JP2002308183A - Mounting structure of water jet pump for planing boat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting structure of a water jet pump facilitating the mounting on a planing boat. SOLUTION: This mounting structure of the water jet pump of the planing boat is required a front/rear directional position adjustment relative to a fixed member side. The front end part of a pump casing is taperedly formed with its diameter becoming narrower toward the front end, a groove is formed in the front end so as to circulate the circumference of the casing, and a projecting contraction part circulating the outer circumferential face is formed. A seal member formed with a lip circulating the internal circumferential face and projecting inward in the rear end is disposed so that the lip entered in the groove, and a tapered recess part, which smashes, at least, the contraction part of the seal member, smashes the lip in the groove, and is mated with the front end of the pump casing disposed with the seal member in the front end is formed in the fixed member side so as to seal a part between the fixing member side and the pump casing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mounting structure for a water jet pump used as a propulsion device for a personal watercraft.

[0002]

2. Description of the Related Art A planing watercraft propelled by a water jet pump, for example, a personal watercraft (Personal Watercaft: abbreviated as "PWC"), receives water (water) from a water intake port provided at the bottom of a ship or the like. (Including seawater)
And accelerate with a water jet pump,
The water jet pump, which is disposed rearward, jets rearward from the jet port of the water jet pump and moves forward. In this water jet pump, an impeller is rotatably disposed in a casing formed in a cylindrical body having an inner periphery having a circular cross section. The water jet pump is roughly divided into an outer diameter (outer edge) of an impeller blade and a base having a circular cross section to which the blade is attached, and a pump casing covering the impeller expands in diameter from the suction side to the pressurization side. So-called "mixed flow type" water jet pump and impeller blade outer diameter
There is a so-called "axial flow type" water jet pump in which a base having a circular cross section to which the outer edge and the blade are attached, and a pump casing covering the impeller are straight from the suction side to the pressurization side. In the case of a water jet pump, the size of the gap between the pump casing and the outer edge of the blade of the impeller has a very large effect on pump performance. Specifically, if the gap is too large, the pump performance is reduced. If the gap is too small, the tip (outer peripheral end) of the blade may temporarily contact the inner wall of the pump casing. is there. For this reason,
Generally, the gap between the inner wall of the pump casing and the outer edge of the blade of the impeller is set to about 0.20 to 0.30 mm.

However, in the case of the mixed flow type water jet pump, when the position of the impeller in the casing of the water jet pump in the axial direction changes back and forth, the pump casing and the outer edge of the blade of the impeller are accordingly moved. The gap will change.
Therefore, assembling is performed while adjusting the axial position of the impeller with respect to the pump casing as described below so that the gap between the casing and the outer edge of the blade of the impeller is maintained within the above-described predetermined value. That is, FIG.
As shown in the figure, in the mixed flow type water jet pump P, the pump casing 1C is divided into a "front casing 1Cf" and a "rear casing 1Cr" at a portion having the largest diameter. 1C
r, a pump rotating shaft 1S is rotatably disposed via a bearing 1H with its front end protruding forward. An impeller 1Z that rotates integrally with the pump rotation shaft 1S is provided at the front end of the pump rotation shaft 1S. In this arrangement, the bearing support side of the pump rotating shaft 1S and the impeller 1 are arranged such that the gap between the inner wall of the pump casing 1C (front casing 1Cf), which is an inclined surface, and the outer peripheral edge of the impeller 1Z is within a predetermined range.
A suitable number of thin-plate-shaped gap adjusting shims 35 are interposed between Z and Z, and then a female screw hole at the rear end of the impeller 1Z is screwed and attached to a male screw at the front end of the pump rotating shaft 1S. . Then, as described above, when the assembling of the impeller 1Z is completed, the front casing 1Cf is attached to the rear casing 1Cr in which the pump rotation shaft 1S and the impeller 1Z are assembled.
Both are fixed with mounting bolts not shown. Then, when the assembly of the water jet pump is completed, a gap gauge is inserted into the gap between the inner wall of the front casing 1Cf and the outer peripheral edge of the impeller 1Z from the outside (outside of the pump suction port), and a predetermined gap is inserted. After checking whether it is within the clearance range, while inserting the spline shaft of the propeller shaft connected to the engine side into the small personal watercraft into the spline hole formed at the front end of the impeller, Will be installed.

However, when the clearance is not within the predetermined clearance range during the inspection with the clearance gauge, the mounting bolt is loosened to remove the front casing from the rear casing, and further remove the impeller from the pump rotating shaft. Increase or decrease the number of shims, assemble the water jet pump again,
Check the gap again. Therefore, in some cases, the water jet pump is repeatedly assembled and disassembled to adjust the gap. In addition, since the measurement of the gap with the gap gauge is a measurement of a curved gap, it is necessary to accurately measure the gap in the width direction of a tongue-shaped “gaps gauge” that is commercially available and generally used. Not be able to
Further, the number of times of the disassembly and assembly is increased.

As a prior art of the above-mentioned mixed flow type water jet pump, there is Japanese Patent Publication No. 60-30599 (US Pat. No. 4,541,808). As a prior art of an axial flow type water jet pump, Japanese Patent Publication No. 3-11955, There is Kaihei 9-207885.

An object of the present invention is to provide a water jet pump mounting structure which is applicable to the mixed flow type water jet pump and can be easily mounted on a personal watercraft.

[0007]

A mounting structure for a water jet pump for a personal watercraft according to the present invention is used as a propulsion device for a personal watercraft, and requires a water jet that needs to be adjusted in the front-rear direction with respect to a fixed member. In the mounting structure of the pump, the front end of the pump casing is formed into a tapered shape having a small diameter at the front end, and the tapered front end is formed so as to orbit around the casing.
A seal member having a groove, a convex contracted portion surrounding the outer peripheral surface, and a lip protruding inward around the inner peripheral surface at the rear end is formed by the lip of the seal member. The front end of the pump casing in which the sealing member is disposed at the front end is disposed on the fixing member side so that at least the contracted portion of the sealing member is crushed and the lip is crushed in the groove. A tapered concave portion corresponding to the tapered front end was formed, and a water jet pump was disposed on the fixed member side while sealing between the fixed member side and the pump casing. It is characterized by the following.

According to the mounting structure of the water jet pump configured as described above, the position of the front end of the water jet pump is slightly displaced in the front-rear direction with respect to the fixing member, or becomes a reference. Even if the seal member is disposed at the position, the seal member is deformed to provide a seal function. Therefore, the mounting structure is preferable as the mounting structure of the above-mentioned mixed flow type water jet pump in which the mounting position of the water jet pump changes or the overall length changes.

In the mounting structure of the water jet pump, if the front end of the sealing member is bent toward the front end face of the front casing, the mounting of the water jet pump to the fixing member becomes easy.

[0010] In the mounting structure of the water jet pump, if the shrinking portions are arranged at two places with a gap therebetween, a structure having higher sealing performance is obtained.

The mixed flow type water jet pump includes:
In a mixed flow type water jet pump used as a propulsion device of a planing boat, a pump casing divided into a front casing and a rear casing is divided into a front casing and a rear casing, and a position in a front-rear direction with respect to the rear casing is uniquely determined and arranged. Of the front casing, in which the impeller is housed inside, is mounted on the rear casing side via a shim so that a predetermined gap is formed between the inner wall of the front casing and the outer peripheral edge of the impeller. In the case of the water jet pump, the impeller is disposed so as to be at a predetermined position relative to the rear casing during assembly, and in this state, the front casing is disposed relative to the rear casing, and the impeller is disposed on the inner wall of the front casing. The rear casing and the front casing are joined until the peripheral edges touch Is measured, and according to the value, a shim of a predetermined thickness (the gap formed by each shim is checked in advance, and the minimum number of shims exceeding the measured value is determined. If the shim is interposed between the rear casing and the front casing, a predetermined gap between the inner wall of the front casing and the outer peripheral edge of the impeller can be easily obtained. (In addition, the above-mentioned "shim for predetermined thickness"
The shim may have a predetermined thickness by using a plurality of shims, or shims having various thicknesses may be prepared in advance, and the shim having that thickness may be selected. The “predetermined thickness”
A thickness obtained by adding a longitudinal dimension corresponding to a gap dimension to be formed between the outer peripheral edge of the impeller and the inner wall of the front casing to the above measured value. In this case, unlike the related art, it is not necessary to remove the impeller each time, and the gap between the rear casing and the front casing is a gap parallel to the thickness direction of the gap gauge. Since the measurement can be performed accurately, the assembly having the predetermined gap can be efficiently performed.

The mixed flow type water jet pump is a mixed flow type water jet pump used as a propulsion device of a personal watercraft.
A pump rotating shaft is rotatably disposed on the rear casing, and an impeller is attached to the pump rotating shaft so as to rotate integrally with the pump rotating shaft. The front casing is fixed at a predetermined distance between an inner wall of the front casing and an outer peripheral edge of the impeller. May be attached to the rear casing via a shim for adjustment so as to provide a gap between them. According to the mixed flow type water jet pump configured in this manner, Then, the impeller is fixed to a pump rotating shaft rotatably disposed on the rear casing, and in this state, the front casing is joined to the rear casing until the outer peripheral edge of the impeller abuts on the inner wall of the pump casing. The gap between the rear casing and the front casing is measured in accordance with the measured value. Leave verify clearance portion in advance, the minimum number of shims above the value for the measured value)
Is interposed between the rear casing and the front casing, a predetermined gap between the inner wall of the front casing and the outer peripheral edge of the impeller can be easily obtained. (Note that the "shim for a predetermined thickness" may be a predetermined thickness using a plurality of shims, or shims of various thicknesses may be prepared in advance, and a shim of that thickness is selected. Further, the “predetermined thickness” is obtained by adding a dimension in the longitudinal direction corresponding to a gap dimension to be formed between the outer peripheral edge of the impeller and the inner wall of the front casing to the measured value. Also in this case, unlike the conventional case, it is not necessary to remove the impeller each time, and the gap between the rear casing and the front casing is a gap parallel to the thickness direction of the gap gauge. Since the measurement can be performed very easily and accurately by the gap gauge, the assembly having the predetermined gap can be efficiently performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A water jet pump mounting structure according to one embodiment of the present invention will be described below, together with the structure of a diagonal flow type water jet pump as the water jet pump, when applied to a personal watercraft. By way of example, the configuration will be described in more detail with reference to the drawings. FIG. 1 is an overall side view of a personal watercraft employing a water jet pump mounting structure according to an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 shows a detailed configuration of the water jet pump shown in FIG. FIG. 4 is an enlarged view of a main part of the water jet pump shown in FIG. 3, and FIG.
Is an exploded side sectional view showing a state in one process of assembling the mixed flow type water jet pump shown in FIG. 6, and FIG. 6 is an exploded side sectional view showing the next process shown in FIG.

In FIGS. 1 and 2, A is a hull, and this hull A is composed of a hull H and a deck D covering the hull H. A connection line connecting the hull H and the deck D all around is a gunnel line. G, and in this embodiment, the gunnel line G is located above the waterline L of the personal watercraft. As shown in FIG. 2, an opening 16 whose upper surface is substantially rectangular in plan view along the longitudinal direction of the hull A is formed slightly behind the center of the deck D, as shown in FIG. As shown in FIG.
A seat S for riding is arranged above. The engine E is arranged in a space (referred to as an “engine space”) 20 having a “convex” cross-sectional shape surrounded by the hull H and the deck D below the seat S. This engine E is a multi-cylinder (three-cylinder in this embodiment) engine E, and has a crankshaft 10b mounted in a direction along the longitudinal direction of the hull A as shown in FIG. As shown in FIG. 1, a carburetor 11 and an air intake chamber (not shown) connected to the carburetor 11 are provided on the left side of the engine body 10 (on the port side of the personal watercraft). As
A collective exhaust pipe 13A is disposed above. Further, the exhaust pipe 13A is connected to a silencer 14 disposed diagonally left rear of the engine body 10. Silencer 1
4, an exhaust pipe 13 </ b> B whose end extends outside the rear end of the hull A
However, it is bent upward to avoid the water jet pump P. As shown in FIG. 1, the output end of the crankshaft 10b projecting rearward from the engine body 10 is connected to a water jet pump P via a propeller shaft 15 as shown in FIGS. Is integrally rotatably connected to the front end of the impeller 1Z. The rear end of the impeller 1Z is integrally and rotatably connected to a pump rotation shaft 1S of the water jet pump P. And this impeller 1
Z has its outer periphery covered with a pump casing 1C,
Water taken in from a water supply port 17 provided on the bottom surface of the personal watercraft is taken in through a water suction passage, pressurized and accelerated by a water jet pump P, and the jet nozzle 1R whose water passage cross-section becomes smaller as it goes backward. , And is ejected from a rear injection port to obtain a propulsive force. In FIGS. 1 and 2, reference numeral 21 denotes a steering handle. By operating the handle 21 right and left, the steering nozzle 18 behind the injection nozzle 1R is swung right and left to perform steering in a desired direction. It is configured to be able to.
A reverse deflector 19 (see FIG. 1) is disposed above and behind the steering nozzle 18 so as to be able to swing downward about a horizontally arranged swing shaft. The steering nozzle 1
8 The water discharged backward from the steering nozzle 18 is turned forward by swinging to the rear lower position, so that the water can be moved backward.

1 and 2, reference numeral 12 denotes a rear deck. The rear deck 12 is provided with an openable / closable hatch cover 29, and a small-capacity storage box is formed below the hatch cover 29. I have. Also, in FIG.
22 is a fuel tank for supplying fuel to the engine E,
Reference numeral 3 denotes a front hatch cover, and a box (not shown) for storing equipment and the like is provided below the hatch cover 23. Also, above the front hatch cover 23,
Another hatch cover 25 is arranged to form a two-layer hatch cover, and the hatch cover 25 accommodates a life jacket or the like through an opening (not shown) provided on a rear end surface. Is available. In FIG. 2, reference numeral 26 denotes an ignition device for supplying high-voltage electricity to the ignition plug 10d at appropriate timing, reference numeral 27 denotes an oil tank for mixing, and reference numeral 28 denotes a battery.

The water jet pump P, which is enlarged in FIG. 3 and shown in the present embodiment, is a mixed flow type water jet pump and is configured as follows.
That is, as shown in FIG. 3 in an enlarged manner, the pump casing 1C is composed of a front casing 1Cf and a rear casing 1Cr, which are divided into two parts at the thickest portion. As shown in FIG. 4 in a further enlarged manner, a thin plate-shaped (1 in this embodiment)
A predetermined number of shims 5, each having a thickness of 0.5 mm, for example, up to about four, can be interposed. Further, in the embodiment, a knocking pin (not shown) for positioning is protruded from one of the casings at the joint so that the shim 5 can be positioned, and a positioning hole (not shown) corresponding to the knocking pin is formed. ) Is provided on the shim 5 side so as to be positioned with respect to the front or rear casing. Also, this Sim 5
In order to provide rust prevention performance, stainless steel is used as a material. As shown in FIG. 3 or FIG. 4, a barrel-shaped partition 1q having a front bearing housing Bh1 is formed integrally with the rear casing 1Cr, and is provided inside the barrel-shaped partition 1q. Represents a space 1j and a stationary vane (rectifying vane) outward.
1t is formed. The stationary blade 1t is provided with an impeller 1 having a pitch angle and flowing in the water jet pump P.
In addition to rectifying the rotational flow formed by the above, the partition 1q is connected to be integral with the cylindrical outer shell of the rear casing 1Cr. A rectifying cone 1w is disposed at the rear end of the partition wall 1q so as to cover the rear bearing housing Bh2 formed inside. The bearing housings Bh1, Bh2
, A ball bearing 1H is provided, and a pump rotating shaft 1S is rotatably provided via the ball bearing 1H. An impeller is provided at a front end (a front casing 1Cf side end) of the pump rotating shaft 1S. 1Z is screwed so as to rotate integrally with the pump rotation shaft 1S. In the case of the water jet pump, it is not necessary to use a shim for adjusting the axial position between the impeller 1Z and the pump rotating shaft 1S when attaching the impeller 1Z. Therefore,
The position of the impeller 1Z in the longitudinal direction with respect to the rear casing 1Cr may have a dimensional error of about 1 mm at the maximum due to accumulation of manufacturing tolerances. Therefore, in this mixed flow type water jet pump P, the pump casing 1C is assembled by assembling as follows.
The gap between the inner wall and the outer peripheral edge of the impeller 1Z is adjusted.
That is, as described above, in a state where the pump rotation shaft 1S and the impeller 1Z are fixed to the rear casing 1Cr, the impeller 1Z is placed on the assembly table so as to be located above, and the rear casing 1Cr is From above, gently cover the front casing 1Cf to a position where the outer peripheral edge of the impeller 1Z abuts on the inner wall of the front casing 1Cf.
In the contact state, the gap between the rear casing 1Cr and the front casing 1Cf is measured using a commercially available gap gauge. This measurement can be easily and accurately performed simply by inserting a commercially available tongue-shaped clearance gauge straight. Then, a desired number of the shims 5 are interposed between the rear casing 1Cr and the front casing 1Cf with respect to the measured value, so that the inner wall of the pump casing 1C (the front casing 1Cf) and the outside of the impeller 1Z. A gap within a predetermined dimensional range is formed between the gap and the peripheral edge. More specifically, in this embodiment, when one shim 5 having a plate thickness of 0.5 mm is inserted from the inclination angle of the impeller 1Z arrangement portion of the front casing 1Cf, the gap of 0.1 mm is formed. It is obtained (stored) as design data (or execution data) in advance, and for example, if the measured value of the clearance gauge is 0.7 mm, the rear casing 1
Four shims 5 are interposed between Cr and the front casing 1Cf. Instead of using a plurality of shims 5 in combination, shims having various thicknesses may be facilitated in advance and a shim having a corresponding thickness may be selected. As a result, a gap of 0.26 mm is formed between the inner wall of the pump casing 1C and the outer peripheral edge of the impeller 1Z. Therefore, if the measured value of the clearance gauge is 0.4 mm, the rear casing 1Cr
When the three shims 5 are interposed between the pump casing 1Cf and the front casing 1Cf, the gap between the inner wall of the pump casing 1C and the outer peripheral edge of the impeller 1Z is 0.22 mm.

As described above, in the case of the mixed flow type water jet pump having this configuration, as described above, the impeller 1Z
Is detached from the pump rotation shaft 1S every time when assembly and disassembly are performed, that is, without adjusting the gap between the inner wall of the pump casing 1C and the outer peripheral edge of the impeller 1Z by trial and error.
The clearance can be adjusted easily and in a short time only once without assembling and disassembling many times. When the gap adjustment is completed in this way, as shown in FIG. 7, the front casing 1Cf is fixed to the rear casing 1Cr by mounting bolts 30 arranged around the casing. However, in the case of the mixed flow type water jet pump having this configuration, the total length of the water jet pump P is equal to the number of the shims 5 (or the thickness of a single shim having the corresponding thickness). Will change slightly.

By the way, even if the total length of the water jet pump P changes as described above, if the mounting structure according to the present invention is adopted, the water jet pump P can be easily mounted on the mounting member on the hull while maintaining the seal structure. Can be. That is, as shown in FIG. 3 or FIG.
The front end (portion on the suction port side) 1x is formed in a tapered shape having a slightly smaller diameter on the front end side, and the tapered front end 1x has a groove 2 orbiting around the pump casing 1C. Are formed. In the case of this embodiment, the groove 2 has a rectangular cross section as shown in an enlarged view in FIG. Then, the front end 1x has the shape shown in FIG.
Alternatively, a seal member 4 as shown in FIG. 4 is provided. The seal member 4 is made of soft rubber, has an overall shape conforming to the shape of the front end 1x of the pump casing 1C, and has a front end wall 4f that is open except for the peripheral edge thereof (FIG. 3). Reference). And
On the outer peripheral surface of the seal member 4, there are formed convex (concave semicircular in this embodiment) contracted portions 4 a around the outer peripheral surface at two locations separated from each other in the front and rear directions, and the inner periphery at the rear end. The surface is formed with a lip 4b having a substantially rectangular cross section, which is narrower than the groove 2 protruding inward around the inner peripheral surface and has a larger dimension in the height (depth) direction. The front end 4c of the seal member 4 is bent toward the front end face of the front casing 1Cf to form the front end wall 4f.

The front end 1x of the pump casing 1C is fixed to a fixing member (in this embodiment, "pump bracket") 3 which is fixed to the hull to which the front end 1x of the pump casing 1C is to be attached. 3A is formed as a pump seat. The concave portion 3A has a ring shape with a substantially L-shaped cross section as a whole, and the inner peripheral surface 3a of the concave portion 3A
C is formed of a tapered surface having the same taper angle as the front end 1x. The fixing member 3 also has an opening 3B having the same diameter as the opening of the seal member 4 (more precisely, a slightly larger diameter), and this opening 3B functions as a water passage portion of the water jet pump P. I do.

According to the thus-configured main mounting structure, first, as shown in FIG. 5, the front end 1x of the pump casing 1C to be mounted on the fixing member 3 side.
Then, the bent front end wall 4f is attached along the front surface of the pump casing 1C, and the lip 4b of the seal member 4 is fitted in the groove 2 of the front end 1x. Then, as shown in FIG. 6, the front end 1x of the pump casing 1C having the seal member 4 attached to the front end is inserted into the recess 3A of the fixing member 3 backward (see the direction of arrow X in FIG. 6).
7, the pump casing 1C is fixed to the fixing member 3 side via the spacer 33 by the mounting bolt 31 and the nut 32 screwed to the fixing member 3 side, as shown in FIG. I do. Due to the insertion, as shown in FIG. 4, the lip 4b of the seal member 4 is crushed in the groove 2 to close the groove 2, and the inner peripheral surface 3a of the concave portion 3A forms the convex When the contracting portion 4a is crushed, the space between the fixing member 3 and the pump casing 1C is sealed. Further, depending on the degree of insertion, the front end wall 4f of the seal member 4 is
C is crushed, and this portion is also sealed. Since the sealing member 4 is made of soft rubber, the fixing member 3 and the pump casing 1C
Even if the degree of insertion (the degree of insertion in the longitudinal direction) with respect to the (water jet pump P) changes by about 2 to 3 mm, the sealing property is maintained by the elasticity of the seal member 4 and the above configuration. That is, the total length of the water jet pump P is 1 to 2 m depending on the number of the shims 5 to be interposed.
Even if it changes by about m, the water jet pump P can be attached to the fixing member 3 while maintaining the sealing property.

In the above embodiment, a mixed flow water jet pump for a personal watercraft has been described.
Needless to say, the present invention can be applied to a diagonal flow type water jet pump of a larger planing boat.

Further, in the above-described embodiment, the configuration in the case where the pump rotary shaft is provided on the rear casing side has been described. However, the present invention can be similarly implemented when the pump rotary shaft is provided on the front casing side. Needless to say.

Further, it goes without saying that the present invention can be applied to an axial flow type water jet pump other than the mixed flow type water jet pump.

[0024]

According to the present invention, it is possible to provide a mounting structure which is applicable to a mixed flow type water jet pump and can be easily positioned in an axial direction when mounted on a personal watercraft.

[Brief description of the drawings]

FIG. 1 is an overall side view of a personal watercraft employing a mixed flow type water jet pump according to the present embodiment and a mounting structure thereof.

FIG. 2 is a plan view of the personal watercraft shown in FIG.

FIG. 3 is an enlarged view showing a detailed configuration of the mixed flow water jet pump shown in FIG.

FIG. 4 is an enlarged view of a main part of the water jet pump shown in FIG.

FIG. 5 is an enlarged view showing a state in one process of assembling the mixed flow water jet pump shown in FIG.

FIG. 6 is an exploded side sectional view showing the next step shown in FIG. 5;

FIG. 7 is a plan view showing a state where a pump casing is attached to a fixing member.

FIG. 8 is an enlarged sectional side view showing a structure of a mixed flow type water jet pump of a conventional water jet pump.

[Explanation of symbols]

 P water jet pump 1C pump casing 1Cf front casing 1Cr rear casing 1S pump rotating shaft 1Z impeller 3 fixing member 4 sealing member 5 shim

Claims (3)

[Claims] 1. A water jet pump mounting structure which is used as a propulsion device of a planing boat and requires position adjustment in the front-rear direction with respect to a fixed member side, wherein a front end of a pump casing is reduced in diameter toward the front end. A groove is formed in the tapered front end portion so as to orbit around the casing,
A sealing member having a convex constricted portion surrounding the outer peripheral surface and a lip protruding inward around the inner peripheral surface at the rear end is disposed such that the lip of the sealing member enters the groove. The front end of the pump casing, in which the seal member is disposed at the front end, is formed on the fixed member side such that at least the contracted portion of the seal member is crushed and the lip is crushed in the groove. The water jet pump is disposed on the fixed member side by sealing the gap between the fixed member side and the pump casing by forming a tapered concave portion corresponding to the front end portion. Water jet pump mounting structure. 2. The front end of the seal member is bent toward the front end face of the front casing.
The mounting structure of the described mixed flow water jet pump. 3. The mounting structure for a diagonal flow type water jet pump according to claim 1, wherein the contraction portion is disposed at two places with a space therebetween.