JPS6153482A - Trochoidal pump for engine lubricatioin - Google Patents

Abstract

PURPOSE:To prevent the occurrence of cavitation and noise as well as aim at improvements in a discharge rate, by constituting an opening area till a tooth gap chamber being partitioned off by both teeth of an outer rotor and an inner rotor reaches the maximum capacity, so as to be yet more expandable. CONSTITUTION:A tooth gap chamber 9 being partitioned off by both teeth of an outer rotor and an inner rotor sets a final line 10 of the opening position of a suction port 6 so as to be properly connected to this suction port 6 in time of its maximum capacity, while at the vicinity where the tooth gap chamber 9 is intercepted from a discharge port 7, the tooth gap chamber 6 sets a start line 11 of the opening position of the discharge port 7 so as to be interconnected to the discharge port 7. With this constitution, these rotors 4 and 5 rotate as far as the specified angle whereby the tooth gap chamber 9 is compressed a little from the maximum capacity, and the suction port 6 is opened to the tooth gap chamber 9 till the time just before being connected to the discharge port 7. As a result, suction efficiency is improved, while a cavitation phenomenon in time of rotation at high speed is preventable, improving a discharge rate ever so better, and abnormal wear and noise are also preventable from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a trochoid pump for forced lubrication of an engine.

This type of pump, as shown in FIG. 4 and FIG.
A pair of internally toothed outer rotor (4) and externally toothed inner rotor (5) that engage in trochoidal engagement are placed in a cylindrical sealed chamber (3) formed by the pump body (1) and the pump man bar (2). An arcuate suction port (6) and an arcuate discharge port (7) are opened facing the end faces of these rotors.

All teeth of the outer rotor (4) and inner rotor (5) are always in mesh with each other due to trochoidal meshing, which is different from a normal internal gear pump. The inner rotor (5) is connected to the drive shaft (8), and the rotation of the inner rotor (5) rotates the outer rotor that meshes with the inner rotor (5). Depending on the change, lubricating oil is sucked in from the suction port (6), and lubricating oil is discharged from the discharge port (7). A suction port (6) is provided corresponding to the range in which the interdental space volume expands, and a discharge port (7) is provided.
are provided corresponding to the range in which the volume of the interdental space contracts, and as shown in FIG.
) The opening position (line) of the suction port (6) and the opening position (starting line) of the discharge port (7) are generally determined so that the suction port (6) and the discharge port (7) are disconnected from each other and communicated with the discharge port (7) at the same time.

By the way, this type of pump is driven by engine power, so it can be used in a wide range of rotation speeds, but due to the nature of this type of pump, as the mountain chamber approaches its maximum volume, the suction volume decreases. Since the opening area of the port (6) is reduced and the interdental space is blocked from the suction port (6) when the volume is at its maximum, the suction efficiency is reduced and cavitation occurs at high rotation speeds. This causes problems such as a decrease in the discharge amount, abnormal wear, and noise.

The present invention was made in view of these points, and an object of the present invention is to prevent the cavitation phenomenon at high rotation speeds, improve the discharge amount, and eliminate abnormal wear and noise in a trochoid pump for engine lubrication.

The purpose of this is to use a trochoidal pump for engine lubrication in which an arcuate suction port and a discharge port are opened facing the end faces of a pair of internally toothed outer rotor and externally toothed inner rotor that are trochoidally engaged with each other. The line of the opening position of the suction port is determined so that the mountain chamber defined by the teeth of the inner rotor communicates with the suction port by an appropriate amount at the time of maximum volume, and in the vicinity where the mountain chamber is cut off from the suction port. This is achieved by a trochoid pump for engine lubrication, characterized in that the interdental space communicates with a discharge port (the starting line of the opening position of the discharge port is defined).

Next, embodiments will be described based on the accompanying drawings.

FIG. 1 is a side view of one embodiment of the present invention with the pump cover removed, and a cross-sectional view along the axial direction is the same as that of the conventional example shown in FIG. 4. Pump body (1) and pump cover (
A pair of internally toothed outer rotors (4) in trochoidal mesh are placed in a cylindrical sealed chamber (3) formed by (2) and
) and an externally toothed inner rotor (5) are housed therein.

The inner rotor (5) is fixed to a drive shaft (8) that is rotated by engine power, and its rotation rotates the outer rotor (4). When these rotors (4) (5) rotate counterclockwise in the figure, the suction port (
6) Oil is sucked in through the discharge port (7) and discharged through the discharge port (7) to forcefully send the oil to a predetermined lubrication location. Here, the suction port (6) is connected to the interdental chamber (9) at the meshing position where the interdental chamber volume defined by the teeth of both mouths (4) and (5) has a maximum volume. 6), the line (
10) has been established. On the other hand, the discharge port (7) is connected to the starting line (11) of the opening position of the discharge port (7) so that it communicates when the interdental space (9) is blocked from the suction port (6).
is determined.

That is, as the rotors (4) and (5) rotate by a predetermined angle, the mountain chamber (9) is slightly compressed from its maximum volume as shown in FIG. In the illustrated embodiment, the suction port (6) is opened to the interdental chamber (9) with the maximum volume (the opening position of the suction port (6) is route (
10) is moved in the direction of rotation by angle (θ), and at the same time, the starting line (11) of the opening position of the discharge port (7) is also moved in the direction of rotation by angle (θ). In the illustrated example, the angle (θ) was set to 30°. As described above, the line of the opening position of the suction port is determined so that the interdental chamber defined by the teeth of the outer rotor and the teeth of the inner rotor communicates with the suction port by an appropriate amount at the time of maximum volume, and the interdental chamber The starting line of the opening position of the discharge port is determined so that the interdental chamber (9) communicates with the discharge port in the vicinity where the interdental chamber (9) is cut off from the suction port. The opening area of the port (6) is enlarged compared to conventional products, improving suction efficiency, and even after the mountain chamber (9) reaches its maximum volume, it acts on the fluid from the opening of the suction port (6). Since the lubricating oil further flows into the mountain space (9) due to the inertial force, the volumetric efficiency of the mountain space (9) is improved and cavitation phenomenon at high rotations can be prevented. This improves the discharge amount and prevents abnormal wear and noise. FIG. 3 shows the discharge amount characteristics of the illustrated embodiment and the conventional example. (A) in the figure is the fifth
As shown in the figure, at the engagement position where the interdental chamber has the maximum volume, the interdental chamber (9) is blocked from the suction port (6) and at the same time communicates with the discharge port (7).
Opening position (line) of suction port (6) and discharge port (7)
) is a characteristic diagram of a conventional device in which the opening position (starting line) is set, and cavitation phenomenon occurs from around rotational speeds of 5000 r, p, m.

Due to this occurrence, the discharge amount has begun to decrease. On the other hand (B)
is a characteristic diagram of the embodiment of the present invention shown in FIG. Retraction angle (θ
) is set to 30', the conditions are exactly the same as the conventional example, but the discharge amount does not decrease even in the high rotation range of 500 ° r, p, m or more, and cavitation phenomenon does not occur in the high rotation range. It turns out that it has not occurred.

In the above embodiment, the retraction angle (θ) of the suction port is set to 3.
Although it is set to 0°, the present invention is not limited to this (the shape of the line of the opening position of the suction port may be determined so that the suction port communicates with the interdental space with the maximum volume by an appropriate amount). .

As described above, the present invention defines the line of the opening position of the suction port so that the interdental space defined by the teeth of the outer rotor and the teeth of the inner rotor communicates with the suction port by an appropriate amount at the time of maximum volume, and The simple structure of flJ5, in which the starting line of the opening position of the discharge port is determined in the vicinity where the interdental chamber is blocked from the suction port, so that the interdental chamber communicates with the discharge port, has caused problems in the past in this type of pump. Since it is possible to prevent the cavitation phenomenon during high rotation, the discharge amount is improved, and abnormal wear and noise generation can be prevented.

[Brief explanation of drawings]

1 and 2 are side views of one embodiment of the present invention with the pump cover removed; FIGS. 1 and 3 are characteristic comparison diagrams;
The figure is a sectional view along the axial direction of the conventional example, and FIG. 5 is a side view of the conventional example with the pump cover removed. Explanation of symbols 1...Pump body 2...Bompka, par 4...
・Outer rotor 5...Inner rotor 6...
・Suction port 7...Discharge port 8...Drive shaft 9
...Mountain Room No. 10 i! Figure 2 Rotation speed, (rpm) 30th

Claims (1)

[Claims] In a trochoid pump for engine lubrication, in which an arcuate suction port and a discharge port are opened facing the end faces of a pair of internally toothed outer rotor and externally toothed inner rotor that are trochoidally engaged with each other, the teeth of the outer rotor and the teeth of the inner rotor The line of the opening position of the suction port is determined so that the interdental space divided by the space communicates with the suction port by an appropriate amount at the time of maximum volume, and in the vicinity where the interdental space is cut off from the suction port, A trochoid pump for engine lubrication, characterized in that the starting line of the opening position of the discharge port is determined so that the interdental space communicates with the discharge port.