MOTOR AND PUMP WITH SUCH A MOTOR

Abstract

A motor for a pump has a stator, a rotor with a front and a rear end, and a rotor bearing arrangement for the rotor, the rotor bearing arrangement having a rear bearing receptacle for the rear end of the rotor, and a motor cover on the rear bearing receptacle. The motor cover is connected form-lockingly with the rear bearing receptacle against movement in the axial direction of the motor away from the motor by way of a latching connection with latching projections on the bearing receptacle and elastic resilient latching arms on the motor cover, each of which interacts with one of the latching projections as a latching connection. The resilient latching arms are integrally connected to the motor cover in a region spaced by between 70% and 90% of the radial extent of the motor cover from the longitudinal center axis of the rotor, wherein they are elongate and are elastically movable in at least one direction.

Claims

1. A motor, said motor having: a stator, a rotor with a front end and a rear end, a rotor bearing arrangement for said rotor, said rotor bearing arrangement having a rear bearing receptacle for said rear end of said rotor, and a motor cover in a region of said rear bearing receptacle, wherein said motor cover is connected form-lockingly at a form-locking connection with at least said rear bearing receptacle to make a form-locking connection, wherein said form-locking connection is such that said motor cover is secured against movement in an axial direction of said motor away from said motor, said form-locking connection is configured as a form-locking latching connection with latching projections on said bearing receptacle, at least two elastic resilient latching arms are formed on said motor cover, each of which interacts by way of a latching end with one of said latching projections as a latching connection, said elastic resilient latching arms are integrally connected to said motor cover in a region spaced by more than 50% of a radial extent of said motor cover from said longitudinal center axis of said rotor, said elastic resilient latching arms are elongate and are elastically movable in at least one direction.

2. The motor as claimed in claim 1, wherein said motor is configured as a structural unit with a pump for liquid, in a form of a liquid pump.

3. The motor as claimed in claim 1, wherein said resilient latching arms are all identically configured.

4. The motor as claimed in claim 1, wherein each of said resilient latching arms extends substantially in one plane.

5. The motor as claimed in claim 1, wherein each resilient latching arm, from its integral connection with said motor cover up to a free end with said latching end, is bent at least once.

6. The motor as claimed in claim 5, wherein each resilient latching arm, from its integral connection with said motor cover up to a free end with said latching end, with in each case opposing bends in a form of an S, is bent twice or three times with two or three bends.

7. The motor as claimed in claim 5, wherein said bends give said free end of said resilient latching arm elastic movability and bendability parallel to a longitudinal center axis and elastic movability and bendability in a radial direction.

8. The motor as claimed in claim 1, wherein a bevel is provided as a latching end at said free end of said resilient latching arm, wherein said bevel points away from said longitudinal center axis in a direction from said rear bearing receptacle toward a front bearing receptacle.

9. The motor as claimed in claim 1, wherein each resilient latching arm reduces in width from its integral connection with said motor cover to said free end.

10. The motor as claimed in claim 1, wherein a protruding projection is formed at said free end of each resilient latching arm, which projection protrudes rearward as a manual handle for manually undoing said latching connection.

11. The motor as claimed in claim 1, wherein said latching projections protrude radially from said bearing receptacle by a length of between 1% and at most 20% of a diameter of said rear bearing receptacle.

12. The motor as claimed in claim 1, wherein at least two retaining pegs protrude from said motor cover toward said front end of said rotor parallel to said longitudinal center axis, wherein said retaining pegs engage in recesses in said stator as anti-rotation securing for said motor cover about said longitudinal center axis.

13. The motor as claimed in claim 1, characterized in that said resilient latching arms extend substantially in a radial direction toward said longitudinal center axis.

14. The motor as claimed in claim 1, wherein, starting from their integral connection with said motor cover, said resilient latching arms firstly extend in a radial direction, then bend in a bend toward said front end of said rotor, wherein they are then bent in a further bend toward said longitudinal center axis.

15. The motor as claimed in claim 14, wherein said bends amount to around 90 and are formed with a wide radius.

16. The motor as claimed in claim 14, wherein, after said last bend, said resilient latching arms are again bent round by around 90, such that they then point in a direction roughly parallel to said longitudinal center axis and away from said rotor, wherein said latching end on said resilient latching arm is then arranged adjacent thereto.

17. The motor as claimed in claim 16, wherein said latching end is arranged on said resilient latching arm, and again points with a bend of about 90 toward said longitudinal center axis such that said latching end points toward said longitudinal center axis.

18. The motor as claimed in claim 1, wherein said resilient latching arm is configured such that, in a basic position where said motor cover has not been placed onto said motor and said resilient latching arm has not been force-loaded or snapped onto said latching connection, there is a distance provided between said latching end and said latching projection which points away in a direction of said longitudinal center axis.

19. The motor as claimed in claim 18, wherein said distance amounts to 0.2 cm to 2 cm or 2% to 30% of a length of said resilient latching arm.

20. The motor as claimed in claim 1, wherein said form-locking connection is in direct radially inward direction of said integral connection of said resilient latching arms to said motor cover.

21. A pump with a pump part and with a motor as claimed in claim 1, wherein said motor is arranged on said pump part such that motor and pump part form said pump as a structural unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Exemplary embodiments of the invention are shown schematically in the drawings and are explained in more detail below. In the drawings:

[0030] FIG. 1 is an oblique view of a structural unit with a pump part and a motor according to the invention as a pump according to the invention,

[0031] FIG. 2 is a rear view of the pump with the motor and a motor cover,

[0032] FIG. 3 is a section through the motor according to the invention with motor cover,

[0033] FIG. 4 shows a further section through the motor cover from the perspective of FIG. 3,

[0034] FIG. 5 is a rear view of an alternative motor cover with differently configured resilient latching arms,

[0035] FIG. 6 shows an enlarged portion of FIG. 5 showing movement of one of the resilient latching arms,

[0036] FIG. 7 is a lateral sectional representation through the motor cover of FIG. 5, and

[0037] FIG. 8 is a further representation of movement of the resilient latching arm.

DETAILED DESCRIPTION OF THE EXAMPLES

[0038] FIG. 1 shows a pump 11 according to the invention as a structural unit with a motor 13 which is mounted to a pump part 60 at the rear such that the two form the structural unit 11. The pump part 60 is configured substantially as known from the prior art, for example from the above-stated US 2016/0169230 A1. It has a pump housing 61 with an inlet 62 into a pump chamber 63. An impeller 66 rotates therein and delivers the water through the pump chamber 63 as far as to an outlet 64. The pump is therefore an impeller pump. A heating element may be provided in the pump chamber 63, but this is of no significance here.

[0039] The motor 13 has a stator 15 with a laminated stator core 17, see also the enlarged depictions of FIGS. 3 and 4. In the substantially square laminated stator core 17 with beveled corners, retaining recesses 18 in the form of through-holes or -bores are provided in the corner regions, whose function will be explained in greater detail below. FIGS. 3 and 4 show the stator windings 19 attached to winding holders 20. These winding holders 20 are in turn connected to the laminated stator core 17. The stator windings 19 are arranged relatively close around a housing 30b of the motor 13.

[0040] A rotor 28 with a through rotor shaft is arranged in the housing 30b. The rotor shaft has a rear shaft end 27, which is arranged in a rear bearing receptacle 30a by way of a bearing 31. The rear bearing receptacle 30a is part of the housing 30b. It may be approximately cup-shaped with a rear receiving cup 32. Three latching projections 34, as described above, are provided distributed regularly circumferentially around the receiving cup 32. The latching projections 34 have rearward and obliquely radially outward bevels 35. To the front they are flattened in the radial direction, to achieve the best possible latching action.

[0041] A flat motor cover 38 is placed from the rear onto the motor 13 and thus overlaps the rear side thereof or forms the latter. The motor cover 38 thus consists of a rear side 40, which extends substantially in a plane perpendicular to the longitudinal center axis of the rotor 28. Furthermore, the motor cover 38 has an external frame 50 or the rear side 40 merges directly into the external frame 50. According to FIG. 2, this external frame 50 extends in a roughly square shape with notches in the corner regions and overlaps with the part of the stator windings 19 which projects toward the rear below the laminated stator core 17. Furthermore, the external frame 50 also engages with a front edge by a small amount over the laminated stator core 17. Retaining pegs 52 of the motor cover 38 molded on in accordance with FIG. 4 engage in the above-stated retaining recesses 18. Insertion is facilitated by the depicted conical configuration of the retaining pegs 52. This ensures precise positioning and above all anti-rotation securing and also securing against any shift in the direction at right angles to the longitudinal center axis of the rotor 28. This may additionally or alternatively also be achieved by the front edge of the external frame 50 engaging over the laminated stator core 17 or the winding holder 20.

[0042] According to FIG. 1, a socket housing 53 is molded onto the motor cover 38 or onto the external frame 50, in which a socket 54 is provided for electrical connection of the motor 13 or of the entire structural unit 11. If the pump 60 has the above-stated heating element, electrical connection thereof may advantageously also proceed by way of the socket 54.

[0043] While the retaining pegs 52 in the retaining recesses 18 of the laminated stator core 17 prevent the motor cover 38 from twisting or shifting on the motor 13, the form-locking latching connection according to the invention is still required in order to prevent removal of the motor cover 38 away from the motor along the longitudinal center axis. To this end, the motor cover 38 has three resilient latching arms 42a, 42b and 42c on the rear side 40. These are separated from one another by respective ventilation slots 41. It is clear from FIG. 2 that both the resilient latching arms 42a to 42c and the ventilation slots 41 extend or are configured as it were precisely in the radial direction. The sectional representation in FIG. 3 shows that the resilient latching arm 42a is connected in a connection region 43a with the motor cover 38 or the rear side 40. The parts are produced integrally in a single plastics injection molding operation. Starting from the connection region 43a, the resilient latching arm 42a is bent forward in a first bend 44a of around 80 with a somewhat greater bend. Directly after this first bend 44a the resilient latching arm 42a is bent in the opposite direction by a second bend 45a, specifically around twice as far, i.e., around 160. The first bend 44a and second bend 45a are advantageously regular.

[0044] Directly after this second bend 45a, the resilient latching arm 42a is again bent in the opposite direction in a third bend 46a of around 80, advantageously of somewhat less than the first bend 44a. A latching end 47a of the resilient latching arm 42a following the third bend 46a then, although relatively short, advantageously points once again in the radial direction. An extension thereof should here point precisely toward the longitudinal center axis of the rotor 28.

[0045] The latching end 47a has a bevel 48a pointing downward and to the left, for example with an angle of around 45 to the longitudinal center axis. The angle of this bevel 48 should be roughly parallel to the angle of the bevel 35 of the latching projection 34. The latching end 47 engages behind the latching projection 34, so producing the latching connection. On production of this latching connection, the latching end 47a may slide readily with its bevel 48a along the bevel 35 of the latching projection 34, as is fundamentally known for latching connections. In the process, the latching end 47a deflects radially away from the latching projection 34 due to the elasticity of the resilient latching arm 42a, until it is able to engage behind said latching projection 34.

[0046] To produce the latching connection, an axially protruding projection 49a, which may have a length of 0.5 cm to 1 cm, is molded on shortly before the latching end 47a. By applying pressure to this projection 49a in the axial and radial directions, the latching end 47a may in any case be securely introduced behind the latching projection 34. It is apparent from FIG. 3 that the resilient latching arm 42a has a degree of axial movability regarding its latching end 47a, due to its extending overall in the radial direction and being produced from appropriately elastic, but at the same time robust plastics material. In this direction, the resilient latching arm 42a is, however, intended simultaneously to hold the motor cover 38 on the motor 13 and secure it against removal.

[0047] The repeatedly bent configuration of the resilient latching arm 42a, with its three bends 44a, 45a and 46a, provides a degree of elasticity in the radial direction, which is required to ensure that the latching end 47a can be moved somewhat in the radial direction on production of the latching connection in order then to engage behind the latching projection 34. This movability or bendability in the radial direction to produce the latching connection does not per se impair the retaining action in the axial direction, although naturally the resilient latching arm 42a is somewhat less rigid as a whole as a result.

[0048] By providing three resilient latching arms 42a, 42b and 42c, an overall sufficiently great retention force can be achieved for retaining the motor cover 38 on the motor 13. The precise configuration of the resilient latching arms 42a to 42c is also significant here.

[0049] Provision may moreover be made for the resilient latching arms 42a to 42c to be configured, in a simple configuration, in such a way that the latching connection is automatically produced when the motor cover 38 is slid onto the motor 13 from behind, the retaining pegs 52 engaging in the retaining recesses 18. The latching ends 47 of the resilient latching arms 42 thus engage automatically and independently behind the respective latching projections 34 on the receiving cup 32. It is then impossible, however, for the resilient latching arms 42a to 42c to be preloaded in the position or end position of the resultant latching connection in such a way that they press the motor cover 38 still more firmly against the motor 13 through their own preloading. If this is desired, the resilient latching arms 42a to 42c may be configured such that, in the end position of the motor cover 38 on the motor 13 according to FIG. 4, they still do not engage with their latching ends 47 behind the latching projections 34. They may either rest thereagainst or even be spaced a little therefrom axially when said resilient latching arms 42 are in a basic position. Then, by pressing against the projections 49 in the axial and somewhat in the radial outward direction, each resilient latching arm 42 is moved toward the front end of the motor and thus, in particular with the assistance of the bevels 48 and 35, the respective latching end 47 is pushed behind the projection 34. In the process, the resilient latching arms 42 are preloaded or receive preloading which then, as a permanent force, pushes the motor cover 38 against the motor 13. In this way, a stable, reliable and durable connection is achieved. Unlike with an automatically produced latching connection, on introducing the motor cover 38 from the rear onto the motor 13, a degree of assembly effort is then needed, either using automated equipment or manually, specifically by applying appropriate pressure against the projections 49. This effort is not very great, however, and cannot be performed incorrectly. Furthermore, the preloading on the resilient latching arms 42 achieved in this way may bring about very stable fastening of the motor cover 38 to the motor 13.

[0050] An alternative second exemplary embodiment for the resilient latching arms is shown in FIGS. 5 to 7. The rear view of the motor cover 138 with the rear side 140 according to FIG. 5 shows that, here too, ventilation slots 141 are on the one hand provided in the radial direction. Three resilient latching arms 142a, 142b and 142c are moreover provided, which are each of identical configuration. These resilient latching arms, which are shown in side view in FIG. 7, have a thickness which advantageously corresponds to the material thickness of the remainder of the motor cover 138. However, they are wider, as it were, as shown in FIG. 7. In particular, compared to the resilient latching arms 42 of FIGS. 1 to 4 they are, as it were, rotated by 90 and do not have any bends but rather extend completely straight. A comparison of FIGS. 5 and 7 shows that these resilient latching arms 142a to 142c are radially not at all movable or bendable. Furthermore, they are likewise barely bendable or movable in the axial direction, as here their large width lends significant axial stability. It is therefore also apparent from FIG. 7 that the form-locking latching connection therein, with which a latching end 147a of the resilient latching arm 142a engages behind the latching projection 134 on the receiving cup 132 of the rear bearing receptacle 130, cannot be achieved as described for the first configuration. In this respect, the enlarged rear view of FIG. 6 shows schematically that the resilient latching arms 142a to 142c are movable or bendable in a transverse direction relative to their longitudinal extent, which runs at right angles to the longitudinal center axis. The solid lines in FIG. 6 show how the resilient latching arm 142a is bent sideways to the left when the motor cover 138 is introduced from the rear onto the motor. In the process, the latching end 147a is bent so far to the left that it moves laterally past the latching projection 134. In the end position according to FIG. 7, the resilient latching arm 142a is then bent back into its basic position, which is shown in dashed lines in FIG. 6, with it then engaging with its latching end 147a behind the latching projection 134.

[0051] Since this deflection movement of the resilient latching arm 142a cannot be achieved with the same bevels as in the first exemplary embodiment, one option is to provide for the end of the resilient latching arm 142a to be bent sideways when the motor cover 138 is introduced using similar projections to the projections 49 of the first exemplary embodiment. Manual assembly is then advantageously needed, with the form-locking latching connections being individually produced in each case. In this case, provision may advantageously be made for retaining pegs of the motor cover 138 already to engage in retaining recesses 18 of the laminated stator core 17, so as to prevent the motor cover 138 from rotating relative to the motor.

[0052] Alternatively, bevels may in turn be provided in order to bring about the deflection movement of the end region of the resilient latching arm 142a shown in FIG. 6 when the axial movement occurs, the bevels then being configurable as shown in FIG. 8. This is a view from the longitudinal center axis towards the radial direction and shows on the one hand the projection 134 with a bevel 135 and on the other hand the resilient latching arm 142a with a bevel 148a. The resilient latching arm 142a is introduced in the axial direction of movement per the arrow, and brings about a deflection movement of the end region of the resilient latching arm 142a by the bevels 135 on the one hand and 148a on the other sliding against one another. In the deflected position shown by dashed lines, the resilient latching arm 142a or the latching end 147a thereof may then be moved laterally past the projection 134 in the axial direction. As it moves past, it may spring back there behind into the basic position shown by dotted lines, where it rests form-lockingly against the opposite side of the latching projection 134 from the bevel 135.

[0053] It is clear that this second exemplary embodiment is able to achieve greater force absorption in the axial direction or a stronger latching connection in the axial direction. At the same time, however, it may be that the assembly effort is increased somewhat.