaft An oil supply port 11 of a pressure-feeding type lubrication device is opened on the bearing circumferential surface 9 of 8, and lubricating oil is supplied to the oil supply port 1 by the pressure-feeding type lubrication device.
Pressure-feed lubrication of an idle gear bearing part of an engine timing helical gear transmission device configured to pump lubrication from 1 to a rotating fitting surface 12 between a bearing peripheral surface 9 of an idle gear shaft 8 and a boss hole 7 of an idle gear 4 In the device, the inner periphery of the boss hole 7 of the idle gear 4 during rotation transmission is attached to the spiral piece contact surface portion 13 along the axial direction in a part of the circumferential direction of the bearing peripheral surface 9 of the idle gear shaft 8. The surfaces are pressed against each other, and the spiral piece contact surface portion 13 is pressed against the surface of the bearing peripheral surface 9 of the idle gear shaft 8 at a portion of the peripheral surface slightly above the spiral piece contact surface portion 13 in the rotational direction of the idle gear 4. A pressure-feed lubricating device for an idle gear bearing part of an engine timing helical gear transmission device, characterized in that an oil supply port 11 is opened along the length direction.