Rotor for external rotor electric machine

Abstract

Described is a rotor for an external rotor electric machine, comprising an annular lamination (1) made of steel, permanent magnets (2) attached to the inside of the lamination (1), and a carrier part (3) having a hub (4) for a shaft and attached to the lamination (1). According to the utility model, the provided connecting rod (6) passes through the bearing component (3) and the laminations (1) along the axial direction, and pulls the laminations (1) towards the bearing component (3).

Description

Technical Field

[0001] The utility model relates to a rotor for an outer rotor motor. Background Art

[0002] In a rotor for an outer rotor motor, a back iron ring formed by a stack of sheets of ferromagnetic material (such as steel) must be connected to a bearing member having a hub for the shaft. During operation, this connection must be able to transfer a relatively large torque from the sheets to the bearing member and prevent the sheets from moving axially relative to the bearing member. Summary of the Utility Model

[0003] The object of the utility model is to show how this can be achieved reliably and economically.

[0004] According to the utility model, the rotor has a connecting rod that projects axially through the bearing member and the sheets and pulls the sheets towards the bearing member. When the individual sheets are punched, suitable openings can be made for the connecting rod without additional cost. The connecting rod can be designed as a pin that projects through the openings in the sheets and the matching openings in the bearing member and has end pieces at at least one end that are wider than the channels formed by the openings. For example, the end pieces can be attached to the pin by rivets. These rivets can be integrated with the connecting rod, i.e., suitable for forming the ends of the connecting rod, or separate rivets. The end pieces can also be designed as removable end pieces. One possibility is that the end pieces are screwed onto matching threads on the pin, such as nuts. Another possibility is to form the removable end pieces as clips or clamps.

[0005] The connecting rod can be designed as a pin with removable end pieces at both ends. However, the pin may also have a removable end piece only at one end and a head at the other end that is wider than the channel formed by the openings in the sheet and the bearing member.

[0006] An advantageous improvement of the utility model is that the provided sheets have end rings at the ends facing away from the bearing member, the end rings forming axial stops for the permanent magnets, and the connecting rod also passes through the end rings. In this way, the permanent magnets arranged inside the sheets can be easily fixed to prevent axial movement.

[0007] Another improvement of the utility model is that openings are provided in the metal sheets through which the connecting rod projects, each opening having a circular main region and a slot extending from the main region. The connecting rod substantially completely fills the main region. For example, the circular main region can be a circular surface or have a slightly different shape. The slot extending from the main region can effectively prevent the connecting rod from rotating during tightening of the end piece, for example, by the nose end of the connecting rod head engaging with the slot.

[0008] For example, the length of the slot is between half the width and the entire width of the main opening area, i.e., in the case of a circular main area, between the radius and the diameter. For example, the width of the slot can be between 20% and 40% of the width of the main opening area, i.e., in the case of a circular main area, between 10% and 40% of the diameter of the main area. Description of the Drawings

[0009] More details and advantages of the present utility model will be described with reference to the drawings and in conjunction with the embodiments.

[0010] Figure 1 The rotor of an outer rotor motor is shown;

[0011] Figure 2 A cross-sectional detail view of the rotor is shown; and

[0012] Figure 3 A detailed view of the components of the rotor is shown. Detailed Description of the Invention

[0013] Figure 1 The rotor for an electric motor (more specifically, an outer rotor motor) is shown. The rotor includes a lamination 1 composed of annular ferromagnetic steel sheets, a permanent magnet 2 attached to the inner side of the lamination 1, and a carrier member 3 attached to the lamination 1. The carrier member 3 has a hub 4 for the shaft, which is not shown in the figure. For example, the carrier member 3 can be made of aluminum or an aluminum-based alloy. The sheets in the lamination 1 are made of electrical steel, i.e., soft magnetic steel, such as silicon steel, and are stacked on top of each other in the axial direction. Therefore, the sheet planes of the respective sheets extend perpendicular to the axial direction.

[0014] Each sheet in the lamination 1 can be an annular sheet or each sheet forms only one annular segment.

[0015] The lamination 1 can carry an end ring 5 at the end facing away from the carrier member 3. The end ring 5 forms an axial stop for the permanent magnet 2 and fixes the permanent magnet 2 to prevent its axial movement.

[0016] For example, the permanent magnet 2 can be made of a material based on Nd 2 Fe 14 B and is attached to the lamination 1 by an adhesive, especially in a groove on the inner side of the lamination 1. Another possibility is that the permanent magnet 2 is attached to the lamination 1 by clamping.

[0017] The lamination 1, the carrier member 3, and the end ring 5 are connected by a connecting rod 6. As shown in the cross-sectional view of Figure 2 , the connecting rod 6 projects axially through the carrier member 3, the lamination 1, and the end ring 5. The connecting rod 6 pulls the lamination 1 towards the carrier member 3 and fixes the lamination 1, the carrier member 3, and the end ring 5 to each other.

[0018] The connecting rod 6 is designed as a pin, each pin being arranged in a passage through the lamination 1 and the bearing member 3 and having a detachable end piece 9 at at least one of its ends that is wider than the passage. For example, the end piece 9 can be screwed onto the thread of the connecting rod 6. Corresponding end pieces 9 can be attached to both ends of the connecting rod 6. In the illustrated embodiment, the connecting rod 6 has a detachable end piece 9 only at one end and a head 6a at the other end that is wider than the passage.

[0019] In particular, as Figure 3 shown, the passage is formed by aligned openings 11, 12, 13 in the bearing member 3, the lamination 1, and the end ring 5.

[0020] Figure 3 The assembly of the rotor is shown, namely details of one of the annular sheets 8 forming the lamination 1, details of the bearing member 3, details of the end ring 5, and the connecting rod 6 with the detachable end piece 9.

[0021] The opening 12 in the lamination 1 and the opening 13 in the end ring 5 have a substantially circular main area from which radially inward slots extend. For example, the slots have a width that is one quarter to one half of the diameter of the main area, particularly 15% to 30%, and a length that is one third to one half of the diameter of the main area. During assembly, the lugs of the head 6a can engage with the slots, thereby preventing the connecting rod 6 from rotating when the end piece 9 is screwed on.

[0022] List of reference numerals

[0023] 1 Lamination;

[0024] 2 Permanent magnet;

[0025] 3 Bearing member;

[0026] 4 Hub;

[0027] 5 End ring;

[0028] 6a Head;

[0029] 6 Connecting rod;

[0030] 8 Sheet;

[0031] 9 End piece;

[0032] 11 Opening;

[0033] 12 Opening;

[0034] 13 Opening.

Claims

1. A rotor for an outer rotor motor, comprising: Annular steel lamination (1); A permanent magnet (2) fixed to the inner side of the lamination (1); as well as A carrier component (3) having a hub (4) for the shaft and fastened to the lamination stack (1), characterized in that: A connecting rod (6) protrudes axially through the bearing component (3) and the laminate (1) and pulls the laminate (1) toward the bearing component (3).

2. The rotor according to claim 1, characterized in that The connecting rods (6) are designed as pins, each of which is arranged in a channel passing through the laminate (1) and the supporting member (3) and has an end piece (9) at at least one end with a width greater than the width of the channel.

3. The rotor according to claim 2, characterized in that The end piece (9) is detachable.

4. The rotor according to claim 2, characterized in that The two ends of the pin are provided with detachable end pieces (9).

5. The rotor according to claim 2, characterized in that One end of the pin has a widened head (6a) having a greater width than the channel.

6. The rotor according to claim 3, characterized in that The connecting rod (6) is a threaded pin and the end piece (9) is screwed onto the pin.

7. The rotor according to claim 1, characterized in that The lamination stack (1) has an end ring (5) at the end facing away from the carrier part (3), which forms an axial stop for the permanent magnet (2) and through which the connecting rod (6) also protrudes.

8. The rotor according to claim 1, characterized in that The laminate (1) is formed by a thin sheet (8) having a plurality of openings (12) for the connecting rods (6), wherein the openings (12) each have a circular main area and a groove extending from the main area.

9. The rotor according to claim 8, characterized in that The grooves are directed radially inwards.

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