Electric motor having a stator housing

Abstract

An electric motor having a stator housing, wherein a connection box lower part is arranged on the stator housing, wherein a connection box upper part is placed on and connected to the connection box lower part in order to form a connection box of the electric motor, wherein the connection box receives a box formed from a lower part and an upper part, wherein a carrier arm is formed on the upper part and presses a sensor against the inside wall of the connection box lower part.

Description

[0001] Electric motor with stator housing

[0002] Description:

[0003] The invention relates to an electric motor with a stator housing.

[0004] So-called flexible printed circuit boards are well known.

[0005] The invention is therefore based on the object of developing an electric motor, whereby increased safety can be achieved.

[0006] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0007] Important features of the invention in the electric motor with stator housing are that a terminal box lower part is arranged on the stator housing, in particular is arranged integrally and / or cast or is connected by means of screws, wherein to form a terminal box of the electric motor a terminal box upper part is placed on the terminal box lower part and connected, in particular is connected by means of screws, wherein a box formed from a lower part and an upper part is accommodated in the terminal box, wherein a support arm is formed on the upper part, by which a sensor is pressed against the inner wall of the terminal box lower part, in particular is pressed against it in an elastically prestressed manner.

[0008] The advantage here is that even if the box, consisting of the lower and upper sections, is not firmly connected to the junction box formed by the junction box lower and upper sections, the sensor is pressed sufficiently tightly against the junction box lower section, allowing the measured values ​​to be reliably recorded, particularly with a high signal-to-noise ratio. This increases safety; the box can be made of plastic and therefore acts as additional electrical insulation for the electrical cables arranged in the box compared to the metal junction box.

[0009] Furthermore, manufacturing is simple: simply insert the plastic housing into the metal junction box, pushing the sensor into the contact position, specifically against the inner wall of the junction box base. During insertion, the plastic housing is pressed against the inner wall by the elastic preload of the support arm. This ensures reliable operation even under strong vibrations, because the sensor is firmly pressed against the inner wall of the junction box base.

[0010] In an advantageous embodiment, the terminal box base and / or the terminal box top are made of metal. This is advantageous because the plastic box is protected from external environmental influences by the terminal box. This also contributes to increased safety.

[0011] In an advantageous embodiment, the lower and upper sections are made of plastic. The advantage here is that an elastic plastic can be used. The plastic is more elastic, in particular, it has a higher modulus of elasticity, than the material of the terminal box lower and / or terminal box upper sections. Increased insulation strength and thus safety can be achieved.

[0012] In an advantageous embodiment, the support arm has a region, in particular an end region, in which the wall thickness of the support arm decreases strictly monotonically with decreasing distance from the sensor, in particular wherein the region is arranged closer to the sensor than all other regions of the support arm. The advantage here is that the elasticity of the support arm increases in the region of the sensor and thus manufacturing tolerances can be better compensated for when the sensor is pressed on, in particular with an essentially unchanged contact force. In an advantageous embodiment, the upper part is clip-connected to the lower part. The advantage here is that quick and simple production is possible and a secure connection can be provided.

[0013] In an advantageous embodiment, the terminal box upper part is connected to the terminal box lower part by means of screws, in particular by being pressed against the terminal box lower part by screws. This is advantageous in that a mechanically strong connection is achieved that allows structure-borne noise to be transmitted from the terminal box lower part to the terminal box upper part with only minimal or negligible losses. The contact surface is preferably designed to be sufficiently wide to allow the high contact force applied by screws to be transmitted and the structure-borne noise to be transmitted with minimal losses.

[0014] In an advantageous embodiment, the sensor is mounted on a piece of printed circuit board that is mounted on the support arm, in particular, adhesively bonded to the support arm and / or secured to the support arm by screws. The advantage here is that the stable mounting in the support arm and the elastic pressure against the inner wall ensure good acoustic coupling. This allows for a high signal-to-noise ratio when detecting structure-borne sound, in particular, resulting in a very good measurement signal, which in turn enables reliable operation and thus increases safety.

[0015] In an advantageous embodiment, the circuit board piece is electrically connected to the other circuit board by means of a flexible circuit board section. This is advantageous in that the flexible circuit board section, on the one hand, connects and, on the other hand, can be bent, in particular bent by up to 90°, so that the circuit board piece is not aligned parallel to the other circuit board. The elastic pressing can therefore be provided perpendicular to the insertion direction of the plastic box into the receptacle formed on the terminal box base. The insertion direction is a radial direction with respect to the rotational axis of the rotor shaft of the electric motor. The pressing force is essentially directed in the axial direction.

[0016] In an advantageous embodiment, the flexible printed circuit board section is arranged on the support arm, in particular connected to the support arm. It is advantageous that the support arm can be curved and / or at least allows the pressing force to be non-parallel to the insertion direction. In an advantageous embodiment, the flexible printed circuit board section is a PCB part, in particular a flexible and / or thin PCB part. It is advantageous that the flexible printed circuit board section can be manufactured simply and cost-effectively, and the 90° deflection can be easily achieved.

[0017] In an advantageous embodiment, the flexible circuit board section has conductor tracks arranged on a material that contains at least polyimide, in particular, and an adhesive. This is advantageous because a flexible, i.e., elastic, carrier material can be used in a simple and cost-effective manner.

[0018] In an advantageous embodiment, a flexible printed circuit board is used as the flexible circuit board section. This is advantageous because it allows for mass production, thus enabling cost-effective delivery.

[0019] In an advantageous embodiment, the circuit board piece is positively received in the support arm, in particular, and firmly connected to the support arm. Advantageously, the circuit board piece is precisely received in the support arm and can be pressed against the inner wall or even connected to the support arm, so that the circuit board piece is precisely guided by the upper part of the box, in particular the plastic box.

[0020] In an advantageous design, the support arm is made of a material with a higher modulus of elasticity than the terminal box base. This is advantageous because, during vibrations, the maximum acceleration is proportional to the square of the vibration frequency and proportional to the amplitude of the vibration. Thus, even with zero static play at high frequencies, the box's mounting would be subject to play if the elastic deflection of the support arm were not present.

[0021] In an advantageous embodiment, the lower part is inserted and / or clipped into a receiving area formed on the terminal box base. This is advantageous because the mounting is easy to implement. Furthermore, the mounting can even be carried out without play, particularly in the absence of acceleration, i.e., in the static case. However, in the dynamic case, a maximum acceleration, particularly instantaneous acceleration, is effective, which can create play when mounting the box. This can, however, be prevented by the elastic preload of the support arm.

[0022] In an advantageous embodiment, a printed circuit board stack is arranged in the box formed by the upper and lower parts. The printed circuit board stack comprises printed circuit boards populated with components, which are spaced apart from one another and arranged parallel to one another. This is advantageous in that the mass of the box is increased and thus the inertia of the box, which in turn stabilizes and / or evens out the preload of the support arm over time.

[0023] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0024] The invention will now be explained in more detail using schematic illustrations:

[0025] Figure 1 shows an oblique view of an area of ​​an opened terminal box of an electric motor according to the invention.

[0026] Figure 2 shows a sectional view corresponding to the area.

[0027] Figure 3 shows an upper part 2 in an oblique view.

[0028] As shown in the figures, the electric motor has a stator housing in which the stator winding of the electric motor is accommodated, and a terminal box, the terminal box lower part 4 of which is either designed in one piece with the stator housing, in particular in one piece, or the terminal box lower part 4 of which is connected to the stator housing.

[0029] The terminal box base 4 is preferably made of metal, in particular like the stator housing of the electric motor.

[0030] A terminal box upper part 6 is placed on the terminal box lower part 4, in particular to form the terminal box.

[0031] In particular, the contact surface formed between the terminal box upper part 6 and the terminal box lower part 4 is contained in a contact plane.

[0032] The winding wire ends of the electric motor's stator winding are routed into the terminal box and electrically connected to the terminals located there. Supply lines from the external environment are also routed into the terminal box and electrically connected to the terminals. The supply lines are connected either to a three-phase power system or to the AC terminals of an inverter or converter.

[0033] The terminal box contains a box consisting of a lower part 1 and an upper part 2. The lower part 1 is inserted into a receptacle on the terminal box lower part 4 and is connected by a force fit. Preferably, a positive connection, such as a clip connection and / or screw connection, is also provided, whereby the clip connection enables particularly quick and easy production and maintenance.

[0034] The upper part 2 is connected to the lower part 1, in particular by means of a clip connection. For this purpose, the lower part 1 is preferably provided with projections e that encompass the upper part 2, and wherein projections formed on the projections, in particular nose-shaped projections, engage behind a respective recess formed on the upper part 2.

[0035] Since the upper part 2 and lower part 1 are made of plastic, they can be elastically deflected and / or deformed.

[0036] The e extend in a direction radial to the axis of rotation of the rotor shaft of the electric motor, in particular which is aligned parallel to the normal direction of the contact plane present between the terminal box lower part 4 and the terminal box upper part 6 and / or the contact plane present between the upper part 2 and the lower part 1.

[0037] The normal direction of the contact plane is aligned parallel to the plug-in direction used when placing the terminal box upper part 6 onto the terminal box lower part 4, and / or to the plug-in direction used when placing the upper part 2 onto the lower part 1 to activate the clip connection. The contact plane comprises at least a partial area of ​​the contact surface between the terminal box upper part 6 and the terminal box lower part 4 and / or a partial area of ​​the contact surface between the upper part 2 and the lower part 1.

[0038] In the box formed from the upper part 2 and the lower part 1, a printed circuit board stack 23 is arranged, which has a signal electronics, in particular which comprises a data node and / or is designed as a bus participant and has a brake rectifier.

[0039] The printed circuit board stack 23 is attached to the lower part 1. Another printed circuit board 21 is attached to the upper part 2. A support arm 3 is formed on the upper part 2. This support arm 3 preferably protrudes in the axial direction and presses a sensor arrangement attached to or accommodated on it against the inner wall of the terminal box lower part 4.

[0040] The sensor arrangement preferably comprises an acceleration sensor, in particular a structure-borne sound sensor. However, the sensor arrangement also comprises a temperature sensor.

[0041] The sensor arrangement is preferably mounted on a circuit board piece which is connected to the further circuit board 21, which is fastened to the upper part 2, via a flexible, thin PCB part.

[0042] The support arm 3 is thin and thus elastically deformable. This allows for elastic preload during assembly by placing the upper part 2 onto the lower part 1, which permanently presses the sensor assembly against the inner wall of the terminal box lower part 4.

[0043] Since the terminal box base 4 is made of metal, the sensor arrangement pressed against the inner wall is well coupled with regard to temperature and structure-borne sound.

[0044] The support arm 3 is supported on the box formed from the lower part 1 and the upper part 2. The box itself, in particular the lower part 1, is received in a receptacle formed on the terminal box lower part 4 and is positively connected, in particular preferably clip-connected, to the terminal box lower part 4. However, when vibrations occur, the box is arranged in the terminal box lower part 4 with only a small amount of play. This is because the box is made of plastic, i.e. a more elastic material than the metal of the terminal box lower part 4. Therefore, in contrast to the terminal box lower part 4, the box is a less rigid body, especially under high accelerations and / or strong vibrations. From a dynamic perspective, i.e. with regard to vibrations, the support arm 3 is thus supported on the inertial mass of the box. However, by means of the elastic preload, the sensor arrangement remains pressed against the inner wall, especially during strong accelerations and vibrations.According to the invention, a plastic box is formed from the lower part 1 and the upper part 2. The lower part 1 can be constructed in multiple pieces, in particular from two or more clip-connected pieces. A support arm 3 is formed on the upper part 2, which presses the sensor arranged on a circuit board piece 5 against the inner wall of the junction box lower part 4. The circuit board piece 5 with the sensor is spaced apart from the remaining upper part 2, in particular from the remainder of the upper part 2 remaining when the support arm 3 is removed.Without this elastic preload of the support arm 3, the plastic box is accommodated in the metallic box formed by the terminal box lower part 4 and the terminal box upper part 6. At least in the case of vibrations with an amplitude exceeding a critical level or in the case of acceleration exceeding a critical level, in particular instantaneous acceleration, the plastic box is accommodated in the metallic box with play and is positively connected. However, the elastic compression of the support arm 3 prevents the plastic box from rattling in the metallic box.

[0045] Since the PCB stack is housed in the lower part 1 of the box, the plastic box offers a high inertial mass.

[0046] On the further circuit board 21, evaluation electronics are provided, which evaluate the signals from the sensor. Preferably, this further circuit board also contains a connector part, which is electrically connected to a mating connector part, which is mounted on a circuit board of the circuit board stack 23. The circuit boards of the circuit board stack are equipped with components, so that a signal electronics system is formed, which is designed as a bus participant. In addition, a rectifier acting as a brake rectifier is provided, which is supplied with alternating voltage and supplies a coil winding from its DC voltage side connection, which is arranged in the electric motor and is surrounded by an electromagnetically actuated brake. When the coil winding is energized, the brake is released, and when it is not energized, the brake is applied.

[0047] The terminal box base 4 is connected to the stator housing by means of screws, which accommodate bearings for the rotatable mounting of the rotor shaft. Thus, the structure-borne noise emitted by the bearings is transmitted to the sensor with minimal loss and can thus be detected with a high signal-to-noise ratio. The electrical plug connection between the additional circuit board 21 and the circuit board stack 23 enables quick and easy assembly of the box.

[0048] In further embodiments according to the invention, the support arm 3 is manufactured as a separate part and connected to the upper part 2.

[0049] A connector area is preferably formed on the lower part 1, in which the

[0050] Supply lines and / or stator winding lines can be plugged into a connector fitted to them.

[0051] List of reference symbols

[0052] 1 lower part 2 upper part

[0053] 3 support arm

[0054] 4 Terminal box base

[0055] 5 PCB piece with sensor

[0056] 6 Terminal box top 21 Circuit board

[0057] 23 PCB stacks

Claims

Patent claims:

1. Electric motor with stator housing, wherein a terminal box lower part is arranged on the stator housing, in particular molded and / or cast or connected by means of screws, wherein to form a terminal box of the electric motor a terminal box upper part is placed on the terminal box lower part and connected, in particular connected by means of screws, characterized in that a box formed from a lower part and an upper part is received in the terminal box, wherein a support arm is formed on the upper part, by which a sensor is pressed against the inner wall of the terminal box lower part, in particular is pressed against it in an elastically prestressed manner.

2. Electric motor according to claim 1, characterized in that the terminal box lower part and / or the terminal box upper part are made of metal, and / or that the lower part and the upper part are made of plastic.

3. Electric motor according to one of the preceding claims, characterized in that the support arm has a region, in particular an end region, in which the wall thickness of the support arm decreases strictly monotonically with decreasing distance from the sensor, in particular wherein the region is arranged closer to the sensor than all other regions of the support arm.

4. Electric motor according to one of the preceding claims, characterized in that the upper part is clip-connected to the lower part.

5. Electric motor according to one of the preceding claims, characterized in that the terminal box upper part is connected to the terminal box lower part by means of screws, in particular and is pressed onto the terminal box lower part by screws.

6. Electric motor according to one of the preceding claims, characterized in that the sensor is mounted on a piece of printed circuit board which is received on the support arm, in particular adhesively connected to the support arm and / or fastened to the support arm by means of screws.

7. Electric motor according to one of the preceding claims, characterized in that the circuit board piece is electrically connected to the further circuit board by means of a flexible circuit board section.

8. Electric motor according to one of the preceding claims, characterized in that the flexible printed circuit board section is arranged on the support arm, in particular is connected to the support arm.

9. Electric motor according to one of the preceding claims, characterized in that the flexible printed circuit board section is a PCB part, in particular a flexible and / or thin PCB part.

10. Electric motor according to one of the preceding claims, characterized in that the flexible printed circuit board section has conductor tracks which are arranged on a material which comprises at least polyimide, in particular and an adhesive.

11. Electric motor according to one of the preceding claims, characterized in that a flexible printed circuit board is used as the flexible printed circuit board section.

12. Electric motor according to one of the preceding claims, characterized in that the circuit board piece is received in the holding arm in a form-fitting manner, in particular and is connected to the holding arm in a materially bonded manner.

13. Electric motor according to one of the preceding claims, characterized in that the holding arm is made of a material with a higher modulus of elasticity than the terminal box base.

14. Electric motor according to one of the preceding claims, characterized in that the lower part is inserted and / or clipped into a receiving area formed on the terminal box lower part.

15. Electric motor according to one of the preceding claims, characterized in that a printed circuit board stack is arranged in the box formed from the upper part and the lower part, wherein the printed circuit board stack has printed circuit boards populated with components which are spaced apart from one another and arranged parallel to one another.

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