Electric machine with integrated dam set
Patent Information
- Application Number
- BR112021024800
- Authority / Receiving Office
- BR · BR
- Patent Type
- Patents
- Current Assignee / Owner
- Publication Date
- 2026-08-11
Smart Images
Figure 00000033_0000 
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Abstract
Description
1 / 28 ELECTRIC MACHINE WITH INTEGRATED DAM ASSEMBLY CROSS-REFERENCE TO RELATED REQUESTS
[001] This application claims priority under 35 USC § 119(e) to Provisional Application No. US 62 / 889,540, filed with the USPTO on August 20, 2019, the full contents of which are incorporated herein by reference. DESCRIPTION FIELD
[002] Some non-limiting exemplary embodiments refer generally to electric machine cooling systems and, more particularly, to an electric machine that has an integrated dam assembly to facilitate increased cooling. BACKGROUND OF THE DESCRIPTION
[003] In high-performance electric machine applications, effective thermal management can be a factor in machine performance. Increased power densities of electric machines have led to increases in heat densities, resulting in thermal conditions that may be undesirable. For example, excessive heat generation resulting from losses within stator windings, laminations, and / or magnets can be distributed to a variety of machine components. Excessive heat generation can cause adverse temperature effects. These temperature effects may include magnet demagnetization, component failure, and / or damage to machine insulation.
[004] To solve such issues and improve the thermal designs of electrical machines, a variety of cooling techniques have been employed. SUMMARY OF DESCRIPTION
[005] According to some exemplary modalities, a Petition 870260057514, dated 12 / 06 / 2026, p. 7 / 88 The 2 / 28 electric machine includes a dam assembly to facilitate increased heat transfer and cooling.
[006] According to some exemplary embodiments, an electric machine includes a housing, a stator assembly within the housing, a rotor assembly within the housing, and a dam assembly including a first dam element. The first dam element is disposed at one end of the electric machine. The first dam element includes an air inlet. The air inlet is configured to receive a supply of pressurized air.
[007] Other features and aspects will become apparent by considering the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[008] The detailed description of the drawings refers to the attached figures, in which:
[009] Figure 1 is a schematic diagram illustrating a system that includes an electric machine, according to some exemplary embodiments.
[0010] Figure 2 is an exploded perspective view of an electric machine according to some exemplary embodiments;
[0011] Figure 3 is an exploded perspective view of a rotor assembly arranged in the electric machine according to some exemplary embodiments;
[0012] Figure 4 is a side cross-sectional view of an electric machine according to some exemplary embodiments;
[0013] Figure 5A is a perspective view of a dam element arranged inside the electric machine in Figure 4 according to some exemplary embodiments;
[0014] Figure 5B is a partial cross-sectional side view. Petition 870260057514, dated 12 / 06 / 2026, p. 8 / 88 3 / 28 of one end of the electric machine in Figure 4 according to some exemplary embodiments;
[0015] Figure 5C is an enlargement of Figure 5B in a region labeled Z according to some exemplary embodiments;
[0016] Figure 6A is a partial cross-sectional view of another end of the electric machine of Figure 4 according to some exemplary embodiments;
[0017] Figure 6B is a perspective view of a dam element according to some exemplary embodiments;
[0018] Figure 7 is a flowchart of a method for operating the electric machine in Figure 4 according to some exemplary embodiments; and
[0019] Figure 8 is a side view of a work vehicle according to some exemplary embodiments;
[0020] Unless otherwise specified, similar reference numbers are used to indicate similar elements throughout the various figures. DETAILED DESCRIPTION OF SOME EXEMPLARY MODALITIES
[0021] According to some exemplary embodiments, the stator assembly at least partially surrounds the rotor assembly with a rotor-stator air gap between the stator assembly and the rotor assembly, and pressurized air flows in the rotor-stator air gap.
[0022] According to some exemplary embodiments, the rotor assembly at least partially surrounds the dam assembly with a rotor-dam air gap between the rotor assembly and the dam assembly and pressurized air flows in the rotor-dam air gap.
[0023] According to some exemplary modalities, the Petition 870260057514, dated 12 / 06 / 2026, p. 9 / 88 4 / 28 The first dam element includes a cable port near the air inlet, the cable port being sized to accommodate at least one cable, wherein at least one cable is connected to the electrical machine.
[0024] According to some exemplary embodiments, the first dam element includes an outer surface comprising a mound, at least one of a mound height or width, based on at least one of a stator assembly end turn size or length.
[0025] According to some exemplary embodiments, the first dam element includes an inner portion which includes a surrounding wall, and the surrounding wall is set back from a surface of the outer portion.
[0026] According to some exemplary embodiments, the rotor assembly includes a rotor shaft configured to rotate about a geometric axis and at least two plates, wherein the at least two plates are arranged at opposite ends of the rotor assembly.
[0027] According to some exemplary embodiments, the rotor assembly additionally includes a plurality of cavities that are sized to accommodate a permanent magnet.
[0028] According to some exemplary embodiments, the first dam element is arranged at one end without actuation of the electric machine.
[0029] According to some exemplary embodiments, the first dam element is arranged at one end of the electric machine drive.
[0030] According to some exemplary embodiments, the electric machine additionally includes an end shield having at least one orifice to receive a liquid. Petition 870260057514, dated 12 / 06 / 2026, p. 10 / 88 5 / 28 supply cooling, with the supply coolant circulating around one or more end turns within the stator assembly.
[0031] According to some exemplary embodiments, one or more end turns are submerged in the coolant supply.
[0032] According to some exemplary embodiments, the supply coolant is transmission fluid.
[0033] According to some exemplary embodiments, the dam assembly further comprises a second dam element disposed at another end of the electric machine and the electric machine further includes an end shield having at least one orifice at at least one end of the electric machine to receive a supply coolant, the supply coolant surrounding one or more end turns within the stator assembly.
[0034] According to some exemplary embodiments, one or more end turns are submerged in the coolant supply.
[0035] According to some exemplary embodiments, a gap between the rotor assembly and the dam assembly includes an air pocket to restrict the flow of pressurized air.
[0036] According to some exemplary embodiments, a gap between the rotor assembly and the stator assembly includes an air pocket through which pressurized air flows.
[0037] According to some exemplary embodiments, the rotor assembly is configured to rotate in response to a mechanical torque and the stator assembly is configured to generate an electrical signal in response to the mechanical torque received in the rotor assembly. Petition 870260057514, dated 12 / 06 / 2026, p. 11 / 88 6 / 28
[0038] According to some exemplary embodiments, the stator assembly is configured to receive an electrical signal and the rotor assembly is configured to rotate in response to the electrical signal received in the stator.
[0039] According to some exemplary embodiments, at least one of the pressurized air affects a quantity of supply coolant entering a rotor-stator air gap between the rotor assembly and the stator assembly, by creating a first air bubble in the rotor-stator air gap, or the pressurized air affects a quantity of supply coolant entering a rotor-dam air gap between the rotor assembly and the dam assembly, by creating a second air bubble in the rotor-dam air gap.
[0040] According to some exemplary embodiments, at least one of pressurized air blows the supply coolant away from a rotor-stator air gap between the rotor assembly and the stator assembly, or pressurized air blows the supply coolant away from a rotor-stator air gap between the rotor assembly and the dam assembly.
[0041] According to some exemplary embodiments, the air inlet is sized to supply approximately 3 liters per minute (lpm) of pressurized air.
[0042] According to some exemplary embodiments, a work vehicle includes a transmission configured to control the power to the work vehicle and an electric machine operatively coupled to the transmission, the electric machine comprising a stator assembly, a rotor assembly and a dam assembly, the dam assembly comprising a first dam element including an air inlet. The dam assembly is configured to introduce an air supply. Petition 870260057514, dated 12 / 06 / 2026, p. 12 / 88 7 / 28 pressurized through the air inlet in the first dam element.
[0043] According to some exemplary embodiments, the stator assembly at least partially surrounds the rotor assembly with a rotor-stator air gap between the stator assembly and the rotor assembly, and pressurized air flows in the rotor-stator air gap.
[0044] According to some exemplary embodiments, the rotor assembly at least partially surrounds the dam assembly with a rotor-dam air gap between the rotor assembly and the dam assembly and pressurized air flows in the rotor-dam air gap.
[0045] According to some exemplary embodiments, the first dam element comprises a cable port near the air inlet, the cable port being large enough to accommodate at least one cable, wherein at least one cable is connected to the electrical machine.
[0046] According to some exemplary embodiments, the first dam element comprises an outer portion comprising a mound, at least one of a mound height or width based on at least one of a stator assembly end turn size or length.
[0047] According to some exemplary embodiments, the first dam element includes an inner portion which includes a surrounding wall, in which the surrounding wall is set back from the outer surface.
[0048] According to some exemplary embodiments, the rotor assembly includes a rotor shaft configured to rotate about a geometric axis and at least two plates, wherein the at least two plates are arranged at opposite ends of the rotor assembly. Petition 870260057514, dated 12 / 06 / 2026, p. 13 / 88 8 / 28
[0049] According to some exemplary embodiments, the first dam element is arranged at one end without actuation of the electric machine.
[0050] According to some exemplary embodiments, the first dam element is arranged at one end of the electric machine drive.
[0051] According to some exemplary embodiments, the electric machine further comprises an end shield having at least one orifice for receiving a supply coolant, the supply coolant surrounding a plurality of end turns of the stator assembly.
[0052] According to some exemplary embodiments, the dam assembly further comprises a second dam element disposed at one end of the rotor assembly and the electric machine further comprises an end shield having at least one orifice for receiving a supply coolant, the supply coolant surrounding a plurality of the end turns of the stator assembly.
[0053] According to some exemplary embodiments, a method includes providing a stator assembly and a rotor assembly within a housing, disposing of a dam assembly within the housing, wherein the dam assembly is disposed in relation to the stator assembly and the rotor assembly, wherein the dam assembly comprises a first dam element and a second dam element disposed at opposite ends of the stator assembly and the rotor assembly, and introducing a supply of pressurized air through an air inlet in the first dam element, wherein the pressurized air affects a heat flow between the Petition 870260057514, dated 12 / 06 / 2026, p. 14 / 88 9 / 28 stator assembly and rotor assembly.
[0054] According to some exemplary embodiments, the method additionally includes the introduction of a supply coolant into the dam assembly, wherein the supply coolant surrounds one or more of the end turns of the stator assembly.
[0055] According to some exemplary embodiments, the introduction of the pressurized air supply occurs before the introduction of the supply coolant.
[0056] According to some exemplary embodiments, the method additionally includes rotating the rotor assembly.
[0057] According to some exemplary embodiments, the supply coolant is transmission fluid.
[0058] According to some exemplary embodiments, an electric machine includes a housing, a stator assembly within the housing, wherein the stator assembly includes end turns, a rotor assembly within the housing, wherein the rotor assembly comprises a rotor rod, a dam assembly comprising a first dam element, wherein the first dam element is disposed at one end of the stator assembly and an end shield having a plurality of holes for receiving a supply coolant, wherein the supply coolant surrounds one or more end turns within the stator assembly.
[0059] Figure 1 illustrates a system that has a vehicle with an electric machine, according to some exemplary embodiments.
[0060] With reference to Figure 1, a system 500 may include a vehicle, such as the work vehicle 50 described in more detail below. Petition 870260057514, dated 12 / 06 / 2026, page 15 / 88 10 / 28
[0061] The work vehicle 50 may include a transmission, such as the transmission 52 described below in more detail. The transmission 52 may be operatively coupled to an electric machine, such as the electric machine 100a described below.
[0062] There may be a fluid supply, such as coolant supply 57. Coolant supply 57 may supply a coolant, such as a transmission fluid, to the electric machine 100a and / or other vehicle components 50.
[0063] Included within or adjacent to the electric machine 100a, there may be damming elements, such as the first damming element 152 described below and the second damming element 154 described below.
[0064] At least one of the dam elements, such as dam element 150a, can be connected to a pump, such as air pump 593.
[0065] The air pump 593 can supply air to the electric machine 100a through the first dam element 152 and the air supplied by the air pump 593 can exit through the second dam element 154. The air supplied by the air pump 593 can cool components of the electric machine 100a, such as stator assemblies and / or rotor assemblies.
[0066] Alternatively or additionally, the fluid supplied from the coolant supply 57 may surround and / or submerge components, such as end turns of stator assemblies included in the electric machine 100a. The supplied fluid may cool the components of the electric machine 100a.
[0067] When air is supplied by air pump 593, air pockets can be created around the components of the electric machine 100a, for example, in gaps between the stator assembly and the assembly Petition 870260057514, dated 12 / 06 / 2026, p. 16 / 88 11 / 28 of rotor. Consequently, when the coolant is also supplied by the coolant supply 57, the coolant may not enter the air pockets. The coolant may instead be directed around and / or submerge other components of the electric machine 100a, such as end turns of the stator assembly included in the electric machine 100a.
[0068] With reference now to Figures 2-3, an electric machine 100 may comprise a housing 102 together with a stator assembly 110 and a rotor assembly 108. The housing 102 may comprise an outer cylindrical surface 103 having a removable assembly interface 112 coupled to it or, alternatively, formed integrally therein. Although in Figure 2 the assembly interface 112 is shown as comprising a plurality of assembly holes 113 that are dimensioned to receive one or more similar fasteners and / or connectors, exemplary embodiments are not limited thereto. For example, the assembly interface 112 may comprise a variety of coupling features and mechanisms based on the design of the electric machine 100.
[0069] In some exemplary embodiments, the stator assembly 110 may comprise a plurality of stator laminations arranged adjacently to define a stator core (not shown), each having generally cylindrical configurations. Alternatively or additionally, the stator assembly 110 may comprise a solid and / or split core element, with Figure 2 being only one example of such embodiment.
[0070] As shown in Figure 2, the stator assembly 110 may comprise a number n of slots 122 spaced circumferentially and aligned around an inner surface. Petition 870260057514, dated 12 / 06 / 2026, page 17 / 88 12 / 28 124 (n is an integer), with each of the n slots 122 being measured and dimensioned to accommodate one or more motor windings (e.g., coil windings) extending from the slots 122 to form end turns (e.g., as described below with reference to Figures 5A-6B). In some exemplary embodiments, one or more weld structures 123 may be formed and / or arranged on an outer surface 121 of the stator assembly 110. The weld structures 123 may provide a more secure bonding connection between the stator laminations.
[0071] As shown in Figure 2, the rotor assembly 108 may comprise a rotor rod 104.Furthermore, as shown in Figure 3, the rotor assembly 108 may additionally comprise one or more field-generating structures 126 that are spaced, for example, equidistantly spaced and arranged, for example, symmetrically arranged with respect to each other, for example, around each rotor lamination. One or more field-generating structures 126 may comprise at least two slots 125a, 125b that are dimensioned to receive one or more magnetic elements 106 (for example, permanent magnets). The magnetic elements 106 may be made of and / or include many materials, such as, but not limited to, at least one of ferritic material, NdFeB material and / or samarium cobalt.
[0072] In some exemplary, non-limiting embodiments, such as in Figure 2, the slots 125a, 125b may be arranged in a generally v-shaped configuration to allow the placement of each of the magnetic elements 106 in alternating polarity for the induction of an alternating magnetic field.
[0073] The rotor assembly 108 can rotate in response to an electrical signal (e.g., an AC signal) supplied to the stator assembly 110. For example, the electric machine 100 can operate as a motor. Petition 870260057514, dated 12 / 06 / 2026, p. 18 / 88 13 / 28 Alternatively or additionally, the rotor assembly 108 may rotate in response to a mechanical torque supplied to the rotor assembly 108, and the stator assembly 110 may generate an electrical signal (e.g., an AC signal) in response to the rotation of the rotor assembly 108. For example, the electrical machine 100 may operate as a generator.
[0074] In some exemplary embodiments, a spacer disc 116 may be integrally and / or removablely coupled to an end face 128 of one or more of the rotor laminations. The spacer disc 116 may comprise a plurality of coupling elements 117 that are designed for coincident engagement with spacer receiving openings 134 disposed on or in the end face 128.
[0075] With reference to Figure 3, there may be a plurality of large holes 127 and a plurality of small holes 132 on the end face 128. The plurality of large holes 127 and / or the plurality of small holes 132 may coincide with other components of the electric machine 100. The plurality of large holes 127 and / or the plurality of small holes 132 may help to reduce the inertia of the rotor assembly 108. With the plurality of large holes 127 and / or the plurality of small holes 132, the rotor rod 104 may accelerate and / or decelerate more quickly. The plurality of large holes 127 and / or the plurality of small holes 132 can also help to cool the rotor assembly 108 and / or the magnetic elements 106, for example, if air or another cooling liquid flows through the holes.
[0076] The spacer disc 116 can be used to divert coolant and / or oil to one or both ends of the rotor assembly 108.
[0077] As shown in Figure 3, the spacer disc 116 can be arranged concentrically with respect to the rotor rod 104 and Petition 870260057514, dated 12 / 06 / 2026, p. 19 / 88 14 / 28 positioned so that a portion, for example, a majority portion of each of the field-generating structures 126 is covered by the spacer disk 116. Although in some exemplary embodiments in the present document the spacer disk 116 is shown as including a generally circular configuration, exemplary embodiments are not limited to them and the geometric configuration of the spacer disk 116 may vary.
[0078] The performance of an electric machine can be affected, for example, by the heat generated around the end turns of a stator assembly. The end turns can be cooled, for example, they can be cooled with a coolant, such as an oil, as transmission fluid. However, allowing the coolant to enter the gaps between a rotor and a stator can cause wind loss and / or can cause high friction, leading to, for example, power loss due to a high rotor speed.
[0079] If the coolant, like the transmission fluid, surrounds the end turns of a stator assembly without, or with minimal risk of, the coolant causing energy loss due to high friction, the performance of an electric machine can be improved. For example, the amount of torque supplied by the electric machine can be increased. Alternatively or additionally, the performance requirements of magnets used in the electric machine can be reduced.
[0080] With reference now to Figure 4, a 100a electric machine may include similar features to those discussed above with reference to Figures 2 and 3, and similar descriptions may be omitted for the sake of brevity.
[0081] The 100a electric machine may include and / or have a 110 stator assembly. The 110 stator assembly may have coils with turns of Petition 870260057514, dated 12 / 06 / 2026, p. 20 / 88 15 / 28 end 142a, 142b, 144a, 144b. In addition, the electric machine 100a may have and / or include a rotor assembly 108. The rotor assembly 108 may have or include a rotor rod 104. The rotor assembly 108 may include a plurality of rotor laminations 118.
[0082] In addition, the electric machine 100a may include and / or have a dam assembly 150. The dam assembly 150 may facilitate increased heat cooling of the electric machine 100a, as shown according to some exemplary embodiments. The electric machine 100a may be arranged to extend between an end opposite the rotor shaft 104 and an ear of the rotor shaft 104. For example, the electric machine 100a may be arranged to extend from a front / outer end, for example, non-drive end 155 to a rear / inner end, for example, drive end 157.
[0083] In some exemplary embodiments, a cooling assembly may be disposed within the rotor assembly 108. For example, as illustrated in Figure 4, at least two plates 138a, 138b (e.g., end plates or cooling plates) may be disposed at opposite ends of the rotor assembly 108. Either or both plates 138a and 138b may apply uniform pressure to the laminations at the ends of the rotor assembly 108. There may be a groove G within the cooling plate 138a.
[0084] When the magnetic elements 106 are cooled, for example, by airflow and / or oilflow, there may be an increase in magnetic flux. Consequently, less electric current may be used, thus increasing the efficiency of the electric machine 100.
[0085] Additionally, referring to Figure 4, rotor rod 104 can be rotatably mounted within rotor assembly 108 to Petition 870260057514, dated 12 / 06 / 2026, p. 21 / 88 16 / 28 allow rotor rod 104 to be rotated relative to stator assembly 110 during operation.
[0086] The dam assembly 150 may be disposed within the housing 102 at opposite ends of the electric machine 100a. In some exemplary embodiments, the dam assembly 150 may comprise a first dam element 152 spatially disposed relative to a second dam element 154. The first dam element 152 and / or the second dam element 154 may be made of metal and / or plastic. The first dam element 152 and the second dam element 154 will be discussed in more detail with reference to Figures 5A-6B. The first dam element 152 and the second dam element 154 may not be connected to each other, for example, the first dam element 152 may be separate from the second dam element 154; however, exemplary embodiments are not limited to the same.
[0087] The dam assembly 150 can be arranged to direct a flow of coolant, such as a feed coolant and / or other suitable fluids, such as a transmission oil, around the winding coils and end turns 142a, 142b, 144a, 144b of the electric machine 100a. Furthermore, according to some exemplary embodiments, the end turns 142a, 142b, 144a, 144b can be cooled in a manner that reduces (e.g., minimizes) the amount of coolant flowing into a rotor-stator air gap and / or a rotor busbar.
[0088] Still referring to Figure 4, there may be cabling 120 connected to at least one of the end turns, for example, to end turn 142a. The 120 wiring can connect the electric machine 100 to other electrical components, such as an inverter. Petition 870260057514, dated 12 / 06 / 2026, p. 22 / 88 17 / 28 (not shown). Cable 120 may exit from an opening within one or both of the first dam element 152 or the second dam element 154.
[0089] In addition, there may be a dam inlet 202 near one end, for example, the non-drive end 155 of the electric machine 100a. The dam inlet 202 may be sized to receive an air supply, for example, pressurized air. The air may be pumped into the dam inlet 202, for example, supplied by a pump (not shown). The pump may be a component of the work vehicle 50 described above with reference to Figure 1. For example, the pump may be or correspond to pump 593 discussed above with reference to Figure 1.
[0090] In addition, there may be channels, such as a channel 520a between housing 102 and electrical machine components 100a, such as end shield 710a. The channels may spiral around the electrical machine 100a. The channels may receive a supply of lubricant and / or coolant, which will be described in more detail below. The lubricant and / or coolant may flow around the spiral channels, such as channel 520a. There may be at least one orifice (not shown) in housing 102 and channel 520a may be in fluid communication with a fluid supply, such as the coolant supply 57 described above in relation to Figure 1.
[0091] Although Figure 4 illustrates that the inlet of dam 202 is near the non-drive end 155 of electric machine 100a, exemplary embodiments are not limited to the same and the inlet of dam 202 may be near the drive end 157 of electric machine 100a.
[0092] In addition, there may be end shields 710a, 710b at the ends of the electric machine 100a. Petition 870260057514, dated 12 / 06 / 2026, page 23 / 88 18 / 28 Within the end shields 710a, 710b, there may be several small orifices 505a, 505b, 505c, 505d. The small orifices 505a, 505b, 505c, 505d may be arranged consecutively and uniformly around the end shields 710a, 710b; however, exemplary embodiments are not limited to the same.
[0093] The small orifices 505a, 505b, 505c, 505d may receive a coolant, such as a transmission fluid. The small orifices 505a, 505b, 505c, 505d may be arranged within the end bends 142a, 142b, 144a, 144b. The small holes 505a, 505b, 505c, 505d can direct the coolant around the end turns 142a, 142b, 144a, 144b.
[0094] A diameter of at least one of the small holes 505a, 505b, 505c, 505d may be 2 mm; however, exemplary embodiments are not limited to these. Various small holes 505a, 505b, 505c, 505d may not be limited to those illustrated in the figures. For example, various holes may be twenty or more within one or both of the end shield 710a, 710b, for example, may be twenty-four. The size / diameter and / or number of small holes 505a, 505b, 505c, 505d and / or the placement of the small holes 505a, 505b, 505c, 505d may be based on a size of the electrical machine 110a.
[0095] The coolant may partially or completely surround the end turns 142a, 142b, 144a, 144b of the stator assembly 110. The end turns 142a, 142b, 144a, 144b may be partially or completely submerged in coolant. The coolant may be supplied from a coolant supply source, for example, the coolant supply 57 discussed above with reference to Figure 1. The coolant may exit the machine. Petition 870260057514, dated 12 / 06 / 2026, p. 24 / 88 19 / 28 electrical 100 in or near a transmission (e.g., transmission 52 described with reference to Figure 1).
[0096] As will be appreciated by those versed in the technique, the Figures 1-4 are provided for illustrative and exemplary purposes only and are not intended to limit any exemplary embodiments or their applications. For example, the arrangement and / or structural configuration of the electric machine 100 and / or dam assembly 150 may vary. For example, in some exemplary embodiments, the positional arrangement of the dam assembly 150 may vary based on the machine size (e.g., 180 mm vs. 120 mm). Additionally or alternatively, the internal circuitry and component arrangement of the electric machine 100 may vary according to design and / or specification requirements.
[0097] With reference now to Figures 5A-6B, a more detailed view of the first dam element 152 and the second dam element 154 in relation to other components of the electric machine 100a is shown. In some exemplary embodiments, the first dam element 152 may be disposed at the non-drive end 155 of the electric machine 100a and may have an inner surface 204 integrally formed with an outer surface 203. The first dam element 152 may comprise a mound 217 formed thereon which is dimensioned to accommodate the end turns 142a, 142b. For example, a height and / or width of the mound 217 may be defined based on a size and / or length of the end turns 142a, 142b. The first dam element 152 may include a surrounding wall 208 that partially encircles portions of the end turns 142a, 142b.
[0098] The first dam element 152 may have an inner wall 206 that is dimensioned to accommodate the rotor shaft 104.
[0099] The first dam element 152 may include several Petition 870260057514, dated 12 / 06 / 2026, page 25 / 88 20 / 28 connection areas 250a, 250b, 250c, 250d. The connection areas 250a, 250b, 250c, 250d can be arranged to fix the first dam element 152 to other components of the electric machine 100a. For example, the first dam element 152 can be fixed to the electric machine 100a by means of several screws arranged in the connection areas 250a, 250b, 250c, 250d. Although four connection areas are illustrated, exemplary embodiments are not limited to them.
[00100] As illustrated in Figures 5A and 5B, the first dam element 152 can couple and / or join to other components of the electrical machine 100a. For example, the mount 217 can enclose the end turns 142a, 142b. A wall 205 in the first dam element 152 can have a first surface exposed to air, for example, atmospheric air, and a second surface exposed to other air, for example, pressurized air supplied from a pump connected to the dam inlet 202. The surrounding wall 208 can extend around a portion of the end turns, for example, a portion of the end turn 142b. There can be a cavity C between the surrounding wall 208 and the wall 205. The cavity C can have a slight positive pressure in it when pressurized air is introduced through the dam inlet 202.
[00101] As shown in Figure 5B, a rotor-stator air gap 163 can be formed between the stator assembly 110 and the rotor assembly 108, and a rotor-dam air gap 165 can be formed between the first dam element 152 and the rotor assembly 108. The rotor-stator air gap 163 and / or rotor-dam air gap 165 can form annuli. For example, an annulus can be formed between the rotor assembly 108 and the stator assembly 110, and / or an annulus can be formed between the rotor assembly 108 and the dam assembly 150. A hydraulic diameter d1 is approximately 1 for the rotor-stator air gap. Petition 870260057514, dated 12 / 06 / 2026, p. 26 / 88 21 / 28 163 and a hydraulic diameter d2 of the rotor-dam air gap is about 0.5; however, exemplary embodiments are not limited to these and the rotor-dam air gap 165 may be much shorter in some exemplary embodiments.
[00102] Plate 138a may include groove G, for example, a cutout in it. The surrounding wall 208 connects to the cooling plate 138a within groove G of the cooling plate 138a. Groove G may help stabilize a connection between the first dam element 152 and plate 138a.
[00103] The dam entry 202 may be disposed near a cable port 210. The cable port 210 may be dimensioned to receive multiple cables, such as the cabling 120 described with reference to Figure 4 and / or terminal connections, for example, to and from other electrical components, such as an inverter (not shown). The cable port may be at an upper end of the first dam element 152. Furthermore, although in Figure 5A the dam entry 202 is shown as being disposed at the upper end of the first dam element 152, the length, location and / or arrangement of the dam entry 202 may vary and exemplary embodiments are not limited thereto. For example, the dam entry 202 may be disposed at a lower end of the first dam element 152.
[00104] The inlet of dam 202 can be sized to supply approximately 3 liters per minute (lpm) of air. For example, air supplied through the inlet of dam 202 will flow through air gaps 163, 165. Furthermore, air supplied to air gaps 163, 165 can create air pockets / bubbles that inhibit or reduce the amount of coolant entering the air gap. The inlet of dam 202 can be connected to a pump (not shown), which can supply approximately 3 lpm of air. Petition 870260057514, dated 12 / 06 / 2026, p. 27 / 88 22 / 28 pressurized for electric machine 100.
[00105] Air, such as pressurized air flowing within the electric machine 100a, can enable the electric machine 100a to run cooler and / or at a higher rate of rotation. Pressurized air can also reduce losses in the air gaps 163, 165.
[00106] As shown in Figure 5C, there may be channels, such as channel 520a, between housing 102 and other components of the electric machine 100a, such as end shielding 710. The 520a channels may be contiguous and may spiral around the electric machine 100a.
[00107] Housing 102 may be surrounded by a coolant, such as transmission fluid F, and the transmission fluid F may enter channel 520, for example, it may enter channel 520 through an orifice (not shown) in housing 102.
[00108] There may be a cavity 510a between the end shield 710 and the end gyros, such as end gyro 142a. The transmission fluid F may enter the cavity 510a from at least one small orifice 505a, 505e within the end shield 710. The fluid F may encircle end gyro 142a. The cavity 510a may be in fluid communication with the channel 520a, so that the fluid F may enter through at least one small orifice, such as the small orifice 505a, 505e.
[00109] As air A is pumped from the inlet of dam 202, an air pocket PA may be formed in the rotor-stator air gap 163 and / or an air pocket PB may be formed in the rotor-dam air gap 165.
[00110] Fluid F can be inhibited, or its probability of occurrence reduced, from entering the rotor-stator air gap 163 and / or the rotor-dam air gap 165. The end spindle 142a can be cooled by Petition 870260057514, dated 12 / 06 / 2026, p. 28 / 88 23 / 28 fluid F and / or the rotor shaft 104 illustrated in Figure 5B can be operated at high speed without or with reduced risk of energy loss caused by friction of the coolant F.
[00111] If fluid F, for example, a significant quantity of fluid F were to enter the rotor-stator air gap 163 and / or rotor-dam air gap 165, fluid F might experience a high rate of friction, for example, friction created by the rotation of the rotor shaft 104. However, when air is pumped through the dam inlet 202, a positive pressure differential can be created within the rotor-stator air gap 163 and / or rotor-dam air gap 165. This pressure differential can create air pockets / air bubbles that inhibit fluids, such as fluid F supplied through the small orifices 505a, 505b, 505c, 505d, from entering the rotor-stator air gap 163 and / or rotor-dam air gap 165.Therefore, the fluid F supplied through the small orifices 505a, 505b, 505c, 505d can be directed to the end turns 142a, 142b, 144a, 144b and may not enter or may only partially enter the rotor-stator air gap 163 and / or the rotor-dam air gap 165.
[00112] With reference now to Figures 6A and 6B, the second dam element 154 may have an inner surface 315 and an outer surface 314. The inner surface 315 may include recesses 320 dimensioned relative to the end turns 144a, 144b.
[00113] The second dam element 154 may have a port 310. Port 310 may be an outlet port through which coolant may exit the electrical machine 110a. The coolant, as fluid F described with reference to Figure 5C, may exit the electrical machine 110a, for example, it may exit and fall gravitationally, for example, to other components of a working vehicle 50. For example, fluid F may act as a transmission fluid for the transmission 52 described with reference to Petition 870260057514, dated 12 / 06 / 2026, p. 29 / 88 24 / 28 Figure 1 Alternatively or additionally, fluid F can flow to a drain and / or a reservoir (not shown).
[00114] Furthermore, air, such as air A discussed in Figure 5C, which is pumped through the inlet of the dam 202, can flow out through an opening 306. The air can exit the electric machine 100a.
[00115] The second dam element 154 may include several connection areas 350a, 350b, 350c, 350d, 350e. The connection areas 350a, 350b, 350c, 350d, 350e may be arranged to fix the second dam element 154 to other components of the electric machine 100a. For example, the second dam element 154 may be fixed to the electric machine 100a by means of several screws arranged in the connection areas 350a, 350b, 350c, 350d, 350e. Although five connection areas are illustrated, exemplary embodiments are not limited to them.
[00116] In all electrical machines, air shear in the air gap can create strong winds, which can cause a significant increase in temperature. At higher operating speeds (rotational speeds) of the 100a electrical machine, the generated heat supply is often from 0.5 kW to 1 kW in some 100a electrical machines. The axial directional component of the air flowing through the air gap reduces, for example, minimizes the temperature increase of this air before the air exits the air gap. This air can then be directed out of the 100a electrical machine.This same axial airflow can also reduce the heat flow from rotor assembly 108 to stator assembly 110 (for example, if rotor assembly 108 is the hotter component) and / or can reduce the heat flow from stator assembly 110 to rotor assembly 108 (for example, if stator assembly 110 is the hotter component), as the heat flowing from rotor assembly 108 to the air can be. Petition 870260057514, dated 12 / 06 / 2026, p. 30 / 88 25 / 28 blown out of the air gap.
[00117] Figure 7 illustrates a method of operation of an electric machine, according to some exemplary embodiments.
[00118] With reference to Figure 7, in step S801, air can be pumped to a dam inlet located inside the electric machine. For example, air can be supplied by pump 593 described with reference to Figure 1, and can enter the electric machine 100a through the dam inlet 202 described with reference to Figure 4.
[00119] The air that is pumped to the dam inlet can enter a first dam element, such as the first dam element 152 described with reference to Figure 4, and create a positive pressure differential around the gaps in the electric machine components. For example, there may be a positive pressure created in a gap between a rotor core and a stator core. The air that is pumped through the dam inlet can exit the electric machine, for example, from an opening 306 in a second dam element 154 described with reference to Figure 6B.
[00120] In step S802, a coolant, such as a transmission fluid F described with reference to Figure 5C, can be introduced into the electric machine, such as the electric machine 100a described above. The coolant can enter through cavities, such as small holes 505a, 505b, 505c, 505d, 505e in the electric machine 100a described above. The coolant can partially or completely surround the end turns of the stator elements within the electric machine, such as the end turns 142a, 142b, 144a, 144b of the electric machine 100a.
[00121] The coolant can cool the end turns. Additionally, because of the positive pressure created by the air pumped in step S801, the coolant may not enter. Petition 870260057514, dated 12 / 06 / 2026, page 31 / 88 26 / 28 or it may only partially enter, between the air gaps between the stator and the rotor and / or between the rotor and the dam, such as the air gaps 163, 165 described above. For example, there may be an air bubble / pockets of pure air due to the pressurized air in the rotor-stator air gaps and / or between the rotor dam air gaps. Furthermore, any coolant that enters the rotor-stator air gap and / or rotor-dam air gap may be blown away by the pressurized air.
[00122] In step S803, a rotor assembly, such as rotor assembly 108, can rotate within an electric machine, such as electric machine 100 described above. Because the end turns, such as end turns 142a, 142b, 144a, 144b, have been cooled, for example, cooled in step S802, and / or because there is no, or a small amount of coolant in the air gaps, rotor assembly 108 can operate at high speed and / or with increased efficiency.
[00123] According to some exemplary embodiments, each of the steps described above may be optional. For example, air may be pumped into the first dam element in step S801, while no coolant is supplied (i.e., step S802 is not performed). Step S801 may occur before, after, or simultaneously with step S802. For example, the supply coolant may be introduced before the air is pumped. Step S803 may occur before, after, or simultaneously with one or both steps S801 and S802.
[00124] With reference now to Figure 8, a vehicle, such as a work vehicle 50, may include a roof 60, a steering wheel 66, a steering column 64, a hood 54, a plurality of front wheels 56, a plurality of rear wheels 58, a passage 62 and a transmission 52. Petition 870260057514, dated 12 / 06 / 2026, p. 32 / 88 27 / 28
[00125] The roof 60 may be on top of the work vehicle 50 and may provide shade and / or protection from the elements, such as protection from rain, for a user (e.g., an operator) of the work vehicle 50. The passages 62 may help to escape air from the work vehicle 50. The steering wheel 66 may allow a user to steer the work vehicle 50, for example, by adjusting the orientation of the front wheels 56. The steering wheel 66 may be connected to the steering column 64, which may be connected to the front wheels 56.
[00126] There may be an engine (not shown) under the hood 54. The engine may be or include an internal combustion engine that converts a fuel into mechanical energy to power the components of the work vehicle 50, for example, to drive one or both of the front wheels 56 or the rear wheels 58. The fuel may be an organic fuel, for example, a fossil fuel.
[00127] Alternatively or additionally, there may be an electric machine, such as an electric machine 100a described above, which converts electrical energy into mechanical energy. For example, the work vehicle 50 may not convert fuel, such as a fossil fuel, into mechanical energy. The work vehicle 50 may additionally correspond to a hybrid electric vehicle, for example, a vehicle that is powered by means of an electric machine and by means of an internal combustion engine.
[00128] Transmission 52 can be operatively coupled to electric machine 100a. Transmission 52 can adjust the power to one or both front wheels 56 and rear wheels 58.
[00129] Without in any way limiting the scope, interpretation or application of the claims set forth below, a technical effect of one or more of the exemplary embodiments disclosed herein includes a cooling system and / or a method Petition 870260057514, dated 12 / 06 / 2026, page 33 / 88 28 / 28 operation for an electric machine having a dam assembly to facilitate increased cooling.
[00130] Although the above describes exemplary embodiments of some exemplary embodiments, these descriptions should not be viewed in a limiting sense. Instead, other variations and modifications may be made without departing from the scope and spirit of some exemplary embodiments, as defined in the appended claims. Petition 870260057514, dated 12 / 06 / 2026, page 34 / 88
Claims
1 / 4 CLAIMS 1. Electric machine (100) characterized in that it comprises: a housing (102); a stator assembly (110) within the housing (102); a rotor assembly (108) within the housing (102); and a dam assembly (150) comprising a first dam element (152), wherein the first dam element (152) is disposed at one end of the electric machine (100), wherein the first dam element (152) includes an air inlet (202); wherein the air inlet (202) is configured to receive a pressurized air supply; and wherein the first dam element (152) comprises an outer surface (203) comprising a mount (217), at least a height or width of the mount (217) based on at least a size or length of an end turn (142) of the stator assembly (110).
2. Electric machine (100), according to claim 1, characterized in that: the stator assembly (110) at least partially surrounds the rotor assembly (108) with a rotor-stator air gap (163) between the stator assembly (110) and the rotor assembly (142), and pressurized air flows in the rotor-stator air gap (163).
3. Electric machine (100), according to claim 1, characterized in that: the rotor assembly (108) at least partially surrounds the dam assembly (150) with a rotor-dam air gap (163) between the rotor assembly (108) and the dam assembly (150), and pressurized air flows in the rotor-dam air gap (165). Petition 870260057514, dated 12 / 06 / 2026, page 35 / 88 2 / 4 4. Electric machine (100), according to claim 1, characterized in that the first dam element (152) is disposed at a non-drive end (155) of the electric machine (100).
5. Electric machine (100), according to claim 1, characterized in that the first dam element (152) is disposed at a drive end (157) of the electric machine (100).
6. Electric machine (100), according to claim 1, characterized in that the electric machine (100) further comprises at least one end shield (710a, 710b) having at least one opening (505a, 505b, 505c, 505d) for receiving a supply coolant (F), wherein the supply coolant (F) surrounds one or more end turns (142a, 142b, 144a, 144b) within the stator assembly (110).
7. Electric machine (100), according to claim 6, characterized in that one or more end swivels (142a, 142b, 142c, 142d) are submerged in the supply coolant (F).
8. Electric machine (100), according to claim 6, characterized in that the supply coolant (F) is a transmission fluid.
9. Electric machine (100), according to claim 1, characterized in that the dam assembly (150) further comprises a second dam element (154) disposed at another end of the electric machine (100), and the housing (102) includes at least one opening (520a) for receiving a supply coolant (F), wherein the supply coolant (F) surrounds one or more end turns (142a, 142b, 144a, 144b) within the stator assembly (110).
10. Electric machine (100), according to claim 9, characterized in that one or more end swivels (142a, 142b, 144a, 144b) are submerged in the supply coolant (F).
11. Electric machine (100), characterized in that it comprises: a housing (102); a stator assembly (110) within the housing (102); a rotor assembly (108) within the housing (102); and a dam assembly (150) comprising a first dam element (152), wherein the first dam element (152) is disposed at one end of the electric machine (100), wherein the first dam element (152) includes an air inlet (202); wherein the air inlet (202) is configured to receive a supply of pressurized air; and wherein the first dam element (152) comprises a cable port (210) near the air inlet (202), wherein the cable port (210) is sized to receive at least one cable (120), wherein at least one cable (120) is connected to the electric machine (100).
12. Electric machine, according to claim 11, characterized in that the first dam element (152) comprises an inner portion including a wall (206), wherein the wall is recessed from the outer surface (203).
13. Electric machine (100), according to claim 12, characterized in that the rotor assembly (108) includes a rotor rod (104) configured to rotate around a geometric axis, and at least two plates (138a, 138b), wherein the at least two plates are disposed at opposite ends of the rotor assembly (108).
14. Electric machine (100), according to claim 13, characterized in that the rotor assembly (108) additionally includes a plurality of cavities (510) that are sized to receive a permanent magnet (106). Petition 870260057514, dated 12 / 06 / 2026, p. 38 / 88