KR100422512B1 - Balance shaft assembly - Google Patents

Abstract

An object of the present invention is to provide a balance shaft assembly having a structure that is not subjected to rotational resistance by the engine oil, and does not cause bubble generation in the engine oil.

To this end, the present invention is accommodated in the oil pan and rotates at a double speed in conjunction with the crankshaft, a balance shaft having an eccentric mass, a carrier for rotatably supporting the balance shaft, and a crankshaft gear mounted at the end of the balance shaft In the balance shaft assembly comprising a drive gear that rotates in engagement with the,

An air introduction check valve at an upper portion of the carrier, the air being opened so that air in the crankcase flows into the carrier when the internal pressure in the crankcase increases;

And an oil discharge check valve which is opened when the internal pressure of the crankcase is lowered in the lower portion of the carrier to operate to discharge oil accumulated in the carrier to the crankcase.

Description

Balance shaft assembly with structure that can reduce rotational resistance by oil

The present invention relates to a balance shaft assembly having a structure capable of reducing the rotational resistance by oil.

The crankshaft should rotate smoothly without vibration, but the center of the crank journal and the center of the crankpin are eccentric. Accordingly, a balancing weight is provided on the crank arm opposite the crank pin to maintain balance during rotation.

For this purpose, the crankshaft of a small engine is made by integrating the shaft and the balancing weight after fabricating it, and then balancing it. In the large engine, the shaft and the balancing weight are manufactured separately and assembled by bolts.

Although the crankshaft itself can be balanced by the above method, the vibration of the engine caused by the explosion stroke is large or small depending on the arrangement and number of cylinders. Therefore, the vibration of the engine during operation can be solved only by the balancing weight. There is a problem that can not be.

In the four-cylinder engine, the secondary vibration force can be solved by the three-cylinder engine, and the primary vibration force cannot be solved by the balancing weight of the crankshaft alone.The vibration of the engine is transmitted from the engine mount to the body of the body, causing room noise, which prevents comfortable operation. Therefore, the balance shaft is used to improve the ride comfort.

This system is equipped with two shafts parallel to the crankshaft (for four-cylinder engines), the weight of this shaft (balance shaft), the direction of rotation (the two shafts rotate in opposite directions) and the rotational speed (double speed of the crankshaft). By appropriately selecting the road rotation), the vibration caused by the secondary vibration force of the four-cylinder engine in series is reduced.

3 shows the conventional balance shaft assembly 20 (only one of the two balance shafts), so that the balance shaft 22 having the eccentric mass 21 is rotatably supported by the carrier 23. At the end of the balance shaft 22, a drive gear 24 is mounted, and the drive gear 24 rotates in engagement with a drive gear (not shown) of the crankshaft to offset the occurrence of vibration.

By the way, the balance shaft assembly 20 is rotated at a high speed in a state normally locked in the oil pan, the following problems have appeared.

In the case of the balance shaft assembly which is immersed and rotated in the oil of the oil pan, the eccentric mass portion 21 is provided through the gap between the journals 25 and 26 and the carrier 23 at the front and rear of the balance shaft 22. The engine oil is introduced into the empty space 27 in the carrier 23 opposite to the eccentric mass portion 21 when the balance shaft 22 is rotated at high speed when the oil fills the space 27. The oil sticks to the sticky oil, which causes the sticky oil to hinder the high speed rotation, causing the engine output loss. Also, the high speed rotating balance shaft 22 stirs the engine oil to generate bubbles in the engine oil. If air bubbles are generated in the engine oil, it may cause breakage of HLA and other noise, incomplete oil supply, and deterioration of lubrication function.

Accordingly, the present invention has been proposed in view of the above-described object of the present invention to provide a balance shaft assembly having a structure that does not receive rotational resistance caused by engine oil and does not cause bubble generation to the engine oil.

In order to achieve the above object, the present invention is accommodated in an oil pan and rotates at a double speed in conjunction with a crankshaft, and has a balance shaft having an eccentric mass part, a carrier for rotatably supporting the balance shaft, and an end portion of the balance shaft. A balance shaft assembly comprising a drive gear mounted and engaged with a crankshaft gear to rotate,

An air introduction check valve at an upper portion of the carrier, the air being opened so that air in the crankcase flows into the carrier when the internal pressure in the crankcase increases;

And an oil discharge check valve which is opened when the internal pressure of the crankcase is lowered in the lower portion of the carrier to operate to discharge oil accumulated in the carrier to the crankcase.

1 is a side view of a balance shaft assembly of a rotational resistance reduction structure according to the present invention;

2 is a cross-sectional front view of the in-phase balance shaft assembly (A-A cross-sectional view of Figure 1)

3 is a prior art

※ Explanation of codes for main parts of drawing

1: Balance shaft assembly 2: Balance shaft

3: carrier 4: drive gear

5: Carver 6: Eccentric Mass

7,8: Journal 9: Oil Seal

10 ball 11: spring

12: Check valve for air introduction 13: Ball

14: spring 15: oil discharge check valve

16: space

Hereinafter, the configuration of the present invention will be described with reference to the accompanying drawings.

1 is a side view of the balance shaft assembly according to the present invention, Figure 2 is a front sectional view (A-A cross-sectional view) of the balance shaft assembly according to the present invention.

In the figure, the balance shaft assembly 1 indicated by reference numeral 1 includes a balance shaft 2, a carrier 3, a drive gear 4, and a cover 5 fixed to an oil pan.

The balance shaft (2) has an eccentric mass (6) with its center of gravity directed to one side with respect to the central axis, and oil seals to prevent oil from entering through the front and rear journals (7) (8). (9) is interposed between the carrier 3.

In addition, an air introduction check valve 12 including a ball 10 and a spring 11 is installed at an upper portion of the carrier 3, and a ball 13 and a spring 14 are also disposed at a lower portion of the carrier 3. An oil drainage check valve 15 is provided.

According to the present invention having the configuration described above, the vibration is attenuated by maintaining the balance by rotating the balance shaft 2 by receiving power through the drive gear 4 in conjunction with the crankshaft rotation while the engine is being driven. The oil in the oil pan is prevented from flowing into the carrier 3 through the gap between the sliding portion of the 8 and the carrier 3, and the internal pressure in the crankcase becomes greater than the spring 11 elastic force. As a result, the ball 10 compresses the spring 11 and the air introduction check valve 12 opens to allow air to flow into the space 16 in the carrier 3.

On the contrary, when the internal pressure of the crankcase falls, the ball 13 compresses the spring 14 due to the difference between the high pressure in the space 16 and the oil discharge check valve 15 opens to flow into the space 16. Since the oil is discharged to the outside of the carrier 3 through the oil discharge check valve 15 opened together with the air, there is very little oil remaining in the space 16, and the oil is transferred to the resistor when the balance shaft 6 rotates. It does not work, and bubbles generated by the oil strike are also greatly reduced.

According to the present invention as described above, the oil seal is provided so that oil does not flow into the carrier supporting the balance shaft, and the oil introduced into the empty space in the carrier, that is, the empty space opposed to the eccentric mass, passes through the oil seal, and the crank Carrier by oil discharge check valve opened by pressure difference at the moment when internal pressure of crankcase decreases with air introduced into carrier through air introduction check valve which is opened at high pressure due to internal pressure fluctuation of case By discharging to the outside, the rotational resistance caused by the oil is greatly reduced during the high speed rotation of the balance shaft, which prevents the engine output from being reduced, and also reduces the occurrence of air bubbles caused by the oil sway, thereby preventing damage and noise of each component. And, it is effective to prevent the deterioration of the lubrication function by the bubble.

Claims (3)

In a balance shaft assembly comprising a balance shaft accommodated in an oil pan and interlocked with a crank shaft at a double speed or a constant speed, the balance shaft having an eccentric mass, and a carrier wrapped around the balance shaft and rotatably supported therein. An air introduction check valve at an upper portion of the carrier, the air being opened so that air in the crankcase flows into the carrier when the internal pressure in the crankcase increases; When the internal pressure of the crankcase is lowered in the lower portion of the carrier is opened, the oil discharge check valve which operates to discharge the oil accumulated in the carrier to the crankcase; to reduce the rotational resistance by oil, characterized in that consisting of Balanced shaft assembly. The method of claim 1, The balance shaft assembly of the structure which can reduce the rotational resistance by the oil characterized by the oil seal which interrupts oil inflow in the carrier site | part which supports the journal part of the said balance shaft. The method of claim 1, The air introduction and oil discharge check valve is a balance shaft assembly of the structure that can reduce the rotational resistance by the oil, characterized in that consisting of a ball and a spring.