JPS6242149Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary pump used as a fuel pump for an internal combustion engine, and more particularly to a rotor support structure.

An example of the structure of a rotary fuel pump for an internal combustion engine will be briefly explained with reference to FIG. The inside is filled with fuel.

When the rotor 7 of the pump section 2, which is penetratingly supported by the drive shaft 5 and engaged with the protrusion 6a of the joint 6 to prevent rotation, rotates as the motor 1 rotates, the outer periphery of the rotor 7 as shown in FIG. A roller 8 into which a plurality of grooves 7a formed in the wall are fitted is pushed outward by centrifugal force and rotates while being pressed against the inner circumferential wall of an annular housing 9 housing the rotor 7. At this time, the volume of the portion defined by the inner circumferential wall of the housing 9, the rotor 7, and the roller 8 changes, so that the fuel sucked into the gap from the suction port 3 is pushed out into the space on the motor 1 side.
It is designed to be discharged from the discharge port 4.

By the way, in a rotary pump, which is a positive displacement pump, in order to ensure high volumetric efficiency, it is necessary to reduce the gap between the rotor 7 and the housing 9 as much as possible, and also to ensure stability of volumetric efficiency and durability. In order to ensure quietness, it is necessary to minimize the play in the rotation of the rotor 7.

However, conventionally, as shown in FIG. 3, the rotor 7 is directly supported by the drive shaft 5 of the motor 1, which is passed through a hole 7b provided in the center of the rotor 7. In order to suppress run-out, misalignment, rattling, etc. with respect to the rotor 7, it is necessary to improve the assembly accuracy of each part, which poses a problem of high cost.

The present invention was developed in view of these conventional problems. A sleeve is provided with one end press-fitted into a hole formed in the housing, and a hole formed at the center of the rotor is fitted into the outer periphery of the sleeve to allow the rotor to be mounted. A rotary pump rotor that solves the above problems by having a structure in which the drive shaft of the rotor is passed through the hole of the sleeve, and the drive shaft and the rotor are engaged with each other with a gap to prevent rotation. The purpose is to provide a supporting structure.

The present invention will be explained below based on FIG. 4 showing one embodiment. However, in FIG. 4, the same components as those in the diagram of the conventional example will be described with the same reference numerals. In the figure, one end of a sleeve 10 is press-fitted into a drive shaft bearing hole 9a formed in a housing 9 and fixed therein. The rotor 11 is fitted onto the outer periphery of a portion of the sleeve 10 that protrudes into the pump chamber inside the housing 9 to receive the rotor 11 therein. On the other hand, the hole 10 of the sleeve 10
a through the drive shaft 5 end of the motor, and
The protrusion 12a of the joint 12, which is press-fitted and fixed onto the outer periphery of the drive shaft 5, is engaged with and attached to the anti-rotation groove 11a formed in the rotor 11.

Here, the hole 10a of the sleeve 10 is provided with a taper whose diameter increases toward the fuel discharge side, while the groove 11a of the rotor 11 is formed with a gap C between it and the protrusion 12a of the joint 12.

In such a configuration, the rotation of the drive shaft 5 is caused by the protrusion 1
2a and the groove 11a, and the rotor 11 rotates around the sleeve 10. In this case, the drive shaft 5 is
Even if runout, misalignment, play, etc. occur, these runouts, misalignment, play, etc. are absorbed by the gap C and are not transmitted to the rotor 11. On the other hand, the rotation accuracy of the rotor 11 is limited relative to the housing 9. Due to the fixed sleeve 10, high precision can be maintained without causing misalignment, and high volumetric efficiency can be ensured.

As a result, the assembly precision of these parts can be lowered and costs can be reduced.

In this embodiment, since the sleeve 10 is tapered, the vibration of the drive shaft 5 can be more effectively absorbed by the gap between the taper and the drive shaft 5.

As explained above, according to the present invention, even if the drive shaft experiences vibration, misalignment, play, etc. with respect to the rotor, the rotation accuracy of the rotor can be stabilized.
As a result of lowering the accuracy of parts assembly, manufacturing costs can be significantly reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a conventional rotary type fuel pump, Fig. 2 is a front view showing the same pump as above, Fig. 3 is an enlarged view of the main part of Fig. 1,
FIG. 4 is a sectional view of a main part of a rotary pump showing an embodiment of the present invention. 5... Drive shaft, 9... Housing, 10... Sleeve, 10a... Hole, 11... Rotor, 11a
...Groove, 12a...Protrusion.

Claims (1)

[Scope of utility model registration request] In a rotary pump, which pumps and transports liquid by engaging and rotating a rotor housed in a pump chamber of a housing with a rotary drive shaft, a sleeve is provided with one end press-fitted into a hole formed in the housing. A hole formed at the center of the rotor is inserted into the outer periphery of the sleeve to pivotally support the rotor, and a drive shaft of the rotor is passed through the hole of the sleeve, and a gap is provided between the drive shaft and the rotor to prevent rotation. A rotor support structure of a rotary type pump characterized by being engaged.