JPS622250Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a trochoid pump for an internal combustion engine, the rotor of which is housed within a cylinder block and driven by a timing pulley.

Conventionally, as a lubricating oil pump for an internal combustion engine, a trochoid pump having two rotors, an inner rotor and an outer rotor, each having a trochoid curved surface in a pump chamber is widely known.

When such a trochoid pump is installed in an internal combustion engine, the drive shaft to which the rotor is attached is rotated by a timing pulley that is rotated via a timing belt from a crank pulley attached to the front end of the engine's crankshaft. It is supposed to rotate.

In addition to the timing pulley for the trochoid pump mentioned above, the timing belt drives the camshaft drive pulley that drives the valve train of the engine, etc. These pulleys and the timing belt drive the timing pulley. It is stored inside the belt cover, and on the front side of the timing belt cover, a V-belt pulley is installed further forward of the crankshaft to which the above-mentioned crank pulley is attached.
Drives a generator, water pump, etc. via a belt,
A fan is also attached to the front of the water pump to cool the radiator.

As mentioned above, the overall length of the engine is determined by the auxiliary equipment installed on the front of the internal combustion engine, and in order to downsize the internal combustion engine, it is necessary to prevent these auxiliary equipment from protruding from the front of the internal combustion engine. It is desirable to be able to get closer to the cylinder block side.

The present invention was developed in response to the above-mentioned needs, and by incorporating a part of the trochoid pump into the cylinder block and also placing the timing pulley for driving the trochoid pump close to the cylinder block, the internal combustion The purpose is to shorten the overall length of the engine.

To explain this point in more detail, for example, as shown in FIG _.
In the conventional example where the shaft is mounted on Z ₂ , shaft B is supported in the form of a double-supported bearing, so the force applied to pulley A can be distributed and received by both bearings, and the shaft is almost parallel to the bearing. It has the advantage that it does not impair bearing performance. However, in this case, when the pump is embedded in the cylinder block body, the right bearing Z ₂
will be mounted on the cylinder block, and the left bearing Z ₁ will be mounted on the pump lid. As a result, extra machining of the cylinder block is required, and it is also necessary to center the bearing Z ₂ on the block side and the bearing Z ₁ on the lid side, which requires high precision machining. There is.

In order to solve the above-mentioned drawbacks of the one shown in FIG. 3, the one shown in FIG. 4 was also proposed.

That is, the shaft B of the pulley A is supported in a cantilevered manner by one bearing _Z3 . Although this conventional example can solve the above-mentioned drawbacks of the one shown in FIG. 3, it has the following drawbacks.

In other words, when a load is applied to the pulley A and the shaft B is tilted, as shown in FIG. 5, point contact occurs at the end of the bearing, and the bearing surface pressure becomes locally extremely large, resulting in seizure.

In order to avoid this, it has been proposed that the axial length of the bearing be extremely long, but this has the disadvantage that the pump itself becomes very large.

The present invention is an attempt to solve the above-mentioned drawbacks of the conventional example, and its principle is as shown in _FIG .
The load surface of the pulley is placed on the same plane as bearing _Z4 . As a result, the load applied to the pulley acts directly on the bearing, which prevents the shaft from tilting as shown in Figure 5. It also allows the pulley to be placed close to the cylinder block, making the entire engine more compact. This means that it can be summarized as follows.

That is, in the present invention, a rotor part forming a trochoid pump is attached to one end of a drive shaft, and the drive shaft is cantilevered so that the rotor part is housed in an opening bored in the cylinder block of the engine. A case member having a supporting bearing is arranged, and a timing pulley having an umbrella-shaped cross section is attached to the other end of the drive shaft so that the meshing teeth of the timing pulley are close to the cylinder block. Ru.

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a trochoid pump 2 installed at the front end of a cylinder block 1 of a timing belt-driven internal combustion engine according to an embodiment of the present invention.

An inner rotor 3a and an outer rotor 3b having a trochoidal curved surface are attached to the end of the drive shaft 4 of the trochoid pump 2 on the cylinder block 1 side. The rotor 3b also rotates, and the volume between the inner rotor 3a and the outer rotor 3b changes in a sinusoidal manner, so that lubricating oil is continuously sucked in and delivered.

Therefore, the inner rotor 3a and the outer rotor 3b are built into holes provided in the cylinder block 1, and the inner rotor 3a and the outer rotor 3b are provided on the back side of the cylinder block 1 as shown in FIG. This trochoid pump 2 shown by the dotted line
Drill holes for an oil inlet 5 and an oil outlet 6 are provided.

Next, the drive shaft 4 is connected to the trochoid pump 2.
The case member 7 is rotatably supported in a cantilevered state by a bearing 8 provided in a case member 7 which serves as a lid member of the cylinder block 1.
The bolt is inserted into the bolt hole 11 and fixed in position by the two knob bushes 9a and 9b.

The lubricating oil that has lubricated the bearing 8 in FIG. It is now being returned to the case.

Further, a timing pulley 16 is attached to the end of the drive shaft 4 opposite to the cylinder block 1 by means of its boss portion 16a.
The overall cross-sectional shape of the timing pulley 16 is formed into an umbrella shape so that the meshing teeth of the timing pulley 16 are closer to the cylinder block 1 than the timing pulley 6a.

Timing pulley 1 of this trochoid pump 2
6 is driven by a crank pulley attached to the front end of a crankshaft (not shown) of this internal combustion engine via a timing belt (not shown).

In the trochoid pump 2 configured in this way, the position of the bearing 8 and the position of the meshing teeth of the timing pulley 16 are approximately the same in the vertical direction, and are also close to the cylinder block 1, so that the timing pulley 16 is Even if the tension of the belt is applied, the bearing 8 portion can sufficiently bear the tension.

Generally, when the inner rotor 3a and outer rotor 3b are built into the cylinder block 1, it is common sense to support both rotors 3a and 3b of the drive shaft 4 by one bearing. However, in the present invention, as mentioned above, the meshing teeth of the timing pulley 16 and the bearing 8 are arranged at almost the same position and are also close to the cylinder block 1, so that one bearing 8 can be This makes it possible to hold and support the device.

In addition, as shown in Fig. 2, the trochoid pump 2 has an eccentric axis as shown by E, and it is necessary to assemble the drive shaft 4 in such an eccentric position while maintaining accuracy. A structure having one bearing 8 as proposed is more advantageous than a structure supported by two bearings in terms of processing and assembly.

Therefore, in an internal combustion engine to which the trochoid pump of the present invention is applied, the timing belt can be stretched close to the cylinder block, and many auxiliary machines installed on the front of the internal combustion engine can be placed on the cylinder block side. This has the advantage that the overall length of the engine can be shortened.

In addition, conventionally, the tension of the timing belt was applied to the end of the crankshaft to which the crank pulley with the timing belt stretched was attached, creating stress that could cause the crankshaft to break.However, by applying the present invention. As a result, the crank pulley is brought closer to the cylinder block, and the moment of force applied to the crankshaft is also reduced, which is effective in preventing accidents of crankshaft breakage.

Further, in the present invention, a part of the trochoid pump is built into the cylinder block, which is effective in reducing the size and weight of the engine, as well as reducing its cost.

The present invention can be effectively applied mainly to a trochoid pump for a timing belt-driven internal combustion engine.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a trochoid pump installed in a cylinder block of an internal combustion engine according to an embodiment of the present invention, and FIG. 2 is a front view taken along the line A-A in FIG. The figure is a schematic diagram of the conventional example,
The figure is a schematic diagram explaining the principle of the present invention. DESCRIPTION OF SYMBOLS 1... Cylinder block, 2... Trochoid pump, 3a... Inner rotor, 3b... Outer rotor, 4... Drive shaft, 7... Case member, 8... Bearing, 16... Timing pulley, 16a... boss department.

Claims (1)

[Scope of utility model registration request] A rotor part forming a trochoid pump is attached to one end of the drive shaft, and the rotor part has a bearing that supports the drive shaft on a cantilever so that the rotor part is housed in an opening bored in a cylinder block of the engine. A trochoid pump for an internal combustion engine, in which a case member is arranged, and a timing pulley having an umbrella-shaped cross section is attached to the other end of the drive shaft so that the meshing teeth of the timing pulley are close to the cylinder block.