Motor and bearing current measurement system including the same

Abstract

A motor according to one embodiment of the present invention comprises: a housing; a shaft penetrating at least a portion of the housing; and a bearing portion coupled to the housing and supporting the shaft, wherein the bearing portion may include: a bearing; a bearing cover surrounding the bearing; and a conductor ring coupled to the bearing cover and in contact with the bearing.

Description

Technology Field

[0001] The present invention relates to a motor and a bearing current measuring system including the same. Background Technology

[0003] Drive motors can be utilized as essential devices in various industrial fields, such as manufacturing, energy, and transportation. In particular, bearings play a critical role in supporting the motor's rotating components, minimizing friction, and maintaining performance and reliability. However, in inverter-based motor control systems, galvanic corrosion currents can occur in the bearings, leading to bearing damage. This can result in problems such as abnormal noise, motor performance degradation, and operational failure.

[0004] While bearing conditions can be indirectly monitored by measuring the existing Common Mode Voltage (CMV), there may be limitations in accurately measuring the corrosion current because the CMV voltage is not fully converted into the corrosion current of the bearing. Furthermore, the direct measurement of corrosion current presented problems in that it was difficult to utilize in industrial settings due to high installation costs and technical complexity. The problem to be solved

[0006] In order to solve at least some of the above-mentioned problems, the motor of one embodiment and the bearing current measuring system including it are intended to provide a configuration capable of directly measuring the electrolytic current flowing through the bearing.

[0007] The motor of one embodiment and the bearing current measuring system including the same are intended to provide a structure that facilitates the measurement of the electrolytic current of the bearing by reducing the physical distance from the bearing. means of solving the problem

[0009] In one embodiment of the present invention for achieving the above objective, the motor comprises: a housing; a shaft penetrating at least a portion of the housing; and a bearing portion coupled to the housing and supporting the shaft, wherein the bearing portion may include: a bearing; a bearing cover surrounding the bearing; and a conductor ring coupled to the bearing cover and in contact with the bearing.

[0010] The diameter of the bearing cover may be larger than the diameter of the bearing.

[0011] The bearing cover may comprise: a bearing space in which the bearing is located; and a ring space connected to the bearing space in which the conductor ring is located.

[0012] The width of the bearing space above may be thicker than the width of the ring space above.

[0013] The above bearing cover may include an insulator.

[0014] The width of the bearing cover may be longer than the width of the bearing.

[0015] In one embodiment of the present invention for achieving the above objective, a bearing current measuring system comprises: a motor; and a data acquisition system electrically connected to the motor, wherein the motor comprises: a housing; a shaft penetrating at least a portion of the housing; and a bearing portion coupled to the housing and supporting the shaft, wherein the bearing portion may comprise: a bearing; a bearing cover located between the bearing and the housing; and a conductor ring coupled to the bearing cover and in contact with the bearing.

[0016] The above conductor ring can be electrically connected to the data collection system.

[0017] The above data collection system can be electrically connected to the housing.

[0018] The motor may further include: a rotor coupled to the shaft and rotating together with the shaft; and a stator surrounding the rotor and supported by the housing. Effects of the invention

[0020] A motor according to one embodiment of the present invention and a bearing current measuring system including the same can directly measure the electrolytic current flowing in the bearing.

[0021] A motor according to one embodiment of the present invention and a bearing current measuring system including the same can provide a structure that facilitates the measurement of the electrochemical current of a bearing by reducing the physical distance from the bearing. Brief explanation of the drawing

[0023] FIG. 1 is a perspective view illustrating a bearing current measurement system according to one embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a motor according to one embodiment of the present invention. FIG. 3 is an exploded perspective view showing a bearing part according to one embodiment of the present invention. Specific details for implementing the invention

[0024] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0025] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0026] Terms such as "~part," "~section," "~part," etc. may be used to describe various components, but said components should not be limited by said terms. These terms may refer not only to physically or visibly distinguishable components but also to descriptions of the function or configuration of a relevant part, even if the distinction or division is not clearly defined.

[0027] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0028] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0029] In the description below, terms related to direction such as "front," "rear," "side," "front," "back," "up and down," "top," "upper," "top," "bottom," "lower," "bottom," and "left and right" are defined based on the motor (MT). Additionally, while terms such as "first," "second," etc., may be used to describe various components, the order, size, location, or importance of these components is not limited by these terms; they are named solely for the purpose of distinguishing one component from another.

[0030] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings.

[0031] In the drawing, D1 may be referred to as the first direction (D1), D2 intersecting the first direction (D1) as the second direction (D2), and D3 intersecting the first direction (D1) and the second direction (D2) as the third direction (D3). The third direction (D3) may be referred to as the upward direction, and the direction opposite to the third direction (D3) may be referred to as the downward direction. Additionally, the first direction (D1) and the second direction (D2) may each be referred to as the horizontal direction.

[0033] FIG. 1 is a perspective view illustrating a bearing current measurement system (ST) according to one embodiment of the present invention, FIG. 2 is a cross-sectional view illustrating a motor (MT) according to one embodiment of the present invention, and FIG. 3 is an exploded perspective view showing a bearing part (9) according to one embodiment of the present invention.

[0034] Referring to FIGS. 1 and 2, a bearing current measurement system (ST) according to one embodiment may include a motor (MT) and a data acquisition system (SY). A motor (MT) according to one embodiment may include a housing (1), a shaft (3), and a bearing part (9). A motor (MT) according to one embodiment may optionally include a rotor (5) and a stator (7).

[0035] The bearing current measuring system (ST) can measure the current flowing through the bearing (93). By measuring the current flowing through the bearing (93), the bearing current measuring system (ST) can predict the degree of wear progression of the bearing (93). The bearing current measuring system (ST) can prevent or manage the wear of the bearing (93) by measuring the bearing current that is the direct cause of damage to the bearing (93).

[0036] The housing (1) may have an internal space (1h). The housing (1) may support a shaft (3), a stator (7), a rotor (5), and a bearing part (9). However, the motor (MT) structure supported by the housing (1) is not limited thereto. The housing (1) may have a cylindrical shape, but the shape of the housing (1) is not limited thereto. The housing (1) may have a first axis (AX1) extending in a first direction (D1) as a central axis.

[0037] The shaft (3) may penetrate at least a portion of the housing (1). The shaft (3) may extend toward the internal space (1h). The shaft (3) may have a first axis (AX1) as its central axis. The shaft (3) may extend toward the internal space (1h) with the first axis (AX1) as its central axis. The shaft (3) may rotate with the first axis (AX1) as its central axis. The shaft (3) may have an internal empty space. The shaft (3) may have a hollow (3h). The hollow (3h) may extend in a first direction (D1) with the first axis (AX1) as its central axis. However, the shape of the shaft (3) is not limited thereto. The shaft (3) may not have a hollow (3h).

[0038] The stator (7) can be coupled with the housing (1). The stator (7) can be supported by the housing (1). The stator (7) can surround the rotor (5). The stator (7) can surround at least a portion of the shaft (3).

[0039] The stator (7) may include a core structure with coils wound around it. The core may be made of a highly conductive magnetic material to minimize magnetic loss. The core may provide an efficient magnetic flux path. The shape of the core may have a slot structure to distribute magnetic flux density evenly.

[0040] The coil may include copper or aluminum wire. The coil may be wound evenly in each slot of the stator (7) to form a rotating magnetic field to drive the rotor through a three-phase alternating current. The coil may be wrapped with an insulating coating or an insulating film. The insulating coating or insulating film may prevent short circuits in the coil.

[0041] However, the structure of the stator (7) is not limited to this. The stator (7) may have a slotless structure without slots. The stator may have various shapes, and for example, the stator (7) may include a permanent magnet.

[0042] The rotor (5) can rotate together with the shaft (3). The rotor (5) can rotate in conjunction with the shaft (3). The rotor (5) can surround at least a portion of the shaft (3). However, the combination of the rotor (5) and the shaft (3) is not limited to this. The rotor (5) can be positioned between the shafts (3) that are spaced apart from each other and combined with the shaft (3).

[0043] A rotor (5) according to one embodiment may include a core. A rotor (5) according to one embodiment may optionally include a permanent magnet or a coil. A permanent magnet may be attached to or inserted into the core. A magnetic force is generated between the permanent magnet of the rotor (5) and the stator (7) by an alternating magnetic field generated by the stator (7), so that the rotor (5) can perform rotational motion. The permanent magnet may include at least one of neodymium (Nd), iron (Fe), boron (B), samarium, cobalt, Alnico, or ferrite. The material of the permanent magnet is not limited thereto.

[0044] The coil may be wound on the core of the rotor (5). The coil may generate an induced current inside the rotor and interact with the magnetic field of the stator (7). The coil may contain copper (Cu), but the type of conductor coil is not limited thereto.

[0045] The rotor (5) can rotate by interacting with the stator (7). For example, if an alternating current is supplied to the stator (7), a change in the magnetic field may occur due to a change in the current flowing through the stator (7). An induced current may be generated in the rotor (5) due to the change in the magnetic field of the stator (7). An electromagnetic force is generated in the rotor (5), causing the rotor (5) to rotate. Additionally, if a direct current is supplied to the rotor (5), the rotor (5) can rotate by receiving an electromagnetic force from the magnetic field formed by the stator (7). At this time, the rotor (5) may optionally include a commutator to change the direction of the current flowing in the same direction.

[0046] The bearing portion (9) can support the shaft (3). The bearing portion (9) can be coupled with the housing (1). The bearing portion (9) can be positioned between the shaft (3) and the housing (1). The shaft (3) can rotate relative to the housing (1) by means of the bearing portion (9). The bearing portion (9) according to one embodiment may include a bearing (93), a bearing cover (91), and a conductor ring (92). The bearing portion (9) according to one embodiment may optionally include a wire (WR).

[0047] The bearing (93) can support the shaft (3). The bearing (93) can be located between the shaft (3) and the housing (1). The bearing (93) can allow the shaft (3) to rotate relative to the housing (1). The bearing (93) can be located on both sides of the shaft (3). Multiple bearings (93) may be provided. However, for the convenience of writing the specification, multiple bearings (93) will be described as a single entity. The bearing (93) can surround at least a portion of the shaft (3).

[0048] A bearing cover (91) may surround a bearing (93). A bearing cover (91) may be positioned between the bearing (93) and the housing (1). The bearing cover (91) may include an insulator. For example, the bearing cover (91) may include at least one of rubber, ceramic, plastic, silicone, synthetic resin, and Teflon (PTFE). However, the type of bearing cover (91) is not limited thereto and may include various materials capable of insulating between the bearing (93) and the housing (1).

[0049] Referring to FIGS. 2 and 3, the diameter of the bearing cover (91) may be larger than the diameter of the bearing (93). The width of the bearing cover (91) may be thicker than the width of the bearing (93). The bearing cover (91) may have a bearing space (91h1) in which the bearing (93) can be positioned.

[0050] The conductor ring (92) can be combined with the bearing cover (91). The bearing cover (91) may have a ring space (91h2) in which the conductor ring (92) can be positioned. The conductor ring (92) can come into contact with the bearing (93). More specifically, the conductor ring (92) can come into contact with the outer ring of the bearing (93). The conductor ring (92) can be electrically connected to the bearing (93). The ring space (91h2) can be connected to the bearing space (91h1) so that the conductor ring (92) can come into contact with the bearing (93).

[0051] The conductor ring (92) may include at least one of copper (Cu), aluminum (Al), iron (Fe), or nickel (Ni). However, the material included in the conductor ring (92) is not limited thereto.

[0052] The bearing (93) may overlap one side of the conductor ring (92). The width of the conductor ring (92) may be thinner than the width of the bearing (93). The width of the bearing space (91h1) may be thicker than the width of the ring space (91h2).

[0053] When the rotor (5) rotates, an electromagnetic field is generated, and a voltage can be induced between the shaft (3) and the structure surrounding the shaft (3). Current can flow along the discharge path due to the induced voltage. When the current generated by the induced voltage flows through the bearing (93), bearing current can flow.

[0054] When bearing current flows along the bearing (93), a discharge occurs, which may cause fine holes to form on the metal surface of the bearing (93). Additionally, the discharge on the surface of the bearing (93) creates a high-temperature environment, and the lubricant is damaged, which may increase friction between the bearing (93) and the shaft (3) as well as friction inside the bearing (93). Damage to the surface of the bearing (93) may induce vibration and degrade the performance of the bearing (93). Consequently, when bearing current is generated, not only does the performance of the bearing (93) decrease, but the lifespan of the bearing (93) is also reduced, and the problem may escalate into a defect in the entire motor (MT).

[0055] The wire (WR) can be electrically connected to the conductor ring (92). The wire (WR) can be exposed to the outside of the housing (1). The wire (WR) can be electrically connected to the data collection system (SY). When the bearing current flows along the bearing (93), the bearing current can move to the conductor ring (92) and flow out through the wire (WR). The data collection system (SY) can receive the bearing current transmitted from the conductor ring (92) and collect and analyze it.

[0056] The data acquisition system (SY) can be electrically connected to the housing (1) as well as the conductor ring (92). The data acquisition system (SY) can directly measure the bearing current by being connected to the conductor ring (92) and the housing (1). According to one embodiment, the data acquisition system (SY) may include a data acquisition (DAQ) device and a computer. The DAQ device can convert physical signals into digital data so that they can be processed or stored by a computer. According to one embodiment, the DAQ device may optionally include a signal conditioning device, a converter, a digital input / output device, and a communication interface. The signal conditioning device can convert the signal detected from the conductor ring (92) into a form that the DAQ device can process. The signal conditioning device can amplify, filter, and convert the signal detected from the conductor ring (92). The converter can convert an analog signal into a digital signal. The digital input / output device can collect digital data or send command signals. The communication interface can transmit and receive data between the DAQ device and the computer. The computer can receive data from the DAQ device and process and visualize it. The data collection system (SY) can be located outside the housing (1).

[0058] According to the motor (MT) and the bearing current measurement system (ST) including the same according to exemplary embodiments of the present invention, the management of the bearing (93) can be facilitated by directly measuring the bearing current. Electrolytic corrosion of the bearing (93) is associated not only with the lifespan and wear of the bearing (93) but also with the overall lifespan of the motor (MT). In this regard, the bearing current may need to be continuously managed. The bearing current measurement system (ST) can determine the wear and corrosion status of the bearing (93) by continuously observing, recording, and analyzing the bearing current. As a result, the management of the bearing (93) can be facilitated and the safety of the motor can be increased.

[0060] Although the invention has been described with reference to the above embodiments, a person skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims. Explanation of the symbols

[0062] ST: Bearing Current Measurement System MT: Motor SY: Data Collection System WR: Wire 1 : Housing 1h : Interior space 3 : Shaft 3h : China 5 : Rotor 7 : Stator 9: Bearing section 91 : Bearing cover 91h1 : Bearing space 91h2: Ring space 92 : Conductor ring 93 : Bearing AX1: 1st axis

Claims

Claim 1 A motor comprising: a housing; a shaft penetrating at least a portion of the housing; and a bearing portion coupled to the housing and supporting the shaft, wherein the bearing portion comprises: a bearing; a bearing cover surrounding the bearing; and a conductor ring coupled to the bearing cover and in contact with the bearing. Claim 2 In claim 1, the diameter of the bearing cover is larger than the diameter of the bearing. Claim 3 In claim 1, the bearing cover comprises: a bearing space in which the bearing is located; and a motor having a ring space connected to the bearing space in which the conductor ring is located. Claim 4 In claim 3, the width of the bearing space is thicker than the width of the ring space of the motor. Claim 5 In claim 1, the bearing cover is a motor comprising an insulator. Claim 6 In claim 1, the width of the bearing cover is thicker than the width of the bearing. Claim 7 A bearing current measuring system comprising: a motor; and a data acquisition system electrically connected to the motor, wherein the motor comprises: a housing; a shaft penetrating at least a portion of the housing; and a bearing portion coupled to the housing and supporting the shaft, wherein the bearing portion comprises: a bearing; a bearing cover located between the bearing and the housing; and a conductor ring coupled to the bearing cover and in contact with the bearing. Claim 8 In claim 7, the conductor ring is a bearing current measurement system electrically connected to the data acquisition system. Claim 9 In claim 8, the data acquisition system is a bearing current measurement system electrically connected to the housing. Claim 10 In claim 7, the motor further comprises: a rotor coupled to the shaft and rotating together with the shaft; and a stator surrounding the rotor and supported by the housing, forming a bearing current measuring system.

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