Drive, in particular electric motor
Patent Information
- Application Number
- EP2023706530
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-02-15
- Filing Date
- 2023-01-23
- Publication Date
- 2024-12-25
AI Technical Summary
Existing electric motor drives lack a high degree of protection against vibrations and contamination, as conventional sealing methods fail to achieve tightness due to unmachined raw casting surfaces, leading to inefficiencies in vibration damping and protection against external particles.
The electric motor drive incorporates a metal casting stator housing with a frame-shaped adapter and an injection-molded part that acts as a damping element, positioned in a recess with unmachined raw casting surfaces, providing vibration damping and contamination protection without achieving tightness, while cable bushings and secure fastening mechanisms enhance stability and prevent particle ingress.
The solution effectively dampens vibrations and prevents large dirt particles from entering the motor, while maintaining cost-effective production and stability, allowing for secure fastening and independent cooling of the stator and power electronics.
Smart Images
Figure 1.1
Abstract
Description
[0001] Drive, especially electric motor
[0002] Description:
[0003] The invention relates to a drive, in particular an electric motor.
[0004] It is common knowledge that a drive must be powered electrically.
[0005] From DE 10 2009 008 703 A1, a terminal box for an electrical machine is known as the closest prior art.
[0006] A series of electric motors is known from DE 10 2004 063 920 A1.
[0007] The invention is therefore based on the object of developing a drive with a high degree of protection.
[0008] According to the invention, the object is achieved by the drive according to the features specified in claim 1.
[0009] Important features of the invention in the drive, in particular an electric motor, are that the drive has a stator housing and an adapter connected to the stator housing, in particular a frame-shaped adapter, in particular an adapter frame or frame, wherein the stator housing is connected to a bearing plate which accommodates a bearing of a rotor shaft of the drive, in particular for rotatably supporting the rotor shaft, wherein the adapter is connected on its side facing away from the stator housing to a lower part which, with a cover part placed on the lower part, forms a terminal box of the drive, wherein the adapter is produced as a cast part made of metal and / or the stator housing is produced as a cast part made of metal, wherein on the side of the adapter facing the stator housing, a recess is formed which runs around the adapter, in particular which is completely and / or closed,wherein the recess has a bottom region and two wall regions adjacent to the bottom region, wherein an injection-molded part is received in the recess and rests against a surface region of the stator housing, in particular so that the injection-molded part is elastically deformed,
[0010] - wherein the surface area is unmachined, i.e. is an unmachined raw casting surface area, and / or wherein the recess, in particular the bottom area and the two wall areas, is or are unmachined, i.e. is or are a respective unmachined raw casting surface area.
[0011] The advantage here is that the injection-molded part acts as a dampening element, absorbing vibrations from the adapter against the stator housing. This means that the protruding part of the adapter is dampened. Although the injection-molded part is arranged in a recess similar to a groove, similar to a seal, it does not seal because, unlike a groove, the groove base and wall areas are unmachined and therefore raw casting surfaces. Due to the roughness of the raw casting surfaces, sealing cannot be achieved. However, vibrations from the adapter against the stator housing can be dampened. The drive is therefore designed with a high degree of protection because, in addition to the seals, the injection-molded part fits so tightly against the stator housing and the adapter that correspondingly large dirt particles are prevented from penetrating the area between the stator housing and the adapter.
[0012] In an advantageous embodiment, the adapter and the lower part are designed as a single piece, in particular as a one-piece, in particular as a cast part. This is advantageous in that simple, cost-effective production is possible and machining of the seat and the contact surface of the injection-molded part is not necessary. The injection-molded part thus lies in contact with raw casting surface areas. In particular, this does not result in a high level of tightness, but vibration damping can be achieved. In an advantageous embodiment, cable bushings for the passage of electrical supply lines and data bus lines are arranged in the lower part. It is advantageous in this case that the lower part together with the cover part forms the connection box and the supply lines lead through the cable bushings to connection devices, in particular connection terminals, which are accommodated in the lower part.
[0013] In an advantageous embodiment, the injection-molded part is a plastic injection-molded part. This allows for simple, cost-effective production.
[0014] In an advantageous embodiment, the injection-molded part is an elastomer. This allows for damping of vibrations in the area of the adapter that extends beyond the stator housing.
[0015] In an advantageous embodiment, the respective raw casting surface area is not machined. This is advantageous because it enables cost-effective production.
[0016] In an advantageous embodiment, the surface region is flat, wherein the normal direction of this flat surface region has a first angle to a first direction, the amount of which is between 10° and 80°, wherein the first direction is aligned parallel to the direction of a bore axis of a threaded bore of the bearing plate or the stator housing, wherein a connecting screw is screwed into the threaded bore, which presses the adapter towards the stator housing, in particular wherein the connecting screw is pushed through a sealing ring which bears against the stator housing. It is advantageous in this case that the pressing force generated by the screws has a normal component and a component perpendicular thereto, so that in operative connection with a correspondingly inversely inclined contact surface only the two normal components then result.This allows the adapter to be securely attached to the stator housing and / or bearing plate. Slipping along the contact surface is prevented. Overall, this increases service life because the drive is more stable against external forces than if the normal direction of the contact surface were aligned parallel to the first direction, in particular, the direction of the clamping force of the screws.
[0017] In an advantageous embodiment, a first of the two wall sections is shorter, particularly along the first direction, than the second of the two wall sections. This is advantageous because the shorter wall section can be made stiffer, thus achieving high stability.
[0018] In an advantageous embodiment, the adapter is tapered toward the stator housing, in particular so that the maximum area enclosed by the adapter in a plane whose normal direction is parallel to the first direction, in particular the mounting direction, increases monotonically with increasing distance of the plane from the stator housing. It is advantageous in this case that the terminal box can be made wider than the connection area of the adapter on the stator housing.
[0019] In an advantageous embodiment, the injection-molded part rests against a further surface region of the stator housing, the further surface region being flat, the normal direction of this flat further surface region having a second angle to the first direction which is inverted to the first angle, in particular thus having the opposite sign of the first angle, the first direction being aligned parallel to the direction of a bore axis of a threaded bore in the bearing plate or the stator housing, a connecting screw being screwed into the threaded bore, which presses the adapter towards the stator housing. It is advantageous in this case that the contact surface of the further surface region is inclined in the opposite direction to the inclination of the contact surface of the first surface region. This ensures that the adapter rests securely on the stator housing.
[0020] In an advantageous embodiment, the bearing plate and / or the stator housing has a continuous recess through which an electrical line is led from the interior of the stator housing, in particular from a stator winding arranged in the stator housing, to a connecting device, in particular a connecting terminal, which is accommodated in the lower part, wherein a flat gasket is pressed onto the bearing plate and / or the stator housing by a fastening means, wherein the electrical line is led through an opening, in particular a cross-shaped, continuously slotted area of the flat gasket, in particular wherein the recess opens into the opening and / or the fastening means is a sheet metal part which is pressed onto the flat gasket by two screws, wherein the screws are screwed into threaded holes in the bearing plate or stator housing.The advantage here is that the electrical cable can be led out of the interior of the stator in a sealed manner.
[0021] In an advantageous embodiment, the cover part has signal electronics that are connected by means of a plug connection to power electronics that function as an inverter and feed the stator winding via at least the electrical line. Advantageously, power electronics and signal electronics can be arranged in the junction box, with the signal electronics being heat-dissipated via the cover part and the power electronics being thermally connected to the lower part. The signal electronics are electrically connected to the power electronics via a plug connection. This allows the power electronics and signal electronics to be operated at different temperature levels. The injection-molded part creates an air cushion between the lower part and the stator housing, acting as a thermal barrier between the stator housing and the power electronics. The injection-molded part also functions as a partial thermal barrier between the adapter and the stator housing.In this way, the stator can be cooled more independently of the power electronics, especially towards the environment.
[0022] In an advantageous embodiment, tab areas are formed on the injection-molded part, each of which protrudes through a respective interruption in the wall area, in particular the shorter of the two wall areas, wherein the respective tab area is widened on the side of the wall area, in particular the shorter of the two wall areas, facing away from the recess, in particular for the positive locking of the injection-molded part in the adapter, wherein the respective tab area is elastically clamped in the respective interruption in the wall area, in particular the shorter of the two wall areas. The advantage here is that the injection-molded part is secured in a positive locking manner. The tab areas are only clamped in the area of the interruption and thus elastically deformed.The inwardly projecting, widened part of the tab area is not elastically deformed, in particular it is spaced apart from the stator housing and bearing plate, in particular since this part projects into a free space area, in particular within the adapter.
[0023] In an advantageous embodiment, the injection-molded part is delimited in the recess on one side by the adapter and on the other side by the stator housing and / or bearing plate, in particular to prevent slipping out in or against the first direction, in particular the mounting direction. It is advantageous that the injection-molded part is secured with a positive fit.
[0024] In an advantageous embodiment, the wall areas, especially those with the recess, are also designed to extend all the way around. This is advantageous because the wall areas, together with the recess, are designed to extend all the way around the outer edge of the adapter. This allows for the largest possible surface area to be enclosed and protected. Furthermore, the damping effect of the injection-molded part is optimized due to the greatest possible leverage.
[0025] In an advantageous embodiment, the wall regions are spaced apart from the stator housing and / or the bearing plate, such that the injection-molded part rests against the stator housing or bearing plate, but not the adapter with its wall regions. It is advantageous in this case that the injection-molded part rests against the stator housing to dampen vibrations of the adapter to the stator housing, but not the adapter with its wall regions. Further advantages emerge from the subclaims. The invention is not limited to the combination of features in the claims. A person skilled in the art will recognize further useful combinations of claims and / or individual claim features and / or features of the description and / or the figures, particularly from the problem and / or the problem arising from a comparison with the prior art.
[0026] The invention will now be explained in more detail using schematic illustrations:
[0027] Figure 1 shows an exploded side view of a first drive according to the invention with an injection-molded part 2 and an adapter 3 provided for receiving this injection-molded part 2.
[0028] Figure 2 shows an enlarged section of the injection-molded part 2 with tab area 9.
[0029] Figure 3 shows a top view with frame-like adapter 3.
[0030] Figure 4 shows the top view with the adapter 3 hidden but with the injection-molded part 2 still present.
[0031] Figure 5 shows the drive in an oblique view.
[0032] Figure 6 shows the drive in plan view.
[0033] Figure 7 shows a sectional view of the drive.
[0034] Figure 8 shows an enlarged section of Figure 7.
[0035] As shown in the figures, the drive comprises an electric motor having a stator housing 1 which surrounds the stator winding of the electric motor in a housing-forming manner.
[0036] The electric motor has a bearing plate on both axial sides to accommodate a bearing for the rotatable support of the rotor shaft. The axial direction is parallel to the rotor shaft's axis of rotation.
[0037] A frame-like adapter is placed on a first bearing plate 8, onto which a lower part of a terminal box is placed, so that the adapter 3 is arranged between the lower part 4 and the bearing plate 8.
[0038] A cover part 5 is placed on the lower part, which comprises power electronics and signal electronics.
[0039] The stator winding is supplied by the power electronics, which includes an inverter whose power semiconductor switches receive their control signals from the signal electronics. This allows the electric motor, in particular its speed or torque, to be controlled or regulated.
[0040] In the lower part 4, connection devices, in particular connection terminals, for supply lines are arranged.
[0041] The adapter 3 protrudes axially from the axial area covered by the bearing shield. Thus, it at least partially projects beyond the stator housing 1.
[0042] The bearing plate 8 and / or the stator housing 1 has or have continuous recesses through which electrical lines, in particular winding wire ends of the stator winding, lead from the interior of the stator housing 1 to a connecting device, in particular a connecting terminal, accommodated in the lower part 4.
[0043] A flat gasket 6 is placed on the bearing plate 8. This gasket has two spaced-apart, cross-slotted passages through which the electrical lines pass. Preferably, the flat gasket is pressed against the bearing plate by sheet metal pieces, with screw heads screwed into threaded holes in the stator housing pressing the flat gasket 6 against the bearing plate 8. Thus, the electrical lines pass through the flat gasket 6, sealing off the interior of the stator from the interior of the terminal box and from the interior area surrounded by the adapter 3.
[0044] The injection-molded part 2 is received in a circumferential recess on the adapter 3 and is pressed against the surface of the bearing plate 8 and / or the stator housing 1. The bearing plate 8 and the stator housing 1 are each designed as a cast part.
[0045] The surface of the stator housing 1 is unmachined in the area where the injection-molded part 2 touches the surface. In particular, the surface roughness in this area corresponds to that of a raw casting. As a result, even if the injection-molded part 2 is made of an elastomer, in particular a plastic, a high degree of sealing, and thus a particularly high degree of protection, cannot be achieved.
[0046] However, it provides a seal against larger particles.
[0047] Cable bushings for supply lines, in particular three-phase lines and data bus lines as well as low-voltage lines, are arranged on the sides of the lower part 4.
[0048] The circumferential recess on adapter 3 is also unmachined and thus designed with a roughness corresponding to the raw casting.
[0049] As can be seen in Figure 8, the recess has a base region and two wall regions, similar to a groove, which has a groove base and two groove walls. The first of the wall regions is shorter than the other of the two wall regions.
[0050] The surface area contacted by the injection-molded part 2 on the stator housing 1 is indeed flat; however, the normal direction of the flat surface area is not parallel to the direction in which the cover part 5 is placed on the lower part 4 and to the direction in which the lower part 4 is placed on the adapter 3.
[0051] The mounting direction is the direction in which the lower part 4 is mounted on the adapter 3 and / or in which the adapter 3 is mounted on the bearing plate 8 and / or in which the cover part 5 is mounted on the lower part 4. In particular, the mounting direction is parallel to the line connecting the center of gravity of the lower part with the center of gravity of the frame 3 and / or with the cover part 5.
[0052] Due to this oblique, in particular non-vertical, alignment of the contact surface of the stator housing 1 or the bearing plate 8 to the mounting direction, the wall areas are designed with different lengths.
[0053] The injection-molded part 2 is inserted into the circumferential recess. The wall regions are thus also designed to be circumferential, with the shorter wall region having an interruption at several points through which a respective tab region 9 formed on the injection-molded part 2 protrudes. Each of these tab regions 9 is widened, so that the injection-molded part 2 is elastically clamped in the respective interruption at the respective points and, due to the widened design of the tab region 9, is held in a form-fitting manner on the shorter wall region in the interior region surrounded by the adapter 3.
[0054] Slipping out in or against the mounting direction is prevented by the fact that the injection-molded part is limited in the recess on the one hand by the adapter 3 and on the other hand by the stator housing 1.
[0055] In this way, the injection-molded part 2 dampens vibrations in the area of the adapter 3 that extends beyond the stator housing 1. The angled design of the contact surface on the stator housing 1 dampens not only vibrations aligned in the direction of contact, but also vibrations perpendicular to it. Thus, the injection-molded part 2 acts as a damping element and additionally prevents contaminants from penetrating the adapter 3.
[0056] From the external environment to the interior area surrounded by the stator housing 1, contaminants such as grains of sand, dust or the like must not only overcome the injection-molded part 2 but also the flat gasket 6.
[0057] The area of the adapter 3 projecting beyond the stator housing 1 and / or the lower part 4 with the cover part 5 placed thereon is additionally secured with screws not shown in the figures, which are screwed into threaded holes in the stator housing. The screws extend through sealing rings 7, so that the interior of the stator is sealed from the interior of the frame 3 and / or the terminal box.
[0058] Thus, although the screws do improve stability and / or rigidity, the adapter 3 does not rest directly against the stator housing 1, so that the injection-molded part 2 acts as a damping part. The adapter 3 is tapered towards the stator housing 1. Thus, the maximum area enclosed by the adapter 3 in a plane whose normal direction is parallel to the mounting direction increases monotonically with increasing distance from the stator housing 1. In further embodiments according to the invention, the adapter 3 and the lower part 4 are designed as a single piece, in particular as a single part. However, a specially adapted part must then be provided for a stator housing 1 of a selected size.
[0059] List of reference symbols
[0060] 1 Stator housing 2 Injection-molded part
[0061] 3 frame-like adapter
[0062] 4 Lower part
[0063] 5 Lid part
[0064] 6 Flat gasket 7 Sealing ring
[0065] 8 Bearing shield
[0066] 9 Tab area
[0067] 10 groove wall
[0068] 50 screw
Claims
Patent claims:
1. Drive, in particular electric motor, comprising a stator housing and an adapter connected to the stator housing, in particular a frame-shaped adapter, in particular an adapter frame or frame, wherein the stator housing is connected to a bearing shield which receives a bearing of a rotor shaft of the drive, in particular for rotatable mounting of the rotor shaft, wherein the adapter is connected on its side facing away from the stator housing to a lower part which, together with a cover part placed on the lower part, forms a terminal box of the drive, wherein the adapter is made as a metal casting and / or the stator housing is made as a metal casting, characterized in that a recess is formed on the side of the adapter facing the stator housing, in particular a completely and / or fully circumferential recess, wherein the recess has a bottom region and two wall regions adjacent to the bottom region.wherein an injection-molded part is received in the recess and rests against a surface area of the stator housing, in particular such that the injection-molded part is elastically deformed, - wherein the surface area is unmachined, i.e., an unmachined raw casting surface area, and / or wherein the recess, in particular the bottom area and the two wall areas, is or are unmachined, i.e., a respective unmachined raw casting surface area.
2. Drive according to claim 1, characterized in that the adapter and the lower part are made in one piece, in particular as a cast part.
3. Drive according to one of the preceding claims, characterized in that cable glands for the passage of electrical supply lines and data bus lines are arranged in the lower part.
4. Drive according to one of the preceding claims, characterized in that Injection molded part is a plastic injection molded part.
5. Drive according to one of the preceding claims, characterized in that the injection-molded part is an elastomer.
6. Drive according to one of the preceding claims, characterized in that the respective raw casting surface area is not machined.
7. Drive according to one of the preceding claims, characterized in that the surface area is flat, wherein the normal direction of this flat surface area has a first angle to a first direction, the magnitude of which is between 10° and 80°, wherein the first direction is aligned parallel to the direction of a bore axis of a threaded bore of the bearing shield or the stator housing, wherein a connecting screw is screwed into the threaded bore, which presses the adapter towards the stator housing, in particular wherein the connecting screw is inserted through a sealing ring which rests against the stator housing.
8. Drive according to one of the preceding claims, characterized in that a first of the two wall areas is shorter, in particular along the first direction, than the second of the two wall areas.
9. Drive according to one of the preceding claims, characterized in that the adapter is designed to taper towards the stator housing, in particular such that the maximum area enclosed by the adapter in a plane whose normal direction is parallel to the first direction, in particular the mounting direction, increases monotonically with increasing distance of the plane from the stator housing.
10. Drive according to one of the preceding claims, characterized in that the injection-molded part rests against a further surface area of the stator housing, the further surface area being flat, wherein the normal direction of this flat further surface area has a second angle to the first direction, which is inverted to the first angle, in particular having the opposite sign of the first angle, wherein the first direction is aligned parallel to the direction of a bore axis of a threaded bore of the bearing shield or the stator housing, wherein a connecting screw is screwed into the threaded bore, which presses the adapter towards the stator housing.
11. Drive according to one of the preceding claims, characterized in that the bearing shield and / or the stator housing has a continuous recess through which an electrical conductor is led from the interior of the stator housing, in particular from a stator winding arranged in the stator housing, to a connection device, in particular a terminal block, which is received in the lower part, wherein a flat gasket is pressed against the bearing shield and / or the stator housing by a fastening means, wherein the electrical conductor is led through an opening, in particular a cross-shaped continuously slotted area of the flat gasket, in particular wherein the recess opens into the opening and / or the fastening means is a sheet metal part which is pressed against the flat gasket by two screws, wherein the screws are screwed into threaded bores of the bearing shield or stator housing.
12. Drive according to one of the preceding claims, characterized in that the cover part has signal electronics which are connected by means of a plug connection to power electronics which function as an inverter and which feeds the stator winding by means of at least the electrical line.
13. Drive according to one of the preceding claims, characterized in that tab areas are formed on the injection-molded part, which each project through a respective interruption of the wall area, in particular the shorter of the two wall areas, wherein the respective tab area is formed wider on the side of the wall area, in particular the shorter of the two wall areas, facing away from the recess, in particular for positive locking of the injection-molded part in the adapter, wherein the respective tab area is elastically clamped in the respective interruption of the wall area, in particular the shorter of the two wall areas.
14. Drive according to one of the preceding claims, characterized in that the injection-molded part is limited in the recess on one side by the adapter and on the other side by the stator housing and / or bearing shield, in particular to prevent slipping out in or against the first direction, in particular in or against the insertion direction.
15. Drive according to one of the preceding claims, characterized in that the wall areas, in particular with the recess, are also designed circumferentially, and / or that the wall areas are spaced away from the stator housing or the bearing shield, in particular so that the injection-molded part rests against the stator housing or bearing shield, but in particular not the adapter with its wall areas.