JPS5813166Y2 - Engine balancer drive device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an engine balancer drive device.

Generally, in an engine having a secondary balancer mechanism, it is necessary to reverse one of the balancer shafts provided on the left and right sides of the crankshaft with respect to the rotational direction of the crankshaft.As shown in Fig. 1, the sprocket 02 provided on the crankshaft 01, Sprocket o4 installed on balancer shaft 03
, sprocket 05 installed on the idle gear shaft
A specially provided reversing mechanism was required to drive the right balancer shaft 09 through the idle gear 07 and the gear 08 by the chino 06 or the like engaged with the balancer shaft 09.

Also, in a balancer device in which a pair of balancer shafts rotate in the same direction with respect to the rotational direction of the crankshaft without the above-mentioned reversing mechanism, in order to rotate both balancer shafts,
The above crankshaft, both balancer shafts have pulleys, gears,
It is necessary to provide a sprocket, etc., and there are drawbacks such as the overall structure of the engine becomes large and the cost increases, including the case where the above-mentioned reversing mechanism is included.

On the other hand, the power source of the oil pump used to supply lubricating oil to the x:/gin is driven via an oil pump gear and an oil pump drive shaft provided on the camshaft and crankshaft.

The oil pump drive shaft is connected to the oil pump's drive gear shaft by a coupling and drives the oil pump, but if used for a long time, the coupling will play and wear, causing shock and vibration, so the drive gear shaft and Blackening occurs between the drive gears that are fitted through the bushings, the retaining part between the drive gear and the driven gear, and the gaps between the above gears and the pump casing, making it impossible to obtain the necessary discharge pressure due to wear of each part, etc. There were concerns about this.

The present invention has been proposed in order to eliminate the various drawbacks mentioned above, and is based on at least one pair of balancer shafts equipped with balance weights that balance the reciprocating masses of pistons, connecting rods, etc. The engine is equipped with an engine oil pump formed by a drive gear and a driven gear, and the drive gear shaft on which the drive gear is attached is driven by the crankshaft. The driven gear shaft to which the driven gear is mounted is formed to serve as one of the two balancer shafts, so that the balancer shaft is driven in the reverse direction with respect to the other balancer shaft. The main object is an engine balancer drive device characterized by:

Next, an embodiment of the present invention will be described with reference to FIGS. 2 to T.

1 is a sprocket attached to a crankshaft (not shown), 2 is a left balancer shaft of at least two pairs of balancer shafts provided on the left and right sides of the crankshaft, and a sprocket τ is attached thereto.

The balancer shaft 3 on the right side is formed to also serve as the driven gear shaft of the oil pump 4.

5 is a driven gear attached to the right balancer shaft 3 formed to also serve as the driven gear shaft,
The right balancer shaft 3 is pivotally supported by the oil pump case 6 via a bearing T.

The balance weight sides of the pair of balancer shafts may be supported as appropriate in a conventionally known manner, and as shown in FIG. ni8aj8b
The journal portion 9 is divided into one bearing 1.
It is planned to be supported by 0□.

11 is a drive gear engaged with the driven gear 5 and attached to the drive gear shaft 12; 13;
is the bearing 14 side end 15 of the drive gear shaft 12.
A sprocket 18 is attached to the oil pump case 6 by a bolt 17 through a washer 16.
This is a bolt for attaching to the cylinder block via a pin 19 etc. for positioning the cylinder block.

20 is a chain engaged with the sprockets 1, 2' and 13; 21 is the suction port of the oil pump 4;
22 is the same discharge port.

23 is a relief valve, which, like a conventionally known valve, includes a plug 24, a plunger 25, and a spring 26.
It consists of

Reference numeral 27 denotes a suction passage for supplying the oil sucked in from the suction port 21 to the oil pump gear 5°11, and 28 denotes an oil passage leading to the discharge port 22 of the oil pump gear.

Since the above embodiment is configured as described above, when the engine is driven, the crankshaft (not shown) rotates at ω as shown by the arrow, the left balancer shaft 2 rotates the sprocket at 2ω due to the chino 20, and the right balancer shaft 2 rotates at 2ω. Drive gear 5 #3 is mounted on the right balancer shaft 3. Drive gear shaft 12 of the oil pump 4 is driven in reverse at 2ω via a drive gear 11 and sprocket 13 mounted on the drive gear shaft 12□.

Therefore, the balance weights 8 provided on the pair of balancer shafts prevent engine vibration, and the oil pump 4 is also driven to suck oil from the suction port 21 and supply it to various parts of the engine from the discharge port 22. Lubrication takes place.

In the above embodiment, the oil pump 4 is driven by the balancer drive mechanism, and one of the balancer shafts is formed to also serve as the driven gear shaft of the oil pump, so the entire engine can be made compact and costs can be reduced.

Furthermore, since the oil pump drive device of the present invention does not have the coupling used to connect the oil pump drive shaft and the drive gear shaft, shocks due to backlash and wear may occur, causing damage to the two gears of the oil pump. Good lubrication can be achieved by preventing wear and gaps between the case and the gear, and the drive gear 11,
The lubricating oil filled between the driven gears 5 has the effect of reducing meshing noise between both gears.

Further, in the above embodiment, the left and right balancer shafts are explained as being reversed with respect to the rotational direction of the crankshaft.
If the rotation is not reversed, one of the two balancer shafts can also be used as the drive gear shaft of the oil pump.

Furthermore, in the present invention, as explained in FIG. 1, the balance weights 8 provided on the pair of balancer shafts are divided into 8a and 8b so that the weight is borne by one bearing 10. Since the bearing at the front end, that is, the bearing of the driven gear shaft of the oil pump in the case of the above embodiment, is not burdened by the balance weight, there is no need to provide a special bearing, and the life of the oil pump is not impaired. It can be effective.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional balancer driving device, Fig. 2 is a schematic explanatory diagram of a balancer device showing an embodiment of the present invention, and Fig. 3 is an explanatory diagram of a conventional balancer driving device.
The figure is an enlarged view of the oil pump in Fig. 2, Fig. 4 is a sectional view taken along the line ■-■ in Fig. 3, Fig. 5 is a simplified sectional view taken along the line V-V in Fig. 3, and Fig. 6 is a sectional view taken along the line V-V in Fig. 3. A sectional view taken along the line W-■ and FIG. 7 are schematic explanatory views showing the positional relationship of the balancer device with respect to the cylinder block of the present invention. 1...Sprocket, 2...Left balancer shaft, 2'...Sprocket, 3...
...Right side balancer shaft, 4...Oil pump, 5...Driven gear, 11...
・Drive gear, 13...Sprocket, 20
...Cheno.

Claims (1)

[Scope of utility model registration request] At least a pair of balancer shafts provided with balance weights to balance the reciprocating mass of the piston, connecting rod, etc. are disposed at left and right set positions with respect to the crankshaft center, and the two balancer shafts are driven in opposite directions with respect to each other by the crankshaft. The engine is equipped with an engine oil pump shaped like ffl'g by a drive gear and a driven gear, the drive gear shaft on which the drive gear is mounted is interlocked with the crankshaft, and the driven gear shaft on which the driven gear is mounted is connected to the engine oil pump. 1. A balancer drive device for an engine, characterized in that the balancer shaft is formed to serve as one of the two balancer shafts so that the same balancer shaft is driven in the reverse direction with respect to the other balancer shaft.