WO2017008797A1 - Electric motor - Google Patents

Abstract

The invention relates to an electric motor having a housing and a rotor, the rotor being mounted in the housing via a fixed/loose bearing, wherein a deep groove ball bearing having an inner ring and an outer ring is provided as a fixed bearing, and wherein the outer ring of the fixed bearing is elastically clamped by means of a spring steel disk in the housing. The aim of the invention is to provide a deep groove ball bearing that can be mounted with simple means, with as few method steps as possible and a small number of components securely and permanently in a deep-drawn steel housing. This problem is solved according to the invention by the features of claim 1.

Description

 Title: Electric motor

description

The invention relates to an electric motor having a housing and a rotor which is mounted in the housing via a fixed / floating bearing, wherein a deep groove ball bearing with an inner ring and an outer ring is provided as a fixed bearing and the outer ring of the fixed bearing by means of a spring steel disc in the housing elastically clamped is.

The shape of the spring steel disc according to the invention is known per se,

especially in spherical bearings such components are used regularly. An essential difference to the genus of the invention is that with spherical bearings, the shaft exerts no axial moment on the bearing. On the other hand, a large axial load can be transmitted to the bearing in a firmly pressed with the shaft inner ring of a deep groove ball bearing, especially in vibration and impact load.

The object of the invention is to define a deep groove ball bearings with simple means, with as few process steps and few components safely and permanently in a deep-drawn steel housing. This object is achieved by the features of claim 1.

It is proposed that the housing is a deep-drawn steel housing (10) or a deep-drawn steel housing pot, the spring steel disc (5) is hardened, the hardness of the spring steel disc (5) is greater than the hardness of the deep-drawn steel housing (10) and the spring steel disc (5 ) has the form of a clamping ring, which in the region radially outside the outer ring (9) has a

closed ring with radially inwardly directed spring arms (2) which act on the outer ring (9) so that each spring arm (2) with an axial and a radial force component acts on the outer ring (9). Due to the different degrees of hardness of the joining partners, the spring steel disc can (5) dig in a force against the joining direction in the deep-drawn steel housing (10) and find a secure fit. The outer ring (9) of the deep groove ball bearing (8) is mounted axially movable in the steel housing (10) and is held only by the spring steel disc (5). When a force against the joining direction against an axial and radial force component acts on the spring arms (2), whereby these, depending on the amount of force, more or less deflect, whereby the distance between adjacent ends of the spring arms (2) increases slightly. With a closed ring, this effect would lead to breakage of the hardened component. Since the indicated frictional connection has proven to be sufficiently strong, no additional security elements or forming operations are required. Thus, a very simple and effective attachment of the deep groove ball bearing (8) is given.

Further developments of the invention are presented in the subclaims.

It is particularly advantageous if the steel housing (10) is galvanized. The

Zinc layer, which is very thin after deep drawing, nevertheless causes the holding force of the spring steel disc (5) in the steel housing (10) to increase significantly.

It is further claimed that the steel housing (10) has a plurality of cascade-like recesses (1 1, 12, 13) and a first recess (1 1) is radially bounded by a first cylinder jacket (21) and for receiving the spring steel disc (5). This recess (1 1) is dimensioned in diameter so that it is sufficient for receiving the spring steel disc (5).

In addition, it is proposed that the steel housing (10) has a second recess (12) defined radially by a second cylinder jacket (22) whose inside diameter is smaller than the inside diameter of the first recess (11) and in that the second recess (12 ) for receiving the deep groove ball bearing (8). The diameter of the second recess (12) differs from the diameter of the first recess (1 1) so that the spring arms (2) extend radially into the region of the second recess (12), so that the outer ring (9) of the deep groove ball bearing (8) by the spring arms (2) can be held in the axial direction. Finally, it is expedient that the steel housing (10) has a third recess (13), which is bounded radially by a third cylinder jacket (23) and whose inner diameter is smaller than the inner diameter of the second

Cylinder shell (22). This recess (13) is designed so that a cap (1 6) is securely mounted. A cap (16) may be required if a housing opening is required to allow access for an assembly tool for pressing the inner ring onto a motor shaft.

It is particularly important that the outer ring (9) of the deep groove ball bearing (8) axially has a greater dimension than the depth of the second recess (12). Only then is a backlash-free recording of the outer ring (9) in the second recess (12) possible.

Advantageously, it is provided that the spring steel disc (5) rests in the mounted state in the axial direction on a stop (6). The axial position of the stop (6) is decisive for the bias with which the spring arms (2) act on the outer ring (9). Thereby, also due to the dimensional tolerances, the joining partner a definable force within calculable tolerance limits possible.

It is provided that the spring steel disc (5) has a cone-shaped clamping region (4), with which it claws in the mounted state on the inner wall of the first cylinder jacket (21) of the steel housing (10). The hold of the spring steel disc (5) in the steel housing (10) increases in a force against the joining direction due to geometric

Laws, because in the situation shown, the cone-shaped clamping region (4) is urged radially outward, whereby the adhesion is reinforced.

It is expressly claimed that the deep groove ball bearing (8) is held exclusively by the frictional connection of the spring steel disc (5) with the steel housing (10) in order to meet the object of the invention.

Another important advantage of the invention is that the deep groove ball bearing (8) by the spring arms (2) is elastically held. This allows Radial loads are cushioned without a permanent deformation occurs.

Last but not least, it makes sense that a force directed axially from the outer ring (9) of the deep groove ball bearing (8) towards the spring arms (2) in the dismounting direction increases the force acting radially on the first cylinder jacket (21) from the clamping area (4).

It has been shown that the spring arms (2) of the spring steel disc (5) in

unmounted state relative to the disk plane should be inclined by 25 ° to 35 ° that the clamping region (4) of the spring steel disc (5) should be inclined in the unassembled state relative to the disk plane by 35 ° to 45 ° and that the outer diameter of the clamping region (4) the spring steel disc (5) should be in the unmounted state 2% to 4% larger than the inner diameter of the first cylinder jacket (21) to effect an optimal holding force of the spring steel disc (5) and an optimal elastic support of the deep groove ball bearing (8).

The invention also includes such housing, which has more than said number of recesses (1 1, 12, 13). In this case, the term "first depression" would mean the depression in which the spring steel disc (5) is received.

An embodiment of the invention will be explained in more detail with reference to an example. Show it:

1 is a sectional view of a deep-drawn steel housing pot,

2 is a spring steel disc in a plan view, in section and spatially,

Fig. 3 is a partial sectional view of a built-in deep groove ball bearing and

Fig. 4 is an assembly drawing of an electric motor.

1 shows a sectional view of a deep-drawn steel housing 10, with a first recess 1 1 for receiving a spring steel disc 5, a second recess 12 for receiving a deep groove ball bearing 8 and a third recess 13 for forming a stop 6 for the deep groove ball bearing 8. A housing opening. 7 is for one Retainer of a press-in device freigespart. The first recess 1 1 is radially inwardly through a first cylinder shell 21, the second recess 12 through a second cylinder shell 22 and the third recess 13 through a third

Cylinder jacket 23 limited.

Fig. 2 shows the spring steel disc 5 in a plan view, a section and spatially. The spring steel disk 5 is circular in its basic form and has three sections in the radial direction. An outer clamping region 4 is tapered cone-shaped. A middle stop ring portion 3 is aligned in the mounted state perpendicular to a motor shaft. Inner spring arms 2 form part surfaces of a conical surface in their entirety. The spring arms 2 are separated by slot-like recesses 14. The recesses 14 extend into the stop ring area 3.

Fig. 3 shows an assembly drawing with the steel housing 10, the

Deep groove ball bearing 8 and the spring steel disc 5. As can be clearly seen, the deep groove ball bearing 8 protrudes from the second recess 12, so that the

Spring steel plate 5 with its spring arms 2 rests on an edge of an outer ring 9 of the deep groove ball bearing 8 and can exert a radial and an axial force component on the outer ring 9. The spring steel disc 5 is in a first

Well 1 1 and the deep groove ball bearing 8 is in a second recess 12th

added. The spring steel disc 5 is clamped with its clamping region 4 on the first cylinder jacket 21 (see FIG. 1). To make this possible, is the

Spring steel disc 5 cured so that its material is harder compared to the steel housing 10. With its stop ring area 3, the spring steel disc 5 bears against the stop 6 of the steel housing 10.

Fig. 4 shows an assembly drawing of an electric motor 1 with the as

Fixed bearing deep groove ball bearing 8, which is fixed to the spring steel disc 5 and acting as a floating bearing 15 second ball bearing. Next is one

Cover cap 1 6 shown, which is secured in the recess 14. The electric motor 1 shown in the application example is an electronically commutated DC motor which has a rotor 18 equipped with permanent magnets 27, a stator 19 wound with a winding 24, and a Housing, which consists of a bearing plate 20 and the steel housing 10 has. The rotor 18 consists of a smooth shaft 25, a rotor core 26, the permanent magnet 27 and a Geberpolrad 28, which is held on a carrier 33 which is axially pressed into recesses 34 of the rotor core 26. Further, a laminated stator core 29, a gear pump 30, a printed circuit board 31, a sensor 17 and a plug 32 are shown.

Electro-motor PCB Spring arm Plug Stop ring area Carrier

Clamping area recesses spring steel disc

attack

housing opening

Deep groove ball bearings

outer ring

steel case

first recess

second recess

third recess

cutout

movable bearing

cap

sensor

rotor

stator

end shield

first cylinder jacket

second cylinder jacket

third cylinder jacket

winding

wave

 Laminated core

 permanent magnet

Geberpolrad

stator lamination

gear pump

Claims

claims 1 . Electric motor (1) having a housing and a rotor (18) mounted in the  Housing is mounted on a fixed / floating bearing, wherein a deep groove ball bearing (8) with an inner ring and an outer ring (9) is provided as a fixed bearing and the outer ring (9) of the fixed bearing by means of an annular  Spring steel disc (5) is elastically clamped in the housing, characterized in that the housing is a deep-drawn steel housing (10) or a deep-drawn steel housing pot, the spring steel disc (5) is hardened, the hardness of the spring steel disc (5) is greater than the hardness of the deep-drawn Steel housing (10) and the spring steel disc (5) has the shape of a clamping disc, which in the region radially outside the  Outer ring (9) has a closed ring with radially inwardly directed spring arms (2) which act on the outer ring (9) so that each spring arm (2) with an axial and a radial force component acting on the outer ring (9). 2. Electric motor (1) according to claim 1, characterized in that the  Steel housing (10) is galvanized. 3. Electric motor (1) according to claim 1 or 2, characterized in that the steel housing (10) has a plurality of cascade-like recesses (1 1, 12, 13) and a first recess (1 1) radially through a first  Cylinder jacket (21) is limited and serves to receive the spring steel disc (5). 4. Electric motor (1) according to claim 3, characterized in that the  Steel housing (10) has a second, radially by a second cylinder jacket (22) limited recess (12) whose inner diameter is smaller than the inner diameter of the first recess (1 1) and that the second recess (12) for receiving the deep groove ball bearing (8). 5. Electric motor (1) according to claim 4, characterized in that the Steel housing (10) has a third recess (13) which radially through a third cylinder jacket (23) is limited and whose inner diameter is smaller than the inner diameter of the second cylinder jacket (22). 6. Electric motor (1) according to claim 1, 2, 3, 4 or 5, characterized in that the outer ring (9) of the deep groove ball bearing (8) has a greater axial extent than the depth of the second recess (12). 7. Electric motor (1) according to claim 1, 2, 3, 4, 5 or 6, characterized  characterized in that the spring steel disc (5) rests in the assembled state in the axial direction of a stop (6). 8. Electric motor (1) according to claim 1, 2, 3, 4, 5 or 6, characterized  characterized in that the spring steel disc (5) has a conical jacket-shaped clamping region (4), with which the spring steel disc (5) in the mounted state on the inner wall of the first cylinder jacket (21) of the steel housing (10) festkrallt. 9. Electric motor (1) according to at least one of the preceding claims,  characterized in that the deep groove ball bearing (8) exclusively by the frictional connection of the spring steel disc (5) with the  Steel housing (10) is held. 10. Electric motor (1) according to at least one of the preceding claims,  characterized in that the deep groove ball bearing (8) by the spring arms (2) is elastically held. 1 1. Electric motor (1) according to at least one of the preceding claims,  characterized in that one of the outer ring (9) of the  Deep groove ball bearings (8) axially on the spring arms (2) directed force in  Dismantling direction radially from the clamping area (4) to the first  Cylinder shell (21) acting force increases. 12. Electric motor (1) according to at least one of the preceding claims, characterized in that the spring arms (2) of the spring steel disc (5) are inclined in the unmounted state relative to the disk plane by 25 ° to 35 °. 13. Electric motor (1) according to at least one of the preceding claims, characterized in that the clamping region (4) of the spring steel disc (5) is inclined in the unmounted state relative to the disk plane by 35 ° to 45 °. 14. Electric motor (1) according to at least one of the preceding claims,  characterized in that the outer diameter of the clamping region (4) of the spring steel disc (5) in the unmounted state is 2% to 4% greater than the inner diameter of the first cylinder jacket (21).