Drive having an electric motor
Patent Information
- Application Number
- EP2023713066
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-04-04
- Filing Date
- 2023-03-16
- Publication Date
- 2025-02-12
AI Technical Summary
Existing electric motor drives face challenges in achieving high performance and safe operation due to inadequate cooling systems, which can lead to overheating and reduced reliability.
The integration of a sealed cooling circuit within the bearing flange of the electric motor, utilizing parallel blind hole-like bores and sealing plugs, allows for efficient heat dissipation and thermal protection without additional parts, while using copper-containing pipes for enhanced safety and corrosion prevention.
This solution enables secure, efficient cooling of the bearing and shaft seal, reducing the risk of overheating and extending the operational lifespan of the motor, while minimizing additional components and ensuring effective heat transfer.
Smart Images
Figure 1.1
Abstract
Description
[0001] Drive with electric motor
[0002] Description:
[0003] The invention relates to a drive with an electric motor.
[0004] It is generally known that a drive with an electric motor is possible.
[0005] The closest state of the art is a liquid-cooled electric motor known from CN 2 10 867 385 U.
[0006] From DE 203 17 814 U1 an electric motor with bearing shields having cooling channels is known.
[0007] An electric motor with cooling channels is also known from CN 2 10 578 071 U.
[0008] A linear drive is known from DE 10 2014 003 758 A1.
[0009] An electric motor with flange cooling is known from DE 102 47 199 A1.
[0010] From DE 10 2018 009 165 A1 a hydraulically actuated clamping device with a block part, a piston and a clamping part is known.
[0011] A liquid-cooled servo motor is known from JP 2010-124 558 A.
[0012] The invention is therefore based on the object of developing a drive with an electric motor, whereby a high performance and safe operation of the drive should be achievable.
[0013] According to the invention, the object is achieved in the drive according to the features specified in claim 1. Important features of the invention in the drive with an electric motor are that the electric motor has a bearing flange and a rotor shaft, wherein a bearing is accommodated in the bearing flange, by means of which bearing the rotor shaft is rotatably mounted, in particular on both sides of the bearing receptacle of the bearing formed in the bearing flange, two blind hole-like bores, in particular longitudinal bores, which are aligned parallel to one another are introduced into the bearing flange and each open into a blind hole drilled in the bearing flange, wherein the blind hole is closed, in particular tightly closed, from the environment by means of a single closure plug screwed into the blind hole, in particular into an internally threaded area of the blind hole.
[0014] The advantage here is that a cooling circuit is integrated into the bearing flange, thus securely sealing the cooling circuit from the interior of the electric motor. Furthermore, heat can be dissipated and efficient cooling is achieved, particularly thermal protection for the bearing and the shaft seal, which are housed in the bearing flange. Furthermore, no additional parts are required except for the sealing plugs. The cooling circuit is not enclosed within the bearing flange, but is designed as a complete cooling circuit together with the pipes connected to the bores.
[0015] In an advantageous embodiment, the area covered by the blind hole in the axial direction overlaps with the area covered by a shaft sealing ring accommodated in the bearing flange in the axial direction, in particular wherein the distance between the blind hole and the shaft sealing ring is smaller than the diameter of the blind hole, in particular wherein the electric motor has a stator winding and wherein the
[0016] Shaft sealing ring is arranged on the side of the bearing facing away from the stator winding, in particular wherein the radial distance area covered by the shaft sealing ring overlaps with the radial distance area covered by the bearing. In particular wherein the shaft sealing ring seals towards the rotor shaft, in particular wherein the axial direction is aligned parallel to the axis of rotation of the rotor shaft and / or the radial distance is the distance to the axis of rotation of the rotor shaft and / or the respective radial distance range is the range of distances related to the axis of rotation of the rotor shaft. It is advantageous here that the cooling takes place in the area of the shaft sealing ring. The area around the sealing seat in the bearing shield, in which the shaft sealing ring is accommodated, is thus cooled and temperature-controlled.Although the load-bearing capacity of the bearing shield in the area of the blind bore is reduced by the insertion of the blind bore, a particularly high load-bearing capacity is not required in the area of the seal seat. However, it is important that the blind bore is axially spaced from the bearing seat of the rotor shaft bearing and from the material located radially outside the bearing seat, as a higher load-bearing capacity is required there.
[0017] In an advantageous embodiment, each of the longitudinal bores is at least partially lined by a respective first pipe part and the blind bore is at least partially lined by a third pipe part, wherein the respective first pipe part is materially connected to the pipe part at least partially lining the blind bore, in particular wherein the bearing plate is made of a first material, in particular stainless steel, and the pipe parts are made of a second material, in particular of a copper-containing material, and the first material is different from the second material. The advantage here is that increased safety can be achieved because the bearing plate only takes over the conduction of the coolant after failure of the pipes. In addition, the material of the pipes is such that, in interaction with the coolant, corrosion can be prevented.This is especially true if the coolant would have a corrosive effect on the material of the bearing plate. In an advantageous embodiment, a first longitudinal bore has a first internal thread at its end region opening into the environment, and the second longitudinal bore has a second internal thread at its end region opening into the environment. The advantage here is that a pipeline can be connected easily, tightly, and securely. Thus, an inlet and an outlet are easily implemented.
[0018] In an advantageous embodiment, the first internal thread area functions as the inlet and the second internal thread area as the outlet. This allows for easy connection of external pipes or hose connectors.
[0019] In an advantageous embodiment, the longitudinal bores are each designed as stepped bores, in particular, wherein the first internal thread region has a larger clear inner diameter than the remaining, in particular further inside, first longitudinal bore, and wherein the second internal thread region has a larger clear inner diameter than the remaining, in particular further inside, second longitudinal bore. This is advantageous because it enables simple manufacturing.
[0020] In an advantageous embodiment, the clear inner diameter of the respective blind-hole-like bore, in particular a longitudinal bore, increases monotonically toward the opening of the respective bore into the surrounding area. This is advantageous because it enables simple manufacturing.
[0021] In an advantageous embodiment, the blind hole is designed as a stepped bore, wherein the clear inner diameter of the blind hole increases monotonically towards the mouth region of the blind hole opening into the surrounding area, in particular wherein the blind hole has the minimum clear inner diameter where the distance between the bearing and the blind hole is the smallest. The advantage here is that a simple and secure seal can be created by the sealing plug. In an advantageous embodiment, sealing compound is arranged between the threaded area, in particular the internal thread area, of the blind hole and an external thread area of the sealing plug. The advantage here is that a secure seal can be achieved.
[0022] In an advantageous embodiment, sealing compound is arranged between the threaded area, in particular the internal thread area, of the blind hole and an external thread area of the respective sealing plug. This has the advantage of preventing crevice corrosion in the thread.
[0023] In a preferred design, the bearing flange is made of stainless steel. This provides excellent thermal conductivity, allowing the heat flow to be directed to the cooling circuit.
[0024] In an advantageous design, the stator housing of the electric motor is made of aluminum. This provides the advantage of high thermal conductivity. This allows heat to flow from the stator housing to the bearing flange.
[0025] In an advantageous embodiment, at each circumferential angular position relative to the rotational axis of the rotor shaft covered by the blind bore, the blind bore is arranged radially between the bearing and the area, in particular the contact area, of contact between the stator housing and the bearing flange. This is advantageous because the heat flowing from the stator housing into the bearing flange can be kept away from the bearing and the shaft seal.
[0026] In an advantageous embodiment, the blind-hole-like bores and the blind hole are permeated by fluid, particularly water. This is advantageous because efficient cooling can be achieved.
[0027] In an advantageous embodiment, the electric motor drives a spindle drive of the drive directly or via a belt drive of the drive or via a gearbox of the drive. The advantage here is that an efficient linear drive with a short axial length can be generated. Heat from the belt drive or gearbox also flows via the bearing flange to the coolant. In an advantageous embodiment, the spindle drive has a rotatably mounted threaded spindle whose axis of rotation is aligned parallel, in particular coaxially, to the axis of rotation of the rotor shaft of the electric motor. The advantage here is that a linear drive can be generated that requires little installation space in the transverse direction to the axis of rotation of the rotor shaft.
[0028] In an advantageous embodiment, a spindle nut screwed onto the threaded spindle is guided linearly in a housing part of the spindle drive by means of a linear guide. This is advantageous in that it enables simple manufacturing. Further advantages arise from the subclaims. The invention is not limited to the combination of features of the claims. Those 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, in particular from the task and / or the task posed by comparison with the prior art.
[0029] The invention will now be explained in more detail using schematic illustrations:
[0030] Figure 1 shows an oblique view of a first drive according to the invention designed as an electric motor.
[0031] Figure 2 shows a sectional view of a portion of the electric motor.
[0032] Figure 3 shows the electric motor with cut-off bearing flange 1 in an oblique view.
[0033] Figure 4 shows a cross-section of the bearing flange 1.
[0034] As shown in Figures 1 to 4, the first drive according to the invention has a bearing flange 1, which accommodates a bearing 20 for supporting the rotor shaft of the electric motor in a finely machined bearing receptacle formed thereon. A shaft seal 21, which is also accommodated in the bearing flange 1, seals the rotor shaft against the bearing flange 1.
[0035] The bearing flange 1 is preferably made of steel, in particular stainless steel, and is connected to a stator housing 4, preferably made of aluminum, which surrounds the stator winding and thus absorbs considerable waste heat flows during operation and dissipates them to the bearing flange 1.
[0036] A liquid cooling channel structure is integrated into the bearing flange 1.
[0037] For this purpose, two blind-hole-like longitudinal bores 40 are provided in the bearing flange, which are parallel to each other. In particular, the two longitudinal bores are arranged on both sides of the bearing mount.
[0038] As shown in Figure 4, both longitudinal bores 40 open into a blind bore 41 formed in the bearing flange, which is closed to the environment by a single sealing plug 42 screwed into a threaded area of the blind bore 41. Preferably, additional sealing compound is provided in the threaded area to achieve increased tightness.
[0039] It is particularly advantageous to apply sealing compound between the respective threaded area, in particular the internal thread area, of the blind hole 41 and an external thread area of the sealing plug 42. This has the advantage of preventing crevice corrosion in the thread.
[0040] The inner diameter of the blind hole 41 is larger in the threaded area than in the area of the blind hole 41 adjacent to the mouth area of the longitudinal holes.
[0041] In addition, the blind hole 41 has a further step in the inner diameter, so that a cover area of the sealing plug 42 can be arranged countersunk in the blind hole.
[0042] In particular, the blind hole 41 is designed as a multi-stage stepped hole and the middle step is designed with a threaded area.
[0043] The inlet 2 of the liquid is provided in the first longitudinal bore 40, so that the liquid, in particular water, flows from there into the blind bore 41 and then from the blind bore 41 via the second longitudinal bore 40 at the outlet 3.
[0044] For the connection of pipes for water supply or drainage, both the inlet 2 and the outlet 3 each have a threaded area whose clear inner diameter is larger than the respective remaining longitudinal bore 40.
[0045] Thus, the bearing flange 1 can be cooled with liquid and the heat flowing from the stator housing 4 into the bearing flange can be dissipated.
[0046] The contact area between bearing flange 1 and stator housing 4 is arranged in a first radial distance area relative to the rotational axis of the rotor shaft, which is radially outside and spaced from the radial distance area covered by the bearing 20 and from the radial distance area covered by the shaft seal 21. Therefore, the blind hole 41 is arranged in the bearing flange in such a way that the maximum
[0047] Distance of the blind hole 41 from the axis of rotation of the rotor shaft is greater than the largest radial distance of the bearing 20 and the shaft sealing ring.
[0048] The blind hole 41 and the longitudinal holes 40 perpendicular thereto are thus arranged as far as possible between the bearing seat and the contact area, so that the bearing 20 and the shaft seal 21 are protected as well as possible from the heat flow.
[0049] Since the outer circumference of the stator housing 4 is essentially cuboid-shaped, the radially outer circumference of the contact surface is square. The bearing mount is cylindrical in the bearing flange 1. The blind bore 41 extends through the interior of the bearing flange 1 and is thus spaced both axially and in every radial direction from the contact area of the bearing flange 1 with the stator housing 4.
[0050] According to the invention, the bearing 20 is protected from overheating, thus also preventing overheating of the bearing's lubricant, particularly grease. Likewise, the functionality of the shaft seal 21 is ensured, as the material of the shaft seal 21 is durable within the intended temperature range for continuous operation.
[0051] In further embodiments of the invention, the blind bore 41 is arranged between the contact area and the bearing 20 and / or shaft seal 21, so that the heat flowing in from the contact area is kept away from the bearing 20 and shaft seal 21. Likewise, the longitudinal bores 40 oriented perpendicular to the blind bore 41 are spaced from the bearing.
[0052] In further embodiments according to the invention, a belt drive can be driven by the drive, which can be driven by the described electric motor, wherein the bearing flange 1 is connected to a housing part of the belt drive and thus heat from the belt drive can also be dissipated to the bearing flange, but in particular on the side of the bearing flange 1 facing away from the electric motor.
[0053] Water cooling of bearing flange 1 enables efficient cooling. The spindle drive features a threaded spindle driven by the belt drive, so that a spindle nut screwed onto the threaded spindle is moved along its linear guide when the threaded spindle is rotated.
[0054] The axial direction is parallel to the direction of the rotation axis of the rotor shaft.
[0055] The area covered by the blind hole 41 and the two longitudinal holes 40 in the axial direction is encompassed by or overlaps with the area covered by the shaft sealing ring 21 in the axial direction.
[0056] Thus, the area covered by the blind hole 41 and the two longitudinal holes 40 in the axial direction is spaced from the area covered by the bearing 20 in the axial direction.
[0057] Since the sealing seat of the shaft seal 21 has a smaller inner diameter than the bearing seat of the bearing 20 in the bearing flange 1, the blind hole 41 can be positioned very close to the shaft seal 21.
[0058] As shown in Figure 2, the radial clearance area covered by the bearing overlaps with the radial clearance area covered by the blind hole 41.
[0059] The radial distances are always related to the axis of rotation of the rotor shaft of the electric motor.
[0060] The radial clearance area covered by the shaft seal 21 overlaps with the radial clearance area covered by the bearing 20.
[0061] In further embodiments according to the invention, the electric motor can also be used to directly drive a spindle drive. In this case, the bearing flange 1 is arranged between the electric motor and the spindle drive. The efficient cooling of the bearing flange 1 thus also enables additional cooling of the spindle drive. The rotor shaft of the electric motor is rotationally connected to the threaded spindle of the spindle drive. A spindle nut screwed onto the threaded spindle and linearly guided in a housing part of the spindle drive is thus linearly displaced back and forth depending on the rotational movement of the rotor shaft, in particular parallel to the direction of the rotational axis of the rotor shaft of the electric motor.
[0062] Preferably, the bearing flange 1 touches the stator housing 4 at its outer circumference, in particular so that the radial distance to the bearing 2 is maximum.
[0063] In further embodiments according to the invention, the bearing flange 1 can also be made of materials with particularly good heat-conducting properties, in particular such as copper and its alloys, and connected to a stator housing 4 preferably made of aluminum, which surrounds the stator winding and thus absorbs considerable waste heat flows during operation and dissipates them to the bearing flange 1.
[0064] In further embodiments according to the invention, a second blind bore is arranged in the bearing flange 1, which is aligned parallel to the first blind bore 41. The longitudinal bores 40 also both open into the second blind bore. Due to the thinner inner diameter of the second blind bore compared to the inner diameter of the first blind bore 41, a uniform flow can be achieved, in particular, the diameters being such that the coolant flow in the first blind bore 41 is equal to the flow in the second blind bore.
[0065] The second blind hole is also closed to the environment by a screwed-in plug.
[0066] The bore axis of the second blind hole and the bore axis of the first blind hole 41 are aligned point-symmetrically with respect to the rotational axis of the rotor shaft, in particular to the intersection point of the rotational axis of the rotor shaft with the plane spanned by the bore axes of the longitudinal bores 40 and the blind holes. In further embodiments according to the invention, the distance between the blind hole 41 and the shaft sealing ring 21 is smaller than the diameter of the blind hole 41. Thus, efficient heat dissipation of the heat loss introduced by the shaft sealing ring 21 is achievable.
[0067] List of reference symbols
[0068] 1 Bearing flange 2 Inlet
[0069] 3 Outlet
[0070] 4 Stator housing
[0071] 20 warehouses
[0072] 21 Shaft seal 40 Longitudinal bore
[0073] 41 Blind hole drilling
Claims
Patent claims:
1. Drive with electric motor, wherein the electric motor has a bearing flange and a rotor shaft, wherein a bearing is received in the bearing flange, by means of which the rotor shaft is rotatably mounted, characterized in that, in particular on both sides of the bearing receptacle of the bearing provided in the bearing flange, two mutually parallel, blind-hole-like bores, in particular longitudinal bores (40), are provided in the bearing flange, which each open into a blind bore (41) provided in the bearing flange, wherein the blind bore (41) is closed to the environment by means of a single sealing plug screwed into the blind bore (41), in particular into an internal thread area of the blind bore (41), in particular tightly closed.
2. Drive according to claim 1, characterized in that the area covered in the axial direction by the blind hole (41) overlaps with the area covered in the axial direction by a shaft seal (21) received in the bearing flange, in particular wherein the distance between the blind hole (41) and the shaft seal (21) is smaller than the diameter of the blind hole (41), in particular wherein the electric motor has a stator winding and wherein the shaft seal (21) is arranged on the side of the bearing (20) facing away from the stator winding, in particular wherein the radial distance area covered by the shaft seal (21) overlaps with the radial distance area covered by the bearing (20).in particular wherein the shaft seal (21) seals towards the rotor shaft, in particular wherein the axial direction is aligned parallel to the axis of rotation of the rotor shaft and / or the radial distance is the distance to the axis of rotation of the rotor shaft and / or the respective radial distance range is the range of distances referred to the axis of rotation of the rotor shaft.
3. Drive according to one of the preceding claims, characterized in that each of the longitudinal bores (40) is at least partially lined by a respective first tube part and the blind bore is at least partially lined by a third tube part, wherein the respective first tube part is materially connected to the tube part that at least partially lines the blind bore (41), in particular wherein the bearing plate is made of a first material, in particular stainless steel, and the tube parts are made of a second material, in particular copper-containing material, and the first material is different from the second material.
4. Drive according to one of the preceding claims, characterized in that a first longitudinal bore has a first internal thread area at its end region opening towards the environment and wherein the second longitudinal bore has a second internal thread area at its end region opening towards the environment.
5. Drive according to one of the preceding claims, characterized in that the first internal thread area functions as an inlet and the second internal thread area as an outlet.
6. Drive according to one of the preceding claims, characterized in that the longitudinal bores are each designed as stepped bores, in particular wherein the first internal thread area has a larger clear internal diameter than the remaining, in particular the further inward, first longitudinal bore and wherein the second internal thread area has a larger clear internal diameter than the remaining, in particular the further inward, second longitudinal bore.
7. Drive according to one of the preceding claims, characterized in that the clear inner diameter of the respective blind-hole-like bore, in particular longitudinal bore, increases monotonically towards the opening of the respective bore into the surroundings.
8. Drive according to one of the preceding claims, characterized in that the blind hole bore (41) is designed as a stepped bore, wherein the clear inner diameter of the blind hole bore (41) increases monotonically from a minimum to the opening area of the blind hole bore (41) opening into the environment, in particular wherein the blind hole bore (41) has the minimum clear inner diameter where the distance between the bearing and the blind hole bore (41) has the smallest value.
9. Drive according to one of the preceding claims, characterized in that sealing compound is arranged between the threaded area, in particular the internal threaded area, the blind hole bore (41) and the external threaded area of the sealing plug.
10. Drive according to one of the preceding claims, characterized in that the bearing flange is made of stainless steel and / or that the stator housing is made of aluminum.
11. Drive according to one of the preceding claims, characterized in that the blind hole bore is aligned perpendicular to the two longitudinal bores, and / or that a second blind hole bore, aligned parallel to the blind hole bore and having a smaller bore diameter than the blind hole bore, is arranged in the bearing flange, wherein the two mutually parallel, blind-hole-like bores, in particular longitudinal bores (40), each open into the second blind hole bore (41), wherein the second blind hole bore (41) is closed to the environment by means of a single sealing plug screwed into the second blind hole bore (41), in particular into an internal thread area of the second blind hole bore (41), in particular tightly closed.
12. Drive according to one of the preceding claims, characterized in that at each circumferential angular position covered by the blind hole (41) with reference to the axis of rotation of the rotor shaft, the blind hole (41) is arranged radially between the bearing and the area, in particular contact area, of contact between the stator housing and the bearing flange.
13. Drive according to one of the preceding claims, characterized in that the blind hole-like bores and the blind hole bore (41) are through which liquid, in particular water, flows.
14. Drive according to one of the preceding claims, characterized in that the electric motor drives a spindle drive of the drive directly or via a belt drive of the drive or via a gearbox of the drive.
15. Drive according to one of the preceding claims, characterized in that the spindle drive has a rotatably mounted threaded spindle whose axis of rotation is aligned parallel, in particular coaxially, to the axis of rotation of the rotor shaft of the electric motor, and / or that a spindle nut screwed onto the threaded spindle is guided linearly in a housing part of the spindle drive by means of a linear guide.