JPH0335526B2 - - Google Patents

Abstract

PURPOSE:To simplify the structure of lubricating oil pass system, to improve engine speed, and to reduce the cost of engines by providing a center hole at the center of a crank shaft and connecting one end of it to a radial direction hole heading the inner face of the bearing metal of a free wheel gear and another end to a power source through a choke bore respectively. CONSTITUTION:A crank shaft 1 is provided with a radial direction hole 21 and center hole 22 for metal lubricating and an enlarged opening section 26 at the right end. And an oil introducing bore 29 is provided to a crank shaft 2. One end of the oil introducing bore 19 is connected to an oil pump 34 through an oil sump 31 and oil pass 32, and another end is to the periphery of a crank pin 5 through a choke bore 37, oil introducing bore 38, and choke bore 39. And a part of pressure oil becomes an oil jet 27 through the choke bore 37 and is supplied to the inner face of a bearing metal 13 through the enlarged opening section 26 and center hole 22. The structure of lubricating oil pass system is, thus, so simple that the improvement of engine speed and the cost reduction of engines can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lubricating device for a starter motor freewheel gear of an engine having a freewheel gear driven by a starter motor rotatably on a crankshaft.

(Prior art) For example, in a motorcycle engine, a freewheel gear driven by a starter motor is rotatably supported on the crankshaft via a bearing metal, and this freewheel gear is connected via a one-way clutch only at the time of starting. It is connected to the crankshaft in such a way that it can apply rotational force to the crankshaft. However, since the freewheel gear is stationary after the engine starts, it is necessary to supply oil for lubricating the bearing metal to the sliding surface between the bearing metal and the rotating crankshaft. An oil collection plate is attached to the side of the gear to collect oil droplets in the crank chamber and supply them to the bearing metal, but this can lead to poor lubrication, especially in high-speed engines such as racers. If the crankshaft bearing near the freewheel gear is metal, pressurized oil can be supplied to the oil introduction hole in the crankshaft through this metal part, and oil can be supplied to the freewheel gear bearing metal from inside the crankshaft. However, in that case, the oil passage structure in the metal part of the crankshaft bearing becomes complicated.

(Object of the Invention) The present invention utilizes an oil introduction hole provided at the center of the crankshaft to lubricate the crank pin and the bearing at the large end of the connecting rod. The purpose is to supply sufficient lubricating oil to the bearing metal from within the crankshaft.

(Structure of the Invention) The present invention includes concentric first and second crankshafts 1 and 2 having a pair of crank arms 3 and 4 that face each other across a space 25 and are integrated via a crank pin 5. A generator 14 is tapered fitted to the tip of the first crankshaft 1 opposite to the crank arm 3, and is secured by a central bolt 15, and a freewheel driven by a starter motor is mounted on the first crankshaft 1 adjacent to the generator 14. The gear 12 is rotatable in only one direction, and the oil introduction hole 29 is located at the center of the second crankshaft 2.
The opening on the opposite side of the crank arm 4 is connected to the oil pump 34 through an oil reservoir 31 sealed with a high-pressure oil seal 35, and the oil introduction hole 29 is connected to the crank pin 5 through an oil introduction hole 38 in the crank pin 5. In a single-cylinder engine having an opening on the surface of the crankshaft, the first and second crankshafts 1 and 2 are supported on the crankcase via ball bearings 8 and 9, and the crank arm 4 of the oil introduction hole 29 in the second crankshaft 2 is supported on the crankcase through ball bearings 8 and 9. A throttle hole 37 is provided at the end of the side, and an enlarged portion 2 is provided at the end of the center hole 22 of the first crankshaft 1 on the crank arm 3 side to receive the oil jet 27 spouted from the throttle hole 37.
6 is provided, and the other end of the center hole 22 is opened toward the large diameter hole 23 that is closed with the bolt, and the large diameter hole 2
3 through the radial hole 21 to the freewheel gear 1
This is a lubricating device for a cell motor freewheel gear with an opening facing the inner circumferential surface of the second bearing metal.

(Example) In Fig. 1, the left and right crankshafts 1,
2 are integrally provided with crank arms 3 and 4, respectively, and both crank arms 3 and 4 are integrally connected by a crank pin 5. A large end of a connecting rod 7 is rotatably supported on the crank pin 5 via a needle bearing 6. The left and right crankshafts 1 and 2 are both rotatably supported by a crankcase (not shown) via crankshaft bearing ball bearings 8 and 9, and a cam and a balancer are mounted on the crankshaft 1 on the left side of the ball bearing 8. The drive sprocket 10 is press-fitted and then the spacer 11 is fitted, and then the freewheel gear 1 is driven by a starter motor (not shown).
The bearing metal 13 on the inner circumference of 2 is rotatably fitted,
A generator 14 is fastened to the left end of the generator 14 with bolts 15 . freewheel gear 1
The outer circumferential surface of the boss cylinder 16 at the center of 2 is supported by a coupling ring 18 via a one-way clutch 17.
The coupling ring 18 is attached to the generator 14 by bolt 1.
It is fixed at 9. The one-way clutch 17 is moved by the starter motor to move the freewheel gear 12 to arrow A.
When the engine is driven in the same direction, the generator 14 is driven in the same direction, but when the engine starts, the generator 1
4 begins to rotate at high speed in the direction of arrow A, one-way clutch 17 cuts off transmission of engine rotation to freewheel gear 12. A radial hole 21 for metal lubrication is provided in the crankshaft 1 so as to face the inner circumferential surface of the metal 13, and a central hole 22 for oil introduction (a longitudinal hole on the center line) communicates with the radial hole 21. ) is formed, and a bolt 1 is inserted into the large diameter hole 23 communicating with the left end of the center hole 22.
A screw hole 24 into which No. 5 is screwed is formed, and an enlarged portion 26 opening toward the space 25 between the crank arms 3 and 4 is formed at the right end. It is devised so that it can be accepted into 22.

The right crankshaft 2 has an oil introduction hole 29 in the center, and the right end of this oil introduction hole 29 opens into an oil reservoir 31 in the clutch cover 30.
The oil reservoir 31 is connected to an oil pump 34 (pressure source) through an oil passage 32 in the clutch cover 30 and an oil filter 33. 35 is a high pressure oil seal. The left end of the oil introduction hole 29 opens into the inter-crank arm space 25 through an oil throttle hole 37 (0.8 to 1 mm in diameter), and faces the needle bearing 6 through an inclined oil introduction hole 38 and a throttle hole 39. It opens on the outer peripheral surface of the crank pin 5.

Next, the operation will be explained. During normal operation after the engine is started, pressurized oil of, for example, 4 to 5 kg/cm ² is supplied into the oil reservoir 31, and most of this pressurized oil is supplied to the needle bearing 6 through the oil introduction hole 29. The remaining part is ejected from the oil throttle hole 37 as an oil jet 27 into the space 25, and this oil jet 27 is injected into the oil center hole 22 from the enlarged portion 26, and flows into the large diameter hole 23 due to inertial force. It accumulates in the radial hole 21 and is forcibly supplied to the inner circumferential surface of the bearing metal 13 by centrifugal force.

(Effects of the Invention) As explained above, according to the present invention, the pressurized oil in the oil introduction hole 29 of the crankshaft 2 on one side of the space 25 between the adjacent crank arms 3 and 4 is
The oil passes through the oil throttle hole 37, becomes the oil jet 27, jumps over the space 25, and is injected into the oil introduction center hole 22 of the other crankshaft 1, so that the oil is introduced into the oil inlet provided to lubricate the connecting rod big end needle bearing 6. Using the hole 29, oil can be forcibly supplied to the inner circumferential surface of the freewheel gear bearing metal 13 from within the crankshaft 1. Inside the crankshaft 1, there is a central hole 22 for introducing oil and a radial hole. Since only the hole 21 needs to be provided, the oil passage structure for lubrication of the freewheel gear bearing metal 13 is not only extremely simple, but also the bearing metal 13 can be lubricated by using the inertia and centrifugal force of the oil jet 27. become certain. Also, since it is no longer necessary to supply pressurized oil from the ball bearing 8 part to the central oil introduction hole 22, the ball bearing 8 can be used instead of the conventional metal one, making it easier to increase the speed of the engine. At the same time, it is possible to reduce costs. In short, in the present invention, the lubricating oil sent to the big end is obtained by the oil sent from the oil pump 34 first entering the oil reservoir 31 sealed with the high pressure oil seal 35, passing through the oil introduction holes 29, 38, and the throttle hole 39 ( (under sufficient pressure due to the presence of the throttle hole 37) to the large end needle bearing 6. Bearing lubrication of the freewheel gear 12 is carried out by ensuring the amount and pressure of oil for large end lubrication as described above, and then transferring the oil jet 27 metered through the throttle hole 37 to the first crankshaft 1 side (left side). side), is received by the widened part 26, is sent into the center hole 22, and is forced into the radial hole 21 from the inside of the large diameter hole 23 using centrifugal force.
Since the freewheel gear 12 is stationary during engine operation and its load is approximately its own weight, this amount and pressure of lubrication are sufficient. In addition, the proportion blocked by cooking stove 7 is 28° out of 360°.
Since the lubrication is only instantaneous, it is sufficient to lubricate the freewheel gear as described above.

(Another Embodiment) As shown in FIG. 2, if a press-fit plug 41 having a throttle hole 37 is adopted, there is no need to directly drill a small-diameter oil throttle hole 37 in a relatively large crankshaft 2, which reduces processing costs. is reduced.

[Brief explanation of drawings]

FIG. 1 is a partial vertical side view of a one-cylinder four-stroke engine to which the present invention is applied, and FIG. 2 is an enlarged vertical cross-sectional view showing another embodiment. 1, 2... Crankshaft, 3, 4... Crank arm, 12
...Freewheel gear, 13...Bearing metal, 2
DESCRIPTION OF SYMBOLS 1... Radial hole, 22... Center hole, 25... Space, 27... Oil jet, 29... Oil introduction hole, 34... Oil pump (pressure source), 37...
...Aperture hole.

Claims (1)

[Claims] 1 comprises concentric first and second crankshafts 1 and 2 having a pair of crank arms 3 and 4 that face each other across a space 25 and are integrated via a crank pin 5; Generator 14 at the tip opposite to arm 3
A freewheel gear 12 driven by a starter motor is provided on the first crankshaft 1 adjacent to the generator 14 so as to be rotatable in only one direction.
The opening of the oil introduction hole 29 at the center of the crankshaft 2 on the side opposite to the crank arm 4 is connected to the oil pump 34 through the oil reservoir 31 sealed with a high-pressure oil seal 35. In a single-cylinder engine that opens on the surface of the crank pin 5 through an oil introduction hole 38, the first and second crankshafts 1 and 2 are supported on the crankcase via ball bearings 8 and 9, and the second crankshaft 2 Oil introduction hole 2 inside
A throttle hole 37 is provided at the end of the center hole 22 of the first crankshaft 1 on the crank arm 3 side, and an enlarged part 26 receives the oil jet 27 spouted from the throttle hole 37.
is provided, and the other end of the center hole 22 is opened toward the large diameter hole 23 that is closed with the bolt, and the large diameter hole 23 is opened.
the freewheel gear 12 through the radial hole 21
A lubricating device for the cell motor freewheel gear with an opening facing the inner peripheral surface of the bearing metal.