KR102069566B1 - Magnet wheel for an electric motor - Google Patents

Abstract

The present invention relates to an electric motor (1) having a stator (19) and a rotor (18) rotatably bearing inside a casing, and having a pulse wheel (2) fixedly rotated with respect to the rotor (18). It is about. The problem of the present invention is that in an electric motor 1 having a pulse wheel 2, it is possible to simply manufacture and install this electric motor, where a small axial mounting length is required and the position for the stator fixing sensor Adjustable and accurate axial positioning is possible. This problem is solved according to the invention by the features of claim 1 and by the features of method claim 22.

Description

Electric motor with magnet pulse wheel {MAGNET WHEEL FOR AN ELECTRIC MOTOR}

The present invention has a stator 19 and an electric rotor having a rotor 18 rotatably bearing supported inside the casing and having a pulse wheel 2 installed with limited rotation relative to the rotor 18. It relates to the motor (1).

DE 198 23 640 discloses a pulse wheel mounted on a shaft, in which press coupling must be achieved in spite of the different thermal expansion coefficients of the metal shaft and the plastic bonded permanent magnet. The problem is solved by the pulsewheel consisting of two axial sections, the first section being cut against the shaft and the second section being pressed as a reinforcing element with the aid of a ring-shaped auxiliary body. However, two axial sections require an enlarged axial installation space. In addition, despite the long installation length, the pulse wheel is fixed only on short sections on one side. The arrangement further requires an additional joining process for the installation of the reinforcing means.

Therefore, the object of the present invention is to allow an electric motor with a pulse wheel to be simply manufactured and installed, where a small axial mounting length is required and the position adjustment and accurate axis of the stator fixing sensor are required. Directional arrangement is possible.

This problem is solved according to the invention by the features of claim 1 and by the features of method claim 22. It is proposed that the pulse wheel 2 consists of a magnet ring 7 which is designed for magnetic properties and a carrier 3 which can be made of a simple plastic material which is not particularly given high requirements in terms of robustness and heat resistance. . The carrier 3 has a fastening means 4 which extends in and engages in the recess 12 of the rotor 18 in the axial direction and is provided with a good form-fit rotational linkage.

Improvements of the invention are disclosed in the dependent claims. The carrier 3 preferably comprises one support or a plurality of supports 6, which are supported to be supported on the shaft 25 of the rotor 18. This support prevents the pulse wheel 2 from being inclined or installed inclined.

In order that this effect can be ensured continuously, the support or the supports 6 have support surfaces / support surfaces 34 that fit the cylinder jacket surface, which support surface directly contacts the shaft 25. It is configured to. Since the shaft 25 also has a cylinder jacket surface, a large area of sufficient support surface or support surfaces 34 is provided that exhibits the disclosed advantages without undergoing shape changes even under vibration loads.

Preferably, three or more supports 6 are provided, to which a shell 29 is radially connected, or the supports 6 are shell-like. This allows for accurate centering of the pulse wheel 2 on the shaft 25.

On the one hand, the support or the supports 6 are provided such that a simple installation is possible without the risk of breakage of the pulse wheel 2 and on the other hand, the coupling between the pulse wheel 2 and the shaft 25 can be performed without backlash as much as possible. It is dimensioned according to partial engagement with the shaft 25.

According to a particularly preferred refinement of the invention, the pulse wheel 2 comprises one or a plurality of axial stoppers 36, which axial stoppers protrude from the pulse wheels in the axial direction. The axial stopper / axial stoppers 36 are axially connected to the support or to the supports 6. The final position of the pulse wheel 2 can thus be determined and adjusted by the axial pressure effect upon installation.

A ring disc hub 30 is connected to the shell 29 or to the shell support 6 in a radial direction. The hub 30 is used to bridge the radial spacing between the shaft 25 or the supports 6 and / or between the shell 29 and the magnet ring 7, Shrinkage of the material which may cause deformation after cooling should not occur as far as possible. The hub 30 is thus disc shaped so that the entire carrier 3 has approximately the same wall strength in its different regions.

In practice, a magnet receiving ring 9 is connected to the hub 30 in the radial direction. Further, the magnet receiving ring 9 extends axially through the ring wall 37 at its axial end, respectively, and provides a groove between the magnet receiving ring 9 and the ring walls 37. 33) is configured to be formed. The groove 33 is used as an axial safety device of the magnet ring 7. Since the magnet ring 7 is ring-shaped it also remains stable in the radial direction.

Depending on the embodiment at least part of the magnet ring 7 can be received in the groove 33 or the magnet ring 7 can extend over the groove 33 in the radial direction. The magnet ring 7 also extends axially wide from the outside of the groove 33 so that the axial boundary of the ring wall 37 and the magnet ring 7 is in one plane. This results in a wider magnet ring 7, which is more likely to face the pulse wheel 2 directly. To reinforce this effect, depending on whether the environment allows, the magnet ring 7 can also protrude further beyond the ring wall 37.

The fastening means 4 are at least partially extended in the axial direction and connected to the hub 30. The hub can also be connected to the magnet receiving ring 9 at least partially axially according to the diameter of the fixing means 4 and the dimensions of the corresponding recess 12 of the rotor 18 are determined.

Particularly preferred is an embodiment in which the fixing means 4 taper toward the area farther from the pulse wheel 2. This facilitates the joining process into the recess 12 on the one hand and on the other hand the press-in force increases with the press-in depth. However, since the taper is relatively small, the axial position of the pulse wheel 2 can be adjusted without problem over a large axial region.

This effect is such that the fastening means 4 have a cutout 14 along its axial extension, which cutout is for example formed in the form of a notch 40, a slit 32 and / or a cavity 31. It is further improved by what can be done because doing so achieves some sort of compliance.

The coarser the joint, the better the pressure fit coupling. Thus, it is important that the fixing means 4 are accommodated in the recess 12 of the rotor plate packet 26 by pressure fitting in the axial direction and by shape fitting in the rotation direction.

In order to ensure that the pulse wheel 2 is in its axial position, a spring 42 is disposed between the rotor plate packet 26 and the pulse wheel 2, which springs the pulse wheel 2. And tightly pressurizes onto the second deep groove ball bearing 15 in the axial direction. It is significant that the spring 42 is made of the same material as the carrier 3 and is made of a single member with the carrier since the number of parts and the installation cost do not increase.

The second solution to the problem is achieved by a method having the following method steps: a) preparing a rotor assembly consisting of a shaft 25, a pressed rotor plate packet 26 and a permanent magnet 27 installed ; b) preassembling a pulse wheel (2) in the recess (12) of the rotor plate packet (26); c) pressing a deep groove ball bearing 15 on the shaft 25 and setting a predetermined spacing dimension between the inner ring 39 of the deep groove ball bearing 15 and the shaft end, wherein the pulse wheel And (2) is pushed back into the recess 12 of the rotor plate packet 26, in which way the individual components of the electric motor 1 are influenced by the position of the motor sensor. Manufacturing tolerances can be well compensated.

For further installation, the magnet ring 7 and the permanent magnet 27 of the pulse wheel 2 are configured to magnetize at the same time. This eliminates the need for additional method steps.

Finally, prepare a stator assembly comprising a casing port 10 in which a stator 19 is installed and a first deep groove ball bearing 8 used as a fixed bearing, and the stator assembly is mounted on the rotor assembly. Pressing, the shell-like tool contacts the inner ring 39 of the first deep groove ball bearing 8 and presses onto the shaft 25.

The present invention is explained in more detail based on the following examples. In the drawing:
1 is a front view of a first embodiment of a pulse wheel,
Figure 2 is a three-dimensional view showing a partial cut in the pulse wheel according to FIG.
3 is a view according to FIG. 2 seen from another direction;
4 is a cross-sectional view of the first embodiment of the pulse wheel;
5 is a cross-sectional view showing another embodiment of the pulse wheel,
6 is a front view showing another embodiment of the pulse wheel,
7 shows a pulse wheel installed in the rotor,
8 is a second embodiment of a pulse wheel;
9 is a variation of the second embodiment of the pulse wheel,
Fig. 10 shows an electric motor provided with the pulse wheel of the first embodiment.

Note: In the drawings and the description of the drawings, the symbols with apostrophes and the corresponding symbols without apostrophes refer to the same name. Symbols having an apostrophe and symbols without an apostrophe represent the same components in the drawings and in the description of the drawings, for use in accordance with other embodiments and the prior art. For the sake of brevity, the apostrophe-free name is used in the claims, the opening of the specification, the description of the signs and the abstract.

1 to 6 show the pulse wheel 2 of the first embodiment consisting of the carrier 3 and the magnet ring 7 from various viewpoints. The carrier 3 consists of a ring disc hub 30, to which six fastening means 4, a center shell 29 and a magnet receiving ring 9 are connected. The magnet receiving ring 9 (see FIG. 2) runs radially through two ring walls 37, which are spaced apart from each other. The magnet receiving ring 9 and the ring wall 37 together form a groove 33 (see FIG. 2) which opens radially outwardly. The groove 33 is filled by the magnet ring 7. The magnet ring 7 runs along the ring wall 37 in the radial direction and forms a cylindrical contour. The axial boundary of the magnet ring 7 and the axial boundary of the ring wall 37 are in one plane. The shell 29 protrudes axially with respect to the magnet ring 7 and the ring wall 37. To the shell 29 are connected three supports 6 arranged radially inwardly at an angular distance of about 120 ° to each other, which are used as support means. These supports have support surfaces 34 radially inward, which support surfaces are in close contact with the cylinder jacket surface. In the installed state they are partly engaged with the shaft 25 (see FIG. 7). In the axial direction, the supports 6 each have an axial stopper 36 (see FIG. 2); These are used for mounting to the second deep groove ball bearing 15 (see FIG. 7). The axial stopper 36 protrudes axially with respect to the shell 29. The fastening means 4 take the form of a tapered elongated shell 29, having a cavity 31 and an inwardly slit 32. The fixing means 4 is used as an anti-rotation device for the pulse wheel 2. Chamfer 35 at the end of the fastening means 4 (see FIGS. 3, 4) and also its taper facilitate the introduction of the rotor plate packet 26 into the recess 12 (see FIG. 7). . The taper also contributes to a tight pressure fit engagement in this recess 12. The slit 32 here allows for some degree of bending of the fastening means 4, so that its diameter can be slightly reduced to accommodate the recess 12 of the core packet. The fastening means 4 extends radially from the shell 29 to the magnet receiving ring 9 via the hub 30. The carrier 3 is a unitary member together with the shell 29, the hub 30, the fastening means 4, the support 6 and the magnet receiving ring 9. The magnet ring 7 is a plastic bonded permanent magnet 27 (see FIGS. 1 and 7), for example made of a rare earth magnet such as NdFeB. The pulse wheel 2 is manufactured by a two-component injection molding process, in which a carrier 3 made of a three-dimensionally moldable plastic material is molded in a first cavity and then a magnet ring 7 made of a plastic bonded permanent magnet material. ) Is bonded through molding with the carrier 3 in a second cavity. Very high requirements are not imposed on the material of the carrier 3 as the press fit with the shaft 25 can be omitted due to its conformation with the rotor plate packet 26. The support 6 prevents the possibility of inclination of the pulse wheel 2. 1 shows a conical demolding bevel 41 that facilitates demolding from an injection molding tool. The support 6 does not have a release bevel 41 to provide a predetermined support surface.

FIG. 7 shows the pulse wheel 2 of the first embodiment installed in the rotor 18 with two cutting planes inclined at about 150 ° to each other (see line AA in FIG. 1), where the carrier 3 and the single member are shown. The phosphorus fixing means 4 extend into the recess 12 of the rotor plate packet 26 parallel to the axis and are engaged by a pressure fit. The support 6 of the pulse wheel 2 as a single member with the carrier 3 is seated on the shaft 25. This prevents the tilt of the pulse wheel 2. An axial stopper 36 contacts the inner ring 39 of the deep groove ball bearing 15 in the axial direction. This makes it possible to adjust the depth of pushing the fixing means 4 into the recess 12 when the deep groove ball bearing 15 is joined. Basically the number of fastening means 4 is freely selectable, but it is recommended to provide at least two, preferably three or more fastening means 4.

8 simplifies the second embodiment of the pulse wheel 2 ', the carrier 3' and the magnet ring 7 '. Here, two fixing means 4 'extending in parallel in the axial direction from the carrier 3' form a single member with the carrier 3 '. The fastening means 4 ′ are each provided with four tapered ribs 38, which form a cross-shaped arrangement and are separated from each other by the notches 40. The support 6 is omitted here for the sake of brevity, but it can be formed similarly to the first embodiment. Instead of the discontinuous support, a ring support 6 'may also be used.

9 shows a variant of the second embodiment of the pulse wheel 2 ", wherein the spring 42 made of plastic is a single member with the carrier 3". This spring 42 consists of two rings 13 which are spaced apart from each other and connected to each other by a bridge 17. An additional bridge 17 connects the carrier 3 "with the first of the rings 13. The bridge 17 disposed between the rings 13 is a carrier 3" and a sensor 43. It is shifted by about 90 degrees with respect to the bridge 17 arrange | positioned between (refer FIG. 10). Two axial protrusions 23 are connected to the outer ring 13, which are deviated by about 90 ° with respect to the bridge 17 connecting the rings 13. The protrusion 23 is used as a predetermined support surface for mounting on the rotor plate packet 26. Due to the angular offset between the bridges 17 and the angular offset of the protrusion 23 with respect to the bridge 17, the rings 13 are elastically deflected axially between the bridges 17. By this, bending of the spring 42 becomes possible. It is always ensured that the pulse wheel 2 "contacts the second deep groove ball bearing 15 through the spring 42.

FIG. 10 shows an assembly diagram of the electric motor 1, which is an electric rectifying direct current motor, which is a rotor 18 with a permanent magnet 27, a stator 19 wound by a core 24. ) And casing. The casing consists of a bearing shield 20 and a casing port 10. The rotor 18 is axially in the recess 12 of the rotor plate packet 26 by a flat shaft 25, rotor plate packet 26, permanent magnet 27, and fastening means 4. It consists of a pulse wheel 2 fixed on a carrier 3 (see FIGS. 1 to 6) to be inserted. A sensor (43) disposed radially with respect to the pulse wheel (2) on a circuit board (21) in cooperation with the pulse wheel (2); Alternatively, axial positioning is possible. The circuit board 21 is formed as an overmolded baffle comprising a plug 22. Further, the first deep groove ball bearing 8 fixed by the spring steel disc 5, the second deep groove ball bearing 15, the cover cap 16 fixed in the cutout 14, the flange joint gear pump ( 28 and stator plate packet 11 are shown. In the installation of the pulse wheel 2, the exact position with respect to the rotor 18 can be fitted within some limits for each actual dimension. An axial stopper 36 (see FIGS. 1-6) is used for this purpose, which can be supported on the inner ring 39 of the second deep groove ball bearing 15. In this way an accurate positional arrangement for the sensor 43 is achieved. The pulse wheel 2 and the rotor 18 have three N polarities and three S polarities, respectively.

1 electric motor 30 hub
2 pulse wheel 31 cavity
3 carriers with 32 slits
4 Fastening means 33 groove
5 Spring steel disc 34 support surface
6 Support 35 Chamfer
7 Magnet Ring 36 Axial Stopper
8th deep groove ball bearing 37 ring wall
9 magnet receiving ring 38 rib
10 Casing port 39 inner ring
11 stator plate packet 40 notch
12 recesses 41 demolding bevel
13 ring 42 spring
14 cutouts 43 sensors
15 second deep groove ball bearing
16 cover cap
17 bridges
18 rotor
19 stator
20 bearing shield
21 circuit board
22 plug
23 overhang
24 core
25 shafts
26 rotor plate packet
27 permanent magnets
28 gear pump
29 shell

Claims (24)

An electric motor (1) having a stator (19) and a rotor (18) rotatably supported inside the casing, and having a pulse wheel (2) installed with limited rotation relative to the rotor (18),
The pulse wheel 2 consists of a carrier 3 made of plastic material and a magnet ring 7, the carrier 3 being axially coupled in the recess 12 of the rotor 18. Has 4,
The fastening means 4 are received in the recess 12 of the rotor plate packet 26 by pressure fitting in the axial direction and by shape fitting in the rotation direction,
A spring 42 is disposed between the rotor plate packet 26 and the pulse wheel 2, which spring closely contacts the pulse wheel 2 on a deep groove ball bearing in the axial direction. An electric motor (1), characterized in that to pressurize. The method of claim 1,
The carrier (3) comprises one or a plurality of supports (6), which are supported on the shaft (25) of the rotor (18). The method of claim 2,
The support (6) has at least one support surface (34) adapted to the cylinder jacket surface, which support surface directly contacts the shaft (25). The method according to claim 2 or 3,
The support (6) is characterized in that the dimensions are determined by partial engagement with the shaft (25). The method according to claim 2 or 3,
Three or more supports (6) are provided, characterized in that the shell (29) is connected radially to the support, or the support (6) is shell-shaped. The method according to any one of claims 1 to 3,
The electric motor (1), characterized in that the pulse wheel (2) has one or a plurality of axial stoppers (36), the axial stoppers projecting axially from the pulse wheel. The method of claim 6,
The electric motor (1), characterized in that the axial stopper (36) is in axial contact with one or the plurality of supports (6). The method of claim 6,
The electric motor (1), characterized in that the pulse wheel (2) can be supported axially in the inner ring (39) of the deep groove ball bearing by the axial stopper (36). The method of claim 5,
An electric motor (1), characterized in that a ring disc hub (30) is connected radially to the shell (29) or the shell-like support (6). The method of claim 9,
An electric motor (1), characterized in that a magnet receiving ring (9) is connected radially to the hub (30). The method of claim 10,
The magnet receiving ring 9 extends axially by a ring wall 37 at its axial end, respectively, and a groove 33 between the magnet receiving ring 9 and the ring wall 37. An electric motor (1), characterized in that is formed. The method of claim 11,
The electric motor (1), characterized in that at least part of the magnet ring (7) is received in the groove (33). The method of claim 12,
The magnet ring (7) is characterized in that it extends through the groove (33) in the radial direction. The method of claim 13,
The magnet ring 7 is characterized in that it extends axially wide from the outside of the groove 33 so that the axial boundary of the ring wall 37 and the magnet ring 7 is in one plane. Electric motor (1). The method of claim 9,
The electric motor (1), characterized in that the fixing means (4) are at least partly connected to the hub (30) in the axial direction. The method of claim 10,
The electric motor (1), characterized in that the fastening means (4) are at least partly connected to the magnet receiving ring (9) in the axial direction. The method according to any one of claims 1 to 3,
The fastening means (4) are characterized in that they taper toward the area farther away from the pulse wheel (2). The method according to any one of claims 1 to 3,
The fastening means 4 has a cutout 14 along its axial extension, which cutout is in the form of a notch 40 or one or both of the slits 32 or the cavity 31. An electric motor 1, which can be formed. delete delete The method of claim 1,
The spring (42) is made of the material of the carrier (3) and is characterized in that it is a single member with the carrier. A method of installing a pulse wheel (2) on the rotor (18) of the electric motor (1) of any one of claims 1 to 3 comprising a casing and a stator (19),
a) preparing a rotor assembly consisting of a shaft 25, a pressed rotor plate packet 26 and a permanent magnet 27 installed;
b) preassembling a pulse wheel (2) in the recess (12) of the rotor plate packet (26);
c) pressing a deep groove ball bearing on the shaft 25 and setting a predetermined spacing dimension between the inner ring 39 of the deep groove ball bearing and the shaft end, wherein the pulse wheel 2 is again A method of installing a pulse wheel (2) comprising the step of pushing into the recess (12) of the rotor plate packet (26). The method of claim 22,
d) magnetizing the rotor (18), wherein the permanent magnet (27) and the magnet ring (7) of the pulse wheel (2) are magnetized simultaneously. The method of claim 22,
e) preparing a stator assembly comprising a casing port 10 in which a stator 19 is installed and a deep groove ball bearing used as a fixed bearing is installed;
and f) pressing a shelled tool against the inner ring 39 of the deep groove ball bearing onto the shaft 25 to press the stator assembly onto the rotor assembly. 2), the installation method.

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