JPS63138179A - trochoidal pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a trochoidal pump for pumping lubricating oil for an internal combustion engine, and in particular to a trochoidal pump that can automatically maintain almost constant pressure on the discharge side. Regarding.

[Description of Prior Art] A trochoid pump is commonly used as a pump for pumping lubricating oil for an internal combustion engine. This conventional trochoid type pump is disclosed in Japanese Patent Application Laid-open No. 57-159984, for example.
J:, including the inner rotor and outer rotor of the conventional trochoid type pump, is shown in Figure 5. As shown in FIG. 6, a cylindrical portion 12 is integrally formed in the pump body 10, and a cylindrical outer rotor 14 that exactly fits therein is rotatably mounted inside the cylindrical portion 12. (FIG. 5), on the wall surface of the internal space of the outer rotor 14, inner #16 are formed that protrude from five locations at equal angles. The rotation center of this outer rotor 14 is the fifth
The pump body IO has a rotating shaft 18, which is indicated by a point P in the figure.
is rotatably held, and a driving force 20 is fixed to one end of the rotating shaft 18, and an inner rotor 22 housed in the cylinder of the outer rotor 14 is fixed to the other end. This inner rotor 22 is.

It has a protrusion 24 extending in all directions at equal angles for engaging with the inner part 116 of the outer rotor 14 and rotating the outer rotor 14. The center of the rotational shaft 18 of the inner rotor 22 is indicated by a point Q in FIG. 5, and the rotational center point Q of the inner rotor 22 and the rotational center point P of the outer rotor 14 are eccentric by a length a. The inner rotor 22 and the outer rotor 14 are always in contact with each other on the center line X connecting a point Q and a point P (at the tips of the lowermost external teeth in FIG. 5).

A plate 26 is provided on the side surface of the inner rotor 22 and the outer rotor 14, and the plate 26 has a semicircular first opening 28 and a semicircular first opening 28 that forms a part of the passage of either the suction port or the discharge port. A second opening 30 is formed. The first opening 28 and the second opening 30 are partitioned by a partition wall 32 extending along the center &ax connecting points Q and P.

In the trochoidal pump configured as described above, as the inner rotor 22 rotates, the outer rotor 14 is rotated in the same direction.

At this time, the inner rotor 22 and the outer rotor 14 rotate at a ratio of 4:5 in proportion to the number of rotors. The rotation center point Q of the inner rotor 22 and the outer rotor 1
Since the rotation center point P of 4 is eccentric, those P and Q
In the first opening 28 and the second opening 30, which are divided by the center line The first opening 28 becomes the suction side, and the second opening 30 becomes the discharge side. On the other hand, in the case of counterclockwise rotation, the second opening 3
0 is the suction side, and the first opening 28 is the discharge side.

[Problems to be Solved by the Invention] In the trochoidal pump, the lubricating oil discharge rate increases in proportion to the rotational speed of the rotating shaft 18 connected to the engine. When the rotational speed of the rotating shaft 18 increases, the pressure on the discharge port side increases, and the rotational torque increases accordingly.As a result, the power loss increases and the life of the pump increases. It had the disadvantage of being shorter.

[ffi Akira's [Object 1] The present invention has been made in view of the above points, and by changing the rotational center position of the outer rotor with respect to the rotational center position of the inner rotor when the pressure on the discharge side increases. A trochoid that automatically reduces the pressure on the discharge side to a predetermined level, reduces the driving force of the pump when the rotational speed of the shaft is large, and improves the durability of the pump. The purpose is to provide a type pump.

[Means for Solving the Problems] In order to achieve the above object, the present invention forms an inlet port and a discharge port in a pump body, rotatably holds a rotating shaft in the pump body, and controls the rotation of the shaft. An inner rotor having a plurality of external teeth formed thereon is fixed to a shaft, and a cylindrical outer rotor having a plurality of internal teeth formed inside that meshes with the outer teeth of the inner rotor is rotatably held within the pump body. ,
In a trochoid type pump, an outer rotor rotates as the inner rotor rotates, and fluid is transferred from the suction port to the discharge port via between the outer teeth of the inner rotor and the inner teeth of the outer rotor. , an eccentric ring that is rotatably fitted and held in the pump body so as to align the center of rotation with the rotation axis, and whose inner side is fitted onto the outer periphery of the outer rotor; and a means for rotating the eccentric ring; a plunger that is slidably attached; a biasing means that always biases the plunger to a predetermined position; and a biasing means formed in the pump body, one end of which opens to the discharge port and the other end of which biases the plunger to the predetermined position due to an increase in pressure. A fluid pressure introduction passage communicating with a space for sliding in a direction opposite to the biasing direction of the biasing means.

[Operation] When the pressure at the discharge port increases to a predetermined pressure or more, the plunger is caused to slide against the spring. LF of this plunger! Along with the J motion, the outer rotor is rotated together with the eccentric ring. The center of rotation of this eccentric ring is different from the center of rotation of the outer rotor, so the position of the center line connecting the center of rotation of the outer rotor and the center of rotation of the inner rotor is relative to the position of the inlet and outlet. , thereby reducing the suction and exhalation volumes.

In this way, when the pressure on the discharge side exceeds a predetermined pressure, the suction volume and discharge volume are reduced to automatically reduce the pressure on the discharge port side, keeping the pressure on the discharge port side approximately at a predetermined value. It is.

[Example] Next, the present invention will be explained based on the drawings.

FIG. 1 is a sectional view of a main part of an embodiment of a trochoidal pump according to the present invention, with the inner rotor and outer rotor removed. Figures 2 to 4 are configuration diagrams of the present invention showing the positional relationships among the inner rotor, outer rotor, eccentric ring, and rack. FIG. 3 shows a state in which the lubricating oil has an intermediate discharge amount, and FIG. 4 shows a state in which the lubricating oil has a minimum discharge noise. In these figures, the same numbers as in Figures 5 and 6 indicate the same parts.
In the present invention as well, the outer rotor 1
The rotation center P of the inner rotor 22 and the shaft center Q of the rotation shaft 18 of the inner rotor 22 are eccentric by an amount a.

A cylindrical eccentric ring 40 is attached to the outside of the outer rotor 14. The inner surface of this cylindrical eccentric ring 40 is shaped to fit exactly with the outer surface of the outer rotor 14.
Further, the center of the outer diameter (rotation center) of this eccentric ring 40 is the same as the rotation center Q of the inner rotor 22. Involute teeth 44 are formed on the outer periphery of the outer rotor 14. The pump body 42 is formed with a circular part 46 that fits and accommodates the eccentric ring 40, and the center of the diameter of the inner wall of this cylindrical part 46 is the same as the rotation center Q of the inner rotor 22. .

A plunger 48 is slidably attached to the pump body 42, and at the tip of the plunger 48 is a rack 5 that engages with the impole Fa 44 of the eccentric ring 40.
0 is fixed. A pair of flanges 54 that sandwich an O-ring 52 are formed in the middle of the plunger 48 in the longitudinal direction, and a spring 58 is interposed between the upper flanges 54 and a cover 56 attached to the pump body 42. There is. The spring 58 biases the plunger 48 downwardly in FIG. 1 to maintain the plunger 48 in the position shown in FIG.

When the plunger 48 is held at a predetermined position by the spring 58, the center lax connecting point Q and point P is
It is set to be in the same direction as the longitudinal direction Y of the partition wall 32 that partitions the first opening 28 and the second opening 30.

A space FA60 is formed in the pump body 42 at the lower surface of the flange 54 below the plunger 48, and when the pressure applied to this space 60 becomes higher than a predetermined value, the plunger 48 resists the spring 58. is set to rise upward in FIG. The pump body 42 has one end connected to the first opening 28 and the other end connected to this space. s6
An introduction passage 62 leading to 0 is formed, and pressure on the discharge side is introduced into the space 60.

Next, we will explain the operation. When the rotation speed of the zero-rotation shaft 18 is small and the pressure at the discharge port is small, only a small pressure is applied to the space 60, so the plunger 48 or the spring 5
In this state, the eccentric ring 40, the outer rotor 14, and the inner rotor 22 are in the relationship shown in FIG. That is,
It is located in the same direction as the center line connecting point Q and point P or the longitudinal direction Y of the partition wall 32 that partitions the first opening 28 and the second opening 30. Therefore, the discharge amount in this state can be set according to the rotation speed.

Next, when the pressure on the discharge port side becomes higher than the predetermined pressure, the pressure increases to the space a! I60, the plunger 48 is connected to the spring 5
8 from the state shown in FIG. A rack 50' slides together with the plunger 48, whereby both the eccentric ring 40 and the outer rotor 14 are rotated about point Q. Here, FIG. 3 shows a state in which the eccentric ring 40 is rotated 45 degrees to the left about point Q from the state shown in FIG. , FIG. 4 shows a state in which the eccentric ring 40 is rotated 90 degrees to the left about point Q from the state shown in FIG. 2, that is, the center line or center i! It shows a state tilted 90° to the left from lY.

In this way, when the center line X connecting point P and point Q changes with respect to the partition wall 32 (center line Y) that separates the suction port and the discharge port, the suction rate and the discharge amount decrease.

In particular, at a position where the center line X is rotated by 90 degrees with respect to the center line Y, the suction and discharge amount becomes zero because the center kQx performs suction and discharge in a direction perpendicular to the suction port and the discharge port. In this way, by rotating the eccentric ring 40 and making an angle between the center line X and the center line Y, the discharge amount is reduced,
As a result, excessive pressure on the discharge side can be reduced.

Thereafter, when the pressure on the discharge side decreases to a predetermined pressure, the pressure acting on the space 60 becomes smaller, the spring 58 pushes the plunger 48 downward in FIG. It is rotated clockwise from the state shown in FIG. 4 to the state shown in FIG. 2.

[Effects of the Invention] As described above, according to the trochoidal pump according to the present invention, an eccentric ring that is rotatable coaxially with the rotation axis of the inner rotor is attached to the outside of the outer rotor, and the eccentric ring is rotated by the pressure on the discharge port side. When the pressure increases, the eccentric ring is rotated to reduce the suction capacity and discharge capacity, and the pressure on the discharge port side can be automatically returned to the original value. Therefore, even when the rotational speed of the rotating shaft is high, the driving force of the pump can be reduced and the durability of the pump can be improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of a trochoidal pump according to the present invention, with the inner rotor and outer rotor removed, and FIGS. 2 to 4 show the positions of the inner rotor, outer rotor, eccentric ring, and rack. A configuration diagram of the present invention showing the relationship; FIG. 5 is a cross-sectional view of a conventional trochoid pump at main points including the inner rotor and outer rotor; FIG. 6 is a cross-sectional view taken along line A-A in FIG. It is. 14...Outer rotor, 16...Inner teeth, 18...Rotating shaft. 22... Inner rotor, 24... External teeth, 28... First opening. 30...Second opening, 40...Eccentric ring, 42...Pump body, 44.
·····teeth. 48...Plunger, 50...
Rack, 58... Spring, 60...
...Space section, 62...Introduction passage. Patent applicant Mitsubishi Motors Corporation Mikuni Kogyo Co., Ltd. Agent Patent attorney Takashi Yashima City Figure 1 Figure 5 Figure 61 ■

Claims (1)

[Claims] A suction port and a discharge port are formed in the pump body, a rotating shaft is rotatably held in the pump body, an inner rotor having a plurality of external teeth is fixed to the rotating shaft, and an inner rotor is formed with a plurality of external teeth. A cylindrical outer rotor having a plurality of inner teeth formed inside to mesh with the teeth is rotatably held within the pump body, and the outer rotor is rotated as the inner rotor rotates, and the outer rotor is rotated by the rotation of the inner rotor. In a trochoid type pump that transfers fluid from a suction port to a discharge port via between the external teeth of an inner rotor and the internal teeth of an outer rotor, the rotation center is aligned with the rotation axis and the pump body is rotatably fitted to the pump body. an eccentric ring which is held and whose inner side is fitted onto the outer periphery of the outer rotor; a plunger which is slidably attached to the pump body and has means for rotating the eccentric ring; and the plunger is always kept in a predetermined position. a space portion formed in the pump body, one end of which opens to the discharge port and the other end of which slides the plunger in a direction opposite to the biasing direction of the biasing means due to an increase in pressure; A trochoid type pump characterized by comprising a fluid pressure introduction passage leading to.