JPH11270487A - Wesco type pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Wesco type pump whose pumping performance can be enhanced while the producibility is heightened. SOLUTION: A first housing 21 is equipped concentrically with a mounting recess 30 to admit fitting of a partitioning ring 3 and a bearing hole for a drive shaft, wherein the depth T2 of the recess 30 is made smaller than the width T1 in axial direction of the ring 3, and the axial direction width of a pump chamber is specified by T1 , and thereby the inner side faces of the housings 21 and 22 confronting the ring 3 and pump impeller are formed flush. This allows easy and accurate setting of the side gaps between the first and second housings and the pump impeller and the gap between the ring and pump impeller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pump chamber defined by opposing surfaces of a first housing and a second housing coupled to each other and an inner peripheral surface of a partition ring fitted to the first housing. The present invention relates to a Wesco type pump in which a pump impeller is rotatably accommodated, and a drive shaft passing through one housing is connected to a center portion of the pump impeller to rotate the pump impeller.

[0002]

2. Description of the Related Art Such a Wesco type pump has been disclosed in
It is already known as disclosed in JP-A-82087.

[0003]

In order to operate such a Wesco type pump efficiently, it is necessary to provide a space between the first and second housings and the pump impeller and a space between the partition ring and the pump impeller. It is necessary to set the gap accurately.

However, in the Wesco type pump disclosed in the above publication, the partition ring is formed to be thinner than the pump impeller, and the first concave portion in which the entire partition ring is fitted, and the first recess for accommodating one side of the pump impeller. The two recesses are formed in the first housing in a stepped manner, and the recess for accommodating the other side of the pump impeller is formed in the second housing, so that a side gap between both housings and the pump impeller is formed. In order to set accurately, both recesses of the housing must be machined with high accuracy, and such machining is troublesome and productivity is poor. In addition, since the drive shaft that is fitted and connected to the pump impeller is supported by the second housing that does not support the partition ring, it is difficult to ensure concentric accuracy between the partition ring and the pump impeller. It is also difficult to set a constant gap between the impeller.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and accurately determines a side gap between the first and second housings and the pump impeller and a gap between the partition ring and the pump impeller. It is an object of the present invention to provide the above-mentioned Wesco type pump which can be set easily and can increase productivity while improving pump performance.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to an opposing surface of a first housing and a second housing coupled to each other, and an inner periphery of a partition ring fitted to the first housing. The pump impeller is rotatably housed in a pump chamber defined by a surface and a drive shaft that penetrates one housing to rotate the pump impeller at the center of the pump impeller. A mounting recess for fitting the partition ring and a bearing hole for rotatably supporting the drive shaft are formed concentrically in the first housing, and the depth of the mounting recess is smaller than the axial width of the partition ring. No, the first and second housings are coupled to hold the partition ring, and the partition ring of each housing is defined to define the axial width of the pump chamber by the axial width of the partition ring. And the first, characterized in that the formation of the inner surface facing the pump impeller flush.

[0007] According to the first feature, it is possible to perform concentric machining of the mounting concave portion and the bearing hole in the first housing, and easily obtain high concentric accuracy thereof. As a result, the distance between the pump impeller and the partition ring is reduced. The gap can be easily set constant. Since the axial width of the pump chamber is determined only by the axial width of the partition ring, its high dimensional accuracy can be easily obtained, and therefore, the side gap between the pump impeller and the housing can be easily set to a constant value. can do.

Further, in addition to the above-mentioned features, the present invention further comprises a plurality of press-fitting protrusions arranged at equal intervals in the circumferential direction on the outer peripheral surface of the partition ring, and only these press-fitting protrusions are deformed. The second feature is that the housing is press-fitted into the mounting recess.

According to the second feature, at the time of press-fitting the partition ring into the first housing, only the press-fitting projections arranged at equal intervals on the outer periphery of the partition ring are uniformly deformed, so that the press-fitting load is set relatively small. As a result, the partition ring can be securely attached to the first housing without eccentricity, and the inner peripheral surface of the ring can be prevented from being deformed by the press-fit load.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIG. 1 is a partially longitudinal side view of a fuel pump device for an internal combustion engine to which the present invention is applied, FIG. 2 is an enlarged view of a part of FIG. 1, FIG. 3 is a single plan view of a partition ring, and FIG. 5 is a sectional view taken along line 4-4 of FIG. 1, and FIG. 5 is a sectional view taken along line 5-5 of FIG.

First, in FIG. 1, the fuel pump device A is
The pump comprises a Wesco pump P and an electric motor M for driving the pump. These are housed in a common casing 1 and are connected to each other.

[0013] Wesco-type pump P includes a first housing 2 ₁ fitted spigot to one end inner peripheral surface of the casing 1, the partition ring 3 is attached to the first housing 2 _1,
While the first housing 2 ₁ and face each other across the partition ring 3, the pump chamber 4 and the second housing 2 ₂ which is fitted to the casing 1, defined by the two housings 2 _1, 2 ₂ and the partition ring 3 a pump impeller 5 is rotatably accommodated, the two housings 2 _1, 2 ₂ by caulking the end of the casing 1 is coupled to each other so as to sandwich the partition ring 3, at the same time the casing 1 both bind Is done. At that time, for positioning around the housings 2 _1, 2 ₂ mutual axis, the housings 2 _1, 2 ₂
Positioning grooves ₆₁ and 62 positioning projection 7 of the casing 1 peripheral surface ₂ of the outer peripheral surface are engaged.

The first and second housings 2 ₁ and 2 ₂ are made of an aluminum alloy, and the partition ring 3 is made of a synthetic resin.

The electric motor M is housed in the central portion of the casing 1, a drive shaft 9 fixed to the rotor 8, provided coaxially to the first housing 2 ₁ and the bracket 10 are opposed across the rotor 8 The bearing holes 11 and 12 are rotatably supported at both ends via bushes 13 and 14, and one end thereof is connected to the center of the pump impeller 5 so that the rotation of the rotor 8 drives the pump impeller 5 to rotate. Has become. As shown in FIGS. 1 and 5, the connecting structure of the drive shaft 9 and the pump impeller 5 includes a connecting shaft portion 9 a having a circular section formed at one end of the drive shaft 9 and a connecting portion formed at the center of the pump impeller 5. The connecting shaft portion 9a is configured so as to be detachable from the connecting hole 5a.

The bracket 10 is caulked to the other end of the casing 1 together with a connector 15 covering the outer surface.

As shown in FIGS. 2, 3 and 5, the outer peripheral edge of one side of the pump impeller 5 and the outer peripheral edge of the other side thereof are
A large number of first blade grooves 17 ₁ and second blade grooves 17 _{2 are respectively provided.}
Are arranged in the circumferential direction, and the first blade groove 17 ₁ group and the second blade groove 17
First circumferential groove 18 ₁ and the second peripheral groove 18 ₂ is formed in the first housing 2 ₁ and the second respective opposite sides of the housing 2 ₂ which communicates with each of the blade grooves 17 _two groups.

[0018] The second housing 2 _2, suction port 19 communicating with the pump chamber 4 is provided. Also in the first housing 2 _1, a discharge port 20 communicating with the pump chamber 4 inside the electric motor M is provided in close proximity with the inlet port 19 and the circumferential direction.

On the inner peripheral surface of the partition ring 3, a suction area 21 and a discharge area 22 communicating with the suction port 19 and the discharge port 20, respectively, and a partition 23 extending in an arc shape between the areas 21 and 22 are provided. Except for this, a circumferential partitioning ridge 24 is formed, and the partitioning ridge 24 is arranged so as to face a boundary between the first and second blade grooves 17 ₁ and 17 ₂ .

The fuel pump device A is shown in FIG.
Not used immersed in fuel oil in fuel tank. Drive
The drive shaft 9 causes the pump impeller 5 to move in the direction of arrow R in FIG.
When driven to rotate, the second housing 2_TwoSuction port 1
The fuel sucked in from the pump impeller 5 is
Second blade groove 17₁, 17_TwoAnd the first and
And the second circumferential groove 18₁, 18_TwoWhile creating a swirling flow between
From the first housing 2₁From the discharge port 20
Discharged. Meanwhile, the first and second blade grooves 17 ₁, 17
_TwoPartition of partition ring 3 projecting toward the boundary of group
The ridges 24 are provided on both blade grooves 17.₁, 17_TwoSwirling flow within
This avoids interference and improves pump efficiency.

The fuel discharged from the discharge port 20 passes through the inside of the electric motor M, and is supplied from an outlet port 25 provided in the connector 15 to a fuel supply section (not shown) of the engine.

[0022] Now, the mounting structure to the first housing 2 ₁ of the partition ring 3 will be described with reference to FIGS. 2-5.

As shown in FIGS. 2 and 5, the first housing 2 _1, circular mounting recess 30 is formed by concentric machining of the bearing hole 11 on the surface facing the second housing 2 _2. The partition ring 3 is formed on the inner peripheral surface of the mounting recess 30.
Is mounted as follows.

As shown in FIGS. 3 and 4, on the outer peripheral surface of the partition ring 3, three or more (four in the illustrated example) press-fitting projections 31 arranged at equal intervals in the circumferential direction and one or more positioning protrusions 31 are provided. A projection 32 is formed.

Here, the diameter of the general outer peripheral surface of the partition ring 3 is D ₁ , the diameter of the circumscribed circle of the plurality of press-fitting projections 31 is D ₂ ,
When the diameter of the inner peripheral surface of the mounting recess 30 is D ₃ ,
These are set according to the following equations.

D ₁ <D ₃ <D ₂ (1) When the axial width of the partition ring 3 is T ₁ and the depth of the mounting recess 30 is T ₂ , It is set according to the following equation.

[0027] _{T 1> T 2 ··········· (2} ) On the other hand, the first inner peripheral surface of the housing 2 _1, positioning grooves 33 corresponding to the positioning projection 32 is formed .

[0028] In Thus, in the partition ring 3 the inner peripheral surface of the first housing 2 _1, when pressed while the alignment of both the positioning projection 32 and positioning 33, as shown in FIG. 5, the positioning projections 32 and The positioning members 33 are fitted with each other, and all the press-fitting projections 3
1 receives compressive deformation evenly. It is pressed against the inner peripheral surface of the mounting recess 30 with a high surface pressure.

[0029] Thus the partition ring 3, first it is being mounted to the housing 2 ₁ in the circumferential direction by a predetermined position, during the press-fitting, so deforming the only press-fitting projections 31,
With the partition ring 3 can securely mounted to the first housing 2 ₁ with a relatively small press-fitting load, the inner peripheral surface of the partition ring 3, in particular it is possible to avoid deformation caused by press-fitting load of the partition ridge 24. In addition, due to the uniform deformation of each press-fitting projection 31, the concentric accuracy between the partitioning ridge 24 of the partitioning ring 3 and the mounting recess 30 and, consequently, the mounting recess 30 and the bearing hole 11 formed concentrically can be increased. Therefore, if the pump impeller 5 is connected to the drive shaft 9 which is supported on the bearing hole 11 via the bush 13, high concentric accuracy is given to the pump impeller 5 and the partition ring 3. the circumferential gap g ₂ between the partition ridge 24 of the partition ring 3 can be kept constant as desired.

After the mounting, the partition ring 3 has one end protruding from the mounting recess 30 as shown in FIG. 2 according to the above-mentioned formula (2), and the second housing abuts on one end thereof. By connecting 2 ₂ to the first housing 2 ₁ , the partition ring 3 is connected to both housings 2 ₁ , 2 _2.
Sandwiched between.

The axial width T ₁ of the partition ring 3 defines the axial width of the pump chamber 4, and in order to do so, the partition ring 3 and the pump impeller 5 of the first and second housings 2 ₁ and 2 ₂ are used. Are formed flush with each other. Then, the thickness T ₃ of the pump impeller 5 rotatably accommodated in the pump chamber 4, the side gap g between the both side surfaces of the pump impeller 5, and the housings 2 _1, 2 inner surfaces of _2
The width corresponding to ₁ is set to be smaller than the axial width T ₁ of the partition ring 3.

Incidentally, the axial width T ₁ of the partition ring 3
And the wall thickness T ₃ of the pump impeller 5
Since the high accuracy can easily out, the side gap g ₁ of the pump impeller 5 on both sides can be kept constant as desired.

As described above, the gap g _{2 on} the outer periphery of the pump impeller 5 and the gap g ₁ on both sides can be easily kept constant as desired, so that the productivity can be improved. Stable and maintainable.

The present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the present invention. For example, the partition ring 3 can be made of an aluminum alloy.

[0035]

As described above, according to the present invention, the opposing surfaces of the first housing and the second housing coupled to each other and the inner peripheral surface of the partition ring fitted to the first housing are defined. The pump impeller is rotatably housed in a pump chamber, and a drive shaft passing through one of the housings is connected to the center of the pump impeller so as to rotate the pump impeller. The mounting recess for fitting the ring and the bearing hole for rotatably supporting the drive shaft are formed concentrically, and the depth of the mounting recess is made smaller than the axial width of the partition ring. The first and second housings are coupled to be clamped, and the axial width of the pump chamber is defined by the axial width of the partition ring. Since the inner surfaces facing each other are formed flush, concentric machining of the mounting recess and bearing hole in the first housing and the definition of the axial width of the pump chamber only by the axial width of the partition ring become possible. The concentric accuracy of the pump impeller and the dimensional accuracy of the axial width of the pump chamber can be easily maintained high, so that the gap between the pump impeller and the partition ring and the side gap between the pump impeller and the housing can be easily adjusted. It can be set to a constant value, which can improve both productivity and pump performance.

Further, according to the present invention, on the outer peripheral surface of the partition ring,
A plurality of press-fitting protrusions arranged at equal intervals in the circumferential direction are formed, and only these press-fitting protrusions are deformed. The partition ring is press-fitted into the mounting recess of the first housing. The ring can be securely mounted to the housing without eccentricity, and furthermore, deformation of the inner peripheral surface of the ring due to the press-fitting load can be prevented, which can contribute to ensuring pump performance.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional side view of a fuel pump device for an internal combustion engine to which the present invention is applied.

FIG. 2 is an enlarged view of FIG.

FIG. 3 is a plan view of a single unit of a partition ring.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

[Explanation of symbols]

P ···· Wesco-type port D ₁ ··· Diameter of general outer peripheral surface of partition ring D ₂ ··· Diameter of circumscribed circle of a plurality of press-fitting projections D ₃ ··· Diameter of inner peripheral surface of mounting recess T ₁ ···· Axial width of partition ring T ₂ ··· Depth of mounting recess T ₃ ··· Pump impeller wall thickness g ₁ ··· Side gap g ₂ ··· Circumference 2 ₁ first housing 2 ₂ second housing 3 partition ring 4 pump chamber 5 pump impeller 9 drive shaft 11 ... Bearing holes in the first housing 24...

Claims (2)

[Claims] A first housing (2 ₁ ) and a second housing (2 ₂ ) which are connected to each other;
A pump impeller (5) is rotatably housed in a pump chamber (4) defined by an inner peripheral surface of a partition ring (3) fitted to the housing (2 ₁ ), and the pump impeller (5)
A drive shaft (9) penetrating through one of the housings is connected to the center of the pump so that the partition ring (3) is fitted to the first housing (2 ₁ ). Recess (30) and drive shaft (9)
Is formed concentrically with the bearing hole (11) for rotatably supporting the shaft, and the depth (T ₂ ) of the mounting recess (30) is made smaller than the axial width (T ₁ ) of the partition ring (3). None,
The first and second housings (2 ₁ , 2 ₂ ) are combined to hold the partition ring (3), and the axial width (T ₁ ) of the partition ring (3) is used to adjust the axial width of the pump chamber (4). A wesco-type pump in which the inner surfaces of the housings (2 ₁ , 2 ₂ ) facing the partition ring (3) and the pump impeller (5) are flush with each other. 2. The partitioning ring according to claim 1, wherein a plurality of press-fitting projections are formed on an outer peripheral surface of the partition ring at equal intervals in a circumferential direction of the partitioning ring. A wesco type pump characterized in that the partition ring (3) is press-fitted into the mounting recess (30) of the first housing (2 ₁ ).