US3906886A

US3906886A - Water jet for a speed boat

Info

Publication number: US3906886A
Application number: US433293A
Authority: US
Inventors: Gerd Elger
Original assignee: Allianz Technik AG
Current assignee: Allianz Technik AG
Priority date: 1974-01-14
Filing date: 1974-01-14
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23

Abstract

In a water jet drive mounted inboard in a speed boat, a drive shaft drives an impeller shaft over a bevel gear drive within a stator housing. Both the drive shaft and the impeller shafts are rotatably mounted in a pair of spaced bearings within the stator housing, the bearings for each of the shafts are located each on an opposite side of the beveled gear drive.

Description

United States Patent [191 Elger 1 Sept. 23, 1975 WATER JET FOR A SPEED BOAT [75] Inventor: Gerd Elger, Winterthur, Switzerland [73] Assignee: Allianz-Technik AG, Basel,

Switzerland [22] Filed: Jan. 14, 1974 [21] Appl. No.: 433,293

[52] [1.5. Cl. 115/16; 115/42; 60/221 [51] Int. C1. B63I-I 11/02 [58] Field of Search l15/1l,14,16, 42, 34 R;

[56] References Cited UNITED STATES PATENTS 3,044,260 7/1962 Hamilton 115/16 FOREIGN PATENTS OR APPLICATIONS France 115/34 R 1,189,779 4/1970 Canada 114/151 Primary Examiner-Trygve M. Blix Assistant ExaminerSherman D. Basinger Attorney, Agent, or Firm-Toren, McGeady and Stanger [57] ABSTRACT In a water jet drive mounted inboard in a speed boat, a drive shaft drives an impeller shaft over a bevel gear drive within a stator housing. Both the drive shaft and the impeller shafts are rotatably mounted in a pair of spaced bearings within the stator housing, the bearings for each of the shafts are located each on an opposite side of the beveled gear drive.

2 Claims, 3 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of2 3,906,886

FIG!

WATER JET FOR A SPEED BOAT SUMMARY OF THE INVENTION .a relatively long stator housing. As, in addition, the

shaft of the driving bevel gear must pass outside the stator housing both the design and manufacture of the stator housing become complicated. Furthermore, a guidance device is required in order to correctly guide the current paths of the water accelerated by the impeller. The housing and guidance device lead to an elongated construction. Quite apart from the high material and manufacturing costs, a long housing is also disadvantageous in that the area wetted by the water becomes relatively. large which increases the flow resistance, and, therefore, unfavourably influences the efficiency.

The problem of the invention -is to construct a water jet drive of the above-mentioned type so that the stator housing and its impeller shaft as well as the guidance device is shorter and lighter than in the past, so that the area to be wetted by the water is smaller and consequently the efficiency of the water jet drive rises, that the introduction of the axial thrust into the stator housing takes place in the shortest manner thereby increasing the lifeof the water jet drive and that finally its material andmanufacturing costs are reduced.

According to the invention, this problem is solved in that the impeller shaft bearings are arranged inside the stator housing on both sides of the bevel gear drive and the stator housing is constructed as a guidance device.

In this surprisingly simple manner it ispossible to make the water jet drive about 40% shorter than in the past and to construct the housing and guidance device as one casting. As the bevel gear drive is enclosed by bearings the overhung mounting becomes superfluous, the impeller shaft becomes shorter and its bending load is greatly reduced.. Due to the smaller wettable surface area the .flow losses in the guidance device areconsiderably reduced and,.as a result, the efficiency is increased. The shorter construction not only affords more space in the boat but also, due to the possibility of placing the water intake further aft, the dangerous sucking in of air which has previously always occurred at high speeds, is prevented. The shorter and more compact construction also permits rational construction and saves material and weight.

According to a preferred embodiment, the pumpside. bearing is placed in the stator housing by means of a one-part bearing flange, while the bearing remote from the flow is placed directly thereinand the end of the stator housing remote from the flow is covered by a twopart bell-like member.

The bell-like member comprises two bell domes, one arranged concentrically to the other, whereby the inner bell dome is detachably fixed to the stator housing and the outer bell dome is detachably fixed to a central extension of the inner bell dome.

According to a further feature of the invention, the driving bevel gear is also rotatably supported in two spaced locations, whereby the first hearing is located in i an attachment on the outer casing and the second bearing in the stator housing projection projecting into the bearing frame of the bevel gear drive, so that, once again the overhung mounting is avoided.

To permit access to the bearing box of the bevel gear drive inside the stator housing the latter has an opening opposite the attachment of the outer casing for receiv ing one of the bearings of the driving bevel gear which can be sealed by an insert having the cross-sectional shape of the stator housing.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic showing ofa portion of a speed board containing the water jet drive of the present invention;

FIG. 2 is a cross-section through the set of pumps of a water jet drive according to the invention, and

DETAILED DESCRIPTION OF THE INVENTION includes a rotor or impeller 4 (FIG. 2) fixed to a horizontal impeller shaft 5 rotatably mounted in the socalled stator housing 8 by means of two spaced bearings 6 and 7. Between the bearings, in the form of ball bearings, is positioned a bevel gear drive 9 having a driver bevel gear 10 located on the impeller shaft. The

driving bevel gear. 11 of the gear drive isfixed to a drive.

shaft 12 extending perpendicularly to the impeller shaft 5. The drive shaft 12 is also rotatably mounted in stator housing 8 by means of two spaced

bearings

13 and 14, in the form of ball bearings with bearing 13 arranged in a projection 14 on the bearing frame 16 and bearing 14 in an attachment on the outer surface of the stator housing. Driver bevel gear 10 and bearing 13 are 10- cated in the bearing frame 16 of the stator housing 8 which is sealed all round against entry of water.

The pump-side bearing 6, located adjacent to the impellcr, is arranged by means of a bearing flange 17 in a front end opening 18 and bearing 7 remote from the impeller is arranged directly in a front end opening 19 of the stator housing. A springloaded sealing ring 20 seals the bearing point of bearing 6 against the entry of water.

The front end opening 19 remote from the impeller is covered by a twopart bell-like member 22 which comprises two concentrically arranged bell domes 23 and 24. The inner bell dome 23 is fixed to the projection 25 on the end of the stator housing remote from the impeller by means of screws 26 and the outer bell FIG. 3 is a section following the line ll II of FIG. I

dome 24 is fixed by a screw 27 to a central extension 28 of the inner bell dome and is supported via a bead 29 on its wide end on the stator housing. Sealing ring 32 seals the bearing and therefore also bearing frame 16 against the penetration of water.

In order, during assembly of the perpendicular drive shaft 12, to be able to insert bearing 13 into bearing frame 16, an opening 35 is provided in stator housing 8 which is scalable in water-tight manner by an insert 36 which has in cross-section the shape of the stator housing at this point.

The stator housing 8 itself is in the form of an inner shell 37 and an outer shell 38 spaced apart to form a partitioned duct 40 which serves as a guidance device. The duct 40 is partly interrupted only in the area of the inlet 41 of drive shaft 12. lnlet 41 is sealed in watertight manner with the aid of sealing ring 42 and cover plate 43.

An intake 44 is attached to the impeller end of the stator housing and an outlet 45 is attached to its opposite end,

As can be gathered from the above. the described water jet drive is extremely short and compact and the stator housing with the guidance device represents only a single casting. Thus, in this case the advantage of a short pump is not lost as a result of the disadvantage of a very long pump/motor construction.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

I claim:

l. A water jet drive mounted inboard in a speed boat which has a water inlet in the bottom of the boat and a jet nozzle outlet in the stern of the boat, comprising a stator housing positioned in the boat and forming an annular flow passage and having an inlet end connected to the water inlet into the boat and an outlet end connected to the jet nozzle outlet from the boat, a drive shaft arranged to be driven by a motor mounted in the boat and said drive shaft extending into said stator housing, a driving bevel gear mounted on said drive shaft within said stator housing, an impeller shaft mounted in said stator housing and extending in the direction of flow between the inlet end and the outlet end of said stator housing, a driver bevel gear positioned on said impeller shaft and arranged to be driven by said driving bevel gear, wherein the improvement comprises first bearing means provided within said stator housing for rotatably supporting said impeller shaft and second bearing means provided within said stator housing for rotatably supporting said drive shaft, said first bearing means comprises a pair of spaced first bearing mem bers mounted on said impeller shaft, each on an opposite side of said driver bevel gear, and said second bearing means comprises a pair of second bearing members mounted on said drive shaft, each on an opposite side of said driving bevel gear, said stator housing comprises an annular-shaped inner shell and an annular-shaped outer shell encircling and spaced outwardly from said inner shell, said inner and outer shells defining therebetween an annular flow passage through said stator housing, said inner shell having a first end directed toward the inlet end of said stator housing, and a second end directed toward the outlet end of said stator housing, said impeller shaft extending through the first end of said inner shell, an impeller mounted on said impeller shaft between the inlet end of said stator housing and the first end of said inner shell, a bearing flange mounted in the first end of said inner shell, one of said first bearing members supported in said bearing flange, the other one of said first bearing members supported directly in the second end of said inner shell, a two-part bell-like member attached to the second end of said inner shell and forming a closure over the second end of said inner shell, said two-part bell-like member comprises an inner bell dome attached to the second end of said inner shell and projecting therefrom toward the outlet end of said inner housing, said inner bell dome having a centrally positioned extension extending toward the outlet end of said stator housing, and an outer bell dome concentrically arranged about said inner bell dome and detachably secured to said centrally positioned extension on said inner bell dome.

2. A water jet drive mounted inboard in a speed boat which has a water inlet in the bottom of the boat and a jet nozzle outlet in the stern of the boat, comprising a stator housing positioned in the boat and forming an annular flow passage and having an inlet end connected to the water inlet into the boat and an outlet end connected to the jet nozzle outlet from the boat, a drive shaft arranged to be driven by a motor mounted in the boat and said drive shaft extending into said stator housing, a driving bevel gear mounted on said drive shaft within said stator housing, an impeller shaft mounted in said stator housing and extending in the direction of flow between the inlet end and the outlet end of said stator housing, a driver bevel gear positioned on said impeller shaft and arranged to be driven by said driving bevel gear, wherein the improvement comprises first bearing means provided within said stator housing for rotatably supporting said impeller shaft and second bearing means provided within said stator housing for rotatably supporting said drive shaft, said first bearing means comprises a pair of spaced first bearing members mounted on said impeller shaft, each on an opposite side of said driver bevel gear, and said second bearing means comprises a pair of second bearing members mounted on said drive shaft, each on an opposite side of said driving bevel gear, said stator housing comprises an annular-shaped inner shell and an annular-shaped outer shell encircling and spaced outwardly from said inner shell, said inner and outer shells defining therebetween an annular flow passage through said stator housing, a tubular-shaped projection secured to and extending outwardly from said outer shell and forming an opening through said outer shell for said drive shaft, one of said second bearing members mounted in said projection, a bearing frame supported within said inner shell, a projection attached to said bearing frame, and the other one of said second bearing members mounted in said projection on said bearing frame and positioned between said driving bevel gear on said drive shaft and said impeller shaft, said inner and outer shells each have an opening therethrough in alignment with said tubular-shaped projections on said outer shell and located on the opposite side of said stator housing from said tubular-shaped projections, and a removable insert positioned in the openings in said inner and outer shells and forming a water-tight scaled closure therefor, said insert shaped to conform to the configuration of said inner and outer shells forming said stator housing.

Claims

1. A water jet drive mounted inboard in a speed boat which has a water inlet in the bottom of the boat and a jet nozzle outlet in the stern of the boat, comprising a stator housing positioned in the boat and forming an annular flow passage and having an inlet end connected to the water inlet into the boat and an outlet end connected to the jet nozzle outlet from the boat, a drive shaft arranged to be driven by a motor mounted in the boat and said drive shaft extending into said stator housing, a driving bevel gear mounted on said drive shaft within said stator housing, an impeller shaft mounted in said stator housing and extending in the direction of flow between the inlet end and the outlet end of said stator housing, a driver bevel gear positioned on said impeller shaft and arranged to be driven by said driving bevel gear, wherein the improvement comprises first bearing means provided within said stator housing for rotatably supporting said impeller shaft and second bearing means provided within said stator housing for rotatably supporting said drive shaft, said first bearing means comprises a pair of spaced first bearing members mounted on said impeller shaft, each on an opposite side of said driver bevel gear, and said second bearing means comprises a pair of second bearing members mounted on said drive shaft, each on an opposite side of said driving bevel gear, said stator housing comprises an annular-shaped inner shell and an annular-shaped outer shell encircling and spaced outwardly from said inner shell, said inner and outer shells defining therebetween an annular flow passage through said stator housing, said inner shell having a first end directed toward the inlet end of said stator housing, and a second end directed toward the outlet end of said stator housing, said impeller shaft extending through the first end of said inner shell, an impeller mounted on said impeller shaft between the inlet end of said stator housing and the first end of said inner shell, a bearing flange mounted in the first end of said inner shell, one of said first bearing members supported in said bearing flange, the other one of said first bearing members supported directly in the second end of said inner shell, a two-part bell-like member attached to the second end of said inner shell and forming a closure over the second end of said inner shell, said two-part bell-like member comprises an inner bell dome attached to the second end of said inner shell and projecting therefrom toward the outlet end of said inner housing, said inner bell dome having a centrally positioned extension extending toward the outlet end of said stator housing, and an outer bell dome concentrically arranged about said inner bell dome and detachably secured to said centrally pOsitioned extension on said inner bell dome.

2. A water jet drive mounted inboard in a speed boat which has a water inlet in the bottom of the boat and a jet nozzle outlet in the stern of the boat, comprising a stator housing positioned in the boat and forming an annular flow passage and having an inlet end connected to the water inlet into the boat and an outlet end connected to the jet nozzle outlet from the boat, a drive shaft arranged to be driven by a motor mounted in the boat and said drive shaft extending into said stator housing, a driving bevel gear mounted on said drive shaft within said stator housing, an impeller shaft mounted in said stator housing and extending in the direction of flow between the inlet end and the outlet end of said stator housing, a driver bevel gear positioned on said impeller shaft and arranged to be driven by said driving bevel gear, wherein the improvement comprises first bearing means provided within said stator housing for rotatably supporting said impeller shaft and second bearing means provided within said stator housing for rotatably supporting said drive shaft, said first bearing means comprises a pair of spaced first bearing members mounted on said impeller shaft, each on an opposite side of said driver bevel gear, and said second bearing means comprises a pair of second bearing members mounted on said drive shaft, each on an opposite side of said driving bevel gear, said stator housing comprises an annular-shaped inner shell and an annular-shaped outer shell encircling and spaced outwardly from said inner shell, said inner and outer shells defining therebetween an annular flow passage through said stator housing, a tubular-shaped projection secured to and extending outwardly from said outer shell and forming an opening through said outer shell for said drive shaft, one of said second bearing members mounted in said projection, a bearing frame supported within said inner shell, a projection attached to said bearing frame, and the other one of said second bearing members mounted in said projection on said bearing frame and positioned between said driving bevel gear on said drive shaft and said impeller shaft, said inner and outer shells each have an opening therethrough in alignment with said tubular-shaped projections on said outer shell and located on the opposite side of said stator housing from said tubular-shaped projections, and a removable insert positioned in the openings in said inner and outer shells and forming a water-tight sealed closure therefor, said insert shaped to conform to the configuration of said inner and outer shells forming said stator housing.