Magnetic braking system

Abstract

A magnetic braking system for an agricultural irrigation system is described. The braking system includes a series of permanent magnets to prevent the rotation of a shaft relative to a stator magnet. The magnetic brake can be disengaged by rotation of a shaft through the utilization of centrifugal force-generated linear motion, which separates a rotating magnet from the stator magnet once the centrifugal force reaches a certain amount. In this deployed state, the magnetic brake does not impact rotational speed of the shaft. Once the centrifugal force falls below a certain threshold, biasing members return the linear motion assembly back into a nondeployed state, re-engaging the magnetic brake. A drive assembly can include a dynamic brake designed to slow rotation of a shaft to a threshold rotational speed, and a stopping brake designed to, at this threshold rotational speed, activate and prevent or substantially prevent the shaft from rotating.

Description

UMCOMP.043WO PATENTMAGNETIC BRAKING SYSTEMCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 685177, filed August 20, 2024, the entire content of which is incorporated herein by reference in its entirety.BACKGROUND OF DISCLOSUREField of Disclosure

[0002] The present disclosure relates to the field of braking systems for use in mechanized agricultural equipment, and more particularly to a magnetic braking system disengaged by centrifugal force-generated linear motion.Background

[0003] Center pivot and linear irrigation systems are well known in the art for their ability to irrigate large sections of land. Typically, such systems are capable of watering a quarter section of land, e.g., 160 acres, or more. A center pivot irrigation system generally includes an elongated primary irrigation pipe that extends radially outward from a center pivot. When activated, the irrigation pipe rotates around the pivot, thereby watering the area that the irrigation system passes over and resulting in a circular pattern of water coverage about the central pivot point. The length of time involved in a 360 degree rotation of the irrigation pipe may be up to several days in traditional systems. Likewise, linear systems are included of similar irrigation pipes, but move linearly across sections of land to be irrigated.

[0004] In conventional irrigation systems, the elongated irrigation pipe or span is supported at spaced apart intervals by a plurality of wheeled towers. Extending between each set of adjacent towers is a truss arrangement utilized to support the span and the water deployment system. Sprinklers are located at spaced intervals along the length of the span or a parallel water conduit. The wheels of each tower are normally positioned perpendicular to the span to permit the tower to follow a prescribed path, either circular for center pivot systems or linear for linear systems.

[0005] Whether center pivot or linear, each tower is typically provided with a drivetrain to distribute motive power to the wheels and operable to move the tower in synchronization with the other towers such that the overall length of the span can be maintained in substantially a straight line as the irrigation system moves through its prescribed path. In most conventional systems, the drivetrain consists of a motor, a divider gearbox, at least one drive shaft, at least one wheel drive gearbox and at least one wheel hub. More specifically, either an electric or hydraulic motor, referred to as a center drive or drive gear motor, is coupled to a divider gearbox centrally located along the base of the tower. The divider gearbox is used to reduce the power input from the motor and divide the power output for transmission to the powered wheel hubs typically positioned at the outer edge of the tower's base. Each wheel hub is attached to a wheel drive gearbox and is driven by a driveshaft extending from the power output shaft of the divider gearbox. Since such irrigation systems may take several days to complete a single watering cycle rotation, the output revolutions per minute of the center drive motors and drive shafts are geared to be very low, generally in the range of 28-86 rpm.

[0006] When the center pivot or linear irrigation system would be in motion, the center drive motor would cause the system to either rotate or transfer linearly across the irrigated areas. When not in use however, the irrigation systems need brakes or some other system set in place to prevent free movement of the towers. As it is common that irrigation systems are often used on uneven, sloping or even hilly ground, there is a concern that the machinery could roll uncontrolled down the incline as the output shaft “back drives”, i.e., rolling backwards down a slope, or “forward drives”, i.e., rolling forwards down a slope, the gearing of a gearbox attached to the irrigation systems’ motor. Such uncontrolled motion can result in damage to the drivetrain and the irrigation equipment itself. The towers may move freely in situations where the irrigated farmland is not level, where wind or other forces are moving the towers, or by other situations affecting farming areas. Traditional systems have relied on mechanical braking through the use of brake disks, or design choices in gearboxes to severely limit the free motion of irrigation systems. An example of an irrigation system drivetrain assembly which utilizes specific design choices to apply a natural braking force to the system is disclosed in U.S. Patent Number 10,502,283, incorporated herein by reference in its entirety and made a part of this specification.

[0007] Traditional systems may opt for including a worm gear configuration to drive the system, by rotating a threaded shaft which then interacts with the worm gear connected to theirrigation system towers. While these systems limit back-driving or forward-driving their irrigation systems, they also typically have efficiencies of only about 50%, as approximately half of the input power is lost by the gearbox due to friction.

[0008] Systems which employ the use of mechanical brakes also have their drawbacks, as electromechanical or electromagnetic brakes utilize electrical components. These additions to the system require the brakes to be generally enclosed. Further difficulties arise, as the extreme weather conditions of cold, heat and precipitation often result in a buildup of condensation within even an enclosed case. Because of this environment, the brake components have a tendency to rust. This becomes a particular problem when the machinery has been idle for a period of time, such as during the winter season. In such cases, the brake components often rust bond together, rendering the brake inoperable. In addition to any resultant rusting to the brake components, this moisture can cause malfunction of the electrical components of the brake. Thus, such electromechanical or electromagnetic brakes have been found to be undesirable for use in the drivetrain of agricultural irrigation equipment.

[0009] Therefore, it would be desirable to provide a braking system which would neither require a designed efficiency losses to apply a natural brake nor utilize a braking system prone to damage due to fatigue or degradation of braking components, and rather be preferably mechanically operable and designed to minimize its susceptibility to the elements.SUMMARY OF DISCLOSURE

[0010] These and other objects are achieved through the centrifugal permanent magnet brake (e.g., Centrifugal-Magnet brake) for rotating machines of the present disclosure. The braking system includes a series of permanent magnets within a stator magnet to prevent the rotation of a shaft also fitted with a series of permanent magnets which can be part of a drivetrain. The magnetic brake can be disengaged by rotation of a shaft through the utilization of centrifugal force-generated linear motion, which separates a rotating magnet from the stator magnet once the centrifugal force reaches a certain amount. In this deployed state, the magnetic brake does not impact rotational speed of the shaft. Once the centrifugal force falls below a certain threshold, biasing members return the linear motion assembly back into a nondeployed state, re-engaging the magnetic brakes.

[0011] According to some embodiments, the techniques described herein relate to a magnetic brake system for an agricultural system, the magnetic brake system including: a shaft; arotating magnet assembly disposed on the shaft, the rotating magnet assembly having at least one translating magnet recess to house at least one translating magnet; a fixed magnet assembly positioned radially aligned with the rotating magnet assembly, the fixed magnet assembly having at least one fixed magnet; and a centrifugal weighted assembly disposed on the shaft and connected to the rotating magnet assembly, the centrifugal weighted assembly configured to rotate and translate with the rotating magnet assembly along the shaft; wherein the centrifugal weighted assembly further includes at least one biasing member applying a retaining force in a first direction along the shaft; wherein the at least one translating magnet of the rotating magnet assembly is configured to magnetically interact with the at least one fixed magnet of the fixed magnet assembly; wherein after the shaft rotates at a threshold rotational speed the centrifugal weighted assembly and the rotating magnet assembly along the shaft translate linearly in a second direction substantially opposite the first direction; and wherein after the centrifugal weighted assembly and the rotating magnet assembly translate linearly in the second direction, the rotating magnet assembly magnetically disengages from the fixed magnet assembly.

[0012] According to some embodiments, the techniques described herein relate to a magnetic brake system, wherein the fixed magnet assembly and the rotating magnet assembly each include at least two magnets.

[0013] According to some embodiments, the techniques described herein relate to a magnetic brake system, wherein at least two fixed magnets within the fixed magnet assembly are aligned with at least two of the at least one translating magnets within the rotating magnet assembly.

[0014] According to some embodiments, the techniques described herein relate to a magnetic brake system, wherein the rotating magnet assembly is prevented from rotating relative to the shaft.

[0015] According to some embodiments, the techniques described herein relate to a magnetic brake system, further including a guard positioned radially outward from the centrifugal weighted assembly; wherein the guard is positioned such that it is radially outward from the centrifugal weighted assembly.

[0016] According to some embodiments, the techniques described herein relate to a magnetic brake system, wherein the guard is prevented from rotating relative to the shaft by a key.

[0017] According to some embodiments, the techniques described herein relate to a magnetic brake system including: a shaft; a rotating magnet assembly disposed on the shaft, the rotating magnet assembly having at least one translating magnet recess to house at least one translating magnet; a fixed magnet assembly positioned radially in line with the rotating magnet assembly, the fixed magnet assembly having at least one fixed magnet; and a translation assembly including a stationary component, a translating component, and at least one centrifugal weight carrier; and wherein the translating component is attached to the rotating magnet assembly; and wherein the at least one centrifugal weight carrier is configured such that when the magnetic brake system, the rotating magnet assembly, and the translation assembly rotate at a threshold rotational speed, the at least one centrifugal weight carrier converts from an engaged state to a disengaged state, and the translating component disengages the rotating magnet assembly from the fixed magnet assembly.

[0018] According to some embodiments, the techniques described herein relate to a magnetic brake system, wherein the translating component includes an aligner protrusion; wherein the stationary component includes an aligner cavity; and wherein the translating component remains in rotational alignment with the stationary component through contact between the aligner protrusion and the aligner cavity.

[0019] According to some embodiments, the techniques described herein relate to a magnetic brake system, wherein the at least one centrifugal weight carrier is configured to convert from the engaged state to the disengaged state at the threshold rotational speed by modifying a centrifugal weight attached to the at least one centrifugal weight carrier.

[0020] According to some embodiments, the techniques described herein relate to a magnetic brake system, wherein the rotating magnet assembly further includes a weight aligner interface configured to interface with a magnetic aligner interface on the translating component.

[0021] According to some embodiments, the techniques described herein relate to a magnetic brake system, wherein the translating component further includes at least one aligner cover to align a weight resting section of the at least one centrifugal weight carrier to a weight resting point on the translating component.

[0022] According to some embodiments, the techniques described herein relate to a magnetic brake system including: a stationary magnet array positioned circumferentially about a shaft; and a translating magnet array positioned radially inward from the stationary magnetic arraywhen in a first position and configured to rotate with the shaft; wherein the translating magnet array is configured to translate axially along the shaft to from the first position to a second position when the shaft rotates beyond a threshold speed, wherein, when in the first position, the stationary magnetic array is magnetically engaged with the translating magnetic array and rotation of the shaft is resisted; and, wherein, when in the second position, the stationary magnetic array is magnetically disengaged from the translating magnetic array and rotation of the shaft is substantially unrestricted.

[0023] According to some embodiments, the techniques described herein relate to a magnetic brake system, where the threshold rotational speed is 600 rotations per minute.

[0024] According to some embodiments, the techniques described herein relate to a magnetic brake system, further including a propeller operably connected to the shaft, wherein rotation of the shaft rotates the propeller, and wherein rotation of the propeller provides cooling to one or more components of the magnetic brake system.

[0025] According to some embodiments, the techniques described herein relate to a drivetrain assembly for use in an irrigation system configured to maintain a rest position when a motor is deactivated, the drivetrain assembly including: a magnetic brake system including an input shaft; an electromagnetic motor connected to the input shaft, the electromagnetic motor controlled by a variable frequency drive, wherein the variable frequency drive includes: a rectifier configured to convert voltage from alternating current to direct current, the rectifier connected to a power source providing alternating current; a direct current link including one or more dynamic braking resistors; and an inverter configured to drive the electromagnetic motor, and a gearbox with an output shaft, the gearbox connected to the input shaft and the output shaft connected to a wheel, the wheel configured to rest on a surface with a slope; wherein the electromagnetic motor rotates the input shaft above a threshold rotational speed and disengages the magnetic brake system when the variable frequency drive issues an active command; wherein, when the variable frequency drive does not issue the active command, the one or more dynamic braking resistors slow rotation of the output shaft such that rotation of the input shaft is below the threshold rotational speed of the magnetic brake system when the wheel is on the surface with the slope, and wherein, when the input shaft rotates below the threshold rotational speed, the magnetic brake system engages and substantially prevents rotation of the input shaft.

[0026] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the one or more dynamic braking resistors are configured to be removable from the variable frequency drive.

[0027] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the direct current link includes only one dynamic braking resistor.

[0028] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the one or more dynamic braking resistors include a heat dissipation feature.

[0029] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the heat dissipation feature is a heat fin.

[0030] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the heat dissipation feature is a resistor housing.

[0031] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the resistor housing is cooled by an adjacent fluid flow.

[0032] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the adjacent fluid flow is provided by an irrigation system.

[0033] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the one or more dynamic braking resistors are positioned in an expected flow path of a propeller operably connected to the shaft of the magnetic brake system, wherein the propeller is positioned to provide airflow to both the magnetic brake system and the one or more dynamic braking resistors while the shaft rotates.

[0034] According to some embodiments, the techniques described herein relate to a drivetrain assembly, further comprising a thermal switch operatively connected to the variable frequency drive and configured to read a temperature of one or more components of the drivetrain assembly, wherein when the thermal switch detects that one or more components of the drivetrain assembly reaches or exceeds a critical temperature, the variable frequency drive ceases issuing the active command.

[0035] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the threshold rotational speed is 600 rotations per minute of the input shaft.

[0036] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the slope is measured from a horizontal plane.

[0037] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the slope is 30 percent.

[0038] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the slope is 0 percent.

[0039] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the one or more dynamic braking resistors are arranged in parallel.

[0040] According to some embodiments, the techniques described herein relate to a drivetrain assembly for use in an irrigation system configured to maintain a rest position when a motor is deactivated, the drivetrain assembly including: a stopping brake system including an input shaft; a motor connected to the input shaft; a dynamic brake system connected to the input shaft; and a gearbox with an output shaft, the gearbox connected to the input shaft and the output shaft connected to a wheel, the wheel configured to rest on a surface; wherein, when the motor is active, the motor rotates the input shaft above a threshold rotational speed and disengages the stopping brake system; wherein, when the motor is inactive, the dynamic brake system slows rotation of the output shaft such that rotation of the input shaft is below the threshold rotational speed of the stopping brake system when the wheel is on the surface with a slope, and wherein, when the input shaft rotates below the threshold rotational speed, the stopping brake system engages and substantially prevents rotation of the input shaft.

[0041] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the stopping brake system includes a magnetic brake system.

[0042] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the stopping brake system includes an electromagnetic brake.

[0043] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the dynamic brake system includes a variable frequency drive.

[0044] According to some embodiments, the techniques described herein relate to a drivetrain assembly further comprising a thermal switch operatively connected to the motor and configured to read a temperature of one or more components of the drivetrain assembly, wherein when the thermal switch detects that one or more components of the drivetrain assembly reaches or exceeds a critical temperature, the motor becomes inactive.

[0045] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the dynamic brake system includes an electromagnetic brake.

[0046] According to some embodiments, the techniques described herein relate to a drivetrain assembly, wherein the dynamic brake system includes a regenerative braking system.BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1A shows an irrigation system with a drive assembly according to one embodiment;

[0048] FIG. IB shows a drive assembly for controlling the position of an irrigation system according to one embodiment;

[0049] FIG. 2 shows a magnetic brake system according to one embodiment;

[0050] FIG. 3A shows a perspective view of a partially deconstructed magnetic brake system according to one embodiment;

[0051] FIG. 3B shows an alternative perspective view of a partially deconstructed magnetic brake system according to FIG. 3 A;

[0052] FIG. 3C shows a fixed magnetic assembly to be used in a magnetic brake system according to one embodiment;

[0053] FIG. 4A shows one embodiment of a magnetic brake system in a first configuration according to one embodiment;

[0054] FIG. 4B shows one embodiment of a magnetic brake system in a second configuration according to one embodiment;

[0055] FIG. 4C shows a cross-sectional view of the magnetic brake system of FIG. 4A in a first configuration;

[0056] FIG. 4D shows a cross-sectional view of the magnetic brake system of FIG. 4B in a second configuration;

[0057] FIG. 5A shows a focused view of a aligner cover according to one embodiment of a magnetic brake system;

[0058] FIG. 5B shows a partially deconstructed view of the aligner cover from FIG. 5A;

[0059] FIG. 6 shows steps for operation of a magnetic brake system according to one embodiment;

[0060] FIG. 7 shows steps for operation of a magnetic brake system according to one embodiment;

[0061] FIG. 8A shows a drivetrain assembly including a magnetic brake, motor assembly, and gearbox according to one embodiment;

[0062] FIG. 8B shows a partially deconstructed view of the drivetrain assembly of FIG. 8A;

[0063] FIG. 9A shows a magnetic brake system according to one embodiment;

[0064] FIG. 9B shows portions of a magnetic brake system according to one embodiment;

[0065] FIG. 9C shows portions of a magnetic brake system according to one embodiment; and

[0066] FIG. 9D shows portions of a magnetic brake system according to one embodiment.DETAILED DESCRIPTION OF EMBODIMENTSOverview

[0067] The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of embodiments of this disclosure are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.

[0068] In accordance with the present disclosure, a magnetic braking system configured to substantially prevent movement of the shaft when activated without utilizing friction-based braking systems which are susceptible to the elements is disclosed. The magnetic braking system can incorporate the use of fixed permanent magnets and rotating permanent magnets to control operation of the braking system. In an engaged position, the fixed permanent magnet and the rotating permanent magnet can substantially stop movement of the drivetrain using the magnetic force between the fixed magnet and the translating magnet. In a disengaged position, the translating magnet can be moved relative to the fixed magnet to a position where the magnetic force does not inhibit movement of the drivetrain.

[0069] In one embodiment, the magnetic braking system uses a translation assembly to translate a rotating magnet assembly away from a fixed magnet assembly. The braking systemcan be configured such that the centrifugal force of the rotation of a shaft causes the translation assembly to translate a rotating magnet assembly along the shaft. In some embodiments, the translation assembly can have weights to move radially outward and linearly displace the fixed magnets based on the centrifugal force generated by the rotation of the shaft. The magnetic braking system can provide automatic braking for an irrigation system without using a friction-based braking mechanism. More specifically, the magnetic brake mechanism disengages a permanent magnet brake rotor from a permanent magnet brake stator using centrifugal force. The innovative brake system offers enhanced efficiency and reliability in various applications where stopping and immobilization of a drivetrain is required. The braking mechanism uses permanent magnets that are aligned without frictional contact. The magnetic attraction between the fixed and rotating magnets provide braking force. When the drivetrain is in operation, the centrifugal force exerted on the braking system disengages the braking force.

[0070] Designing a braking system utilizing this concept brings several benefits. Advantageously, the braking system here does not require repair or maintenance as frequently as other traditional braking systems. For example, traditional braking systems can compress or clamp a rotating disk with a high friction surface to slows the rotation of a shaft. Electromagnetic, mechanical, and hydraulic braking systems operate under a similar principle. These braking systems, while being relatively simple to implement, require maintenance due to the degradation of working components, such as a worn down brake pads or disks, and can be damaged in cases where debris is lodged between braking surfaces. However, due to the lack of any intentional friction between parts in the present braking system, maintenance related to friction will be lower than existing braking systems.

[0071] Advantageously, the current disclosure does not require any additional components to be routed to the braking system, and as such further reduces the maintenance requirement. Other braking systems which utilize permanent magnets overcome the braking force by applying an electromagnetic field to cancel the field generated by a permanent magnet, thus freeing the shaft and allowing it to rotate. However, this along with other similar concepts requires routing of electrical power and sensors through the braking system, something which increases costs and reduces practicality of the braking system, especially in remote-deployment situations susceptible to the elements (e.g., for use in crop irrigation systems).

[0072] Advantageously, the current disclosure can increase the utility of center pivot irrigation systems. Current systems which rely on intentional inefficiencies in the gearbox to brake a center pivot irrigation system are limited by the amount of power that can be safely transmitted through the gearbox. By utilizing a braking system from the current disclosure, center pivot irrigation systems can rotate at higher speeds, or operate on a continuous move drivetrain, opening up various possible additional uses for the systems.

[0073] Advantageously, due to the higher efficiency from the drive motors (such as the wheel gearbox 10 disclosed herein) due to the current braking system over a braking system with designed inefficiencies as a natural brake, irrigation systems can move at a faster pace, and would cost less energy overall to be driven the same distance. This could also be utilized to use the same irrigation system to irrigate larger farmlands by either extending the length of a center pivot irrigation system or extending the track of a linear irrigation system. Having a larger variability in speed also increases the system’s efficacy for chemigation uses, or the addition of chemicals or pesticides to the farmland. Adjustment of the speed of the higher efficiency drive motors and center pivot system can also allow the system to also distribute fertilizer to crops, which requires a different drive speed than when watering crops. Furthermore, the higher speed irrigation systems could utilize sensors or cameras to gather real time data of the farmland. Traditional irrigation systems which were slower were less suited for this task as their low speed meant that data was gathered very slowly and would likely not be representative of the status of the entire farmland area being maintained by the irrigation system.

[0074] Advantageously, the use of the permanent magnet-based system eliminates the need for additional external actuation mechanisms or controls, simplifying the overall brake system design. Additionally, this approach ensures a rapid and reliable engagement and disengagement of the brake, enabling both quick starting and quick stopping or immobilization of the rotating machine.

[0075] Advantageously, the disclosed brake mechanism offers improved efficiency and performance compared to conventional power-off braking systems. It minimizes wear and tear on the brake components, as engagement and disengagement occur without frictional contact, preserving the integrity and longevity of the brake system. Furthermore, the absence of mechanical wear reduces maintenance requirements and increases the overall operational lifespan of the brake mechanism. The brake mechanism disclosed can be applied to various rotating machines involvedin energy conversion, such as electric motors, internal combustion engines, gas turbines, wind turbines, hydraulic turbines, and more. Its versatility makes it suitable for a range of industries and sectors.

[0076] Advantageously, a brake according to the current disclosure is beneficial compared to other braking systems which rely upon powered braking units. The braking system as disclosed herein can apply its braking force until a threshold rotational speed is met, without introducing inefficiencies in the braking system once the brake is disengaged. Therefore, upon the magnetic brake engaging with a shaft, the brake automatically applies, preventing the connected shaft from freely turning, thus providing reliable immobilization and preventing potential related hazards or accidents.

[0077] As such, the present disclosure presents a power-off brake mechanism for rotating machines that employs centrifugal force-induced linear motion to disengage a permanent magnet brake rotor from a permanent magnet brake stator. The braking system disclosed herein provides enhanced efficiency, reliability, and ease of operation, making it an ideal solution for a wide range of applications requiring stopping and immobilization of rotating machinery.Irrigation System

[0078] FIG. 1 A illustrates an embodiment of an irrigation system 1 for providing water for agricultural purposes. The irrigation system 1 can include a water piping and delivery system 2 and a drive assembly 4. The drive assembly can be powered by various drive systems, such as a variable frequency drive. The drive system can be housed within a control box 2240. The control box 2240 can be located on the top of the irrigation system 1, along the length of the irrigation system 1, or elsewhere on the irrigation system 1. In some embodiments, the irrigation system 1 can include a second housing 2260 to enclose further components, such as resistors according to some embodiments disclosed herein. An embodiment of a drive assembly 4 is illustrated in more detail in FIG. IB. A drive assembly 4 can have a center drive 3, a wheel gearbox 10, a shaft or drive shaft 8 and one or more driveline couplers 11. A center drive 3 can have motor 5 connected to a gearbox 6 to deliver a torque to a drive shaft 8. A magnetic brake system 100 (illustrated in FIG. 2) could be incorporated with the gearbox 6 to provide braking to the irrigation system 1. Driveline couplers 11 are shown connecting the drive shafts or shafts 7, 9 of the gearboxes 10 and center drive 3 to the drive shafts 8. Drive shafts 8 typically have a driveline coupler 11 at eachend to allow the shafts 8 to be quickly and easily pulled apart and put back together to facilitate field maintenance and / or towing from field to field.

[0079] In some embodiments, the gearbox 6 and / or gearbox 10 can be a higher helixangle worm gear type reducer, a hypoid gear design, a bevel gear design, or other designs. In some embodiments, the gearbox 6 and / or gearbox 10 can be a gearbox as claimed and described in U.S. Patent No. 10,502,283 to Smith et al., the entirety of which is incorporated by reference herein.

[0080] In use, hub 14 on the gearbox 10 can connect with a wheel. The center drive 3 can drive the drive shaft 8 which in turn can drive the gearbox 10. The gearbox 10 can transfer the motion of the turning drive shaft 8 into a rotational motion at the hub 14 to turn the wheel and drive an irrigation system 1. The gearbox 10 can be either non-towable or towable. The wheel gearbox 10 can have a handle (not shown) that can be used to disengage the gears inside the gearbox to allow free rotation of the hub 14. Alternatively, the wheel gearbox could be fitted with a towable hub.

[0081] In a towable state, a driveline coupler 11 can be separated so that the wheel gearbox 10 can be rotated or pivoted to a new orientation. Also, the handle can be used to disengage the gears inside the wheel gearbox 10. In this state, the wheel gearbox 10 is no longer connected to the center drive 6 and is free to rotate. In a typical operation a farmer or user can attach a system 1 in a towable state to a tractor or truck and tow the system to a new location, such as to a different field. Examples of a towable wheel gearbox can be found in US Patent No. 6,237,863, entitled “Disengageable Worm Wheel Gearbox,” which is incorporated herein by reference in its entirety and made a part of this specification.Magnetic Braking System

[0082] FIG. 2 illustrates an embodiment of the magnetic brake system 100. The magnetic brake system 100 can include a rotating magnet assembly 200 (e.g., translating magnet array, translating magnetic array, etc.) positioned on a shaft 102 and a fixed magnet assembly 300 (e.g., a stationary magnet array, stationary magnetic array, stator magnet, stator magnet assembly, etc.) connected to the drive train 4. The rotating magnet assembly 200 can be coupled to a translation assembly 400. The rotating magnet assembly 200 and the translation assembly 400 can rotate with the shaft 102. A guard structure 500 can be positioned around at least a portion of the translation assembly 400 and / or the rotating magnet assembly 200.

[0083] The magnetic brake system 100 is illustrated in a first position, in which the brake is engaged. During operation, the translation assembly 400 can translate the rotating magnet assembly 200 to a second position, in which the brake is disengaged.

[0084] The rotating magnet assembly 200 and translation assembly 400 can be positioned in a first configuration where the rotating magnet assembly 200 is magnetically aligned with the fixed magnet assembly 300. The translation assembly 400 can be coupled to the shaft 102 and can be configured to transition from a first configuration (e.g., an engaged configuration) to a second configuration (e.g., a disengaged configuration) after a threshold rotational speed of the shaft 102 is reached. The translation assembly 400 can be coupled to the shaft 102 by keying, interlocking of gears, or other methods. The magnetic force between the rotating magnet assembly 200 and fixed magnet assembly 300 can be substantially reduced in the second configuration. The magnetic forces between the rotating magnet assembly 200 and fixed magnet assembly 300 that secure the translation assembly 400 in the first configuration can be overcome by applying sufficient torque to the shaft 102. In some embodiments, the translation assembly 400 can resist up to 75 in-lbs. of static torque until the shaft 102 begins rotating. In some embodiments, the translation assembly 400 can resist more than 75 in-lbs. of static torque until the shaft 102 begins rotating. In some embodiments, the translation assembly 400 can resist up to 32 in-lbs. of dynamic torque as the shaft 102 is rotating. In some embodiments, the translation assembly 400 can resist up to 24 in-lbs. of dynamic torque as the shaft 102 is rotating. In some embodiments, the translation assembly 400 can resist different static torques and / or dynamic torques as desired or required for a specific use case.

[0085] The fixed magnet assembly 300 can be configured such that the fixed magnets arranged within the fixed magnet assembly 300 correspond to the magnets arranged within the rotating magnet assembly 200. The magnets within the fixed magnet assembly 300 and the magnets within the rotating magnet assembly 200 can be configured to maximize their magnetic attractive forces.

[0086] In some embodiments, the magnetic brake system 100 can further include a guard 500 to protect components of the magnetic brake system 100 during operation. The guard 500 can be configured to rotate with the shaft 102. This may be accomplished by including key-like structures which slot into zones of the shaft 102, or by utilizing other methods known by one skilled in the art to prevent relative rotation of two members. In some embodiments, the guardstructure 500 can act as a flywheel or other rotating body to increase and / or carry rotational energy and momentum as the magnetic brake system 100 rotates. In some embodiments, the rotational energy carried by the guard structure 500 can even out vibrations as the translation assembly 400 increases or decreases speed.

[0087] In some embodiments, the magnetic brake system 100 can include a fan blade or propeller system operably connected to the shaft 102. The propeller can rotate with the shaft 102 to provide cooling to one or more components of the magnetic brake system 100, a motor assembly 2200 (shown in FIG. 8A), and / or any other components while the shaft rotates. In some embodiments, the fan can provide cooling to systems outside the magnetic brake system 100.

[0088] The subassemblies of the magnetic brake system 100, including the rotating magnet assembly 200, the fixed magnet assembly 300, and the translation assembly 400, will be described in more detail with respect to FIGS. 3A-3C. FIGS. 3A and 3B depict an exploded view of components and subassemblies of the embodiment of the magnetic brake system 100. FIG. 3C illustrates an exploded view of the fixed magnet assembly 300.

[0089] The fixed magnet assembly 300 can include a series of fixed magnets 304 positioned within recesses 205 of a magnetic enclosure 302 (as shown in FIG. 3C). The fixed magnet assembly 300 can be circumferentially about a shaft, and the rotating magnet assembly 200 can be positioned radially inward from the fixed magnet assembly 300. The fixed magnets 304 can be placed at defined intervals about a central axis of the fixed magnet assembly 300. In some embodiments, the fixed magnets 304 can be spaced such that the magnetic field surrounding each of the fixed magnets 304 does not significantly impact the magnetic field surrounding adjacent fixed magnets 304. The number of fixed magnets in the fixed magnet assembly 300 could be equal to, less than, or greater than the number of translating magnets 204 in the rotating magnet assembly 200. In some embodiments, the fixed magnets 304 can be positioned in the same or a similar way to how the translating magnets 204 are positioned within the rotating magnet assembly 200, such that each translating magnet 204 could have a fixed magnet 304 positioned directly adjacent the rotating magnet assembly 200 within the fixed magnet assembly 300. In embodiments where the fixed magnet assembly 300 has a different number of magnets than the rotating magnet assembly 200, the magnets within the fixed magnet assembly 300 may still be positioned radially outwards from at least one of the magnets located in the rotating magnet assembly 200. Advantageously, changing the number of fixed magnets 304 and / or rotatingmagnets 204 could increase or reduce the braking force created by the magnetic brake system 100, allowing for customization of a magnetic brake system 100 once installed on the field. The braking force can be increased by having a 1 :1 pairing between fixed magnets 304 and rotating magnets 204. To reduce the braking force, the number of rotating magnets 204 can be less than the number of fixed magnets 304. In some embodiments, the fixed magnet assembly 300 can be configured to be radially offset, in line, or otherwise radially or linearly positioned relative to the rotating magnet assembly 200. The magnetic enclosure 302 can include an outer enclosure which can be secured to the drivetrain. The inner enclosure can be secured within the outer enclosure. The inner and outer enclosure can have mating interfaces, such as slots or grooves, for correctly positioning and securing the enclosure 302 to the drivetrain. Additionally, the thickness of the inner wall can be configured to have a defined offset of the fixed magnet assembly 300 from the rotating magnet assembly 200. This can be used to control the strength of the magnetic field between the fixed magnet assembly 300 from the rotating magnet assembly 200.

[0090] The rotating magnet assembly 200 can be configured to house one or more translating magnets 204 in recesses 205 in a translating magnet housing 202. The translating magnet recesses 205 can be spaced radially around the rotating magnet assembly 200. In some embodiments, the translating magnets 204 can be uniformly spaced around the translating magnet housing 202. In some embodiments, the translating magnets 204 can be non-uniformly spaced around the translating magnet housing 202. The rotating magnet assembly 200 can be permanently or removably secured to the translation assembly 400. In some embodiments, the rotating magnet assembly 200 can be permanently attached to the translating component 420 (i.e., by welding, sintering, mechanical connection, chemical connection, or other methods known by one skilled in the art to two connect two bodies). In some embodiments, the rotating magnet assembly 200 can include features which engage with corresponding features on the translating component 420. In the illustrated embodiment, the rotating magnet assembly 200 can include a weight aligner interface 206, weight aligner mounting holes 208, or other features which could be utilized to connect the rotating magnet assembly 200 with the translating component 420 of the translation assembly 400. The translating component 420 could have corresponding features, such as an alignment interface 429. The translating magnets 204 can be secured within recesses 205 of the housing 202. The housing 202 can be surrounded by a cover 210. The housing may include a protrusion or lip with a larger diameter that extends beyond the edge of the cover 210 on thetranslation assembly 400 side of the housing 202. The lip can be configured such that it abuts the face of the outer face of the fixed magnet assembly enclosure 302. The lip can help to position the rotating magnet assembly 200 within the fixed magnet assembly 300. For example, the lip can prevent the rotating magnet assembly 200 from moving axially through the fixed magnet assembly 300.

[0091] The translation assembly 400 and the rotating magnet assembly 200 are coupled together. The rotating magnet assembly 200 and translation assembly 400 can be configured to rotate along with the shaft 102. In some embodiments, this can be accomplished by utilizing any or all of the following methods: (1) including key-like structures which slot into zones of the shaft 102, (2) utilizing mounting components 422 mechanically connecting the translating component 420 to fixed magnet assembly 300 rotating magnet assembly 200; (3) incorporating a magnetic aligner interface 429 or feature configured to interact with a weight aligner interface 206 on the rotating magnet assembly 200; (4) having a plurality of aligner protrusions 428 of a translating component 420 align with a plurality of aligner cavities 432 of a stationary component 430; (5) or by utilizing other methods known by one skilled in the art to prevent relative rotation of two members.

[0092] The translation assembly 400 can be configured to move the rotating magnet assembly 200 between the first configuration (FIGS. 4A and 4C) and the second configuration (FIGS. 4B and 4D). Figure 4C illustrates a cross-sectional view of Figure 4A, and Figure 4D illustrates a cross-sectional view of Figure 4B. The translation assembly 400 can include a plurality of centrifugal weight carriers 410, a translating component 420, and a stationary component 430. The translating component 420 can be fixedly attached to the rotating magnet assembly 200. The centrifugal weight carriers 410 can be coupled to the stationary component 430 and be in contact with at least a contact surface 423 of the translating component 420. In some embodiments, centrifugal weight carriers 410 may be coupled to the translating component 420. The translating component 420 and stationary component 430 can be configured to rotate with the shaft 102 through the use of slots and keys, welding, or other forms of attaching two bodies known by one skilled in the art. The centrifugal weight carriers 410 can be coupled to one or more weight retention biasing members 402. As illustrated in FIG. 3A, the weight retention biasing members 402 are springs. In some embodiments, these members can bias the centrifugal weightcarriers 410 to be in a first position in the first configuration where the centrifugal weight carriers 410 have their center of mass located more radially inward.

[0093] The centrifugal weight carriers 410 are configured to move from the first position to a second position in the second configuration where the centrifugal weight carriers 410 have their center of mass located more radially outward. The centrifugal force that is induced in rotation of the centrifugal weight carriers 410 can be affected by changing the centrifugal weights 414 which are attached to the centrifugal weight carriers 410. While in the braking state, in some embodiments the centrifugal weight carrier 410 can contact the stationary component 430 on the weight resting section 416 of the centrifugal weight carrier 410.

[0094] The centrifugal weight carrier 410 can include a slot 412 to allow portions of the stationary component 430 to pass through the centrifugal weight carrier 410, such as illustrated in FIGS. 5A and 5B. FIGS. 5A and 5B depict an excerpted detail view depicting a stationary component 430 according to one embodiment for a magnetic brake system 100 as described herein. The centrifugal weight carrier 410 can further include a plurality of covers 436 configured to increase longevity of the magnetic brake system 100 by reducing rattling of the centrifugal weight carriers 410. In some embodiments the covers 436 can be positioned on protrusions 435 proximal to where a centrifugal weight carrier 410 contacts the stationary component 430. The covers 436 can be attached to the protrusions 435 by methods known by ones skilled in the art, such as by mechanically attaching them with threaded screws. The cover 436 can attach a bearing holding a shim bar 438 to the stationary component 430 which can allow the centrifugal weight carrier 410 to rotate along the bar’s surface.Operation of Magnetic Braking System

[0095] FIGS. 4A and 4B depict a side view of the translation assembly 400 in its first configuration and in its second configuration, respectively. The process of transitioning the translation assembly 400 from its first configuration to the second configuration relies on centrifugal forces generated by the rotation of offset weights 410. The shaft 102, the rotating magnet assembly 200, and translation assembly 400 can be configured to rotate together. The drivetrain can apply a sufficient amount of torque to the shaft 102 to overcome the magnetic attraction between the rotating magnet assembly 200 and the fixed magnet assembly 300. The magnetic brake system 100 can be configured where once the shaft 102 rotates at a thresholdrotational speed, the centrifugal forces induced in the centrifugal weight carriers 410 transitions the magnetic brake system 100 from its first configuration to its second configuration.

[0096] Once the shaft 102 rotates at the threshold rotational speed, the translating component 420 and the rotating magnet assembly 200 translate axially along the shaft 102 away from the fixed magnet assembly 300. This causes the magnetic brake system 100 to move from its first configuration to its second configuration. More specifically, at the threshold rotational speed, the centrifugal weight carriers 410 pivot around a pivot axis 433 on the stationary component 430 in an arc 1100 and the centers of mass of the centrifugal weights 414 move radially outwards. The centrifugal weight carriers 410 apply force against the translating component 420 at a contact surface 423, which causes the translating component 420 to translate axially along the shaft 102. The rotating magnet assembly 200 is also translated along the shaft in axial direction 1000. This movement along the shaft can magnetically disengage the rotating magnet assembly 200 from the fixed magnet assembly 300, allowing free rotation of the shaft 102.

[0097] When the rotational speed of the shaft 102 lowers below the threshold rotational speed, the forces exerted by the biasing members 402 and plurality of magnets between the fixed magnets 304 and translating magnets 204 overcome the centrifugal forces on the centrifugal weight carriers 410. The net forces on the centrifugal weight carriers 410 direct them radially inward, having the centrifugal weight carriers 410 return to a first configuration where they rest on the stationary component 430. The translation assembly 400 and rotating magnet assembly 200 translate in a direction opposite the axial direction 1000, thus, engaging the magnetic braking system.

[0098] The threshold rotational speed where the magnetic brake system 100 converts from its first configuration to its second configuration is affected by several factors, including but not limited to: the dimensions of the centrifugal weight carrier 410, the radial offset of the pivot axis 433 from the center of the shaft 102, the centrifugal weight 414 of the centrifugal weight carriers 410, the number of centrifugal weight carriers 410, the number of translating magnets 204 and fixed magnets 304, the orientation of the translating magnets 204 and fixed magnets 304, the radius of the rotating magnet assembly 200 or fixed magnet assembly 300, the number of weight retention biasing members 402, and / or the forces exerted by of the weight retention biasing members 402.

[0099] The threshold rotational speed is the rotational speed necessary for the centrifugal forces induced in the centrifugal weight carriers 410 overcome the resistive forces keeping the centrifugal weight carriers 410 in their first configuration. The threshold rotational speed can be modified by changing parameters or characteristics of one or more of the factors described above. For example, the rotational speed could be reduced by increasing the weight or number of weight carriers. The threshold rotational speed can be specifically configured for various specific use cases, increasing the range of applicability of the magnetic brake system 100.

[0100] In some embodiments, the rotating magnet assembly 200 can be configured to not contact the fixed magnet assembly 300. This can be accomplished by positioning of the magnetic brake system 100, by including friction eliminating components, or by eliminating contact between the rotating magnet assembly 200 and fixed magnet assembly 300. The absence of frictional contact could result in smoother braking operations, minimized vibrations, noise, and heat generation associated with friction-based systems, and improved overall performance and longevity of the braking system. The rotating magnet assembly 200 may only interact with the fixed magnet assembly 300 by the magnetic forces of the magnets dispersed between the two assemblies. The number of magnets within the rotating magnet assembly 200 and fixed magnet assembly 300, as well as the radius of the rotating magnet assembly 200 and fixed magnet assembly 300, are factors which contribute to the overall braking force of the magnetic brake system 100.Method of Disengaging Magnetic Braking System

[0101] Figure 6 illustrates an example method 600 of disengaging the braking system according to some embodiments disclosed herein. This flow diagram is provided for the purpose of facilitating description of aspects of some embodiments. The diagram does not attempt to illustrate all aspects of the disclosure, should not be considered limiting, and can have additional steps inserted throughout the method.

[0102] At block 602, rotational force is applied to the shaft 102 of the magnetic brake system 100 while the magnetic brake system 100 is in its first configuration. In the first configuration, the magnetic force between the rotating magnet assembly 200 and the fixed magnet assembly 300 is sufficient to prevent free rotation of the shaft 102 of the magnetic brake system 100. This prevents the irrigation system 1 from moving when the drivetrain is not engaged. Thedrivetrain of the motor is configured to provide sufficient torque to overcome the magnetic force and rotate the shaft 102. The magnetic force between the rotating magnet assembly 200 and fixed magnet assembly 300 can be determined such that it is sufficient to provide braking force for the irrigation system and prevent movement when the drivetrain is not engaged, and allows for the drivetrain to generate torque sufficient of overcome the magnetic force and allow rotation of the magnetic brake system 100 during operation.

[0103] At block 604, the shaft 102 is rotated until a threshold rotational speed is reached. The threshold rotational speed can be the rotational speed necessary for the centrifugal forces induced in the centrifugal weight carriers 410 overcome the resistive forces keeping the centrifugal weight carriers 410 in their first configuration. The threshold rotational speed can be modified by modifying one or more of the factors affecting the affecting one or more of the factors leading to the calculation of the predetermined rotational speed, or by changing other characteristics known by one skilled in the art which would affect the threshold rotational speed. The threshold rotational speed can be specifically configured for various specific use cases, increasing the range of applicability of the magnetic brake system 100.

[0104] At block 606, the magnetic brake system 100 converts from a first configuration to its second configuration. In the first configuration, the brake is engaged and in the second configuration, the brake is disengaged. In some embodiments, the centrifugal forces induced in the centrifugal weight carriers 410 converts the magnetic brake system 100 from its first configuration to its second configuration. The centrifugal weight carriers 410 can convert the magnetic brake system 100 from its first configuration to its second configuration by overcoming a combination of forces (i.e., a retaining force exerted by the weight retention biasing members 402 and a magnetic force felt between the plurality of fixed magnets 304 and translating magnets 204) at the threshold rotational speed. At the threshold rotational speed, the centrifugal weight carriers 410 pivot around a pivot axis 433 on the stationary component 430 and the centers of mass of the centrifugal weights 414 move radially outwards. The centrifugal weight carriers 410 during this outwards movement press against the translating component 420 at a contact surface 423. This force displaces the translating component 420, and by extension the rotating magnet assembly 200, linearly along the shaft in axial direction 1000. This movement along the shaft can magnetically disengage the rotating magnet assembly 200 from the fixed magnet assembly 300, allowing free rotation of the shaft, where rotation of the shaft is substantially unrestricted. In some embodiments, 1the threshold rotational speed can be 600 rotations per minute. However, the threshold rotational speed can be modified as desired or required for a specific use case.Method of Engaging Magnetic Braking System

[0105] Figure 7 illustrates an example method 700 of engaging the braking system according to some embodiments disclosed herein. This flow diagram is provided for the purpose of facilitating description of aspects of some embodiments. The diagram does not attempt to illustrate all aspects of the disclosure, should not be considered limiting, and can have additional steps inserted throughout the method.

[0106] At block 702, the shaft 102 of the magnetic brake system 100 rotates above a threshold rotational speed. At this speed, the centrifugal weight carriers 410 of the magnetic brake system 100 have overcome a combination of forces (i.e., a retaining force exerted by the weight retention biasing members 402 and a magnetic force felt between the plurality of fixed magnets 304 and translating magnets 204) due to the rotational speed of the shaft 102. In some embodiments the centrifugal weight carriers 410 are radially offset from the shaft 102.

[0107] At block 704, the speed of the shaft 102 drops below the threshold rotational speed.

[0108] At block 706, the magnetic brake system 100 transitions from the second configuration to the first configuration. In some embodiments, the centrifugal weight carriers 410 pivot around a pivot axis 433 on the stationary component 430 and the centers of mass centrifugal weights 414 move radially inwards. The innermost portion of the centrifugal weight carriers 410 during this inwards movement applies less force against the translating component 420 at a contact surface 423. The forces exerted by the weight retention biasing members 402 and plurality of magnets between the fixed magnets 304 and translating magnets 204 overcome the centrifugal forces on the centrifugal weight carriers 410. The forces on the centrifugal weight carriers 410 direct them radially inward, having the centrifugal weight carriers 410 return to a first configuration where they rest on the stationary component 430. The translation assembly 400 and rotating magnet assembly 200 translate axially in a direction substantially opposite the axial direction 1000, engaging the magnetic braking system.

[0109] At block 708, the magnetic attraction between the rotating magnet assembly 200 and fixed magnet assembly 300 reduce the speed of the shaft 102 until the shaft 102stops its rotation. The rotating magnet assembly 200 is magnetically engaged with the fixed magnet assembly 300, limiting the free rotation of the shaft 102 of the magnetic brake system 100.

[0110] At block 710, the shaft is no longer able to overcome the magnetic locking forces between the interaction of the rotating magnet assembly 200 and the fixed magnet assembly 300, and the magnetic brake stops the shaft from rotating.Integration of Magnetic Brake into a Drivetrain Assembly

[0111] Figures 8A through 8B depict a drivetrain assembly 2000 including a magnetic brake housing 2100, a motor assembly 2200, and a gearbox 2300 configured to rotate an output shaft 2350 at a one or more configured speeds or range(s) of configured speeds. The magnetic brake housing 2100 can connect a magnetic brake system 3000, which can be substantially similar to a magnetic brake system 100 or other magnetic brake system disclosed herein, to the motor assembly 2200 by an input shaft 2340, which can be similar to other shafts described herein, such as shaft 102. The motor assembly 2200 can rotate the input shaft 2340, which connects to the gearbox 2300 at a gearbox input. The gearbox 2300 can transform, translate, or otherwise manipulate that input rotational energy to rotate an output shaft 2350. In some embodiments, the output shaft 2350 can rotate a wheel. In some embodiments, the output shaft 2350 can connect to driveline couplers like how drive shafts 7,9 connect with driveline couplers 11 as shown in FIG. IB. Driveline couplers 11 can connect the drive shafts or shafts 7, 9 of the gearboxes 10 and center drive 3 to the drive shafts 8. Drive shafts 8 typically have a driveline coupler 11 at each end to allow the shafts 8 to be quickly and easily pulled apart and put back together to facilitate field maintenance and / or towing from field to field.

[0112] The drivetrain assembly 2000 can utilize a magnetic brake system 100 or magnetic brake 3000, or other magnetic brake system as described herein in.

[0113] The magnetic brake 3000 can function similar to the magnetic brake system 100, described herein, and can substantially prevent rotation of the input shaft 2340 when the input shaft 2340 rotates below a threshold rotational speed. The threshold rotational speed of the magnetic brake 3000 can be affected by several factors, including but not limited to the factors affecting the threshold rotational speed of the magnetic brake system 100 as described herein.

[0114] The motor assembly 2200 can include any suitable kind of motor, such as an electromagnetic or electromechanical motor, and can operably be connected to both the magneticbrake 3000 and the gearbox 2300 by the input shaft 2340. The motor assembly 2200 can be configured for operation with a rotational speed controller to vary the speed at which the input shaft can be driven. In some embodiments, the motor assembly 2200 can be controlled by a variable frequency drive (VFD) housed within a control box 2240 which can regulate the speed at which the motor within the motor assembly 2200 rotates. In some embodiments, the motor assembly 2200 can be controlled by a direct online (DOL) tower control system to regulate speed of the motor.

[0115] The VFD can include a power input to receive power from a power distribution grid. The power can be provided to the VFD in various forms such as alternating current (AC) or direct current (DC). The VFD can convert the input power from its present state to a usable state to control the operational speed of a motor assembly 2200. The VFD can provide energy to the motor assembly 2200 by connections through a junction box 2250. The junction box 2250 can include a power output connection 2254 to the motor assembly 2200 and a power input 2252 connected to the control box 2240 housing the VFD. The VFD can be operatively connected to the motor assembly 2200 by the junction box 2250 to issue active commands and to not issue active commands (e.g., the VFD is deactivated, the motor is deactivated, the motor is inactive, etc.), allowing for control of the rotational speed of the motor assembly 2200. The junction box 2250 can be connected to the motor assembly 2200 at one or more points along its housing 2256.

[0116] The gearbox 2300 can be connected to the motor assembly 2200 and the magnetic brake 2100 by an input shaft 2340. The gearbox 2300 can have a gear ratio between the input shaft 2340 and the output shaft 2350 to convert the rotational speed of the input shaft 2340 to a rotational speed of the output shaft 2350. The output shaft 2350 can rotate at a speed that is slower than the input shaft 2340, the same speed as the input shaft 2340, or a higher speed than the input shaft 2340, as desired or required in a chosen use case. The output shaft 2350 can also connect to one or more wheel gearbox units to convert rotation to one or more wheels.

[0117] One possible use of the drivetrain assembly 2000 could be as a drivetrain for a crop irrigation system. Generally, crop irrigation systems can either be center pivot systems, where the system rotates around a central stationary tower, or a linear crop irrigation system, where the system moves linearly across a crop plot. Standard center pivot crop irrigation systems can include a gearbox, motor, and brake system configured to slow or stop the center pivot irrigation system. Existing systems typically utilize braking systems to slow rotation of the wheels supporting theirrigation systems, and rely on intentional inefficiencies in the gearbox and other components of the drivetrain system to keep the center pivot irrigation system at rest.

[0118] Advantageously, the gearbox 2300 used in a drivetrain assembly 2000 does not require these intentional inefficiencies to keep the system at rest. An irrigation system, such as a center pivot irrigation system, utilizing the drivetrain assembly 2000 can utilize a much higher efficiency gearbox, such as a gearbox 6 or gearbox 10 described herein, thus increasing overall efficiency of the system. The irrigation system can remain at rest through the use of the magnetic brake 2100, which engages to substantially prevent the rotation of the input shaft 2340 until it rotates above a threshold rotational speed, as described herein. In some embodiments, the motor assembly 2200 can over-torque the input shaft 2340 to overcome the magnetic force and disengage the magnetic brake 2100. The rotation of the input shaft 2340 can be slowed by various methods, including but not limited to an electromagnetic brake system, a variable frequency drive, or other braking systems. In some embodiments, the rotation of the input shaft 2340 can be slowed below the threshold rotational speed by an active braking system, such including but not limited to an electromagnetic brake, a magnetic mechanical brake, or other means.

[0119] In some embodiments, the drivetrain assembly 2000 can be configured so that the rotation of the input shaft 2340 is lowered sufficiently for the magnetic brake 2100 to engage and substantially prevent rotation of the input shaft 2340 while the motor is disengaged.

[0120] In some embodiments, the drivetrain assembly 2000 can use a VFD to control the rotation of the motor assembly 2200 and slow the rotation of the input shaft 2340 when the motor is disengaged. In some embodiments, the VFD can slow rotation of the input shaft 2340 below a threshold rotational speed to allow the magnetic brake 2100 to substantially prevent rotation of the input shaft 2340.

[0121] In some embodiments, the VFD can include a rectifier to convert voltage from an input source to a useable energy state. In some embodiments, the rectifier can convert the input power from alternating current (AC) power to direct current (DC) power.

[0122] In some embodiments, the VFD can include a direct current link (e.g., DC link, DC bus, direct current bus, etc.) operatively connected to the rectifier to support voltage through the drive from the inverter, and temporarily contain the converted power from the input power source.

[0123] In some embodiments, the VFD can include an inverter comprising a plurality of transistors designed to rapidly alternate in states to drive rotation of motor shaft through induced magnetic fields.

[0124] In standard operation, a VFD is used to regulate the speed of an electromagnetic motor. Without use of a VFD or similar technology, when an electromagnetic motor is driven by AC power, the motor can only operate at a set rotational speed, such as a maximum speed. In systems that include a VFD or similar rotational speed controller, the VFD converts the input power into a useable power form to induce rotation in the electromagnetic motor, allowing it to run at a variable speed.

[0125] However, due to the construction of an electromagnetic motor, rotation of the shaft can also induce a voltage in the motor itself, which can lead to generation of excess energy which would be fed back into the VFD. This can be referred to as “backdriving” the motor, and can lead to damage or destruction of one or more components of a standard VFD system.

[0126] Typically, VFDs attempt to address this issue by including one or more backdriving safety features in the system. This can include regenerative braking, braking resistors, and other methods to convert or store this generated power.

[0127] For regenerative braking, the backdriven power is fed back into the AC power source after being rectified and or otherwise processed by components added to the VFD. However, adding this infrastructure can be costly when deployed on a large scale, and the parts involved can increase maintenance requirements and the costs of manufacturing and installing a braking system for an irrigation system.

[0128] Alternatively, standard systems can also address backdriven power by including a braking resistor designed to convert the DC power generated by the induction to thermal energy. In this system, the added cost to the complexity of the system is decreased relative to providing the power back to the input power source, as there is no need to create additional power line infrastructure for the recovered energy. However, the braking power of this system is limited by the thermal capacity of the braking resistor, and if that capacity is overwhelmed by excessive braking, the systems can fail catastrophically.

[0129] Therefore, a clear need for an affordable and reliable method to prevent backdriven energy from damaging a VFD or its components is needed.

[0130] Advantageously, the drivetrain assembly 2000 as disclosed herein can assist in the braking of a shaft, such as a shaft used for a wheel on a center pivot crop irrigation system, without damaging its components through backdriven energy when the motor is disengaged. According to some embodiments, the VFD controlling the operation of a motor assembly 2200 can include one or more dynamic braking resistors configured to absorb energy generated by backdriving of an output shaft 2350 and expel it as thermal energy. The VFD can connect to the motor assembly 2200 of the drivetrain assembly 2000 by connection to the junction box 2250 to control one or more operational characteristics of the motor assembly 2200. The dynamic braking resistors can be utilized to slow the rotation of an input shaft 2340 sufficiently so that the rotation of the input shaft 2340 drops below a threshold rotational speed, at which point the magnetic brake 2100 engages to substantially resist further rotation of the input shaft. The braking power of the magnetic brake 2100 to resist rotation of the input shaft 2340 can be modified by adjusting one or more components of the magnetic brake 2100, such as any biasing members, the number of and / or strength of the magnets in the rotating magnet assembly 3200 and / or fixed magnet assembly 3300, or by other methods as described herein. The threshold rotational speed of the input shaft 2340 can be modified by adjusting one or more components of the magnetic brake 2100, such as the weight of the centrifugal weight carriers 3410, or by other methods as described herein.

[0131] In some embodiments, the dynamic braking resistor can be of a size or configuration to absorb sufficient thermal energy to slow rotation of the input shaft 2340 to be below a threshold rotational speed during operation, such as when an irrigation system using the dynamic braking resistor is operating under standard conditions. The slope can be measured from a horizontal plane. Standard conditions can vary based on use cases, but in most applications generally a 30 percent slope (e.g., approximately a 17 degree incline) can be expected at any point of a span (e.g., a plot, a field, a ground, etc.) maintained by a center pivot irrigation system. In some embodiments, the dynamic braking resistor can be configured to operate at different slopes (e.g., above a 30% slope, below a 30% slope, or other slopes). In some embodiments, the dynamic braking resistor can be configured to operate at zero slope (i.e., on flat ground). In some embodiments, the span maintained by an irrigation system controlled by a drivetrain assembly 2000 can be uneven over the projected path the irrigation system covers, such that the slope can vary over the course of the field.

[0132] In some embodiments, a VFD can include a plurality of dynamic braking resistors arranged in parallel to increase maximum potential thermal load. Advantageously, a system utilizing a plurality of dynamic braking resistors arranged in parallel could increase the life cycle of the system, and decrease maintenance frequency. In the event that one of the dynamic braking resistors were to fail in a parallel configuration, the remaining dynamic braking resistors could continue to function, providing braking power to the system. In some embodiments, the VFD can include a singular dynamic braking resistor configured to support the entire thermal load of the VFD.

[0133] In some embodiments, the VFD can include a singular dynamic braking resistor with capacity sufficient to act as a brake to slow a center pivot irrigation system’s input shaft 2340 below a threshold rotational speed in standard operating conditions.

[0134] In some embodiments, the dynamic braking resistors can include one or more heat dissipation features to increase the effective maximum thermal load of the dynamic braking resistors. These heat dissipation features can include, but are not limited to, heat fins attached to the dynamic braking resistors, thermal contact systems to transmit thermal energy from the dynamic braking resistors to neighboring components such as the housing 2260 for the VFD, or a propeller system to blow air across the dynamic braking resistors and remove heat through forced convection. One or more of these features can be combined to further increase the effective maximum thermal load of the dynamic braking resistors, such as combining heat fins and a propeller system.

[0135] In some embodiments of a magnetic brake 2100 which include a fan as described elsewhere herein, one or more of the dynamic braking resistors can be located outside a resistor housing 2260 located on a top of the irrigation system 1 to be in an expected flow path of the air moved by the propeller. In these embodiments, the dynamic braking resistors can be cooled by forced convective cooling caused by the propeller. Advantageously, since cooling of the dynamic braking resistors is only required while the input shaft 2340 is turning, operatively connecting the propeller to the input shaft 2340 would create an airflow to cool the dynamic braking resistors while they are receiving a thermal load from a backdriven shaft.

[0136] In some embodiments, the VFD can include a fan operatively connected to the input shaft 2340 positioned to provide cooling to the one or more dynamic braking resistors.

[0137] In some embodiments, the VFD can include a fan driven by power provided by the power delivery system driving the VFD within the control box 2240. The fan can provide cooling and / or ventilate the resistors positioned within a resistor housing 2260.

[0138] In some embodiments, one or more of the dynamic braking resistors can be cooled by a fluid flowing adjacent, on, or through a heat dissipation feature. This fluid flow can cool the heat dissipation feature, which can in turn provide cooling to the one or more dynamic braking resistors. In some embodiments, the resistor housing 2260 can be positioned on a pipe on the irrigation system 1 designed to provide a fluid to a field maintained by the irrigation system l.in such embodiments, the one or more dynamic braking resistors can be cooled by fluid flowing within the irrigation system 1 to be provided to the field maintained by the irrigation system 1.

[0139] In some embodiments, the VFD can include a DC capacitor bank configured to store at least a portion of the backdriven energy generated by the drivetrain assembly 2000 to power a fan positioned to provide cooling to the one or more dynamic braking resistors.

[0140] In some embodiments, the dynamic braking resistors are configured to be easily removable from the resistor housing 2260. One or more portions of the housing 2260 surrounding the dynamic braking resistors can be easily removable with minimal or no tools required. In some embodiments, the dynamic braking resistors can be modular in design. Access to the dynamic braking resistors can allow for easy swapping of damaged or worn parts, or routine maintenance of one or more components of the drivetrain assembly 2000.

[0141] In some embodiments, the dynamic braking resistors may become heated or damaged by excessive heating due to their use. While some embodiments include a fan or other active cooling systems to regulate the temperature of the dynamic braking resistors, excessive heat could result in needing to replace or repair the dynamic braking systems. Accordingly, some embodiments of the resistor housing 2260 can further include one or more thermal switches or sensors to monitor the temperature of one or more dynamic braking resistors.

[0142] In some embodiments, these thermal switches or sensors can be a thermal switch with one or more contacts, a thermal sensing device with one or more outputs, or other component which can be used to trigger the safety system, or signal the VFD or PLC of overheat conditions, to reduce speed or stop the motor. In some embodiments, when one or more dynamic braking resistors reach or exceed a critical temperature, the thermal switch can issue commands to disconnect or temporarily disconnect the drivetrain assembly 2000 from the power source, whichcan slow or stop movement of the irrigation system 1. In some embodiments, the motor assembly 2200 can further include an emergency stop button which can be manually activated to reduce speed or stop the irrigation system 1.

[0143] In some embodiments, these thermal switches or sensors can be operably connected to a safety shut down system, a VFD safety shut down system (e.g., an e-stop circuit), or a supplemental controller (e.g., a programmable logic controller or other type of controller) to reduce speed or to bring the motor to a full stop, thus preventing, or substantially preventing, damage or destruction of the dynamic braking resistors or other components of the drivetrain assembly 2000 during a thermal overload event.

[0144] Traditional irrigation systems, such as center pivot irrigation systems, can rely on intentional inefficiencies in the gearbox correlating to a gearbox 6 or gearbox 10 as described herein to keep the system at rest. Advantageously, an irrigation system that utilizes a drivetrain assembly 2000 does not need to use gearboxes with these designed intentional inefficiencies.

[0145] In some embodiments, the magnetic brake 2100 of the drivetrain assembly 2000 can be driven via a direct online tower control system at a fixed speed, and would not require a VFD to control the speed of the motor assembly 2200.

[0146] Where the drivetrain assembly 2000 is used in an irrigation system, the VFD can include a controller with various sensors suitable to determine the slope of the ground upon that irrigation system covers. This sensed information can be transmitted to the VFD to determine the amount of braking needed to be exerted to lower the rotation of input shaft 2340 below a threshold rotational speed, allowing the magnetic brake 2100 to engage and resist further movement of the irrigation system. Factors used in the determination can include the slope, the wind speed, 2340 motor or machine speed sensors, VFD internal motor data such as amperage & voltage, the uniformity of the ground covered by the irrigation system, and other conditions.

[0147] In some embodiments, a drivetrain assembly could comprise a magnetic brake 3000, a motor assembly 2200, and a gearbox 2300. The drivetrain assembly could comprise an electric brake system to slow rotation of an input shaft 2340 below a threshold rotational speed so the magnetic brake 3000 can prevent rotation of the input shaft 2340 when the motor assembly 2200 is disengaged. In some embodiments, the electric brake system can be controlled by a direct on line (DOL) tower control system. In some embodiments, the electric brake system can function similarly to how the VFD slows rotation of the output shaft 2350. In theseembodiments, the system controlling operation of the electric brake system (which can include a DOL tower control system, an endpoint controller, a VFD, or any other control means) can similarly include control means and sensor means to determine the amount of electric braking needed until the input shaft 2340 drops below a threshold rotational speed, similar to other embodiments of braking systems disclosed herein.

[0148] In some embodiments, a drivetrain assembly could comprise a stopping brake (e.g., a passive break), a motor assembly 2200, and a gearbox 2300. The drivetrain assembly could comprise a dynamic brake (e.g., an overspeed brake, a slowing brake, etc.) to slow rotation of an input shaft 2340 below a threshold rotational speed, and the drivetrain assembly can halt further movement of, for example, an irrigation system 1. Once the input shaft 2340 rotates below the threshold rotational speed, the stopping brake can engage to prevent or substantially prevent rotation of the input shaft 2340 when the motor assembly 2200 is disengaged. In some embodiments, the dynamic brake can be a VFD brake as described herein, an electromagnetic brake, a regenerative braking system, or other braking system. In some embodiments, the stopping brake can be a magnetic brake system such as magnetic brake system 100 or magnetic brake 3000 as described herein, an electromagnetic brake, or other braking system. In these embodiments, the system controlling operation of the dynamic brake (which can include a DOL tower control system, an endpoint controller, a VFD, or any other control means) can similarly include control means and sensor means to determine the amount of braking needed until the input shaft 2340 drops below a threshold rotational speed, similar to other embodiments of braking systems disclosed herein.

[0149] In some embodiments, a drivetrain assembly could comprise a magnetic brake 3000, a motor assembly 2200, and a gearbox 2300. In some embodiments, the magnetic brake 2100 can be configured to not require a separate braking system to lower the speed of the input shaft 2340 below a threshold rotational speed is not necessary. This can be accomplished by changing the weight of the centrifugal weights, by changing the biasing strengths of the biasing members, or by modifying any other component or feature affecting the braking power of the magnetic brake 3000.

[0150] Figures 9A through 9D depict various components of an embodiment of a magnetic brake system 3000 substantially similar to the magnetic brake system 100 shown anddescribed herein. Components of the magnetic brake 3000 can function substantially similar to components of magnetic brake system 100, unless otherwise described herein.

[0151] Figures 9A and 9B depict components of the magnetic brake system 3000. Figure 9A depicts a view of a rotating magnet assembly 3200 and translation assembly 3400 according to one embodiment of a magnetic brake 3000. Figure 9B depicts portions of the cover 3210 and the fixed magnet assembly 3300 can be substantially similar to the cover 210 and the fixed magnet assembly 300 descried herein. The magnetic brake 3000 can further include a fan 3104 or propeller system operably connected to the shaft 3102. The propeller fan 3104 can rotate with the shaft 3102 to provide cooling to one or more components of the magnetic brake system 3000 while the shaft rotates, or components adjacent the fan 3104 or magnetic brake 3000. In some embodiments of drivetrain assemblies which include the magnetic brake 3000, the fan 3104 can be configured to provide cooling airflow to cool one or more components of an adjacent motor assembly 2200.

[0152] Figure 9C depicts an exploded view of a rotating magnet assembly 3200 and translation assembly 3400 according to one embodiment of a magnetic brake 3000. The rotating magnet assembly 3200 can include a rotor magnet lower housing 3202A, rotor magnet upper housing 3202B with a plurality of rotating magnet recesses 3205, a plurality of translating magnets 3204 and cover 3210 substantially similar to a translating magnet housing 202, translating magnet 204, and cover 210 as described herein. In some embodiments, the rotating magnet assembly 3200 can include a magnet spline slider 3212 configured to align the rotating magnet assembly 3200 and translation assembly 3400 with the rotation of the shaft 3102.

[0153] The stationary component 3430 can include a guard structure 3500, which can be substantially similar to a stationary component 430 and guard structure 500 described herein. The stationary component 3430 can have protrusions 3435 to assist with aligning the centrifugal weight carriers 3410, which can function substantially similarly to how the protrusions 435 and cover 436 function to align the centrifugal weight carrier 410 by the slots 412 as described herein, the stationary component 3430 can be connected to the guard structure by screws or other mechanical connection means.

[0154] Figure 9C further depicts a kick-start spring 3460 positioned between the stationary component 3430 and translating component 3420 within the translation assembly 3400. In some embodiments, the kick-start spring 3460 can assist in reducing and / or eliminating ahysteresis effect involved during operation of the magnetic brake 3000. The kick-start spring 3460 can advantageously bias the translating component 3420 from the stationary component 3430. The kick-start spring 3460 can counteract, at least partially, the delayed retraction / expansion of the one or more centrifugal weights 3410 at the threshold rotational speed, to more quickly transition the centrifugal weight carrier 3410 between its expanded or retracted state. The kick-start spring 3460 may be configured to assist in the transition at a threshold rotational speed based on the design of other components of a magnetic brake 3000. For example, the kick-start spring 3460 for a magnetic brake 3000 designed to have a threshold rotational speed at one RPM may be different than a kick-start spring 3460 for a magnetic brake 3000 designed to have a threshold rotational speed at a different RPM.

[0155] Figure 9D depicts portions of the translation assembly 3400 according to one embodiment of a magnetic brake 3000. In some embodiments, the centrifugal weight carrier 3410 can include one or more slots 3412 and a centrifugal weight 3414 substantially similar to a centrifugal weight carrier 410, slot 412, and centrifugal weight 414 as described herein. In some embodiments, the centrifugal weight carrier 3410 can be secured to the translating component 3420 by inserting ends of a pivot axel 3434 into a pivot slot 3427 within a weight aligner shim 3426 fixedly connected to the translating component 3420. The weight aligner shims 3426 can be configured to allow the centrifugal weight carriers 3410 to rotate in a direction 3416 around a pivot axis 3433 when the brake converts between its nondeployed and its deployed states. The centrifugal weight carriers 3410 can be connected to the weight aligner shims 3426 by slotting end portions of their pivot axels 3434 into pivot slots 3427 within the weight aligner shim 3426. Components of the centrifugal weight carrier 410 can be connected to each other with the use of rivets 3415, screws, welding, sintering, or other mechanical connection means.

[0156] In some embodiments, the motor assembly 2200 can further include one or more thermal switches or sensors to monitor the temperature of one or more components within the motor assembly 2200. In some embodiments, these thermal switches or sensors can be a thermal switch with one or more contacts, a thermal sensing device with one or more outputs, or other component which can be used to trigger a safety system, or signal the VFD or PLC of overheat conditions, to reduce speed or stop the machine. In some embodiments, when one or more components of the motor assembly 2200 reach or exceed a critical temperature, the thermal switchcan issue commands to disconnect or temporarily disconnect the drivetrain assembly 2000 from the power source, which can slow or stop movement of the irrigation system 1. In some embodiments, the motor assembly 2200 can further include an emergency stop button which can be manually activated to reduce speed or stop the irrigation system 1.

[0157] In some embodiments, these thermal switches or sensors can be operably connected to a safety shut down system, a VFD safety shut down system (e.g., an e-stop circuit), or a supplemental controller (e.g., a programmable logic controller or other type of controller) to reduce speed or to bring the motor to a full stop, thus preventing or substantially preventing damage or destruction of the dynamic braking resistors or other components of the drivetrain assembly 2000 during a thermal overload event.

[0158] Conditional language used herein, such as, among others, “can,” “could,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and / or states. Thus, such conditional language is not generally intended to imply that features, elements and / or states are in any way required for one or more embodiments or that one or more embodiments necessarily include these features, elements and / or states.

[0159] Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

[0160] While the above detailed description may have shown, described, and pointed out novel features as applied to various embodiments, it may be understood that various omissions, substitutions, and / or changes in the form and details of any particular embodiment may be made without departing from the spirit of the disclosure. As may be recognized, certain embodiments may be embodied within a form that does not provide all of the features and benefits set forth herein, as some features may be used or practiced separately from others.

[0161] Additionally, features described in connection with one embodiment can be incorporated into another of the disclosed embodiments, even if not expressly discussed herein, and embodiments having the combination of features still fall within the scope of the disclosure.For example, features described above in connection with one embodiment can be used with a different embodiment described herein and the combination still fall within the scope of the disclosure.

[0162] It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes of the embodiments of the disclosure. Thus, it is intended that the scope of the disclosure herein should not be limited by the particular embodiments described above. Accordingly, unless otherwise stated, or unless clearly incompatible, each embodiment of this disclosure may include, additional to its essential features described herein, one or more features as described herein from each other embodiment disclosed herein.

[0163] Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0164] Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a subcombination.

[0165] Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Otheroperations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and / or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added.

[0166] Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products.

[0167] For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0168] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, 0.1 degree, or otherwise.

[0169] The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in31the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.

[0170] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of “including, but not limited to”.

[0171] Reference to any prior art in this description is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavor in any country in the world.

[0172] The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the description of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

[0173] Where, in the foregoing description, reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth. In addition, where the term “substantially” or any of its variants have been used as a word of approximation adjacent to a numerical value or range, it is intended to provide sufficient flexibility in the adjacent numerical value or range that encompasses standard manufacturing tolerances and / or rounding to the next significant figure, whichever is greater.

[0174] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. For instance, various components may be repositioned as desired. It is therefore intended that such changes and modifications be included within the scope of the invention. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present invention. Accordingly, the scope of the present invention is intended to be defined only by the claims.

Claims

WHAT IS CLAIMED IS:

1. A magnetic brake system for an agricultural system, the magnetic brake system comprising: a shaft; a rotating magnet assembly disposed on the shaft, the rotating magnet assembly having at least one translating magnet recess to house at least one translating magnet; a fixed magnet assembly positioned radially aligned with the rotating magnet assembly, the fixed magnet assembly having at least one fixed magnet; and a centrifugal weighted assembly disposed on the shaft and connected to the rotating magnet assembly, the centrifugal weighted assembly configured to rotate and translate with the rotating magnet assembly along the shaft; wherein the centrifugal weighted assembly further comprises at least one biasing member applying a retaining force in a first direction along the shaft; wherein the at least one translating magnet of the rotating magnet assembly is configured to magnetically interact with the at least one fixed magnet of the fixed magnet assembly; wherein after the shaft rotates at a threshold rotational speed the centrifugal weighted assembly and the rotating magnet assembly along the shaft translate linearly in a second direction substantially opposite the first direction; and wherein after the centrifugal weighted assembly and the rotating magnet assembly translate linearly in the second direction, the rotating magnet assembly magnetically disengages from the fixed magnet assembly.

2. The magnetic brake system of Claim 1, wherein the fixed magnet assembly and the rotating magnet assembly each comprise at least two magnets.

3. The magnetic brake system of Claim 2, wherein at least two fixed magnets within the fixed magnet assembly are aligned with at least two of the at least one translating magnet within the rotating magnet assembly.

4. The magnetic brake system of any of Claims 1 -3, wherein the rotating magnet assembly is prevented from rotating relative to the shaft.

5. The magnetic brake system of any of Claims 1 -4, further comprising a guard positioned radially outward from the centrifugal weighted assembly;wherein the guard is positioned such that it is radially outward from the centrifugal weighted assembly.

6. The magnetic brake system of Claim 5, wherein the guard is prevented from rotating relative to the shaft by a key.

7. A magnetic brake system comprising: a shaft; a rotating magnet assembly disposed on the shaft, the rotating magnet assembly having at least one translating magnet recess to house at least one translating magnet; a fixed magnet assembly positioned radially in line with the rotating magnet assembly, the fixed magnet assembly having at least one fixed magnet; and a translation assembly comprising a stationary component, a translating component, and at least one centrifugal weight carrier; and wherein the translating component is attached to the rotating magnet assembly; and wherein the at least one centrifugal weight carrier is configured such that when the magnetic brake system, the rotating magnet assembly, and the translation assembly rotate at a threshold rotational speed, the at least one centrifugal weight carrier converts from an engaged state to a disengaged state, and the translating component disengages the rotating magnet assembly from the fixed magnet assembly.

8. The magnetic brake system of Claim 7, wherein the translating component comprises an aligner protrusion; wherein the stationary component comprises an aligner cavity; and wherein the translating component remains in rotational alignment with the stationary component through contact between the aligner protrusion and the aligner cavity.

9. The magnetic brake system of any of Claims 7-8, wherein the at least one centrifugal weight carrier is configured to convert from the engaged state to the disengaged state at the threshold rotational speed by modifying a centrifugal weight attached to the at least one centrifugal weight carrier.

10. The magnetic brake system of any of Claims 7-9, wherein the rotating magnet assembly further comprises a weight aligner interface configured to interface with a magnetic aligner interface on the translating component.

11. The magnetic brake system of any of Claims 7-10, wherein the translating component further comprises at least one aligner cover to align a weight resting section of the at least one centrifugal weight carrier to a weight resting point on the translating component.

12. A magnetic brake system comprising: a stationary magnet array positioned circumferentially about a shaft; and a translating magnet array positioned radially inward from the stationary magnet array when in a first position and configured to rotate with the shaft; wherein the translating magnet array is configured to translate axially along the shaft to from the first position to a second position when the shaft rotates beyond a threshold speed, wherein, when in the first position, the stationary magnet array is magnetically engaged with the translating magnet array and rotation of the shaft is resisted; and, wherein, when in the second position, the stationary magnet array is magnetically disengaged from the translating magnet array and rotation of the shaft is substantially unrestricted.

13. The magnetic brake system of any of the preceding claims, where the threshold rotational speed is at least 600 rotations per minute.

14. The magnetic brake system of any of the preceding claims, further comprising a propeller operably connected to the shaft, wherein rotation of the shaft rotates the propeller, and wherein rotation of the propeller provides cooling to one or more components of the magnetic brake system.

15. A drivetrain assembly for use in an irrigation system configured to maintain a rest position when a motor is deactivated, the drivetrain assembly comprising: a magnetic brake system according to any of the preceding claims comprising an input shaft; an electromagnetic motor connected to the input shaft, the electromagnetic motor controlled by a variable frequency drive, wherein the variable frequency drive comprises: a rectifier configured to convert voltage from alternating current to direct current, the rectifier connected to a power source providing alternating current;a direct current link comprising one or more dynamic braking resistors; and an inverter configured to drive the electromagnetic motor, and a gearbox with an output shaft, the gearbox connected to the input shaft and the output shaft connected to a wheel; wherein the electromagnetic motor rotates the input shaft above a threshold rotational speed and disengages the magnetic brake system when the variable frequency drive issues an active command; wherein, when the variable frequency drive does not issue the active command, the one or more dynamic braking resistors slow rotation of the output shaft such that rotation of the input shaft is below the threshold rotational speed of the magnetic brake system when the wheel is on a surface with a slope, and wherein, when the input shaft rotates below the threshold rotational speed, the magnetic brake system engages and substantially prevents rotation of the input shaft.

16. The drivetrain assembly of Claim 15, wherein the one or more dynamic braking resistors are configured to be removable from the variable frequency drive.

17. The drivetrain assembly of any of Claims 15-16, wherein the direct current link comprises only one dynamic braking resistor.

18. The drivetrain assembly of any of Claims 15-17, wherein the one or more dynamic braking resistors include a heat dissipation feature.

19. The drivetrain assembly of Claim 18, wherein the heat dissipation feature is a heat fin.

20. The drivetrain assembly of Claim 18, wherein the heat dissipation feature is a resistor housing.

21. The drivetrain assembly of Claim 20, wherein the resistor housing is cooled by an adjacent fluid flow.

22. The drivetrain assembly of Claim 21, wherein the adjacent fluid flow is provided by an irrigation system.

23. The drivetrain assembly of any of Claims 15-22, wherein the one or more dynamic braking resistors are positioned in an expected flow path of a propeller operably connected to the shaft of the magnetic brake system, wherein the propeller is positioned to provide airflow to both the magnetic brake system and the one or more dynamic braking resistors while the shaft rotates.

24. The drivetrain assembly of any of Claims 15-23, further comprising a thermal switch operatively connected to the variable frequency drive and configured to read a temperature of one or more components of the drivetrain assembly, wherein when the thermal switch detects that one or more components of the drivetrain assembly reaches or exceeds a critical temperature, the variable frequency drive ceases issuing the active command.

25. The drivetrain assembly of any of Claims 15-24, wherein the threshold rotational speed is at least 600 rotations per minute of the input shaft.

26. The drivetrain assembly of any of Claims 15-25, wherein the slope is measured from a horizontal plane.

27. The drivetrain assembly of any of Claims 15-26, wherein the slope is 30 percent or more.

28. The drivetrain assembly of any of Claims 15-26, wherein the slope is 30 percent or less.

29. The drivetrain assembly of any of Claims 15-28, wherein the one or more dynamic braking resistors are arranged in parallel.

30. A drivetrain assembly for use in an irrigation system configured to maintain a rest position when a motor is deactivated, the drivetrain assembly comprising: a stopping brake system comprising an input shaft; a motor connected to the input shaft; a dynamic brake system connected to the input shaft; and a gearbox with an output shaft, the gearbox connected to the input shaft and the output shaft connected to a wheel, the wheel configured to rest on a surface; wherein, when the motor is active, the motor rotates the input shaft above a threshold rotational speed and disengages the stopping brake system; wherein, when the motor is inactive, the dynamic brake system slows rotation of the output shaft such that rotation of the input shaft is below the threshold rotational speed of the stopping brake system when the wheel is on the surface with a slope, and wherein, when the input shaft rotates below the threshold rotational speed, the stopping brake system engages and substantially prevents rotation of the input shaft.

31. The drivetrain assembly of Claim 30, wherein the stopping brake system comprises a magnetic brake system according to any of the preceding claims.

32. The drivetrain assembly of any of Claims 30-31, wherein the stopping brake system comprises an electromagnetic brake.

33. The drivetrain assembly of any of Claims 30-32, wherein the dynamic brake system comprises a variable frequency drive.

34. The drivetrain assembly of any of Claims 30-33, further comprising a thermal switch operatively connected to the motor and configured to read a temperature of one or more components of the drivetrain assembly, wherein when the thermal switch detects that one or more components of the drivetrain assembly reaches or exceeds a critical temperature, the motor becomes inactive.

35. The drivetrain assembly of any of Claims 30-34, wherein the dynamic brake system comprises an electromagnetic brake.

36. The drivetrain assembly of any of Claims 30-35, wherein the dynamic brake system comprises a regenerative braking system.

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