JP2000227016A - Lubrication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication device capable of eliminating unstableness for oil supply to an oil pump due to the pulsation of a relief valve, and stably discharging oil from the pump. SOLUTION: In a lubrication device by a drysump method equipped with a scavenging pump 9 for returning oil lubricated an engine 11 to an oil tank 14 via an oil recovering passage 15, an oil pump 10 for supplying oil from the tank 14 to the engine 11 via an oil supply passage 16, and a relief valve 17 provided on the passage 16 to automatically open a valve element at the time of given pressure or more; a surplus oil returning passage 18 is provided which is returning surplus oil from the valve 17 to the tank 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry sump type lubricating apparatus, and more particularly to a lubricating apparatus which suppresses pulsation of a relief valve and stably supplies oil to an oil pump.

[0002]

2. Description of the Related Art Conventionally, a dry sump system has been known mainly for lubrication of an internal combustion engine. In this dry sump method, as shown in FIG. 3, oil returned after lubricating the engine 1 is collected by a scavenging pump 2 and stored in an oil tank 3 provided separately.
This is a lubrication system in which oil is supplied to the engine 1 by an oil pump 4 from the engine. In such a dry sump method,
As the oil pump 4, for example, a trochoid pump is used.
When the oil supply pressure from the oil pump 4 becomes equal to or higher than a predetermined value, a relief valve 5 that automatically opens the valve body is provided.
The relief valve 5 is configured to be built in the main body of the oil pump 4.

[0003]

In the conventional dry sump system, a relief valve 5 is built in the main body of the oil pump 4 so that the oil from the relief valve 5 is supplied near the inlet of the oil pump 4. Has become.

By the way, in the trochoid type oil pump 4, for example, pulsation occurs due to oil suction as shown in FIG. On the other hand, pulsation due to oil relief as shown in FIG. 4B also occurs in the relief valve 5, and when pulsation due to oil suction and pulsation due to oil relief are added, FIG.
A pulsation as shown in FIG.

That is, as shown in FIG. 4 (c), in the case of the conventional dry sump type engine 1, since the relief valve 5 is built in the main body of the oil pump 4, the oil pump 3 The high-pressure oil from the relief valve 5 is relieved on the oil pump 4 side, and reverse flow pulsation appears in one cycle at the oil pump 4 inlet side. Therefore, the oil at the inlet side of the oil pump 4 is unstable, and the oil cannot be discharged from the oil pump 4 stably.

Further, as shown in FIG. 4 (c), a portion where the oil supply pressure to the oil pump 4 locally rises appears, and at this time, cavitation tends to occur due to high pressure of air bubbles in the oil. It is likely to cause damage to the rotor (gear) of the pump 4.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described circumstances, and is intended to eliminate instability of oil supply to an oil pump due to pulsation of a relief valve and to stably discharge oil from the oil pump. It is an object of the present invention to provide a lubricating device that can perform the lubrication.

Another object of the present invention is to eliminate a local increase in oil supply pressure to an oil pump, suppress cavitation due to bubbles of air in oil, and prevent damage to a rotor (gear) of an oil pump. To provide an improved lubrication device.

[0009]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a scavenging pump for returning oil lubricating an engine to an oil tank via an oil recovery passage is provided. A dry sump type lubricating system including an oil pump that supplies oil to an engine through an oil supply passage, and a relief valve that is provided in the oil supply passage and that automatically opens a valve body when a predetermined pressure or more is reached. An excess oil return passage 18 for returning excess oil from the relief valve 17 to the oil tank 14 is provided.

According to a second aspect of the present invention, the oil recovery passage 15a and the surplus oil return passage 18a are joined.

The invention according to claim 3 is characterized in that the oil recovery passage 15a and the surplus oil return passage 18a merge at an acute angle to the oil flow direction.

The invention according to claim 4 is characterized in that the oil discharge phases of the oil pump 10 and the scavenging pump 9 are set to opposite phases.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a lubricating device according to an embodiment of the present invention.

[First Embodiment] FIG. 1 is a schematic structural view for explaining in principle a first embodiment of a lubricating device according to the present invention.

In the lubricating device 8 of this embodiment, a scavenging pump 9 and an oil pump 10 are provided on the same shaft. The rotation axis of a crankshaft (not shown) of the engine 11 and the rotation axes of the scavenging pump 9 and the oil pump 10 are parallel to each other, and a crank pulley 12 provided on a crankshaft (not shown) and a scavenging pump 9 are provided. The lubrication pump drive pulley 13 provided on the oil pump 10 is connected, for example, by a belt 12a, so that the scavenging pump 2 and the oil pump 10 are driven by the driving force of the engine 1.

The lubricating device 8 of the present embodiment is of a dry sump type and is provided separately from the engine 11 and the oil tank 14 and communicates with an oil recovery passage 15. A scavenging pump 9 for returning to the tank 14 is provided. That is, the oil that has lubricated the engine 11 is collected in the oil tank 14 by the scavenging pump 9 provided in the oil collection passage 15.

The oil tank 14 communicates with the engine 11 through an oil supply passage 16.
An oil pump 10 that supplies oil from an oil tank 14 to the engine 11 is provided in the middle of the oil tank 14. That is, the oil stored in the oil tank 14 is supplied to the oil supply passage 1
6 The engine 1 is driven by an oil pump 10
1 to provide lubrication.

A relief valve 17 is provided on the downstream side of the oil pump 10. When the oil pressure in the oil supply passage 16 becomes higher than a predetermined value, the valve body opens to relieve excess high-pressure oil.

In the lubricating device 8 of the present embodiment, an excess oil return passage 18 for returning the high pressure excess oil of the relief valve 17 to the oil tank 14 is provided.

According to the present embodiment, the relief valve 17
An excess oil return passage 18 for returning excess high-pressure oil from the oil tank 14 to the oil tank 14 is provided.
7 can be absorbed by the oil tank 14. That is, the high-pressure surplus oil of the relief valve 17 is
Since the oil is directly returned to the oil tank 14 through the surplus oil return passage 18, there is no influence of the high-pressure surplus oil discharged from the relief valve 17 near the inlet of the oil pump 10 in the oil supply passage 16.
7, the instability of oil supply to the oil pump 10 due to the pulsation is eliminated, the oil is stably supplied to the oil pump 10, and the oil can be stably discharged from the oil pump 10. It is possible to eliminate a local increase in oil supply pressure near the inlet of the oil pump 10 due to the pulsation of the relief valve 17, which has been a problem, suppress cavitation, and prevent damage to the rotor (gear) of the oil pump 10. Thus, an excellent effect of stabilizing an oil film such as a metal clearance (not shown) inside the engine 11 can be achieved.

[Second Embodiment] FIG. 2 is a schematic configuration diagram for explaining in principle the second embodiment of the lubricating device according to the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, the oil recovery passage 15a and the surplus oil return passage 18a join. The oil recovery passage 15a and the surplus oil return passage 18a merge at an acute angle (A °) with respect to the oil flow direction at the merge point, and the merge angle (A °) is preferably, for example, 20 ° or less.

The oil discharge phases of the oil pump 10 and the scavenging pump 9 are set to opposite phases.

According to this embodiment, the oil recovery passage 15
a and the excess oil return passage 18a are merged, so that the device configuration is simplified. Further, since the oil recovery passage 15a and the surplus oil return passage 18a merge at an acute angle with respect to the oil flow direction at the junction,
Oil can be prevented from flowing into the oil recovery passage 15a or the surplus oil return passage 18a, respectively.
Further, since the oil discharge phases of the oil pump 10 and the scavenging pump 9 are set to be opposite to each other, the influence of the oil pressure of the scavenge pump 9 on the valve opening characteristics of the relief valve 17 can be reduced.

The lubricating device according to the present invention is not limited to the above-described embodiment, but can be applied to a drive system that requires a lubricating device.

[0026]

As described above, according to the lubricating device according to the present invention, a scavenging pump for returning oil lubricating an engine to an oil tank through an oil recovery passage, and an oil for oil from the oil tank are provided. In a dry sump type lubricating device including an oil pump that supplies an engine through a supply passage and a relief valve that is provided in the oil supply passage and that automatically opens a valve body when a predetermined pressure or more is reached, a relief valve from the relief valve Since the excess oil return passage for returning excess oil to the oil tank is provided,
Eliminates the instability of oil supply to the oil pump due to the pulsation of the relief valve, enables stable discharge of oil from the oil pump, and eliminates the local increase in oil supply pressure to the oil pump. Cavitation due to air bubbles inside can be suppressed, and damage to the rotor (gear) of the oil pump can be prevented.

Further, since the oil recovery passage and the surplus oil return passage join at an acute angle to the oil flow direction,
It is possible to prevent the oil in the oil recovery passage from flowing into the surplus oil return passage.

Further, since the oil discharge phases of the oil pump and the scavenging pump are set to be opposite to each other, the influence of the oil pressure of the scavenge pump on the opening characteristics of the relief valve can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining in principle a first embodiment of a lubrication device according to the present invention.

FIG. 2 is a schematic configuration diagram for explaining in principle a second embodiment of the lubrication device according to the present invention.

FIG. 3 is a schematic configuration diagram for explaining a conventional lubrication device in principle.

4A is a graph illustrating pulsation of oil suction by an oil pump, FIG. 4B is a graph illustrating pulsation of discharge oil from a relief valve, and FIG. 4C is a graph illustrating pulsation and relief of an oil pump; The graph which added the pulsation by a valve.

[Explanation of symbols]

 Reference Signs List 1 engine 2 scavenging pump 3 oil tank 4 oil pump 5 relief valve 8 lubrication device 9 scavenging pump 10 oil pump 11 engine 12 crank pulley 12a belt 13 lubrication pump drive pulley 14 oil tank 15, 15a oil recovery passage 16 oil supply passage 17 Relief valve 18, 18a Excess oil return passage

Claims (4)

[Claims] A scavenging pump for returning oil lubricating the engine to an oil tank via an oil recovery passage; an oil pump for supplying oil from the oil tank to the engine via an oil supply passage; A surplus oil return passage 18 for returning surplus oil from the relief valve 17 to the oil tank 14 in a dry sump lubrication system including a relief valve provided in the passage and automatically opening a valve body when the pressure exceeds a predetermined pressure. A lubricating device comprising: 2. The lubricating device according to claim 1, wherein the oil recovery passage 15a and the surplus oil return passage 18a are joined. 3. The lubricating device according to claim 2, wherein the oil recovery passage 15a and the surplus oil return passage 18a join at an acute angle with respect to the oil flow direction. 4. The lubricating device according to claim 2, wherein the oil discharge phases of the oil pump 10 and the scavenging pump 9 are set to opposite phases.