Underwater propulsion unit

Description

[0001] The invention relates to an underwater drive unit for a swimming and diving aid, wherein the underwater drive unit is assigned at least one propeller, an electric motor with a motor housing, a motor shaft which transmits the driving force of the electric motor to the propeller, and a control unit which is arranged in an electronics housing and is connected to the electric motor via connecting cables, and wherein at least part of the underwater drive unit is arranged in at least one water-floodable space in a hull of the swimming and diving aid.

[0002] Such swimming and diving aids are known from DE 10 2004 049 615 B4. They have a handle arrangement that a user can hold on to while resting with part of their upper body on the top of the hull of the watercraft. A flow channel is arranged within the hull, in which a propeller is housed. The propeller is driven by an electric motor that is supplied with power via accumulators. For this purpose, the propeller is connected to the electric motor via a drive shaft. The electric motor is held in a housing that extends to the propeller. The drive shaft is guided from the housing to the propeller via a sealing cassette. On the side facing away from the propeller, the housing is closed by a housing cover.The thus watertight housing with the electric motor can be arranged in a water-flooded space in the hull of the swimming and diving aid, thus dissipating its waste heat into the flowing water. For this purpose, the propeller, the electric motor, and an associated control unit are designed as an underwater drive unit and arranged in the flow channel. The control unit is also arranged in a watertight housing. Another swimming and diving aid is disclosed in JP 2002-362488 A. EP 1 104 080 A2 discloses a watertight connection between a motor housing and a control unit housing.

[0003] In order to control the electric motor with the help of the control unit, appropriate electrical connections between the control unit and the electric motor are required. This requires openings in both the electric motor housing and the waterproof housing of the control unit, through which the connecting cables are routed and which must be sealed separately. This is complex to manufacture, prone to errors, and complicates the assembly of the underwater drive unit.

[0004] The object of the invention is to provide a waterproof underwater drive unit for a swimming and diving aid, which, for example, enables a simple, water-protected electrical connection between an electric motor and a control unit of the underwater drive unit.

[0005] The object of the invention is achieved by the features of claim 1 in that the electronics housing is connected to the motor housing in a watertight manner all the way around, leading to an opening in the electronics housing and a housing opening in the motor housing. The connecting cables between the control unit and the electric motor can thus be routed through the opening in the electronics housing and the housing opening in the motor housing without having to be individually sealed at the respective housings. Only the transition between the housings needs to be sealed. This enables an electrical connection between the control unit and the electric motor that is simple and cost-effective to produce and protected against water ingress.

[0006] According to a particularly preferred embodiment of the invention, it can be provided that the electronics housing is connected to the motor housing in a watertight plug-and-play manner. The electronics housing and the motor housing can thus be connected in a watertight manner simply, quickly and without additional fastening elements. The plug-and-play connection can reduce the assembly time of the underwater drive unit and thus the manufacturing costs. Furthermore, a plug-and-play connection enables easy access for servicing, since the motor housing and the electronics housing can be easily separated from one another and opened separately. Connecting cables leading out of the motor housing through the housing opening can be connected to the control unit when the electronics housing is open. The electronics housing is then closed. The connecting cables are arranged so that they are led through the opening in the electronics housing.The motor housing and the electronics housing are then plugged together, so that the opening in the electronics housing and the opening in the motor housing are sealed watertight by the plug connection. Alternatively, a plug connection for the intended electrical connections can be arranged between the electric motor and the control unit in the area of ​​the opening in the electronics housing and the opening in the motor housing.

[0007] Particularly simple assembly of the underwater drive unit can be achieved by having the electronics housing with a sealing section surrounding the opening, which plugs around the motor housing in a connection area, and by providing sealing elements between the sealing section and the connection area. The electronics housing can then be easily plugged onto the motor housing with its sealing section. The sealing is achieved by the sealing elements between the sealing section and the connection area, thus protecting the opening of the electronics housing and the housing opening of the motor housing from water ingress.

[0008] An easy-to-manufacture and well-sealing plug-in connection between the motor housing and the electronics housing can be provided by arranging at least one groove bordered by webs on the motor housing surrounding the connection area, running transversely to the plug-in direction of the electronics housing, and by holding a sealing ring in the groove as a sealing element. The webs can be formed in a single step during the manufacture of the motor housing. To seal, all that is needed is to insert a sealing ring into the groove and slide the electronics housing with its sealing section over the connection area of ​​the motor housing. The groove, which is aligned transversely to the plug-in direction of the electronics housing, fixes the sealing ring in its position and prevents it from shifting when the electronics housing is plugged on.When the electronics housing is plugged in, the sealing ring is clamped between the sealing section and the connection area, creating a circumferentially sealed connection. The clamped sealing ring holds the electronics housing and its sealing section to the connection area of ​​the motor housing, so that the two can only be separated with a certain pull-off force. Advantageously, several grooves and sealing rings separated by webs are provided in the connection area. This prevents water from penetrating the motor housing and the electronics housing, even if a sealing ring is defective. Furthermore, the force required to pull the electronics housing off the motor housing is increased.A further advantage arises when the inner surface of the sealing section of the electronics housing is positioned directly adjacent to the webs of the connection area or at a short distance from the webs. This secures the electronics housing radially relative to the motor housing over an axially extended area. This prevents the electronics housing from bending relative to the motor housing when plugged in.

[0009] Advantageously, it can be provided that the motor housing has a substantially cylindrical outer contour, that the motor housing is open on its side facing away from the propeller, that the connection area is arranged on the outer contour of the motor housing so as to circumferentially extend to the housing opening thus formed, and that the electronics housing with its sealing section can be plugged onto the motor housing from the side facing away from the propeller in such a way that the sealing section of the electronics housing surrounds the connection area. The cylindrical outer contour enables simple circumferential sealing, for example with sealing rings. Areas that are difficult to seal, such as corners and edges, are avoided. With a cylindrical outer contour of the connection area and the sealing section that surrounds the connection area, the latter can be plugged onto the connection area easily and without tilting.Since the entire rear end of the motor, facing away from the propeller, lies within the area enclosed by the connection area and the sealing area, the motor housing can be designed open or non-watertight. This simplifies the assembly of the electric motor. Electrical connecting cables can be easily routed out of the motor housing and into the control unit. A separately sealed rear cover is not required and can be eliminated.

[0010] Additional sealing of the cable outlets from the electronics housing or from the motor housing can be avoided by routing the connecting cables through the opening in the electronics housing and through the housing opening in the motor housing.

[0011] According to the invention, sealing of the motor housing in the area opposite the electronics housing is achieved in that the motor shaft is at least partially surrounded by an outer tube, the outer tube is sealed from the floodable space in such a way that a space sealed from the floodable space is formed between the outer tube and the motor shaft, and the outer tube, with its end facing the electric motor, is directly or indirectly connected to the motor housing of the electric motor. This forms a completely sealed underwater drive unit, which can be mounted as a unit in a water-floodable space of the swimming and diving aid.

[0012] The invention is explained in more detail below with reference to an embodiment illustrated in the drawings. They show: Fig. 1 in perspective side view from behind a swimming and diving aid, Fig. 2 a part of an underwater drive unit with an electric motor, Fig. 3 the Figure 2 shown part of the underwater propulsion unit in a sectional view, Fig. 4 in Figure 3 shown electric motor in an enlarged sectional view, Fig. 5 a Figure 3 shown propeller section in an enlarged sectional view, Fig. 6, which in Figure 1 shown swimming and diving aid in a lateral sectional view, Fig. 7 a in Figure 6 shown section of the swimming and diving aid in the area of ​​the electric motor and Fig. 8 a Figure 6 shown section of the swimming and diving aid in the area of ​​its stern.

[0013] Figure 1shows a perspective side view from behind of a swimming and diving aid 10. The swimming and diving aid 10 has a body 11. The body 10 is composed of an upper part 11.6 and a lower part 11.4. The upper part 11.6 is equipped with two handles 16 arranged on either side of the body 11. A user can hold on to these handles 16 and control the swimming and diving aid 10 using control elements 16.1 attached to the handles 16. In particular, the motor power of the swimming and diving aid 10 can be varied here. The user, who holds on to the handles 16, rests with his upper body on a support surface 11.3 in the area behind a display 13 on the upper part 11.6. A bracket 11.7 is attached to the support surface 11.3 for attaching a belt system, with which the user can strap himself to the swimming and diving aid 10. A fastener 12 is located in front of the support surface 11.3.1 for a behind it, in . Figure 6 shown charging socket 12 is arranged. Batteries contained in the fuselage 11 can be charged via the charging socket 12.

[0014] Carrying handles 11.2 are arranged on the side of the hull 11, by which the swimming and diving aid 10 can be carried outside of the water.

[0015] In the direction of travel, in front of the display 13 and between the two handles 16, a removable cover 14 is attached to the hull 11. The cover 14 covers a mounting area (not shown) of the swimming and diving aid 10. Ventilation openings 15.1 are provided on the sides in the cover 15, which are connected to a vent provided in the hull 11 and Figure 6 shown flooding chamber 19.

[0016] In the area of ​​the bow 11.1, water inlets 15.2 are provided through which water can flow into the flooding chamber 19. The flooding chamber 19 can be vented via the vents 15.1 of the cover 14. The water-filled flooding chamber 19 adjusts the buoyancy of the buoyancy aid 10 to maintain a predetermined buoyancy force, allowing both swimming and diving. Water outlets 15.3, covered by slats, are attached to the stern 11.5 of the buoyancy aid 10 and also communicate with the flooding chamber 19. As soon as the buoyancy aid 10 is placed in the water, the flooding chamber 19 is flooded with water that enters through the water inlets 15.2 and water outlets 15.3. As soon as the swimming and diving aid 10 goes into driving mode, a current is generated in the flooding chamber 19.The water enters the flooding chamber 19 through the water inlet openings 15.2. It flows through the flooding chamber 19 and thereby washes around electrical components held in the flooding chamber 19, such as a . Figure 2shown electric motor 30 for driving the swimming and diving aid 10 or the associated accumulators. The water absorbs the power loss of the electrical components and cools them. After flowing through the flooding chamber 19, the water leaves it through the water outlet openings 15.3, which are arranged symmetrically on both sides of a jet outlet 17 of a flow channel 18. A stator 160 is arranged at the end of the flow channel 18, which counteracts the rotation of the water flowing through the flow channel 18, so that the water flows out of the flow channel 18 with as little rotation as possible. The rotational energy of the water is converted into linear kinetic energy and thus serves to drive the swimming and diving aid 10.

[0017] Figure 2 shows part of an underwater drive unit of the swimming and diving aid 10 with an electric motor 30.

[0018] The electric motor 30 is surrounded by a motor housing 40, which has a connection area 41 at its end. On the side of the connection area 41, connection cables 33 are led out of the motor housing 40. Opposite the connection area 41, a shaped adapter 70 is connected to the motor housing 40 by means of cylinder head screws 74. An outer tube 40 is accommodated in the shaped adapter 70, which has a Figure 3 encloses the motor shaft 50 shown. On the side opposite the electric motor 30, the outer tube 60 ends in a propeller section 100 in which a shaft stub 110 is arranged.

[0019] The shaft end 110 is used for mounting a Figure 6 shown propeller 150 for driving the swimming and diving aid 10. At the connection area 41 of the electric motor 30, a Figure 6The electronics housing 120 shown can be connected, which has a control unit (not shown) for controlling the electric motor 30. The motor housing 40, together with the molded adapter 70, the outer tube 60, and the connected electronics housing 120, forms a waterproof unit, which can be fastened with the aid of the cylinder head screws 74 within water-flooded areas of the hull 11 of the swimming and diving aid 10.

[0020] Figure 3 shows the Figure 2 shown part of the underwater propulsion unit in a sectional view. The same components are used as in Figure 2 introduced.

[0021] The drive shaft 50 is accommodated within the outer tube 60. In particular, a central section 51 of the drive shaft 50 is arranged within the outer tube 60. A rotor 32 is attached to a rotor section 53 of the motor shaft 50, as described in more detail in Figure 4 , which in Figure 3 marked with IV. Opposite, the shaft stub 110 is attached to a second receiving section 56 of the motor shaft 50. A corresponding section V of the illustration is enlarged in Figure 5 shown.

[0022] The motor shaft 50 is made of carbon fiber reinforced plastic (CFRP). It transmits the drive force generated by the electric motor 30 to the shaft stub 110 and the Figure 6 shown propeller 150.

[0023] Compared to materials conventionally used to manufacture motor shafts 50, such as steel, CFRP offers the advantage of significantly reduced weight while maintaining very high rigidity. This is of great importance for the swimming and diving aid 10 shown, as it must be as easy to carry out out of the water. The weight is further reduced by designing the motor shaft 50 as a hollow shaft, without significantly reducing the load-bearing capacity of the motor shaft 50. Compared to steel, a motor shaft 50 made of CFRP is significantly less prone to vibration, which leads to improved concentricity and lower noise. Furthermore, the lower weight and reduced vibration reduce the load on the bearings used to rotate the motor shaft 50 about its central longitudinal axis, thereby reducing bearing wear and thus increasing their service life.The inertial mass of the CFRP motor shaft 50 is significantly reduced compared to a steel motor shaft 50, resulting in greater dynamic response for desired changes in the speed of the motor shaft 50 and thus of the propeller 150. At the same time, the energy consumption for accumulating the motor shaft 50 with the propeller 150 is reduced, which leads to an extension of the operating life of the accumulator-powered swimming and diving aid 10.

[0024] To increase the rigidity of the motor shaft 50, it has a multi-layer structure. An inner layer, in which carbon fiber mats with different orientations of the carbon fibers are arranged within the plastic matrix, is followed by a layer with aligned carbon fibers. These are preferably designed as high-modulus carbon fibers, which have a very high modulus of elasticity of, for example, >400,000 N / mm²< in the fiber direction. In the present exemplary embodiment, the high-modulus carbon fibers are aligned essentially in the direction of the longitudinal extent of the motor shaft 50 in order to increase the tensile strength and flexural rigidity of the motor shaft 50. Alternatively or additionally, a CFRP layer with high-modulus carbon fibers arranged transversely to the longitudinal extent of the motor shaft 50 can also be provided. In this arrangement, the additional carbon fibers increase the torsional rigidity of the motor shaft 50.

[0025] The surface of the motor shaft 50 is partially turned, ground, or polished. These post-processing steps ensure a precise, rotationally symmetrical contour of the motor shaft 50, resulting in good concentricity. Cracks in the surface are removed, thus preventing or at least reducing notch stresses that develop at the crack ends under mechanical stress. This reduces the probability of breakage of the motor shaft 50 and increases its load-bearing capacity. To prevent damage to the carbon fibers during post-processing, the motor shaft has a final plastic coating on the outside that does not contain any carbon fibers.

[0026] A sealed space 67 is formed between the motor shaft 50 and the outer tube 60, into which no water penetrates from the outside. This prevents friction between the motor shaft 50 and the water, thus preventing energy losses. Furthermore, the motor shaft 50 is not exposed to lateral transverse forces from flowing past. This reduces the load on the bearings of the motor shaft 50. Furthermore, the motor shaft 50 is not bent by transverse forces transmitted by flowing past water, which results in improved and vibration-free concentricity of the motor shaft 50 and thus holds the propeller 150 in its position within the flow channel 18.

[0027] Figure 4 shows the Figure 3 shown electric motor 30 in an enlarged sectional view.

[0028] The motor shaft 50, made of carbon fiber-reinforced plastic, extends from the outer tube 60 into the interior of the motor housing 40. Its diameter gradually reduces in the area of ​​the transition into the motor housing 40. A front balancing disk 82 with a molded-on bearing seat 82.1 is pushed onto a fixed bearing area 52 of the motor shaft 50 thus formed, until it rests against the formed step of the motor shaft 50. The front balancing disk 82 and the bearing seat 82.1 are integrally bonded to the motor shaft 50 by adhesive. For this purpose, adhesive recesses 82.2 of a defined depth are provided on the inner surface of the bearing seat 82.1 and the balancing disk 82, into which the adhesive is applied in an optimized adhesive thickness predetermined by the adhesive recesses 82.2.

[0029] Following the fixed bearing area 52, the diameter of the motor shaft 50 tapers again in a stepped manner. The motor shaft 50 forms its rotor section 53 here. The rotor 32 of the electric motor 30 is placed onto the rotor section 53 and glued to it. To create an optimal adhesive thickness, adhesive joints 54 are introduced into the surface of the rotor section 53. The rotor 32 is designed in three parts, so that the electric motor 30 can be designed with different power levels by changing the number of installed rotor parts. A stator 31 of the electric motor 30 is provided surrounding the rotor 32. The stator 31 is cast into the motor housing 40 with a potting compound and is thus thermally coupled to the motor housing 40. The heat loss of the electric motor 30 can thus be easily dissipated to the motor housing 40.

[0030] At its end, the motor shaft 50 has a first receiving section 55 in which a balancing disc holder 55.1 is inserted in the form of an axially arranged bore. The balancing disc holder 55.1 has a larger diameter than the inner diameter of the motor shaft 50, which is designed as a hollow shaft. A rear balancing disc 83 with an axially formed pin 83.1 is held in the balancing disc holder 55.1. The diameter of the pin 83.1 is designed to fit precisely to the diameter of the balancing disc holder 55.1, so that the rear balancing disc 83 is securely guided even at high rotational speeds of the motor shaft 50. The pin 83.1 is glued into the balancing disc holder 55.1. For this purpose, the pin 83.1 has circumferential adhesive grooves 83.2, which ensure the formation of an optimal adhesive thickness. On the side of the rear balancing disc 83 opposite the pin 83.1, an axially arranged bearing support 83.3 is formed.

[0031] The electric motor 30 is housed in the cylindrical motor housing 40. At its end facing the shaped adapter 70, the outer shell of the motor housing 40 bends into a mounting area 42 oriented radially toward the motor shaft 50. The mounting area 42 forms an adapter support 42.1, against which the shaped adapter 70 rests flat. The mounting area 42 merges into a bearing area 43 arranged at a distance from the fixed bearing area 52 of the motor shaft 50 and oriented toward the interior of the motor housing 40. The bearing area 43 forms a cylindrical inner surface oriented toward the bearing seat 82.1 of the front balancing disk 82. At its end facing the interior of the motor housing 40, the bearing area 43 has a projection 43.1 oriented radially toward the front balancing disk 82.

[0032] The shaped adapter 70 has a cylindrical tube receptacle 71 into which the outer tube 60 is inserted up to an outer web 61 formed circumferentially on the outer tube 60. The outer tube 60 is thus held by a shaped adapter connection area 62 in the tube receptacle 71 of the shaped adapter 70 over an axially extending area, so that even stronger transverse forces acting on the outer tube 60 can be absorbed. The shaped adapter connection area 62 is glued to the tube receptacle 71. To form a uniform adhesive layer of a suitable thickness, adhesive notches 62.1 are arranged circumferentially in the outer surface of the shaped adapter connection area 62, in which adhesive is collected. In the direction of the motor housing 40, the shaped adapter 70 widens and forms a circumferential mounting ring 72, which has a radially extending inner mounting surface 72 towards the motor housing 40.2 and facing away from the motor housing 40 has a radially extending outer mounting surface 72.1. To the outside, the circumferential mounting ring 72 terminates in the mounting area 42 of the motor housing 40. The shaped adapter 70 is screwed to the motor housing 40 with the cylinder head screws 74 in such a way that the inner mounting surface 72.2 of the mounting ring 72 lies flat against the adapter support 42.1 of the mounting area 42. A circumferential groove is machined into the inner mounting surface 72.2, into which a third sealing ring 132 is inserted. When the shaped adapter 70 is screwed on, the third sealing ring 132 rests against the adapter support 42.1 and thus seals the inner area of ​​the motor housing 40 as well as the sealed space 67 between the motor shaft 50 and the outer tube 60. The outer mounting surface 72.1 is used to mount the drive unit to the hull 11 of the swimming and diving aid 10.Towards the motor housing 40, the shaped adapter 70 has a clamping area 73 adjoining the mounting ring 72. The clamping area 73 engages in the interior space formed by the mounting area 42 of the motor housing 40 and rests with its outer surface circumferentially against the mounting area 42. Between the clamping area 73 and the mounting area 42, a fourth sealing ring 133 is provided in a groove surrounding the outside of the clamping area 73 as a further seal arranged in series with the third sealing ring 132. The clamping area 73 has a slightly smaller inner diameter than the pipe receptacle 71, so that the outer diameter of the shaped adapter connection area 62 of the outer pipe 60 also has a sealing area 63 with a smaller outer diameter in the section of the clamping area 73.Between the clamping area 73 and the sealing area 63, a first sealing ring 130 and a second sealing ring 131 are arranged one after the other in a sealing ring receptacle 63.1 surrounding the shaped adapter connection area 62, which prevent water from entering between the shaped adapter 70 and the outer tube 60.

[0033] A double-row deep groove ball bearing 80 is arranged between the cylindrical inner surface of the bearing area 43 of the motor housing 40 and the bearing seat 82.1 of the front balancing disc 82. The outer ring of the double-row deep groove ball bearing 80 rests against the bearing area 43, and the inner ring rests against the bearing seat 82.1. Towards the interior of the motor housing 40, the outer ring of the double-row deep groove ball bearing 80 rests against the projection 43.1 of the bearing area 43, while the inner ring rests against a shoulder of the front balancing disc 82. On the opposite side, the inner ring is held by a first retaining ring 81, which is secured in a circumferential groove in the bearing seat 82.1. The outer ring of the double-row deep groove ball bearing 80 abuts on this side against an end surface of the clamping area 73 of the form adapter 70. The double-row deep groove ball bearing 80 is thus held on both sides in the axial direction, similar to a fixed bearing.

[0034] At the end facing away from the mold adapter 70, the motor housing 40 has the connection area 41. The connection area 41 is formed by three circumferential webs 41.1, 41.2, 41.3, which separate three grooves 41.4, 41.5, 41.6. In the axial direction, the motor housing 40 is open by a housing opening 44 on the end face facing away from the mold adapter 70.

[0035] The outer region of the housing opening 44 is covered by a disk-shaped receiving shield 90. The receiving shield 90 is radially aligned and flush with the outside of the motor housing 40. The receiving shield 90 is fixed on its side facing the interior of the motor housing 40 with the potting compound that supports the stator 31. Directed radially inward, the receiving shield 90 forms a circular receptacle for a bearing shield 91. The bearing shield 91 is also circular and extends in a stepped manner in the axial direction into the interior of the motor housing 40. In its inner region, it forms an axially aligned bearing shoulder 91.1, which is radially spaced opposite the bearing support 83.3 of the rear balancing disk 83. A heat compensation bearing 84 is provided as a single-row deep groove ball bearing between the bearing shoulder 91.1 and the bearing support 83.3.The inner ring of the thermal balance bearing 84 is axially held on one side by the rear balancing disc 83 and on the opposite side by a second retaining ring 84.1. For this purpose, the second retaining ring 84.1 is clamped into a circumferential groove of the bearing support 83.3.

[0036] A disc magnet 93.1 is embedded in an axially arranged receptacle of the bearing support 83.3 of the rear balancing disc 83.

[0037] On the side of the connecting cables 33, the motor housing 40 is closed by a cover 92. The cover 92 rests against the bearing plate 91 and has openings for the passage of the connecting cables 33. A rotor position sensor 93 is arranged on the cover 92 with suitable fastening means and is positioned opposite the disc magnet 93.1.

[0038] The front balancing disc 82 with the integrally formed bearing seat 82.1, the rotor 32, and the rear balancing disc 83 with its journal 83.1 are bonded to the motor shaft 50, which is made of carbon fiber reinforced plastic. The provided adhesive recesses 82.2, adhesive joints 54, and adhesive grooves ensure an optimal adhesive thickness to achieve a strong connection between the components and the motor shaft 50, allowing even high forces to be transmitted.

[0039] The motor shaft 50 is supported by two bearings in the area of ​​the electric motor 30. The front double-row deep groove ball bearing 80 is designed as a fixed bearing, and the rear thermal compensation bearing 84 is designed as a floating bearing, allowing for different material expansions during temperature changes. Adequate axial length compensation is particularly important for the proposed CFRP motor shaft 50, since carbon fiber-reinforced plastics have a different thermal expansion coefficient than metals, which strongly depends on the orientation of the carbon fibers.

[0040] The two balancing disks 82, 83 with the integrally formed bearing seat 82.1 and bearing support 83.3 are made of metal, in the present embodiment of aluminum. The inner rings of the double-row deep groove ball bearing 80 and the heat compensation bearing 84 therefore do not rest directly on the fiber-reinforced plastic material of the motor shaft 50, but rather on metal force transmission elements connected to the motor shaft 50, such as those formed by the bearing seat 82.1 and the bearing support 83.3. These force transmission elements distribute the forces transmitted from the bearings to the motor shaft 50 over a larger area, so that the carbon fiber-reinforced plastic of the motor shaft 50 is not destroyed by excessive local surface pressure. Furthermore, increased wear on the motor shaft due to relative movement between the motor shaft and the inner rings is avoided. The bearing seat 82.1 of the front balancing disc 82 represents a force transmission element arranged circumferentially around the motor shaft 50, while the bearing support 83.3 of the rear balancing disc 83 represents a force transmission element designed as an end-side axial extension of the motor shaft 50. The motor shaft 50 can be balanced through bores that are drilled radially from the outside into the balancing discs 82, 83.

[0041] The shaped adapter 70 performs several functions. It serves to laterally and axially secure the outer tube 60. Furthermore, in conjunction with the provided sealing rings 130, 131, 132, 133, it seals the interior of the motor housing 40, the area of ​​the double-row deep-groove ball bearing 80, and the sealed space 67 between the outer tube 60 and the motor shaft 50 against water ingress. Mounting the motor shaft 50 in a dry area reduces the requirements for the double-row deep-groove ball bearing 80 used, as it does not require separate sealing. The shaped adapter 70 also provides the outer mounting surface 72.2, with which the drive unit can be mounted to the hull 11 of the buoyancy and diving aid 10. In addition, the shaped adapter 70 serves to axially secure the double-row deep-groove ball bearing 80.

[0042] The motor housing 40 is made of metal and is essentially cylindrical. In the area facing the flange adapter 70, it provides the adapter support 42.1 for the sealed installation of the flange adapter 70 as well as the bearing area for the double-row deep groove ball bearing 80. The motor housing 40 is manufactured in a single production process so that the aforementioned functions can be implemented cost-effectively. The connection area 41 serves as a watertight connection to an electronics housing 120, as is the case with Figure 7 The electronics housing 120 also seals the housing opening 44 of the electric motor 30, which is remote from the molded adapter 70, in a watertight manner, so that the entire electric motor 30 can be arranged in a water-flooded space of the swimming and diving aid 10 and thus efficiently cooled.

[0043] The stator 31 is connected to the motor housing 30 via a potting compound, while the rotor 32 is rigidly connected to the motor shaft 50. Together with the described mounting of the motor shaft 50, this results in a compact design for an electric motor 30 with high drive power and good, low-vibration concentricity. Concentricity is further improved by the provided rotor position sensor 93 with the disc magnet 93.1 as a sensor. The rotor position sensor 93 regulates the magnetic field developing in the electric motor and adjusts the rotor 32 and the stator 31 to a desired position.

[0044] The mounting plate 90 is securely fixed by the potting compound in which the stator 31 is embedded, so that the subsequent components directly or indirectly connected to the mounting plate 90 are also held in precise position. The connecting cables 33 serve to electrically connect the electric motor 30 and the rotor position sensor 93 to a control unit housed in the electronics housing 120.

[0045] To assemble the assembly, the front balancing disc 82, the rotor 32, and the rear balancing disc 83, into which the disc magnet 93.1 is glued, are first glued to the motor shaft 50. The stator 31, together with the mounting plate 90, is connected to the motor housing 40 using the potting compound. The bearing plate 91, the thermal compensation bearing 84, the rotor position sensor 93, and the cover 92 are mounted, with the connecting cables 33 leading out the rear. The first and second sealing rings 130, 131 are inserted into the sealing ring receptacles 63.1 of the outer tube 60, and the outer tube 60 is glued into the tube receptacle 71 of the molded adapter 70. Subsequently, the motor shaft 50 is inserted into the motor housing 40 from the side of the connection area 41 for the electronics housing 120 and the double-row deep groove ball bearing 80 is pushed onto the bearing seat 82.1.After the double-row deep groove ball bearing 80 has been secured with the first retaining ring 81, the outer tube 60 is pushed over the motor shaft 50, and the molded adapter 70, after the third and fourth sealing rings 132, 133 have been inserted, is screwed tightly to the motor housing 40 using the cylinder head screws 74. This creates a compact unit consisting of the electric motor 30 with the connected motor shaft 50 and the outer tube 60, which is easily mounted in the hull 11 of the swimming and diving aid 10.

[0046] Figure 5 shows one in Figure 3 shown propeller section V in an enlarged sectional view.

[0047] The motor shaft 50, made of carbon fiber reinforced plastic, is guided within the outer tube 60. In the area of ​​its end-side, second receiving section 56, a stub shaft receptacle 56.1 is introduced as an axial bore with a larger diameter than the inner diameter of the motor shaft 50, which is designed as a hollow shaft. The aluminum stub shaft 110 is inserted into the stub shaft receptacle 56.1 with a fastening section 117 and glued in. To create a uniform adhesive thickness, circumferential adhesive recesses 118 are incorporated in the fastening section 117 of the stub shaft 110, in which the adhesive collects to a thickness predetermined by the depth of the adhesive recesses 118. To save weight, an axial front bore 116 is introduced into the fastening section 117.

[0048] Adjacent to the fastening section 117, the stub shaft 110 has a circumferential, radially aligned collar 115, which is delimited toward the motor shaft 50 by a shaft stop 115.2 configured as a radially extending surface and, opposite, by a bearing stop 115.1, also configured as a radially extending surface. The shaft stop 115.2 rests circumferentially against the stub shaft receptacle 56.1 on the second receptacle section 56 of the motor shaft 50. The shaft stop 115.2 thus determines the installation depth of the fastening section 117 into the stub shaft receptacle 56.1.

[0049] The collar 115 is followed by a bearing and sealing area 114 of the shaft stub 110 with a cylindrical outer contour, which is arranged within the outer tube 60. With the end of the outer tube 60, the shaft stub 110 merges into a propeller receptacle 112. From the side of the propeller receptacle 112, an axially extending, rear bore 113 is introduced into the shaft stub 110, which, starting from its opening, has an internal thread 111 for mounting the Figure 6 shown propeller 150.

[0050] The outer tube 60 encloses the motor shaft 50 as well as the bearing and sealing area 114 of the shaft stub 110 up to the propeller receptacle 112, which protrudes from the outer tube 60. In the area of ​​a tube reinforcement 64, which encloses part of the bearing and sealing area 114, the wall thickness of the outer tube 60 increases. Subsequently, the wall thickness is gradually reduced at a transition of the tube reinforcement 64 to a centering section 65. The stepped transition forms a stop 64.1 directed towards the end of the outer tube 60. The centering section 65 serves to accommodate a centering star 140, as is Figure 8 is shown. The centering star 140 is glued to the centering section 140. To form a suitably thick adhesive layer, circumferential adhesive joints 66 are provided on the centering section 140. The centering star 140 can thus be pushed onto the centering section 140 up to the stop 64.1 and glued to it.

[0051] The motor shaft 50 is mounted in the bearing and sealing area 114 of the shaft stub 110. For this purpose, a deep groove ball bearing 105 is arranged between the outer tube 60 and the bearing and sealing area 114. The inner ring of the deep groove ball bearing 105 rests against the bearing stop 115.1 formed by the collar 115 and is thus axially fixed in the direction of the motor shaft 50. In the opposite direction, the outer ring of the deep groove ball bearing 105 rests against a wave spring 104, which is axially held opposite by a fourth retaining ring 104.1. The wave spring 104 is designed as a flat wire wave spring and is therefore space-saving. It enables the deep groove ball bearing 105 to move axially, so that different thermal expansions between the motor shaft 50 and the outer tube 60 can be compensated. The fourth retaining ring 104.1 is followed by a second spacer ring 103.2, which fixes a second radial shaft seal 102.2 at a distance from the fourth retaining ring 104.1.A first radial shaft seal 102.2 is arranged between the outer tube 60 and the bearing and sealing area 114 of the shaft stub 110, spaced apart by a first spacer ring 103.1. Following the first radial shaft seal 102.2 are two adjacent felt rings 101.3, 101.4, which are held by a felt ring carrier 101.2 closed by a felt ring carrier cover 101.5 in such a way that they bear against the bearing and sealing area 114. Opposite the second felt ring 101.4, the felt ring carrier cover 101.5 bears against the first radial shaft seal 102.2, thereby axially securing it. The felt ring carrier 101.2 is held towards the end of the outer tube 60 by a third retaining ring 101.1, which is clamped in a circumferential groove of the outer tube 60.

[0052] The motor shaft 50 is supported by the deep groove ball bearing 105 at its end facing the propeller 150. Together with the Figure 4The motor shaft 50 is thus supported at each end of its transmission path from the electric motor 30 to the propeller 150 by the double-row deep groove ball bearing 80 shown. This reliably prevents bending of the motor shaft 50 or vibration of the motor shaft with the mounted propeller 150.

[0053] The area of ​​the deep groove ball bearing 105 and the space 67 between the motor shaft 50 and the outer tube 60 are sealed against the ingress of water and dirt by the two radial shaft seals 102.1, 102.2 and the felt rings 101.3, 101.4.

[0054] The propeller-side bearing and sealing of the motor shaft 50 is carried out on the bearing and sealing area 114 of the aluminum shaft stub 110 as an axial extension of the motor shaft 50. The shaft stub represents a force transmission element with which the guiding forces introduced by the deep groove ball bearing 105 are transmitted to the motor shaft 50. The bearing of the motor shaft 50 and the sealing of the sealed chamber 67 are thus not carried out directly on the pressure- and abrasion-sensitive motor shaft 50 made of carbon fiber reinforced plastic, but on a correspondingly durable metal component.

[0055] Figure 6 shows the Figure 1 The swimming and diving aid 10 shown in a side sectional view. The same designators are used for identical components.

[0056] The hull 11 of the swimming and diving aid 10 is formed from a lower part 11.4 and an upper part 11.6. An underwater drive unit is arranged within the hull 11. In the present embodiment, the underwater drive unit includes the electric motor 30, an electronics housing 120 with a control unit (not shown), the motor shaft 50 made of carbon fiber reinforced plastic with the surrounding outer tube 50, the centering star 140, and the propeller 150.

[0057] The electronics housing 120 is formed by two housing halves 121 and can be opened by removing one housing half 121. In the selected sectional drawing, only the port-side first housing half 121 is shown. A second housing half (not shown) rests watertight with a circumferential second closing surface on a closing surface 121.1 of the first housing half 121. For this purpose, a seal (not shown) is provided between the two closing surfaces 121.1. A sealing section 123 is assigned to the electronics housing 120 via an opening section 122, which encloses an opening 122.1 of the electronics housing 120, and subsequently enclosing the opening 122.1, as described in more detail in Figure 7, which shows an enlarged view of the section labeled VII. The electronics housing 120 changes from a flat to a cylindrical design toward the sealing section 123. With this cylindrically shaped sealing section 123, the electronics housing 120 is plugged onto the connection area 41 provided at the end of the likewise cylindrical motor housing 30. As a result, the electronics housing 120 is connected to the motor housing 30 in a watertight manner.

[0058] The electronics housing 120 is held in the flooding chamber 19 by means of a mounting bracket 124 and associated fastening elements 124.1. The flooding chamber 19 has flooding openings 19.1 through which water can flow into the flooding chamber 19. The electric motor 30 is also arranged within the flooding chamber 19. The electric motor 30 is attached to the hull 11.

[0059] The motor shaft 50 is guided within the outer tube 60 of the electric motor 30 into the flow channel 18 of the swimming and diving aid 10. The flow channel 18 extends from an inlet opening 18.4 on the underside of the swimming and diving aid 10 to the jet outlet 17 at its stern 11.5. It can be formed integrally in the hull 11. In the present embodiment, the flow channel 18 is formed by an upper shell and a lower shell, which are connected to one another by suitable fastening means. In the area of ​​the inlet opening 18.4, a guide element 18.1 is provided, past which the water flows and which forms a lower support for the swimming and diving aid 10.

[0060] The outer tube 60 is held at its end within the flow channel 18 by means of the plastic centering star 140. The propeller 150 is mounted on the shaft stub 110, as can be seen more clearly in Figure 8, which shows an enlarged section of the section labeled VIII. The stator 160 is then mounted in the flow channel 18.

[0061] Through the sealed, pluggable connection of the electronics housing 120 with the motor housing 30, the sealed connection of the outer tube 60 to the motor housing 30, as Figure 4 as well as the propeller-side seal between the outer tube 60 and the motor shaft 50, as described in Figure 5As shown, a completely encapsulated underwater drive unit is created. This can be arranged in water-floodable areas within the hull 10 of the swimming and diving aid 10. In the present embodiment, the electric motor 30 and the control unit arranged in the electronics housing 120 are arranged in the flooding chamber 19, while the outer tube 60 with the motor shaft 50 is arranged in the flow channel 18. When the swimming and diving aid 10 is submerged, the flooding chamber 19 is flooded with water through the flooding openings 19.1 and the water inlet and outlet openings 15.2, 15.3, with the displaced air escaping via the vent openings 15.1, as shown in Figure 1As the swimming and diving aid 10 moves through the water, a current is created within the flooding chamber 19, with the water flowing into the water inlet openings 15.2 located at the bow 11.1 and flowing out again through the water outlet openings 15.3 located at the stern 11.5. The electric motor 30 and the control unit are thus efficiently cooled by the flowing water. Loss heat can be quickly dissipated, allowing the installation of a very high-performance electric motor 30 and associated control unit.

[0062] The electric motor 30 drives the propeller 150 via the motor shaft 50. This generates a water flow within the flow channel 18 from the inlet opening 18.4 to the jet outlet 17, thereby driving the swimming and diving aid 10. The centering star 140 fixes the position of the outer tube 60 at the end, so that the outer tube 60 and the motor shaft 50 mounted therein do not bend or vibrate, even at high flow velocities of the water flowing in the flow channel 18. This results in an underwater propulsion unit that runs extremely smoothly.

[0063] Figure 7 shows one in Figure 6 shown section VII of the swimming and diving aid 10 in the area of ​​the electric motor 30.

[0064] The electronics housing 120 is plugged onto the connection area 41 of the motor housing 40 with its sealing section 123. A sealing ring 134, 135, 136 is held in each of the grooves 41.4, 41.5, 41.6 of the connection area 41. The grooves 41.4, 41.5, 41.6 and thus the sealing rings 134, 135, 136 are aligned circumferentially with respect to the motor housing 40 and transversely to the plug-in direction of the electronics housing 120. The sealing section 123 of the electronics housing 120 is dimensioned such that it encompasses the motor housing 40 in the connection area 41 such that the sealing rings 134, 135, 136 are clamped between the grooves 41.4, 41.5, 41.6 and the sealing section 123, thus sealing the interior areas of the electronics housing 120 and the motor housing 40 from the surrounding flooding chamber 19. The axial end of the motor housing 40 facing away from the molded adapter 70, with the passages for the connecting cables 33, can thus be designed to be open and water-permeable.The pluggable connection between the motor housing 40 and the electronics housing 120 enables simple and quick assembly, as well as easy access for servicing. For assembly, the sealing rings 134, 135, and 136 are first inserted into the grooves 41.4, 41.5, and 41.6. The connecting cables 33 are then connected to the electric motor 30 and the control unit. The housing halves 121 of the electronics housing 120 are then closed, and the electronics housing 120, with its sealing section 123, is pushed onto the connection area 41.

[0065] The electric motor 40 is connected to the hull 11 of the swimming and diving aid 10 via a mounting bracket 34. For this purpose, the mounting bracket 34 is mounted to the hull 11 with one leg using suitable fastening elements 34.2. An angled leg 34.1 has an opening through which the shaped adapter 70 is guided. The shaped adapter 70 rests with its outer mounting surface 72.1 circumferentially on the edge of the opening of the angled leg 34.1. Circumferentially to the opening, the angled leg 34.1 has bores through which the cylinder head screws 74 are guided. The cylinder head screws 74 thus connect the mounting bracket 34, the shaped adapter 70, and the motor housing 40. At one position on the circumference of the opening, none of the otherwise rotationally symmetrically arranged screw connections are provided. This clearly defines the radial mounting position of the electric motor 30.

[0066] Figure 8 shows one in Figure 6shown section VIII of the swimming and diving aid 10 in the area of ​​its stern 11.5 in the assembled state.

[0067] The flow channel 18 is enclosed by a flow channel wall 18.2, which is divided into an upper and a lower shell. The stator 140 is mounted with a mounting sleeve 143 on the centering section 65 of the outer tube 60 up to the Figure 5shown stop 64.1 and glued to the centering section 65. Centering vanes 141 formed on the mounting sleeve 143 are guided to the flow channel wall 18.2 and secured thereto. The centering vanes 141 each have a locking lug 142 at their outer end, which engages in corresponding locking receptacles 18.3 in the flow channel wall 18.2. The centering star 140 thus holds the outer tube 60 and thus the motor shaft 40 in their position within the flow channel 18. The centering vanes 141 are shaped in the direction of water flow such that they have the lowest possible flow resistance.

[0068] The propeller 150 is formed from a base body 152 and propeller blades 151 formed thereon. The propeller 150 is connected to the base body 152 in the Figure 5The propeller 150 is mounted on the propeller mount 112 of the stub shaft 110 shown and connected to it by a mounting screw 153. For this purpose, the mounting screw 153 is guided through an axially extending bore in the base body 152 and screwed into the rear bore 113 of the stub shaft 110, provided with the internal thread 111. The propeller 150 is thus firmly connected to the motor shaft, yet is easily mounted. By supporting the outer tube 60 by the centering star 140, the propeller 150 maintains its exact position in the flow channel 18, even under strong lateral loads from flowing water.

[0069] Following the propeller 150, the stator 160 with stator blades 161 is fixed non-rotatably to the flow channel wall 18.2. The stator blades 161 are integrally formed on a central support 162, which is arranged as an axial extension of the base body 152 of the propeller 150 and thus favorably in terms of aerodynamics. The stator blades 161 have angled regions 161.1 toward the propeller 150. These are aligned to straighten the swirl of the ejected water caused by the propeller 150, so that the rotational energy of the water is converted into linear kinetic energy and thus fed into the drive of the swimming and diving aid 10.

Claims

1. An underwater propulsion unit for a swimming and diving aid (10), wherein at least one propeller (150), an electric motor (30) with a motor housing (40), a motor shaft (50), which transmits the driving force of the electric motor (30) to the propeller (150), and a control device, which is arranged in an electronics housing (120) and is connected to the electric motor (30) via connection cables (33), are assigned to the underwater propulsion unit, and wherein at least part of the underwater propulsion unit is arranged in at least one water-floodable space in a hull (11) of the swimming and diving aid (10), the floodable space having a flooding chamber (19), characterized in that a control unit arranged in the electronics housing (120) and the electric motor (30) are arranged in the flooding chamber (19), that the electronics housing (120) is connected to the motor housing (40) in a water-tight manner circumferentially to an opening (122.1) of the electronics housing (120) and to a housing opening (44) of the motor housing (40), that the motor shaft (50) is surrounded, at least in some regions, by an outer pipe (60), that the outer pipe (60) is sealed with respect to the floodable space in such a way that a space sealed with respect to the floodable space is formed between the outer pipe (60) and the motor shaft (60), that the outer pipe (60) is connected in a sealed manner, directly or indirectly, to the motor housing (40) of the electric motor (30) at its end facing the electric motor (30), and that the motor shaft (50) is guided from the electric motor (30) into a flow channel (18) of the swimming and diving aid (10) within the outer pipe (60).

2. The underwater propulsion unit according to claim 1, characterized in that the electronics housing (120) is connected to the motor housing (40) in a watertight plug-in manner.

3. The underwater propulsion unit according to claim 1 or 2, characterized in that the electronics housing (120) encompasses the motor housing (40) in a plug-in manner in a connection region (41) by means of a sealing portion (123) that extends around the opening (122.1), and sealing elements are provided between the sealing portion (123) and the connection region (41).

4. The underwater propulsion unit according to claim 3, characterized in that at least one groove (41.4, 41.5, 41.6) running transversely to the plug-in direction of the electronics housing (120) and bounded by webs (41.1, 41.2, 41.3) is arranged on the motor housing (40) circumferential to the connection area (41), and that a sealing ring (134, 135, 136) is held in the groove (41.4, 41.5, 41.6) as a sealing element.

5. The underwater propulsion unit according to claim 3 or 4, characterized in that the motor housing (40) has a substantially cylindrical outer contour, in that the motor housing (40) is open on its side facing away from the propeller (150), that the connection region (41) is arranged on the outer contour of the motor housing (40) so as to extend circumferentially around the housing opening (44) formed in this way, and that the electronics housing (40) can be placed, by means of its sealing portion (123), from the side facing away from the propeller (150), onto the motor housing (40) in such a way that that the sealing portion (123) of the electronics housing (40) engages around the connection region (41).

6. The underwater propulsion unit according to one of claims 1 to 5, characterized in that the connection cables (33) are routed through the opening (122.1) of the electronics housing (120) and through the housing opening (44) of the motor housing (40).