JPH0692727B2 - Power unit lubricator for small engines - Google Patents

Abstract

PURPOSE:To reduce the rotating resistance of a speed change gear by providing a pressure releasing hole on an auxiliary tank which is interposed between an oil pump inside an engine case and parts to be lubricated, and communicating the interior of the engine case with the interior of the auxiliary tank, so that the oil level in the engine case can be lowered. CONSTITUTION:An engine case 11 is partitioned into a small chamber as a power transmission chamber 15 and a large chamber via a partition wall 13, and further the large chamber is divided into a crank chamber 19 and a speed change gear chamber 21 via a partition wall 17. On the lower part of the partition wall 13 a penetrating hole 23 is provided to communicate the bottom part of the speed change gear chamber 21 with the bottom part of the power transmission chamber 15. An auxiliary lubricating oil tank 47 is integrally formed inside the speed change gear chamber 21, and the oil pump inside the power transmission chamber 15, after temporarily storing oil in the auxiliary tank 47 via an oil passage 42, supplies it to the parts to be lubricated via oil passages 44. When the pressure inside the auxiliary tank 47 rises, oil is discharged through a pressure releasing pipe 49 so as to be sprayed on speed change gears 41.

Description

The present invention relates to a power unit lubricating device for a small engine.

[Description of Prior Art]

The conventional power unit lubrication device for small engines is
The oil in the oil reservoir in the transmission chamber is supplied to the oil-supplied part by the operation of the oil pump.

[Problems of conventional technology]

However, in such a conventional power unit lubrication device, since the oil sump is formed at the bottom of the transmission chamber, as a result of the operating portion of the transmission coming into contact with the liquid surface of the oil sump, the rotation resistance of the transmission is reduced. It had the disadvantage that it had to be increased.

[Means for Solving the Problems]

An object of the present invention is to eliminate the above-mentioned inconvenience. A transmission chamber having an oil sump is integrally incorporated in a crank chamber in an engine case, and a power transmission chamber is provided on a side surface of the crank chamber and the transmission chamber. The power transmission chamber and the transmission chamber are communicated with each other through a through hole to form an oil reservoir at the bottom of the power transmission chamber and the transmission chamber, and an oil pump is installed in the power transmission chamber. Is a power unit lubrication device for supplying the lubricating oil of section 1 to the portion to be lubricated, wherein a lubricating oil tank is provided in a part of the transmission chamber, and the lubricating oil tank is interposed between the oil pump and the portion to be lubricated. This is achieved by providing a pressure release hole in the lubricating oil tank and communicating the inside of the lubricating oil tank with the transmission chamber by the pressure release hole.

[Operation of the Invention] Since the power unit lubrication apparatus for a small engine according to the present invention is configured as described above, that is, the power transmission chamber is also used as an oil reservoir and the lubricating oil is temporarily stored in the lubricating oil tank. Therefore, the liquid level of the oil sump in the engine case, that is, in the transmission chamber is lower than that of the conventional one, and the operating portion of the transmission can be separated from the liquid level of the oil sump. Rotational resistance is reduced. Lubricant oil is also supplied from the pressure relief hole to the operating portion.

[Explanation of Examples]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, 11 is an engine case. In this engine case 11, a small chamber is divided into a power transmission chamber 15 via a partition wall 13.
And a large chamber is partitioned by a partition wall 17 into a crank chamber 19 and a transmission chamber 21 (see FIG. 2).

Reference numeral 23 is a through hole, which is formed in the lower portion of the partition wall 13.

The through hole 23 connects the bottom of the transmission chamber 21 and the bottom of the power transmission chamber 15, and in other words, the oil sump O of the transmission chamber 21 is expanded to the power transmission chamber 15.

Reference numeral 25 is a piston that moves forward and backward in a cylinder integrally formed with the crank chamber 19. Further, 27 is a connecting rod, which connects the piston 25 and the crankshaft 29. This connecting rod 27
By the crankshaft 29, the forward / backward movement of the piston 25 is transmitted to the engine shaft 31 as a rotational movement. A driving gear 33 is fixed to the engine shaft 31 protruding into the power transmission chamber 15. The driving gear 33 transmits the rotational force to the primary side of the clutch 35 installed in the power transmission chamber 15. Reference numeral 37 denotes a transmission main shaft connected to the secondary side of the clutch 35, and is installed in the transmission chamber 21. Further, 39 is an opposite shaft of the transmission, and the transmission room
21 is installed in parallel with the main shaft 37. The counter shaft 39 and the main shaft 37 are appropriately linked by a speed change gear 41.

Next, 43 is an oil pump, which is installed in the power transmission chamber 15. The oil pump 43 temporarily stores the lubricating oil in the oil sump O (see FIG. 1) in the power transmission chamber 15 in the lubricating oil tank 47 described later via the oil passage 42, and thereafter, via the oil passage 44. The oil is supplied to the oil supply section (the main shaft 37 of the transmission, the counter shaft 39, etc.). Reference numeral 45 denotes an intervening gear (see FIG. 1), which transmits the rotation of the engine shaft 31 to the oil pump 43.

47 is a lubricating oil tank, which is integrally formed in the transmission chamber 21. Reference numeral 49 is a pressure relief pipe corresponding to the pressure relief hole of the present invention, and is fitted on the upper surface of the lubricating oil tank 47. When the inside of the lubricating oil tank 47 becomes overpressured, the depressurizing pipe 49 discharges the lubricating oil so as to spray it onto the speed change gear 41, and adjusts the pressure to an appropriate pressure.

〔The invention's effect〕

Since the power unit lubrication apparatus for a small engine according to the present invention is configured as described above, the transmission chamber having the oil sump is integrally incorporated in the crank chamber in the engine case, and the crank chamber and the transmission chamber are separated from each other. A power transmission chamber is provided on a side surface, the power transmission chamber and the transmission chamber are communicated with each other through a through hole, and the bottoms of the power transmission chamber and the transmission chamber serve as oil reservoirs, and an oil pump is installed in the power transmission chamber. By operating the oil pump, the lubricating oil in the oil sump is supplied to the oil-supplied part. Therefore, unlike the conventional dry sump type lubrication, two oil pumps for supplying oil and returning to the tank are required. In comparison, the number of pumps is small, and the bottoms of the power transmission chamber and the transmission chamber are used as oil reservoirs, a lubricating oil tank is provided in a part of the transmission chamber, and the lubricating oil tank is provided between the oil pump and the portion to be lubricated. With a lubricating oil tank The lubricating oil tank is provided with a pressure release hole, and the pressure release hole communicates the inside of the lubricating oil tank with the transmission chamber, so that the oil sump is expanded to the power transmission chamber and the liquid level of the oil sump is increased. Compared with the conventional type, the operating part of the transmission is separated from the liquid surface of the oil sump, so the rotational resistance of the transmission is reduced, and lubricating oil can be supplied from the pressure relief hole to the operating part. Does not cause insufficient lubrication. In addition, the lubricating oil tank can increase the amount of lubricating oil and reduce deterioration of the oil.

[Brief description of drawings]

1 and 2 show an embodiment of a power unit lubricating device for a small engine according to the present invention. FIG. 1 is a longitudinal sectional view, and FIG. 2 is a sectional view taken along the line II-II in FIG. It is a figure which shows the principal part. O …… Oil sump 11 …… Engine case 15 …… Power transmission chamber 19 …… Crank chamber 21 …… Transmission chamber 23 …… Through hole 37,39 …… Oiled part 43 …… Oil pump 47 …… Lubricating oil Tank 49 ... Pressure release hole

Claims (1)

[Claims] 1. A transmission chamber having an oil sump is integrated into a crank chamber in an engine case, a power transmission chamber is provided on a side surface of the crank chamber and the transmission chamber, and the power transmission chamber and the transmission chamber are provided. The bottoms of the power transmission chamber and the transmission chamber are connected to each other through a through hole to form an oil reservoir, an oil pump is installed in the power transmission chamber, and the oil pump operates to supply the lubricating oil in the oil reservoir to the oil-supplied part. A power unit lubrication device for
A lubricating oil tank is provided in a part of the transmission chamber, the lubricating oil tank is interposed between the oil pump and a portion to be supplied with oil, and a depressurizing hole is provided in the lubricating oil tank. A power unit lubrication device for a small engine, characterized in that the inside of the lubricating oil tank and the interior of the transmission are communicated with each other.