Electric motor with centrifugal pump for flowing fluid through rotor passage

Abstract

A stator; and a rotor body; and an electric motor comprising a rotor having a centrifugal pump for flowing fluid through a flow path extending axially from end to end through the rotor body. The flow path can extend through a magnet hole in the rotor body. The flow path can be formed in a hole of the rotor body that does not contain a magnet. The electric motor can comprise first and second end plates that form the centrifugal pump. The first and second end plates can be clocked with respect to each other. The first and second end plates can be non-locking with respect to each other.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the priority of U.S. Provisional Patent Application No. 63 / 367,564, filed on July 1, 2022, entitled "ELECTRIC MOTOR WITH CENTRIFUGAL PUMP TO FLOW FLUID IN ROTOR CHANNEL", the disclosure of which is hereby incorporated by reference in its entirety.

[0002] This specification relates to an electric motor with a centrifugal pump for flowing fluid in a rotor channel.

Background Art

[0003] In recent years, transportation in the world has begun to shift from power trains that mainly use fossil fuels as the driving source to more sustainable energy sources. Most of such widespread power trains include an electric motor powered by an in - vehicle energy storage device. Since an electric motor generates heat during operation, its efficiency and other performance characteristics depend, in part, on the thermal control strategy.

Summary of the Invention

[0004] In one aspect, an electric motor includes a stator and a rotor having a rotor body and a centrifugal pump for flowing fluid axially from end to end through the rotor body.

[0005] The implementation may include any or all of the following features. The flow path extends through a magnet hole in the rotor body. The flow path is formed adjacent to a magnet located within the magnet hole. The flow path is formed between at least two magnets located within the magnet hole. The flow path is formed within a hole of the rotor body that does not contain a magnet. The rotor body is formed by a laminate, and the laminate includes respective holes that form the flow path. The electric motor includes first and second end plates that form the centrifugal pump, where the first and second end plates are clocked with respect to each other. The electric motor includes first and second end plates that form the centrifugal pump, where the first and second end plates are non-clocked with respect to each other. The electric motor includes first and second end plates that form the centrifugal pump, the flow path includes first and second flow paths formed by the laminate, and a first flow through the first flow path occurs in a direction opposite to a second flow through the second flow path. The electric motor includes first and second end plates that form the centrifugal pump, the flow path includes first and second flow paths formed by the laminate, and a first flow through the first flow path occurs in the same direction as a second flow through the second flow path. The flow path includes first and second flow paths formed by the laminate. The electric motor includes an end plate that forms the centrifugal pump, the centrifugal pump includes an inlet formed in the end plate and an outlet formed in the end plate, where the inlet is aligned with the first flow path and the outlet is aligned with the second flow path, and the centrifugal pump flows a first fluid through the first flow path and a second fluid through the second flow path. The inlet includes a hole through the end plate, a concave region in the end plate that does not abut the laminate, where the concave region covers the first flow path, and an outer peripheral lip that closes the concave region. The electric motor further includes a rib that partitions the concave region so as to guide fluid at the inlet. The concave region has a substantially arcuate shape. The concave region has a substantially wedge-shaped shape.The inlet further includes a scoop that forms the hole. The outlet includes a concave region in the end plate that does not contact the laminate, where the concave region covers the second flow path, and a recess in the outer peripheral lip of the end plate. The concave region is symmetric with respect to the radius of the rotor body. The end plate includes a plurality of pairs each including its own inlet and its own outlet, and the plurality of pairs are distributed on the outer periphery of the end plate. The end plate further includes a site where material has been removed for rotor balance. The inlet of the flow path is formed in the shaft of the rotor. The fluid includes at least one of air or oil.

Brief Description of the Drawings

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Figure 1A

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Figure 2

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Figure 13A

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[0016] Like reference numerals in the various drawings indicate like elements. DETAILED DESCRIPTION

[0017] This specification describes examples of systems and techniques for thermally controlling an electric motor using at least one centrifugal pump having a flow path that extends axially through a rotor. Thereby, for example, similar to the test results described later, the rotor temperature can be significantly reduced even in a severe operating cycle. The end plate for the rotor stack can at least partially provide a centrifugal pump to the rotor. For example, the end plate can be used for one or more other purposes including, but not limited to, adjusting the material distribution when balancing the rotor.

[0018] The examples described in this specification refer to an electric motor. As used herein, the electric motor can be any type of electric motor including, but not limited to, a permanent magnet motor, an induction motor, a synchronous motor, or a reluctance motor.

[0019] The examples described in this specification refer to an upper part, a lower part, a front part, or a rear part. These and similar expressions identify things or aspects in a relative manner based on an explicit or arbitrary concept of perspective. That is, these terms are merely illustrative used for the purpose of explanation and do not necessarily indicate the only possible positions, directions, etc.

[0020] Figures 1A-1B are diagrams showing an example of an end plate 100 that can be used to provide a centrifugal pump to a rotor. The end plate 100 can be used in one or more other examples described elsewhere in this specification. In Figure 1A, the end plate 100 is shown in a plan view, illustrating the surface of the end plate 100 that faces outward from a rotor stack (not shown) when installed. In Figure 1B, the end plate 100 is shown in a plan view, illustrating the surface of the end plate 100 that faces inward from a rotor stack (not shown) when installed. The end plate 100 has a central opening 102 (e.g., circular in shape) that can accommodate a rotor shaft (not shown) and / or other components. The end plate 100 includes holes 104 for attaching rivets that may extend end-to-end through the rotor stack to compress the rotor. For example, the holes 104 can be chamfered on the outer surface of the end plate 100.

[0021] The end plate 100 can form one or more inlets 106 for a centrifugal pump. Through the inlets 106, the centrifugal pump can suck in fluid and flow the fluid through at least one flow path within the rotor body. The end plate 100 can have a surface 108 for abutting against an end of the rotor body (e.g., the outermost side of a plurality of rotor laminations). Also, the inlets 106 can be formed by one or more features defined in relation to the surface 108. In some implementations, the inlet 106 includes a concave region 110. The concave region 110 can be a portion having a thickness smaller than the thickness of the end plate 100 at the surface 108. Therefore, during installation, the concave region 110 of the end plate 100 does not abut against the end of the rotor body. The inlet 106 includes a hole 112 extending through the thickness of the end plate 100. The hole 112 can have any shape, including, but not limited to, a distorted rectangle (e.g., as shown in the figure). Other shapes can also be used for the hole 112. The concave region 110 can have any shape. In some implementations, the concave region 110 can be substantially symmetric with respect to the radius of the end plate 100 (e.g., as shown in the figure). For example, the concave region 110 can be symmetric with respect to the hole 112. In some implementations, the concave region 110 can have a substantially wedge shape (e.g., as shown in the figure).

[0022] The inlet 106 includes an outer peripheral lip 114 that closes the concave region 110. The outer peripheral lip 114 can extend so as to substantially surround the entire outer periphery of the end plate 100, except when referred to in the examples described later. The end plate 100 can have a thickness substantially the same as the thickness at the surface 108 at the outer peripheral lip 114. For example, during installation of the end plate 100, the outer peripheral lip 114 can abut against the end of the rotor body.

[0023] The inlet 106 can include one or more ribs. In some implementations, the recessed region 110 is partitioned by at least one rib 116. For example, the rib 116 can partition the recessed region 110 to guide fluid at the inlet 106.

[0024] The end plate 100 can form one or more outlets 118 for a centrifugal pump. Through the outlets 118, the centrifugal pump can discharge the fluid that has flowed through at least one flow path within the rotor body. That is, the outlets 118 of the end plate 100 can discharge the fluid that has flowed into the rotor from another inlet that was originally at the opposite end of the rotor rather than from any of the inlets 106 of the end plate 100. The outlets 118 can be formed by one or more features defined in relation to the surface 108. In some implementations, the outlets 118 include a recessed region 120. The recessed region 120 can be a portion having a thickness smaller than the thickness of the end plate 100 at the surface 108. Therefore, during installation, the recessed region 120 of the end plate 100 does not abut against the end of the rotor body. The recessed region 120 can have any shape. In some implementations, the recessed region 120 can be substantially symmetric with respect to the radius of the end plate 100 (as shown in the illustration, for example).

[0025] The outlets 118 include recesses 122 in the outer peripheral lip 114. The end plate 100 can have a thickness smaller than the thickness at the surface 108 in the recesses 122. For example, the end plate 100 can have a thickness substantially the same as the thickness of the recessed region 120 in the recesses 122. Due to the recesses 122, the fluid within the recessed region 120 can be discharged from the end plate 100.

[0026] The inlet 106 and the outlet 118 positioned adjacent to each other can form a pair 124. The end plate 100 can include a plurality of exemplary pairs 124 distributed on the outer periphery of the end plate 100. For example, here, the end plate 100 includes three exemplary pairs 124 that are evenly distributed.

[0027] When mounted on the rotor, the end plate 100 can be clocked with a corresponding (e.g., identical) end plate attached to the opposite rotor end. That is, among the possible angular orientations in which the end plate 100 can be mounted (i.e., such that the holes 104 are aligned for riveting), the orientation is selected such that each of the inlets 106 of the end plate 100 is aligned with the corresponding outlet of the other end plate at the opposite end. This clocking enables the centrifugal pump to draw fluid through one of the inlets 106, flow the fluid through the flow path, and discharge the fluid through the outlet at the opposite end plate. Similarly, this clocking enables the centrifugal pump to draw fluid through one of the inlets at the opposite end plate, flow the fluid through another flow path, and discharge the fluid through one of the outlets 118. An example including a centrifugal pump that flows fluid in opposite directions along the rotor stack will be described below with reference to FIG. 10.

[0028] That is, in some of the exemplary designs described herein (e.g., FIGS. 1A - 1B, 6, 7, or 8), clocking is performed during installation to ensure that the inlets and outlets at the opposite ends of the rotor stack are properly aligned with each other. In other designs, such as those shown in FIG. 9, no clocking is required. Rather, this design ensures that the inlets and outlets are automatically aligned with each other at the ends of the rotor.

[0029] In some implementations, the end plate 100 can serve to provide a centrifugal pump to the rotor and can also serve one or more additional purposes. For example, the end plate 100 can also be considered a balance plate for the rotor. Rotor balancing can be performed to ensure that the center of gravity of the rotor is aligned with the rotational axis 126 of the rotor. Here, the rotational axis 126 is located at the center of the central opening 102. If an imbalance is discovered, material can be removed from one or more locations on the end plate 100 to adjust the distribution of the material. In some implementations, the material is preferably removed somewhere within the portion where the end plate 100 has its maximum thickness. This can include, but is not limited to, at least one location within the surface 108. A site 128 within the surface 108 is shown here for illustrative purposes only. Alternatively or additionally, one or more other locations can be used. The site 128 can have any shape. For example, if the material is removed by drilling, the site 128 can have a substantially circular shape.

[0030] FIG. 2 is a diagram showing an example of a rotor stack 200 that can be used with a centrifugal pump to provide cooling. The rotor stack 200 can be used in one or more other examples described elsewhere in this specification. The rotor stack 200 can be rotationally symmetric, and only a part of the rotor stack 200 is shown here for simplicity.

[0031] A stack of a plurality of exemplary rotor stacks 200 can be assembled to form a rotor body. The rotor stack 200 can include at least one rivet hole 202 that can accommodate a rivet that extends axially through the rotor body for axial compression.

[0032] The rotor laminate 200 can include one or more holes for accommodating permanent magnets. Here, the rotor laminate 200 includes holes 204A to 204B and 206A to 206B. One or more magnets can be disposed in one or more of the holes 204A to 204B and 206A to 206B. Here, hole 204A includes magnet 208A, hole 204B includes magnet 208B, hole 206A includes magnet 210A, and hole 206B includes magnet 210B, respectively. Any type of permanent magnet can be used, including but not limited to sintered permanent magnets and / or bonded permanent magnets. Here, holes 204A to 204B and 206A to 206B are inside the rotor. In some implementations, one or more of the holes 204A to 204B and 206A to 206B can alternatively accommodate surface-mounted magnets.

[0033] Holes 204A to 204B and 206A to 206B can be located at any of a plurality of positions within the rotor laminate 200. Here, holes 204A to 204B are symmetric with respect to the radius of the rotor laminate 200. Similarly, holes 206A to 206B are symmetric with respect to the radius of the rotor laminate 200.

[0034] Potting can be used for one or more of magnets 208A to 208B and / or 210A to 210B. For example, a liquid potting material can be injected to flow on at least one side of one or more of magnets 208A to 208B and / or 210A to 210B.

[0035] In some embodiments, potting is not used. Here, holes 204A-1 and 204A-2 are the portions of hole 204A that are not occupied by magnet 208A and are substantially not potted. Similarly, holes 204B-1 and 204B-2 are the portions of hole 204B that are not occupied by magnet 208B and are substantially not potted; holes 206A-1 and 206A-2 are the portions of hole 206A that are not occupied by magnet 210A and are substantially not potted; holes 206B-1 and 206B-2 are the portions of hole 206B that are not occupied by magnet 210B and are substantially not potted. Holes 204A-1 and 204A-2, holes 204B-1 and 204B-2, holes 206A-1 and 206A-2, and holes 206B-1 and 206B-2 can serve as barriers for magnetic flux during operation.

[0036] Holes 204A-1, 204A-2, 204B-1, 204B-2, 206A-1, 206A-2, 206B-1, or 206B-2 can be located at any position within rotor laminate 200. Here, holes 204A-1 and 204B-2 are symmetric with respect to the radius of rotor laminate 200. Similarly, holes 204A-2 and 204B-1 are symmetric with respect to the radius; holes 206A-1 and 206B-2 are symmetric with respect to the radius; holes 206A-2 and 206B-1 are symmetric with respect to the radius.

[0037] One or more of holes 204A-1, 204A-2, 204B-1, 204B-2, 206A-1, 206A-2, 206B-1, or 206B-2 can serve as a flow path through the rotor for thermal control. For example, a fluid can flow through the flow path. Any fluid among a plurality of fluids including a gas (e.g., air) or oil can be used, but is not limited thereto. Therefore, the flow path of the centrifugal pump can extend through one or more of holes 204A-1, 204A-2, 204B-1, 204B-2, 206A-1, 206A-2, 206B-1, or 206B-2. Here, holes 204A-1 and 204A-2 are formed adjacent to magnet 208A. Similarly, holes 204B-1 and 204B-2 are formed adjacent to magnet 208B; holes 206A-1 and 206A-2 are formed adjacent to magnet 210A; holes 206B-1 and 206B-2 are formed adjacent to magnet 210B.

[0038] Additionally or alternatively, the flow path for the fluid flow can be formed in a hole of the rotor body that does not include a magnet. In some implementations, the rotor stack 200 can include a hole 212 that can form at least one flow path. Hole 212 can have any shape including a circular shape, but is not limited thereto. Additional examples are described below with reference to FIGS. 11A-11D.

[0039] Each of holes 204A-1, 204A-2, 204B-1, 204B-2, 206A-1, 206A-2, 206B-1, or 206B-2 can be aligned with an inlet or an outlet (e.g., inlets 106 and outlet 118 in FIGS. 1A-1B) in the end plate of the rotor. In some implementations, each of holes 204A-1, 204A-2, 204B-1, 204B-2, 206A-1, 206A-2, 206B-1, or 206B-2 is aligned with an inlet in the end plate of the rotor and an outlet in the opposite end plate.

[0040] Figure 3 is a schematic view showing a cross-section of an electric motor 300. The electric motor 300 can be used together with one or more other examples described elsewhere in this specification. For clarity, only a part of the electric motor 300 is shown. The electric motor 300 includes a stator 302 and a rotor 304. The rotor 304 is attached to a rotor shaft 306. A differential device 308 can be disposed inside the rotor 304 (e.g., at the center of the rotor shaft 306). That is, the rotor shaft 306 can be a hollow rotor shaft that houses a differential gear assembly for a vehicle. Such a differential gear assembly can provide an active core for the electric motor 300. For example, the active core can include gears, gear bearings, and radial pins assembled as a differential device. One or more hollow extensions (e.g., hollow cross members) can be disposed in the hollow rotor shaft as part of the differential gear assembly. For example, the hollow extension can have one or more through holes in which pins can be disposed (e.g., by friction fitting).

[0041] The rotor 304 can have a body formed by a laminate (e.g., the rotor laminate 200 of FIG. 2). The rotor 304 can have one or more centrifugal pumps. A flow path 310 can be formed in the rotor 304. For example, the flow path 310 can be formed by one or more of the holes 204A-1, 204A-2, 204B-1, 204B-2, 206A-1, 206A-2, 206B-1, 206B-2, or 212 of FIG. 2. The rotor 304 can have an inlet 312 that communicates with the flow path 310. For example, the inlet 312 can be formed by the inlet 106 of FIGS. 1A-1B. The rotor 304 can have an outlet 314 from the flow path 310. For example, the outlet 314 can be formed by the outlet 118 of FIGS. 1A-1B. The inlet 312 and the outlet 314 can be formed in respective exemplary end plates 316 for the rotor 304. For example, the exemplary end plates 316 can be identical to each other. In some implementations, the end plates 316 can be clocked or non-clocked relative to each other.

[0042] During operation, a fluid (e.g., air, oil, or other substances) can flow into the rotor 304 at the inlet 312. This fluid is considered to have a relatively low temperature. As the fluid passes through the flow path 310, it absorbs thermal energy from the rotor 304. Therefore, when it reaches the outlet 314, the fluid is considered to have a relatively high temperature. In some implementations, the electric motor 300 has a plurality of flow paths corresponding to the flow path 310, and all the flow paths conduct the fluid in the direction illustrated by this example (e.g., from right to left in the drawing). In other embodiments, one or more flow paths can conduct the fluid in the opposite direction (e.g., from left to right in the drawing). For example, the rotor 304 can have the same number of flow paths from right to left as from left to right.

[0043] Alternatively, the flow path 310 can provide a flow of fluid through the rotor shaft 306. In some implementations, a flow path 318 can be formed in the rotor shaft 306, and a flow path 320 can be formed through the rotor stack. The flow path 320 can be radially oriented and located at the center of the rotor 304 (e.g., as illustrated), or can be axially offset towards either end of the rotor body. The flow paths 318 and 320 form an inlet for the flow path 310, thereby providing a flow of fluid into the flow path 310. Thereafter, the fluid that has flowed into the flow path 310 can flow in either one or both directions within the flow path 310. For example, the flow path 310 can direct the flow from the flow path 320 towards the opposite ends of the rotor body.

[0044] FIG. 4 is a diagram showing examples of diagrams 400 and 402 regarding the tests of the end plates of FIGS. 1A - 1B. Diagrams 400 and 402 may illustrate the features of one or more other examples described elsewhere in this specification. Each of diagrams 400 and 402 shows the rotor temperature (e.g., magnet temperature) shown on the vertical axis as a function of time shown on the horizontal axis. Diagrams 400 and 402 correspond to different test cycles (e.g., different operating loads) for the rotor.

[0045] Diagram 400 includes graph 404 and graph 406. Graph 404 reflects the rotor temperature when the centrifugal pump is not used. For example, graph 404 shows that the temperature approaches a value of X degrees Celsius in part of the test cycle. On the other hand, graph 406 shows that the rotor temperature is maintained significantly lower than temperature X. Therefore, arrow 408 schematically illustrates that the centrifugal pump can significantly lower the temperature during the test cycle.

[0046] Diagram 402 includes graph 410 and graph 412. Graph 410 reflects the rotor temperature when the centrifugal pump is not used. For example, graph 410 shows that the temperature approaches a value of Y degrees Celsius in part of the test cycle. On the other hand, graph 412 shows that the rotor temperature is maintained significantly lower than temperature Y. Therefore, arrow 414 schematically illustrates that the centrifugal pump can significantly lower the temperature during the test cycle.

[0047] FIG. 5 is a diagram showing another example of a rotor stack 500 that can be used with a centrifugal pump to provide cooling. The rotor stack 500 can be used in one or more other examples described elsewhere in this specification. The rotor stack 500 may be similar to the rotor stack 200 (FIG. 2) in some respects. Below, for the sake of brevity, only the differences between the rotor stack 500 and the rotor stack 200 will be discussed in comparison.

[0048] The rotor laminate 500 includes holes 502. In some implementations, the holes 502 are formed between at least two magnets in the rotor laminate 500. For example, magnets 504A and 504B can be disposed within hole 204A such that hole 502 is formed between magnets 504A and 504B. Thus, a flow path for a centrifugal pump can be formed between at least two magnets of the rotor laminate 500, such as between magnets 504A and 504B. The rotor laminate 500 can include one or more other holes for the same centrifugal pump or other centrifugal pumps. Such holes can be formed adjacent to and / or between magnets, to name just two examples.

[0049] Figures 6-9 illustrate other examples of end plates 600, 700, 800, and 900 that can be used to provide a centrifugal pump to a rotor. One or more of end plates 600, 700, 800, or 900 can be used in one or more of the other examples described elsewhere in this specification.

[0050] End plate 600 is shown in a perspective view, illustrating the surface of end plate 600 that faces outward from a rotor laminate (not shown) when installed. Alternatively, the opposite surface of end plate 600 (not shown) faces inward toward the rotor laminate when installed. End plate 600 has a central opening 602 (e.g., circular in shape) that can accommodate a rotor shaft (not shown) and / or other components. End plate 600 includes holes 604 for attaching rivets that can extend end-to-end through the rotor stack to compress the rotor. For example, holes 604 can be chamfered on the outer surface of end plate 600.

[0051] The end plate 600 can form one or more inlets 606 for a centrifugal pump. Through the inlets 606, the centrifugal pump can suck in fluid and flow the fluid through at least one flow path within the rotor body. The end plate 600 can have a surface for abutting against an end of the rotor body (for example, the outermost side of a plurality of rotor laminations). Also, the inlets 606 can be formed by one or more features defined in relation to such a surface. In some implementations, the inlet 606 includes a concave region 608. The concave region 608 is not visible here. The concave region 608 can be a portion having a thickness smaller than the thickness of the end plate 600 at the laminate abutting surface. Therefore, during installation, the concave region 608 of the end plate 600 does not abut against the end of the rotor body. The inlet 606 includes a hole 610 extending through the end plate 600. The hole 610 can have any shape, including but not limited to a deformed rectangle (for example, a non-planar rectangle as shown in the figure). Other shapes can also be used for the hole 610. The concave region 608 can have any shape. In some implementations, the concave region 110 can be substantially symmetric with respect to the radius of the end plate 600. In some implementations, the concave region 608 can have a substantially wedge shape (for example, as shown in the figure).

[0052] The inlet 606 includes an outer peripheral lip 612 that closes the concave region 608. The outer peripheral lip 612 can extend to substantially surround the entire outer periphery of the end plate 600, except when mentioned in the examples described later. The end plate 600 can have a thickness substantially the same as the thickness at the laminate abutting surface at the outer peripheral lip 612. For example, during installation of the end plate 100, the outer peripheral lip 612 can abut against the end of the rotor body.

[0053] The inlet 606 can include one or more ribs. In some implementations, the concave region 608 is partitioned by at least one rib 614. For example, the rib 614 can partition the concave region 608 to guide the fluid at the inlet 606.

[0054] The end plate 600 does not have an outlet for the centrifugal pump. Rather, the outlet for the flow path supplied from the inlet 606 is at the end opposite to the rotor and is formed in the other end plate. For example, in the other end plate, a portion that can be an opening can be provided on the outer diameter of the rotor so that the flow can exit from the end plate. That is, the design of the present subject can be any of the following: (i) all inlets are arranged at one end of the rotor and all outlets are arranged at the other end, in which case all the flow flows from one end of the rotor to the other end (where the loop is closed by the flow moving through the air gap between the rotor and the stator); or (ii) the inlets and outlets can alternate within the same end plate and, in the opposite end plate, the flow direction can be changed alternately along the length of the rotor.

[0055] The inlet 606 can include a scoop 616 at the orifice 610. During operation, the scoop 616 can grab the fluid (e.g., air or oil) and push it into the inlet 606.

[0056] The end plate 600 can be non-clocking with respect to the end plate at the end opposite to the rotor body. For example, all rotational positions of the end plate 600 can align the inlet 606 with the corresponding outlet in the opposite end plate.

[0057] Turning now to end plate 700, it may be similar to end plate 600 or 100 in some respects. In the following, for the sake of brevity, only the differences between end plate 700 and end plate 600 or 100 will be discussed. End plate 700 has an inlet 702 that includes a hole 704, a recessed region 706, and an outer peripheral lip 708 that closes the recessed region 706. The recessed region 706 is not visible here. The recessed region 706 has a bow shape. In some implementations, the (invisible) wall 710 that defines the recessed region 706 may be curved. For example, the wall may curve in a direction opposite to the direction of rotation of end plate 700. The (invisible) rib 712 can partition the recessed region 706 to guide fluid at the inlet 702. For example, the rib 712 may have a bow shape.

[0058] Next, turning to end plate 800, it may be similar to end plate 700, 600 or 100 in some respects. In the following, for the sake of brevity, only the differences between end plate 800 and end plate 700, 600 or 100 will be discussed. End plate 800 has an inlet 802 that includes a hole 804, a recessed region 806, and an outer peripheral lip 808 that closes the recessed region 806. The recessed region 806 is not visible here. The recessed region 806 has a wedge shape. The (invisible) rib 810 can partition the recessed region 806 to guide fluid at the inlet 802. The inlet 802 may include a scoop 812 at the hole 804. During operation, the scoop 812 can grab fluid (e.g., air or oil) and push it into the inlet 802.

[0059] Finally, the end plate 900 is shown in plan view, and the surface of the end plate 900 that faces outward from the rotor stack (not shown) during installation is illustrated. Instead, the opposite surface of the end plate 900 (not shown) faces inwardly toward the rotor stack during installation. The end plate 900 has a central opening 902 (e.g., of circular shape) that can accommodate a rotor shaft (not shown) and / or other components. The end plate 900 includes holes 904 for attaching rivets that may extend end-to-end through the rotor stack to compress the rotor. For example, the holes 904 can be chamfered on the outer surface of the end plate 900.

[0060] The end plate 900 can form one or more inlets 906 for a centrifugal pump. Through the inlets 906, the centrifugal pump can draw in fluid and flow the fluid through at least one flow path within the rotor body. The end plate 900 can have a surface for abutting against the end of the rotor body (e.g., the outermost of a plurality of rotor stacks). Also, the inlets 906 can be formed by one or more features defined in relation to such a surface. In some implementations, the inlets 906 include a (not visible) recessed region 908. The recessed region 908 can be a portion having a thickness less than the thickness of the end plate 900 at the laminate abutment surface. Thus, during installation, the recessed region 908 of the end plate 900 does not abut against the end of the rotor body. The inlets 906 include holes 910 that extend through the thickness of the end plate 900. The holes 910 can have any shape, including but not limited to a deformed rectangle (e.g., as shown in the figures). Other shapes can also be used for the holes 910. The recessed region 908 can have any shape. In some implementations, the recessed region 908 can be substantially symmetric with respect to the radius of the end plate 900 (e.g., as shown in the figures). For example, the recessed region 908 can be symmetric with respect to the holes 910. In some implementations, the recessed region 908 can have a substantially wedge shape (e.g., as shown in the figures).

[0061] The inlet 906 includes an outer peripheral lip 912 that closes the concave region 908. The outer peripheral lip 912 can extend to substantially surround the entire outer periphery of the end plate 900, except when referred to in the examples described later. The end plate 900 may have a thickness substantially the same as that at the laminate contact surface at the outer peripheral lip 912. For example, when the end plate 900 is mounted, the outer peripheral lip 912 can contact the end of the rotor body. The inlet 906 can include one or more ribs. For example, the ribs can partition the concave region 908 to guide the fluid at the inlet 906.

[0062] The end plate 900 can form one or more outlets 914 for the centrifugal pump. Through the outlets 914, the centrifugal pump can discharge the fluid and flow the fluid through at least one flow path in the rotor body. That is, the outlets 914 of the end plate 900 can discharge the fluid that has flowed into the rotor from another inlet originally at the opposite end of the rotor rather than from any of the inlets 906 of the end plate 900. The outlets 914 can be formed by one or more features defined in relation to the laminate contact surface. In some implementations, the outlets 914 include a (not visible) concave region 916. The concave region 916 can be a portion having a thickness smaller than the thickness of the end plate 900 at the laminate contact surface. Therefore, when mounted, the concave region 916 of the end plate 900 does not contact the end of the rotor body. The concave region 916 can have any shape. In some implementations, the concave region 916 can have a wedge shape (for example, as shown in the figure).

[0063] The outlet 914 is provided with a recess 918 in the outer peripheral lip 912. The end plate 900 may have a thickness smaller than the thickness at the laminate contact surface at the recess 918. For example, the end plate 900 may have a thickness substantially the same as that of the concave region 916 at the recess 918. Through the recess 918, the fluid in the concave region 916 can be discharged from the end plate 900.

[0064] The inlet 906 and the outlet 914 positioned adjacent to each other can form a pair 920. The end plate 900 can include a plurality of exemplary pairs 920 distributed on the outer periphery of the end plate 900. For example, here, the end plate 900 includes six exemplary pairs 920 evenly distributed.

[0065] When attached to the rotor, the end plate 900 can be non - clocking with a corresponding (e.g., identical) end plate attached to the opposite rotor end. That is, among all possible angular orientations in which the end plate 900 can be attached (i.e., such that the holes 904 are aligned for riveting), each of the inlets 906 of the end plate 900 aligns with the corresponding outlet of the other end plate at the opposite end, and vice versa. Each of these angular orientations enables the centrifugal pump to draw fluid through one of the inlets 906, flow the fluid through the flow path, and discharge the fluid through the outlet at the opposite end plate. Similarly, each of these angular orientations enables the centrifugal pump to draw fluid through one of the inlets at the opposite end plate, flow the fluid through another flow path, and discharge the fluid through one of the outlets 914. Therefore, the end plate 900 and the identical end plate at the opposite end of the rotor body are non - clocking with each other.

[0066] FIG. 10 is a schematic view showing cross-sections of end plates 1000 and 1002 and air passages 1004 and 1006 within a rotor stack to explain the flow of fluid by a centrifugal pump. This 60-degree cross-section shows a view of the fluid volume formed by the rotor stack and the passages of end plates 1000 - 1002. Passages 1004 and 1006 are given here as examples. All connections between end plates 1000 and 1002 can serve as fluid flow paths. This 60-degree cross-section includes eight fluid flow paths, and a full rotor includes 48 fluid flow paths. For example, referring to FIG. 2, all holes 204A-1, 204A-2, 204B-1, 204B-2, 206A-1, 206A-2, 206B-1, and 206B-2 can also serve as fluid flow paths in this example. The example shown can be used in one or more other examples described elsewhere in this specification. Each of end plates 1000 - 1002 here corresponds to end plate 900 of FIG. 9. For example, end plates 1000 and 1002 correspond to the case where both the inlet and outlet are in a 60-degree cross-section (rather than a 120-degree cross-section) and no clocking of end plates 1000 and 1002 is required during assembly. Hole 1008 within end plate 1000 can correspond to either hole 204A - 204B or 206A - 206B of FIG. 2.

[0067] The rotor has an inlet 1010 leading to passage 1004 and then leading to an outlet 1012. Similarly, the rotor has a hole 1008 leading to passage 1006 and then leading to an outlet 1014. Inlet 1010 and outlet 1014 are formed here in end plate 1002. Similarly, outlet 1012 and hole 1008 are formed here in end plate 1000. The rotor allows fluid to flow through passages (including but not limited to passages 1004 and 1006) (e.g., in directions opposite each other) for thermal control of the rotor.

[0068] Figures 11A - 11D are diagrams showing examples where various positions within the rotor stack are used as fluid flow paths. Figures 12A - 12C are diagrams showing radial views of the rotor stack in Figures 11A - 11D. Any or all of the features can be used in one or more of the other examples described elsewhere in this specification. In each of Figures 11A - 11D, a portion of the rotor stack is shown axially. The stack includes a plurality of rotor laminations, but only the outermost rotor lamination is visible in each figure. The other rotor laminations of each stack may be referred to by example, and some of their features may be made visible for illustrative purposes. Each visible rotor lamination is shown only partially for simplicity and may have a pattern that repeats itself in the rotational direction about the rotor axis.

[0069] The rotor lamination 1100 (Figure 11A) includes magnets 1102A disposed in openings each having holes 1102A - 1 and 1102A - 2 respectively. The rotor lamination 1100 also includes magnets 1102B disposed in openings each having holes 1102B - 1 and 1102B - 2 respectively. One or more of holes 1102A - 1, 1102A - 2, 1102B - 1, or 1102B - 2 can serve as flow paths for a centrifugal pump that flows fluid through at least a portion of the rotor stack. The rotor stack having the rotor lamination 1100 has no inclination in the position of the magnets along the length of the rotor axis. Thus, it can be said that the rotor lamination forms a single stack 1200 as shown in the radial view by Figure 12A. That is, the single stack 1200 is a stack of rotor laminations where none of the laminations are offset by rotation.

[0070] Here, an example including an inclined rotor will be described. The rotor laminate 1104 (FIG. 11B) includes magnets 1106A disposed in openings each having holes 1106A-1 and 1106A-2. The rotor laminate 1104 also includes magnets 1106B disposed in openings each having holes 1106B-1 and 1106B-2. This figure also shows features from one of the other rotor laminates in the same rotor stack as the rotor laminate 1104. The other rotor laminates, not shown here, can be disposed behind or in front of the rotor laminate 1104 in this perspective, and include magnets 1108A disposed in openings each having holes 1108A-1 and 1108A-2, and magnets 1108B disposed in openings each having holes 1108B-1 and 1108B-2. The magnets 1106A and 1108A located at different axial depths along the rotor shaft are inclined relative to each other here. Similarly, the magnets 1106B and 1108B located at different axial depths along the rotor shaft are also inclined relative to each other here. The inclination occurs because the rotor laminate forms two stacks 1202 and 1204, as shown in the radial view by FIG. 12B. Here, the arrow 1206 of stack 1204 schematically shows that the magnets of stack 1204 are offset by rotation relative to stack 1202.

[0071] The fact that there is an inclination in the position of the magnet means that the corresponding holes formed adjacent to the inclined magnet are not necessarily aligned in a straight line from one end to the other end of the rotor. Therefore, one or more interconnects can be used to provide a continuous path for the fluid flow. FIG. 11C shows the rotor stack 1104 and also shows the interconnect 1110 that connects the holes 1106A-1 and 1108A-1 to each other. Similarly, the interconnect 1112 connects the holes 1106A-2 and 1108A-2 to each other; the interconnect portion 1114 connects the holes 1106B-1 and 1108B-1 to each other; and the interconnect portion 1116 connects the holes 1106B-2 and 1108B-2 to each other. Any or all of the interconnects 1110-1116 can be formed as openings in the rotor stack (including, but not limited to, the holes 212 in FIG. 2). For example, the hole 212 can be arranged to at least partially overlap both holes of any pair of the above-described holes in a direction perpendicular to the rotor axis. FIG. 11D shows the interconnects 1110-1116, which may be formed in a common rotor stack, here the rotor stack 1118, or may be distributed among two or more rotor stacks. FIG. 12C schematically shows in a radial view that the interconnect 1208 can serve as an intermediate (or middle) cross-section disposed between the stacks 1202 and 1204 and connecting the inclined stack holes. The interconnect 1208 can at least partially overlap the respective holes of the stacks 1202 and 1204 so that the flow path can continue through the length of the inclined rotor.

[0072] As shown in the previous example, the interconnection can be any of a plurality of possible structures. In some implementations, the interconnection 1208 is a separate plate of the rotor stack, and this plate has no magnets. Thereafter, for example, the interconnection 1208 can only function as a fluid interconnection. In some implementations, the interconnection 1208 is a separate stack of laminates within the rotor, and the stack has magnets and also has flow channels. In some implementations, one or more of the interconnections 1110 - 1116 are part of the stacks 1202 and 1204 only in the mating region. In some implementations, one or more of the interconnections 1110 - 1116 are part of the stacks 1202 and 1204 throughout the rotor stack.

[0073] Figures 13A - 13B show examples related to an end plate 1300 having an outlet flow path 1302 and an end plate 1304 having an inlet flow path 1306, respectively. The end plate 1300 has six exemplary outlet flow paths 1302 disposed surrounding its outer periphery. Each of the outlet flow paths 1302 can be created by a method of forming a recess from the surface of the outermost rotor laminate, whereby fluid can move through the flow path within the rotor. For an end plate at the opposite end of the rotor such as the end plate 1304, the fluid can exit through the outer diameter outlet.

[0074] The end plate 1304 has a pair of six exemplary inlet flow paths 1306 disposed surrounding its outer periphery. Each of the inlet flow paths 1306 can be created by a method of forming a recess from the surface of the outermost rotor laminate, whereby fluid can move through the flow path within the rotor.

[0075] In a design using end plates 1300 and 1304, fluid can flow into the rotor from inlet flow path 1306 on one side of the rotor. The fluid can flow through the holes of the laminate (e.g., adjacent magnets therein) along the length of the rotor from one end of the rotor to the other end. The fluid can exit the rotor at the outer diameter of outlet flow path 1302 at the other end of the rotor. Such a loop of fluid flow can be closed by the fluid flowing through the air gap between the rotor and the stator. Therefore, this example of plate design provides a one-way flow of fluid along the rotor stack.

[0076] Either or both of end plates 1300 or 1304 can have one or more schedulers 1308. For example, scheduler 1308 can ensure that the stack of end plates and rotor laminates are properly oriented relative to each other. Either or both of end plates 1300 or 1304 can have one or more holes 1310 for retaining pins. As another example, holes 1310 can be used to hold the laminates and compress them together.

[0077] The terms "substantially" and "about" used throughout this specification are used to account for and consider minor variations such as those resulting from variations during processing. For example, they can refer to less than or equal to ±5%, for example less than or equal to ±2%, for example less than or equal to ±1%, for example less than or equal to ±0.5%, for example less than or equal to ±0.2%, for example less than or equal to ±0.1%, for example less than or equal to ±0.05%. Also, as used herein, indefinite articles such as "a" or "an" mean "at least one".

[0078] It is to be understood that all combinations of the above concepts and additional concepts discussed in more detail below (subject to such concepts not being mutually inconsistent) are contemplated as being part of the subject matter of the invention disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are contemplated as being part of the subject matter of the invention disclosed herein.

[0079] Multiple implementations have been described. Nevertheless, it will be understood that various modifications can be made without departing from the spirit and scope of this specification.

[0080] In addition, the logical flows shown in the figures do not require the particular order, or sequential order, shown to achieve desirable results. In addition, other processes may be provided, or processes may be eliminated from the flows described, other components may be added to the systems described, or other components may be removed from the systems described. Accordingly, other implementations are within the scope of the following claims.

[0081] Certain features of the described implementations have been shown as described herein, but now many modifications, substitutions, changes, and equivalents will occur to those skilled in the art. Accordingly, it should be understood that the appended claims are intended to cover all such modifications and changes that fall within the scope of these implementations. They are presented by way of example only and not of limitation, and it is to be understood that various changes in form and detail may be made. Except for mutually exclusive combinations, any part of the apparatus and / or method described herein can be combined in any combination. The implementations described herein may include various combinations and / or sub-combinations of the functions, components, and / or features of the different implementations described.

Claims

1. A stator; and A rotor body; and A rotor having a centrifugal pump for flowing a fluid through a flow path extending axially from end to end through the rotor body Comprising an electric motor.

2. The flow path extends through a magnet hole in the rotor body, the electric motor according to claim 1.

3. The flow path is formed adjacent to a magnet located in the magnet hole, the electric motor according to claim 2.

4. The flow path is formed between at least two magnets located in the magnet hole, the electric motor according to claim 3.

5. The flow path is formed in a hole of the rotor body that does not contain a magnet, the electric motor according to claim 1.

6. The rotor body is formed by a laminate, and the laminate includes respective holes forming the flow path, the electric motor according to claim 1.

7. The electric motor includes first and second end plates forming the centrifugal pump, and the first and second end plates are clocked with each other, the electric motor according to claim 6.

8. The electric motor includes first and second end plates forming the centrifugal pump, and the first and second end plates are non-clocked with each other, the electric motor according to claim 6.

9. The electric motor includes first and second end plates forming the centrifugal pump, the flow path includes first and second flow paths formed by the laminate, and a first flow through the first flow path occurs in a direction opposite to a second flow through the second flow path, the electric motor according to claim 6.

10. The electric motor includes first and second end plates forming the centrifugal pump, the flow path includes first and second flow paths formed by the laminate, and a first flow through the first flow path occurs in the same direction as a second flow through the second flow path, the electric motor according to claim 6.

11. The flow path includes first and second flow paths formed by the laminate, the electric motor according to claim 6.

12. ​ The electric motor includes an end plate forming the centrifugal pump, the centrifugal pump includes an inlet formed in the end plate and an outlet formed in the end plate, wherein the inlet is aligned with the first flow path and the outlet is aligned with the second flow path, and the centrifugal pump flows a first fluid through the first flow path and flows a second fluid from the second flow path. The electric motor according to claim 11.

13. The inlet according to claim 12 includes a hole through the end plate, a concave region in the end plate that does not contact the laminate, wherein the concave region covers the first flow path, and an outer peripheral lip that closes the concave region. The electric motor according to claim 12.

14. The electric motor according to claim 13 further includes a rib that partitions the concave region so as to guide the fluid at the inlet.

15. The concave region according to claim 13 has a substantially arcuate shape. The electric motor according to claim 13.

16. The concave region according to claim 13 has a substantially wedge shape. The electric motor according to claim 13.

17. The inlet according to claim 13 further includes a scoop that forms the hole. The electric motor according to claim 13.

18. The outlet according to claim 12 includes a concave region in the end plate that does not contact the laminate, wherein the concave region covers the second flow path, and a recess in the outer peripheral lip of the end plate. The electric motor according to claim 12.

19. The concave region according to claim 18 is symmetric with respect to the radius of the rotor body. The electric motor according to claim 18.

20. The end plate according to claim 12 includes a plurality of pairs each including a respective inlet and a respective outlet, and the plurality of pairs are distributed on the outer periphery of the end plate. The electric motor according to claim 12.

21. The end plate according to claim 12 further includes a portion where material has been removed for rotor balancing. The electric motor according to claim 12.

22. The inlet of the flow path is formed in the shaft of the rotor. The electric motor according to claim 1.

23. The fluid according to claim 1 includes at least one of air or oil. The electric motor according to claim 1.

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