JPS61190192A - Motor driven fuel pump for car - Google Patents

Abstract

PURPOSE:To eliminate an impeller driving device, reduce a cumulative error, and facilitate assembling, by providing a joint on which a projecting part for driving an impeller is provided in an integrated form, and adjusting the end play for an armature on the both ends of a bearing. CONSTITUTION:Two to three washers 14 are assembled on the pump chamber side end face of the bearing of a housing 4, and a joint 11 is fitted over an armature shaft 9 from its end and is press fitted and positioned by means of a knurling part 10 provided on the shaft 9 so that an end play G becomes 0.1-0.3mm. Plural projecting parts 12 are provided in an integrated form with the joint 11 on the pump chamber side of the joint 11, while grooves 13 while are fitted to the projecting parts 12, are provided on an impeller 3, enabling the impeller 3 to synchronously rotate with the armature shaft 9 and the joint 11 which is press fitted to the shaft 9. Thereby, the end play G can be easily adjusted at the press fitting position of the joint 11, reducing a cumulative error, improving assembling accuracy, and eliminating an impeller driving device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electric fuel pump for a vehicle, and particularly to a fuel pump suitable for adjusting the end play of an amateur.

[Background of the invention]

There are generally two methods for adjusting the end play of this type of vehicle electric fuel pump. One method is called internal end play adjustment, which involves a distance collar installed at one end of the armature core. , the assembly dimensions of the armature determined by the commutator provided at the other end, the end face of the bearing provided in the pump chamber housing, the end face of the bearing provided in the end cover, and the case. The end play is the dimensional difference between the assembled dimensions of the case, and the assembled dimensions of the armature are determined by the press-fit position dimensions of the distance collar, armature core, and commutator, and these are determined by the dimensional tolerances of the parts and the press-fit position. Due to the accumulation of dimensional tolerances, the dimensional width is at least about ±0.2. Also, the case assembly dimensions have a dimensional width of at least about ±0.2 due to cumulative tolerances of the bearing portion of the housing, the bearing portion of the end cover, the case, etc. To assemble these, always manage the assembly dimensions, group the varying dimensions by a certain width dimension,
Then, the end play is adjusted by combining several types of adjusting washers with different thicknesses prepared in advance and installing them between the distance collar and the bearing and between the commutator and the bearing.

This is accompanied by an increase in the number of man-hours due to an increase in the dimension control process, and also causes assembly defects due to work errors.

Next, as another method, the end play method described in the drawings of Utility Model Application Publication No. 56-117053 is to receive the armature shaft tip with a plate provided in the pump casing, position the armature in one direction, The dimensions of each part are managed based on the plate. Here, the dimensional control process can be reduced by shifting the center positions of the magnet and armature core in the axial direction in advance and making the tip of the armature shaft relatively large so that it always contacts the plate. However, the tip of the armature shaft is generally spherical, but if the center of the spherical surface is misaligned during manufacturing, a rattling noise with the plate will occur, causing noise. In addition, if the shaft material and plate material selection, surface treatment, etc. are not appropriate, wear will occur, making it impossible to ensure proper dimensions, resulting in performance deterioration and noise.

[Object of the Invention] An object of the present invention is to provide an electric fuel pump for a vehicle that has a structure with little cumulative error, is easy to assemble, and can reduce the dimensional control process.

[Summary of the invention]

The present invention achieves the above object by incorporating washers at both ends of a bearing provided in the pump chamber housing, and press-fitting the joint for rotating the impeller in synchronization with the armature shaft onto the tip of the armature shaft to adjust the end play. It is something to do.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a longitudinal sectional view of a fuel pump device showing an embodiment according to the present invention. When the armature 6 rotates, the impeller 3 rotating synchronously with the armature 6 generates a pumping action in the pump chamber, and fuel flows into the pump chamber through the suction hole 2 of the end cover 1, and the rotation of the impeller 3 causes centrifugal force and Energy is accumulated by the frictional force of the fuel, and is forced through the discharge hole 5 of the housing 4, the inside 7 of the smearing machine, and from the discharge pipe 8 into the piping.

Here, the explanation will be given with reference to FIG. 2, which is a detailed diagram of the pump chamber.

The bearing 15 press-fitted into the housing 4 and the bearing 15
In order to reduce the frictional force during rotation between the end face of the distance collar 17 provided on the armature shaft 9 and the motor side end face of the bearing 15 of the housing 4, the armature shaft 9 of the armature 6 passes through the armature shaft 9. Three washers 16 are installed, and a similar washer 1 is installed on the pump chamber side end surface of the bearing 15 of the housing 4.
4, insert the joint 11 from the tip of the amateur shaft 9, and make sure that the end play is 0.1 to 0.
．． The armature shaft 9 is press-fitted and positioned using a knurling portion 10 provided on the armature shaft 9 so that the armature is 3 wm.

A plurality of protrusions 12 are provided on the pump chamber side of the joint 11.
is integrally provided with the joint 11, and the impeller 3
is provided with a plurality of grooves 13 that fit with the protrusion 12, and rotates synchronously with the armature shaft 9 and a joint 11 press-fitted into the armature shaft 9. Here, the dimensional relationship for obtaining appropriate end play will be explained using FIG. The length between the end face of the distance collar 17 and the tip of the amateur shaft 9 is LI; the length between the end face of the distance collar 17 and the stepped part of the amateur shaft 9 is L2;
The variation width of the dimensional tolerance of L3 is absorbed by the recess 20 of the impeller 3.

Further, since the bearing 15 is made of sintered metal, the dimensional tolerance width can be relatively small.
By using the dimensions of both end surfaces of 5 as a reference, the dimensional tolerance width of Ll and L is within the assembly process capacity of a general armature 6, which is assembled by stacking parts on the axis of the armature shaft 9. This end play can be adjusted at the press-fit position with the joint, making it very easy.

Next, the knurling part 10 provided on the amateur shaft 9
serves both to position the joint 11 and to stop it from turning. Furthermore, the armature 6 is inserted into the housing 4 through the bearing 15 with an appropriate end play that allows it to rotate freely, and when it is attached to the motor part, it will not fall off even if it is attracted by the magnet inside the motor. Easy to assemble. Here, the concave portion 19 of the joint 11 is a relief when the joint 11 is press-fitted into the knurling portion 10 of the amateur shaft 9.

〔Effect of the invention〕

As described above, according to the present invention, since the end play of the armatures is aligned at both ends of the bearing assembled in the housing by the press-fitting position of the joint, the cumulative error is small, so-called assembly accuracy is good, and the joint has blades. Since it has a protrusion for driving the vehicle, there is no need to provide a special impeller drive device, making it possible to obtain a vehicle electric fuel pump that is inexpensive and easy to assemble.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a fuel pump device showing an embodiment according to the present invention, FIG. 2 is a detailed sectional view of section A in FIG. 1, and FIG. 3 is a side view of an armature shaft. DESCRIPTION OF SYMBOLS 1... End cover, 2... Suction hole, 3... Impeller, 4... Housing, 5... Discharge hole, 6... Armature, 7... Inside of electric motor, 8...・Discharge pipe, 9・
...Amateur shaft, 10...Knurling part, 1
DESCRIPTION OF SYMBOLS 1...Joint, 12...Protrusion, 13...Groove, 14...Washer, 15...Bearing, 16...
Washer, 17...Tistance collar, 18...
・Recessed part, 19... Recessed part, 2o... Recessed part, 21...
Recess, G...end play, LL...dimension, L2.
...Dimensions, L3...Dimensions.

Claims (1)

[Claims] 1. In a fuel pump having a pump section driven by an electric motor, a joint is provided at both ends of a bearing assembled to the pump housing to adjust the end play of the armature, and the joint has a protrusion for driving an impeller. An electric fuel pump for a vehicle characterized by being integrally formed.