JP2018183042A - Electrically rectified dc motor and method for assembling electrically rectified dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrically rectified DC motor (1) including a stator (2) having a stator sheet packet (3) and a cup-shaped housing (4) with winding wire and a permanent magnet rotor (5) housed in the stator sheet packet (3); and to find simple economic potential for inserting the pre-magnetized permanent magnet rotor into the cup-shaped housing without damaging magnetic coating, without resulting in shavings formation, and without damaging a user interface on an axis section.SOLUTION: The problem is solved according to the invention through features of claim 1.SELECTED DRAWING: Figure 1

Description

  The invention comprises a stator (2) with windings and a stator packet packet (3) and a cup-shaped housing (4), and a permanent magnet rotor (5) housed in the stator packet packet (3). The invention relates to an electronically commutated direct current motor (1) having a shaft (6), a plastic hub (7) and a magnetized permanent magnet (8).

  This type of direct current motor is widely used and used in various fields. They can be used in dry or moist areas, where they are filled with liquid or are externally exposed to liquid. For example, this type of DC motor is used as a drive for an oil pump. When sealing requirements are high, these motors often have cup-shaped housings. Because it reduces the number of interfaces to be sealed. Permanent magnet rotors used in electronically rectified direct current motors are often magnetized in the final assembled state. In that case, the magnetization of the permanent magnet rotor is usually negatively affected by the stator geometry. In order to achieve better magnetisation of the permanent magnet rotor and the corresponding optimum efficiency of the DC motor, the permanent magnet rotor is preferably magnetized in the magnetizer prior to assembly. The problem then is the considerable radial force acting between the permanent magnet rotor and the stator during the joining process. Radial forces can lead to collisions and / or scraping of the permanent magnet rotor, in particular of the permanent magnets in the stator laminations packet. In that case, swarf is produced which negatively affects the bearing properties, bearing life, wear properties, etc. Also, the coating of the permanent magnet may be damaged. They also reduce the life and affect the functionality of the motor by corrosion of the magnetic material.

  In order to ensure the non-contact mounting of the DC motor in the stator, a complex joining device is required, which houses the DC motor and the stator equally rigidly and joins them in a defined manner. In that case, the previously assembled rotor must be accommodated in the shaft portion of the device. In many applications, this shaft portion forms or has a customer interface, which can be damaged when housed in a welding tool. Furthermore, this device is formed separately for each rotor type and is therefore not economical.

  The object of the invention is therefore to insert a premagnetized permanent magnet rotor into a cup-shaped motor housing without damaging the magnetic coating, leading to scraping and without damaging the customer interface at the shaft part. To find simple economic possibilities.

  This object is achieved according to the invention by the features of claim 1 or the method features of claim 7. The permanent magnet is coupled to the shaft by a plastic hub. This is one possibility to fix the permanent magnet. The plastic hub also has the added function of a guide that projects radially beyond the permanent magnet. This guide allows the permanent magnet rotor to be in contact with the stator in the area of the guide without damaging the coating of the permanent magnet. This is because the coating maintains a small distance to the stator laminations packet. This solution is realizable in a simple and economical manner and allows joining of the permanent magnet rotors without damaging the customer interface at the shaft end.

  The development of the invention is explained in detail in the subclaims. The cup-shaped housing has on the one hand a closed cup bottom and on the other hand a mounting opening. The guide is arranged at the end of the permanent magnet rotor close to the cup bottom. Thereby, it is ensured that the guide is first introduced into the rotor notch of the stator laminations packet and the permanent magnet follows.

  Preferably, the radially overhanging guide has a radial extension that is less than half the inner diameter of the stator laminations packet. This design guarantees that the permanent magnet rotor can be joined into the stator without forced wear.

  Preferably the guide has a ring shape. In this way, the permanent magnet rotor can be magnetically pulled in any desired radial direction without damaging the permanent magnet or its coating.

  Furthermore, an introduction slope is provided, which is 15 ° to 30 °, preferably 20 °, with respect to the joining direction. The lead-in slopes increase the alignment tolerance between the stator axis and the rotor axis during the joining process.

  According to a development of the invention, the plastic hub is non-pivotably coupled relative to the permanent magnet and the shaft by means of a primary deformation process. For this purpose, the permanent magnet is provided with a recess into which the projection of the plastic hub is fitted. The shaft is provided with a knurl. Polyamide is provided as a plastic material.

  In order to avoid material deposition, a notch is provided between the shaft and the permanent magnet, which notch is interrupted by the spokes.

  The stator laminations packet consists of laminated individual laminations, which have a chamfered inner edge at the edge of the first lamination facing the mounting opening of the cup-shaped housing. The beveled inner edge results from the punching process (shearing), in which the sheet material is drawn into the sheet plane generally on one side and out of the sheet plane on the opposite side. The orientation of the laminations is usually chosen such that a stator lamination packet with beveled outer edges is first joined into the cup housing. Usually, in this case, the inner edge is likewise bevelled or directed and has a ridge. The present invention avoids an increase in the scraping action because the punching direction when drilling the rotor housing portion is not parallel to the punching direction when cutting out the stator outer diameter.

  For reasons of tolerance and to further reduce the scraping action of the thin packet on the cup housing, the stator is fixed via radially projecting tongues. In order to facilitate the mounting of the stator in the housing, the end portion is not provided with tongues. In the next part, the tongues are provided only in every other sheet, and in the second part each two successive sheets, which are separated by a sheet without tongues There is. This stator formation is used as a compensation measure to compensate for the slightly conical inner contour of the deep drawn housing. Thin plates without tongues allow simple displacement (bending), which reduces the scraping effect. A part with a relatively loose arrangement of individual lamellae with gaps behind each tongue is provided for the part with a relatively small inner diameter of the housing, and a part with a denser, more rigid arrangement of individual lamellae Are provided for areas having a larger inner diameter.

  The shavings are captured by the receiving pocket in one or both winding insulations, in particular if shavings are produced by grinding off the end lamellae in the housing. Other shavings scraped by the tongue usually remain stuck in the gap between the tongues.

Another solution consists of a stator (2) with windings and a permanent magnet rotor (5) housed inside the stator pack packet (3), having a stator pack packet (3) and a cup-shaped housing (4). The permanent magnet rotor has an axis (6), a plastic hub (7) and a magnetized permanent magnet (8), in which case the permanent magnet (8) is an axis (6) by the plastic hub (7). A method of forming an electronically rectified direct current motor (1), coupled with a), and the method comprises the following steps:
a) Prepare the shaft (6) with knurls,
b) prepare a permanent magnet (8) with interlocking geometry;
c) Insert the shaft (6) and the permanent magnet (8) into the cavity of the injection molding tool,
d) injecting a thermoplastic plastic material into the remaining hollow chamber of the cavity, forming a guide (9) with an introduction bevel (14),
e) Remove the permanent magnet rotor (5) from the injection molding machine,
f) magnetize the permanent magnet (8) in the magnetizer,
g) Pull the housing bearing (20) onto the shaft (6),
h) Prepare the housing (4)
i) Prepare the pre-assembled stator (2),
j) Press the stator (2) into the housing (4) with the beveled side of the individual lamella (12),
k) Joining the magnetized permanent magnet rotor (5) first by means of the guide (9) into the stator recess and joining the housing bearing (20) into the housing (4)
It is characterized by things.

  Although other intermediate or final assembly steps are required to fully assemble, they are not the subject of the present invention.

  Embodiments of the invention are described in detail below with the aid of the drawings.

It is a sectional view showing a stator and a permanent magnet rotor. It is an exploded perspective view showing a permanent magnet rotor. It is a fragmentary sectional view of a stator. It is a sectional view of a permanent magnet rotor. It is a front view of a permanent magnet rotor.

  Note: Reference numbers with subscripts (a, b) and non-subscripted reference numerals indicate things with the same name in the drawings and the drawing description. In that case it is another embodiment, use in the prior art, and / or details are variations. The claims, the introductory part, the reference code list and the abstract only have reference numerals without subscripts for the sake of simplicity.

FIG. 1 shows a cross-sectional view of an assembly comprising a stator 2 and a permanent magnet rotor 5 and a bearing shield 36. The stator 2 comprises a stator-thin-plate packet 3 consisting of a cup-shaped housing 4, a housing bearing 20 and individual thin-plates 12 which have bevelled edges 13 and ridges 28. The beveled edge is formed in the punching process. The punching direction when drilling the rotor housing portion 43 is opposite to the punching direction when punching the outer periphery 44 of the individual thin plate 12. As a result, both the stator packet 3 and the rotor 5 can be optimally mounted. At the outer periphery 44, the tongues 26 project radially. The stator 2 is shown simply (without windings, winding insulation and contacts) in order to be able to recognize the beveled edges 13 and the ridges 28 and their orientation more clearly. The individual lamellae are exaggerated in size. The orientation of the stator laminations packet is chosen such that the joining direction of the permanent magnet rotors 5 to be joined is directed to the beveled side of the individual laminations 12. The end lamellae 49 at the ends of the stator lamina packet have no tongues and form as small a gap as possible with the housing 4. The housing 4 has a cylindrical area 29 and a cup bottom 10, which is axially extended by a bearing receptacle 30. The permanent magnet rotor 5 comprises a shaft 6 with a flat 23 used as a customer interface, a plastic hub 7, a permanent magnet 8 and a guide 9 with a guide bevel 14 (see FIG. 3), in that case The guide 9 is arranged at the first end 11 of the permanent magnet rotor 5 facing the cup bottom 10. Since the diameter of the guide 9 is larger than the diameter of the permanent magnet 8, it is impossible for the permanent magnet 8 to contact the stator thin plate packet 3. The housing bearing 20 is clamped on the end of the shaft 31 facing the cup bottom 10 in a force-fit manner. A ball bearing is used as the housing bearing 20 and its outer ring is
As soon as the stator 2 is mounted, it slides into the cup housing 4, in particular the bearing receptacle 30. The spring disc 41 makes it possible to mount the ball bearing without any gaps. The bearing shield 36 has a seal in the form of an O-ring 37, which seal is inserted into the groove 38. The o-ring abuts the housing flange 42 in the assembled condition. Furthermore, a bearing shield bearing 39 is accommodated in the bearing shield 36 and is fixed by the beryllium clip disc 40.

  FIG. 2 shows the permanent magnet rotor 5 with the shaft 6, the plastic hub 7 and the permanent magnet 8 in an exploded perspective view. The shaft 6 has a flat portion 23 as a customer interface, a shaft end 31 for guiding, and a knurl 15 by which the plastic hub can not be rotated relative to the shaft 6 and can be primarily fixed in an axial direction. is there. The plastic hub 7 has a magnet receiving area 32, a guide 9, a holding ring 21, a protrusion 19, a notch 16, a spoke 24, a cutout 17 and a shaft notch 22. The magnet housing area 32 is axially defined by the holding ring 21 and the guide 9. The notches 16 are disposed between the axial notches 22 and the magnet receiving area 32 and are separated from one another by the spokes 24. The notches are used primarily to avoid material deposition. The permanent magnet 8 is here formed as a plastic-bonded permanent magnet ring, which is provided with a recess 18 corresponding to the projection of the plastic hub 7. The outer contour of the magnet housing 32 and the inner contour of the permanent magnet 8 are formed as polygons, whereby an additional pivoting protection is formed.

  FIG. 3 shows a partial cross-section of a stator 2 (without a housing) with stator packet 3 and individual plates 12 which have partially radially overhanging tongues 26. The individual lamellae 12 with the tongues 26 are usually followed by the individual lamellae without the tongues. In an area, two laminae, each with a tongue, are continuous with one another and separated from the other laminae with a tongue by a lamina without a tongue. The end lamellae 49 in the start area 33 and in the end area 34 have no tongues. In these areas, the sheet diameter is smaller than the housing inner diameter, so that a simple connection into the mounting opening 25 (see FIG. 1) is possible. Nevertheless, the gap between the end slat 49 and the housing 4 is chosen as small as possible in order to avoid at least the larger shavings inside the lamella packet. Furthermore, insulators 27a, 27b are shown, which are used to receive the stator winding and to electrically isolate it from the stator laminations 3. The insulating portion 27a has a receiving pocket 35 for receiving and holding shavings generated when the stator thin plate packet 3 is attached in the housing. The arrows indicate the joining direction of the stator thin plate packet 3 when joining into the housing. The first insulating portion 27a first penetrates into the housing and is followed by the start area 33 of the stator laminate packet 3, the loosely laminated first area 45, the closely laminated second area 46, the end The region 34 and finally the second insulating portion 27b enter. In the loosely laminated area 45, the individual lamellae 12a with the tongues 26 and the individual laminas 12b without tongues alternate with one another. In the closely stacked second region 46, two adjacent individual lamellae 12a with tongues 26 and individual laminas 12b without tongues alternate with one another. The reason is the slight conical shape of the housing and the possibility of scraping with the individual thin plates of the preceding first area 45. The tongues 26 in the first area 45 have to be deformed more strongly than the tongues 26 in the second area 46 due to the narrowing of the housing diameter. The first insulation has a sealing edge 47, which abuts the housing.

  4 shows a shaft 6, a flat portion 23, a shaft end 31 for guiding, a knurl 15, a plastic hub 7, a notch 16, a spoke 24, a holding ring 21, a guide 9 of a first end of the permanent magnet rotor 5 and In a front view is shown a permanent magnet rotor 5 having a recess 17 for accommodating the permanent magnet 8 in a defined manner in an injection molding tool. The detail A shows the guide 9 having the guide slope (14) in an enlarged manner, and the guide slope is inclined at an angle α of 20 ° with respect to the joining direction (axially parallel direction).

  FIG. 5 shows the front side of the permanent magnet rotor 5 with the guiding shaft end 31, the plastic hub 7, the notches 16, the spokes 24, the guides 9, the guide bevels 14 and the notches 17. In the example shown, three notches 16 and six notches 17 are provided.

DESCRIPTION OF SYMBOLS 1 DC motor 2 stator 3 stator thin plate packet 4 housing 5 permanent magnet rotor 6 axis 7 plastic hub 8 permanent magnet 9 guide 10 cup bottom 11 1st end 12 individual thin plate 13 chamfered edge 14 introduction slope 15 knurling 16 notch 17 cutout 18 retraction 19 protrusion 20 housing bearing 21 holding ring 22 shaft notch 23 flat portion 24 spoke 25 mounting opening 26 tongue 27 insulating portion 28 ridge 29 cylindrical region 30 bearing housing 31 shaft end 32 to be guided Magnet storage area 33 Start area 34 End area 35 Housing pocket 36 Bearing shield 37 O ring 38 Groove 39 Bearing shield bearing 40 Beryllium clip disc 41 Spring disc 42 Housing flange 43 Rotor housing 44 Outer circumference 4 5 first area 46 second area 47 seal edge 48 outer edge 49 end sheet

Claims (15)

  Electronic with a stator (2) with windings and a stator packet (3) and a cup-shaped housing (4), and a permanent magnet rotor (5) housed inside the stator packet (3) A DC motor (1) that is commutated in a static manner, the permanent magnet stator having a shaft (6), a plastic hub (7) and a magnetized permanent magnet (8), the permanent magnet (8) being a plastic hub Electronically rectified, coupled with the shaft (6) by (7) and with the plastic hub (7) having a guide (9) radially projecting beyond the permanent magnet (8) DC motor.   The cup-shaped housing (4) on the one hand has a closed cup bottom (10) and on the other hand a mounting opening (25), the guide (9) being the cup of the permanent magnet rotor (5) Electronically commutated direct current motor according to claim 1, characterized in that it is arranged at the end (11) close to the bottom (10).   Electronically, according to claim 1 or 2, characterized in that the radially projecting guide (9) has a radial extension which is smaller than half of the inner diameter of the stator laminations packet (3). DC motor rectified.   4. An electronically commutated direct current motor as claimed in claim 1, 2 or 3, characterized in that the guide (9) has a ring-like shape.   5. Electronically rectified direct current according to claim 1, 2, 3 or 4, characterized in that the guide (9) has an introduction bevel (14) or a radius towards the cup bottom (10). motor.   A plastic hub (7) is coupled by means of a primary deformation process in a non-pivotable manner relative to the permanent magnet (8) and the shaft (6) in a complementary manner. The electronically rectified direct current motor according to 5.   Stator lamina packet (3) consists of laminated individual lamina (12) and has a central notch which is used as a rotor housing (43) and is chamfered on the individual lamina (12) with the inner edge (13) And the inner edge is facing the mounting opening (25) of the cup-shaped housing (4) and facing away from the cup bottom (10) of the housing (4) Electronically commutated direct current motor according to at least one of the claims 1 to 6, characterized in that   The same individual lamella (12) has on its outer periphery a beveled outer edge (48) facing the mounting opening (25) of the cup-shaped housing (4) and facing the cup bottom (10) The electronically rectified direct current motor according to claim 7, characterized in that it comprises.   The stator lamina packet (3) consists of various lamellae cuts, and a large number of individual laminae (12) have tongues (26) which project into one angular area, by means of which the stator lamina packet (3) Electronically commutating according to claim 7 or 8, characterized in that C.) is clamped in the housing (4), and a large number of other individual lamellae have cutouts in the same angular area. DC motor.   Electronic according to claim 9, characterized in that the plurality of individual laminae, in particular the end laminae (49) at one or both ends of the stator lamina packet (3), have neither tongues nor cutouts. DC motor rectified.   11. The electronically commutated direct current motor according to claim 10, characterized in that the smallest possible clearance remains between the housing (4) and the end plate (49).   In the first part after the end lamellae, the individual lamellae (12) with the tongues (26) and the individual laminae without tongues are continuous with one another and, in the second part, at least two mutually consecutive tongues 12. An electronically commutated direct current motor as claimed in claim 7, 8, 9, 10 or 11, characterized in that the individual lamellae (12) having are replaced by individual lamellae without tongues.   13. At least one of the preceding claims, characterized in that the stator laminations (3) are continuous with an insulation (27), said insulation having receiving pockets (35) for shavings. Electronically rectified DC motor as described.   The electronically commutated direct current motor according to claim 13, characterized in that the sealing edge (47) of the receiving pocket (35) abuts on the housing (4). A stator (2) having windings and a permanent magnet rotor (5) housed inside the stator thin plate packet (3), having a stator thin plate packet (3) and a cup-shaped housing (4); An electron, wherein the permanent magnet rotor has a shaft (6), a plastic hub (7) and a magnetized permanent magnet (8), the permanent magnet (8) being connected to the shaft (6) by a plastic hub (7) In the method of forming a DC motor (1) that is commutatively rectified, the following method steps
a) Prepare the shaft (6) with knurls,
b) prepare a permanent magnet (8) with interlocking geometry;
c) Insert the shaft (6) and the permanent magnet (8) into the cavity of the injection molding tool,
d) injecting a thermoplastic plastic material into the remaining hollow chamber of the cavity, forming a guide (9) with an introduction bevel (14),
e) Remove the permanent magnet rotor (5) from the injection molding machine,
f) magnetize the permanent magnet (8) in the magnetizer,
g) Pull the housing bearing onto the shaft (6),
h) Prepare the housing (4)
i) Prepare the pre-assembled stator (2),
j) Press the stator (2) into the housing (4),
k) Joining the magnetized permanent magnet rotor (5) in advance into the rotor housing (43) by means of the guide (9) and joining the housing bearing (20) into the housing (4)
A method of forming an electronically rectified direct current motor comprising:

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