System and method for drive coupling of a compressor

Abstract

A coupling device (170) may be disposed between a power source (108) and a compressor (120) to selectively couple the power source to the compressor. A control device may be configured to selectively move the coupling device between a disengaged configuration in which the power source is decoupled from the compressor and an engaged configuration in which the power source is coupled to the compressor via the coupling device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 338,730 filed on May 5, 2022, and is incorporated herein by reference. Technical Field

[0002] The present disclosure relates to rotating machines. More particularly, the present disclosure relates to compressor systems (eg, air compressor systems) that are operably powered by a power source (eg, an internal combustion engine) to provide a pressurized fluid flow. Background Art

[0003] Conventional rotary machines (e.g., air compressors and pumps) typically use a power source that is directly coupled to a driven component. For example, an air compressor system may include a power source having an output shaft that is directly coupled to an input shaft of a compressor (e.g., via a flexible coupling) such that the output shaft and the input shaft rotate together to power the compressor, thereby compressing air.

[0004] The above discussion merely provides general background information and is not intended to be an aid in determining the scope of the claimed subject matter. Summary of the invention

[0005] As generally disclosed herein, embodiments of the present invention may relate to a compressor system (e.g., an air compressor system) and a method for selectively coupling a power source to a compressor. In some cases, the compressor system may include a coupling device disposed between the power source and the compressor to selectively couple the power source to the compressor. The coupling device may be operated by a controller based on one or more operating parameters of the compressor system, for example, to provide a soft start engagement of the power source with the compressor.

[0006] According to some aspects of the present disclosure, a compressor system may include a power source, a compressor, a coupling device, and a control device. The coupling device may be disposed between the power source and the compressor to selectively couple the power source to the compressor. The control device may be configured to move the coupling device between a separation configuration and an engagement configuration. In the separation configuration, the power source may be decoupled from the compressor. In the engagement configuration, the power source may be coupled to the compressor via the coupling device.

[0007] According to some aspects of the present disclosure, a method of operating a compressor system may include: using one or more electronic control devices, when the coupling device is in a disengaged configuration in which the power source is decoupled from the compressor, reducing the speed of the power source from a first speed to a second speed. In addition, the method may include: using one or more electronic control devices, when the speed of the power source is increased from the second speed, increasing the speed of the power source from the second speed to a third speed, and moving the coupling device from the disengaged configuration to the engaged configuration to couple the power source to the compressor so that the output shaft of the power source rotates the input shaft of the compressor.

[0008] According to some aspects of the present disclosure, a method for starting a compressor system may include: using one or more electronic control devices, when the coupling device is in a separation configuration in which the power source is decoupled from the compressor, increasing the speed of the power source from a first speed to a second speed. In addition, the method may include: using one or more electronic control devices, after the power source reaches the second speed, controlling the coupling device to move to an engagement configuration to couple the power source to the compressor so that the power source provides operating power to the compressor. In addition, the method may include: using one or more control devices, after the coupling device reaches the engagement configuration, reducing the speed of the power source from the second speed to a third speed.

[0009] According to some aspects of the present disclosure, a method of operating a compressor system may include: controlling the compressor system to operate in a separation mode using one or more electronic control devices. A coupling device may be controlled to move from an engaged configuration to a disengaged configuration to decouple a power source from a compressor of the compressor system. A first valve may be closed to prevent oil from flowing to a rotor of the compressor. A speed of the power source may be reduced. A pressure in a tank fluidly coupled to the rotor to contain pressurized air from the rotor may be reduced.

[0010] According to some aspects of the present disclosure, a method for starting a compressor system may include: operating a power source at a starting speed using one or more electronic control devices. In addition, the method may include: receiving an indication that a temperature of the power source meets a temperature standard using one or more electronic control devices. In addition, the method may include: in response to receiving the indication, controlling a coupling device to move to an engagement configuration to couple the power source to the compressor so that the power source provides operating power to the compressor.

[0011] According to some aspects of the present disclosure, a method for starting a compressor system in a startup sequence may include: using one or more electronic control devices, when the power source is at a first speed, controlling a coupling device to operably couple the power source to the compressor. With the coupling device operably coupled to the power source, the speed of the power source can be increased from the first speed to a second speed to cause a powered rotation of the compressor. When the compressor is in powered rotation: the coupling device can be controlled to decouple the power source from the compressor; and the speed of the power source can be further increased toward an operating speed.

[0012] The invention summary and the specification abstract are provided to introduce a selection of concepts in a simplified form, which will be further described in the detailed description below. The invention summary and the specification abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the embodiments of the present invention:

[0014] Figure 1 is a schematic diagram of a compressor system having a power source coupled to the compressor via a coupling device according to aspects of the present disclosure;

[0015] Figure 2 is a flow chart of a method of operating a compressor system having a power source coupled to the compressor via a coupling device according to aspects of the present disclosure;

[0016] Figure 3 is a diagram illustrating a soft start function of a compressor system having a clutch with an independent soft engagement function according to aspects of the present disclosure;

[0017] Figure 4 is a diagram illustrating another soft start function of a compressor system having a clutch with an independent soft engagement function according to aspects of the present disclosure;

[0018] Figure 5 is a diagram illustrating a soft start function of a compressor system having a clutch without an independent soft engagement function according to aspects of the present disclosure;

[0019] Figure 6 is a flow chart of a method of operating a compressor system having a power source coupled to the compressor via a coupling device according to aspects of the present disclosure;

[0020] Figure 7 is a diagram illustrating another soft start function of a compressor system with a clutch according to aspects of the present disclosure;

[0021] Figure 8 is a flow chart of a method of operating a compressor system having a power source coupled to the compressor via a coupling device according to aspects of the present disclosure;

[0022] Fig. 9 is a diagram illustrating another soft start function of a compressor system with a clutch according to aspects of the present disclosure;

[0023] Fig.10 is a flow chart of a method of operating a compressor system having a power source coupled to the compressor via a coupling device according to aspects of the present disclosure;

[0024] Fig.11 is a diagram illustrating a start-up sequence of a compressor system having a clutch according to aspects of the present disclosure;

[0025] Fig.12 is a flow chart of a method of operating a compressor system having a power source coupled to the compressor via a coupling device according to aspects of the present disclosure;

[0026] Fig.13 is a diagram illustrating a soft start function of a compressor system having a clutch with an independent soft engagement function according to aspects of the present disclosure; DETAILED DESCRIPTION

[0027] The concepts disclosed in this discussion are described and illustrated by reference to exemplary embodiments. However, the application of these concepts is not limited to the details of the construction and arrangement of the components in the illustrative embodiments, and can be practiced or implemented in various other ways. The terms in this document are used for descriptive purposes only and should not be considered as limiting. As used herein, words such as "including," "comprising," and "having" and variations thereof are intended to cover the items listed thereafter and their equivalents as well as additional items.

[0028] In addition, unless otherwise specified or limited, the terms "about" and "approximately" used herein relative to a reference value refer to a variation range of ±5% (including +5% and -5%) relative to the reference value. Similarly, the term "substantially" used herein relative to a reference value refers to a variation range within ±30% (including +30% and -30%) relative to the reference value. In addition, in this regard, "significantly lower" and "significantly higher" indicate values ​​that are lower and higher than the reference value by more than 30%, respectively. Unless otherwise specified, the ranges listed herein include the endpoints of the ranges.

[0029] Likewise, as used herein, unless otherwise specified or limited, "speed" refers to the rotational speed of a rotating body, which may be measured in revolutions per minute (RPM). Specifically, the "speed" of an engine refers to the rotational speed of the drive shaft of the engine, which in some cases may also be equal to the rotational speed of one or more output shafts of the engine.

[0030] As mentioned above, many conventional compressor systems include direct coupling between the input shaft of the air compressor and the output shaft of the engine. However, as a result, any rotation of the power source drives the air compressor, so the air compressor always causes a potential significant load on the power source. As a result of this arrangement, conventional air compressors usually require a robust starting system that can rotate the power source (e.g., internal combustion engine) and the compressor during the start sequence (i.e., the sequence of control operations of the power rotation (from zero RPM to non-zero speed) of the start engine). In order to overcome the peak inertial force of the air compressor system during the start sequence (especially in cold environments), the power source of the air compressor is usually oversized relative to the expected stable operating load. For a power source that is oversized in almost all cases (i.e., except when starting the engine), this may lead to increased fuel consumption and additional costs. In addition, since the compressor is always coupled to the power source, the system is always under the load of compressed air even when compressed air is not needed (e.g., during startup, when the storage tank is full, or during a pause in the working operation). Similar to what is described above, this may lead to poor engine performance and increased fuel consumption. Furthermore, while some power sources may be run at lower speeds to partially address the above issues, this may result in greater condensate accumulation within the compressor system, which in turn may require maintenance or may result in suboptimal performance.

[0031] Some embodiments of the disclosed technology can provide improved configurations for rotary machines (and specifically, air compressors), including providing systems and methods for selectively decoupling rotary machines from a power source. For example, by selectively decoupling a compressor from a power source, the load imposed by the compressor on the power source can be eliminated, resulting in easier startup. Thus, since the inertial load of the compressor can be selectively removed from the power source, a given compressor can be operated using a smaller (e.g., more fuel-efficient) power source compared to conventional arrangements.

[0032] Aspects of the present disclosure provide a compressor system that includes a coupling device disposed between a power source and a compressor to selectively couple the power source to the compressor. For example, a clutch system (e.g., an electromagnetic clutch system of various known configurations) may be interposed between an output shaft of an engine (or other rotary power source) and an input shaft of the compressor. The coupling device (e.g., a clutch system) may be controlled to selectively move between a disengaged configuration and an engaged configuration during operation of the engine and the compressor.

[0033] Typically, in a disengaged configuration, the coupling device operably decouples the power source from the compressor so that, for example, the power source output shaft and the compressor input shaft can rotate independently of each other. That is, when the coupling device is in a disengaged configuration, the power source can operate without an operating load from the compressor (e.g., so that the output shaft rotates while the input shaft does not rotate). Typically, in an engaged position, the coupling device operably couples the power source to the compressor so that, for example, the power source bears the entire inertial load of the compressor and the output shaft operably provides power to the input shaft (e.g., to provide compressed service air). Therefore, when the coupling device is in an engaged configuration (e.g., so that the output shaft and the input shaft rotate at the same speed), the compressor acts as a load on the power source. In addition, in some cases, the compressor may also include a control device (e.g., an industrial electronic controller or a general-purpose programmable computer), which may be configured to operate the coupling device to move the coupling device between a disengaged configuration and an engaged configuration according to a specific timing or based on other criteria.

[0034] More specifically, in some cases, the coupling device may be configured as a clutch, which includes a driving member (e.g., a clutch or a friction plate) coupled to the output shaft of the power source and configured to rotate therewith (e.g., via a direct connection or an indirect connection such as a gear train). In addition, the clutch may include a driven member (e.g., a pressure plate) coupled to the input shaft of the compressor and configured to rotate therewith (e.g., via a direct connection or an indirect connection such as a gear train). The driving member and the driven member may be moved relative to each other (e.g., in response to a signal from a controller) to allow the clutch to move between an engaged configuration and an engaged configuration, wherein the driving member and the driven member are spaced apart from each other in the engaged configuration, and the driving member and the driven member are in (friction) contact with each other in the engaged configuration. For example, based on an electronic control command from an electronic control device, the driven member may move toward or away from the driving member (e.g., along the rotation axis of the input shaft). Since the driving member rotates with the output shaft, the friction between the driving member and the driven member causes the driven member to rotate with the driving member, so that the power source and the compressor are operably coupled.

[0035] Some embodiments of the disclosed technology may allow the engine and the compressor to be soft-started or soft-engaged via a coupling device to reduce undesirable loads (e.g., inertial loads) on the power source during startup or other operations. For example, while keeping the coupling device in a disengaged state, the controller may be configured to reduce the speed of the power source from a first speed to a second speed (e.g., reducing the speed from preheating or high idle to low idle or below low idle (such as the lowest engine speed)). Once the power source speed (e.g., the power source speed measured at the output shaft) reaches the second speed (e.g., after a predetermined time from when the first engine signal was sent), the controller may increase the speed of the output shaft from the second speed to a third speed (e.g., high idle or running speed). In some cases, the first speed and the third speed may be the same, or they may be different (e.g., the third speed is higher than the second speed). The RPM range corresponding to the engine running state (e.g., low idle state or running state) may vary depending on the specific application, engine size, fuel type and other engine parameters, manufacturer settings or operating conditions. For example, in some cases, the minimum engine speed may be less than 1000 RPM (e.g., between 500 RPM and 900 RPM), the low idle speed may be between 1200 RPM and 1700 RPM, and the operating speed may be between 1800 RPM and 2800 RPM. In some cases, the low idle speed may be between 500 RPM and 900 RPM, or less than or equal to 1000 RPM. In some cases, the high idle speed may be between 1500 RPM and 2100 RPM. In other cases, the RPM range corresponding to the preheat or high idle speed, low idle speed, or operating speed may be different.

[0036] The controller may sometimes operate the coupling device to reach the engagement configuration when the speed of the power source is increasing from the second (e.g., reduced) speed but before the speed of the power source reaches the third (e.g., running) speed to achieve full operational delivery of power. In some cases, this may include: commanding the coupling device to move to the engagement configuration when the speed of the power source is at the second speed (or before increasing from the second speed). For example, the electronic control system may command the clutch to enter the engagement configuration before the electronic control system commands the engine to increase from the reduced (e.g., second) speed. Therefore, in some cases, the clutch may be operated to finally reach the engagement state before the engine speed has increased to significantly above the reduced speed. Therefore, by appropriate command timing, some embodiments may operate the compressor system to ensure the optimal engine speed for initial clutch engagement, while also avoiding excessive engine speed drops (e.g., below no stall or other optimal speeds) due to the initial increase in inertial load from the compressor during compressor startup. In some cases, an engagement signal may be provided at a predetermined time so that the coupling device engages the power source to the compressor when the power source speed is equal to or above the minimum engagement speed. In some cases, the timing of sending the engagement signal may be based on whether the clutch includes an independent soft engagement function (eg, some clutches may be configured to provide a progressive clutch engagement profile that controls relative movement between the driving member and the driven member to gradually increase torque transfer therebetween).

[0037] In some embodiments, to further reduce the initial load application of the power source, the control system can delay opening the inlet valve (e.g., unloading valve) of the air compressor until after the coupling device between the power source and the compressor is in the engaged configuration, and in some cases, until after the power source reaches a third (e.g., operating) speed. For example, the controller can be configured to provide a valve opening signal to the compressor at a predetermined time after the engagement signal or at a predetermined speed (the power source moves from the second (e.g., minimum commanded) speed to the third (e.g., operating) speed).

[0038] In some embodiments, various other control methods may also be applied. For example, as described in further detail below, some methods may include increasing engine speed before clutch engagement, controlling clutch engagement based on coolant temperature, and controlling clutch engagement to help remove waxy oil from the compressor.

[0039] The concepts described herein can be practiced on a variety of different types of rotating machines. Figure 1A representative rotating machine system capable of practicing aspects of the present disclosure is shown in FIG. For the sake of brevity, only one rotating machine system is shown and discussed as a representative rotating machine system. However, as described above, the following embodiments can be practiced on any of a variety of rotating machines (including air compressors, pumps, etc.).

[0040] Figure 1 1 is a schematic diagram of a representative rotating machine configured as a compressor system 100, which may be configured to generate and discharge an air flow or another compressed gas (e.g., a refrigerant). The compressor system 100 generally includes a power source configured to provide power (e.g., rotational power) to a driven component. In the illustrated embodiment, the compressor system 100 is configured as an air compressor system (e.g., a single-stage air compressor system) that is configured to inhale and pressurize atmospheric air to provide a pressurized air flow to a work site via a supply line 104 (e.g., a service line). In other embodiments, the compressor system may be a multi-stage compressor system. In some cases, the compressor system 100 may be configured as a portable compressor system that can be moved between various work sites, or as a fixed (e.g., permanent) compressor system.

[0041] To compress atmospheric air and provide an air flow at the supply line 104, the compressor system 100 includes a power source configured as an engine 108 (e.g., a diesel engine or another type of internal combustion engine), although other types of power sources may also be used. The engine 108 includes and is configured to rotate an output shaft 112 (e.g., a crankshaft or a flywheel) around a first rotational axis 116. The output shaft 112 can be configured to provide (rotational) power to a driven device (i.e., a compressor 120 (e.g., a dry or oil-immersed compressor)), which is configured to pressurize air and discharge an air flow. More specifically, the output shaft 112 can be coupled to an input shaft 124 of the compressor 120, which is configured to rotate around a second rotational axis 126 (e.g., coaxial with the first rotational axis 116). Therefore, the engine 108 can be operably coupled to the compressor 120 so that the engine 108 provides power to the compressor 120.

[0042] Continue to refer Figure 1, the compressor 120 can be configured as an oil-flooded screw compressor, in which oil flows around and between two counter-rotating screws to lubricate and improve the seal between components as changing the size of the unit between the screws compresses the air. For example, atmospheric air can be drawn into the compressor 120 at the air inlet valve 128, compressed as the screws rotate, and then discharged from the compressor 120 as a high-pressure stream at the compressor outlet 130. In some cases, the air inlet valve 128 can be an electronically controlled valve that can be powered by, for example, the battery 110 of the compressor system 100, or it can be a mechanically actuated valve, such as a spring-biased butterfly valve.

[0043] During operation of the compressor 120, some oil may be mixed with the air and carried through the compressor outlet 130. However, it is generally not desirable to provide an air flow containing oil to the rotor. Thus, for example, compressed air from the compressor 120 may pass through the compressor outlet 130 to a separator tank 132, which is configured to separate oil from the pressurized air by a separator element (e.g., a filter or other mechanical separator element having a structure for directing fluid flow or otherwise capturing entrained oil droplets). The oil removed from the air by the separator element 134 may be discharged at the bottom of the separator tank 132 (e.g., discharged to an oil sump), while the pressurized air remains above the oil in the separator tank 132 to provide service as needed.

[0044] In some cases, the oil removed from the air-oil mixture in the separator tank 132 may be reused to lubricate the compressor 120. Specifically, the separator tank 132 may include an oil outlet 136 that allows oil to flow from the oil sump back into the compressor 120 via an oil inlet 138. In some cases, an oil cooler 140 may be disposed upstream of the oil inlet 138 between the separator tank 132 and the compressor 120 to provide a cooled oil flow to the compressor 120, which may help cool the compressor 120 and other components of the compressor system 100 by removing at least some of the heat generated by the compression of the air within the compressor 120. In such cases, a thermal control valve 142 may be disposed upstream of the oil inlet 138 between the separator tank 132 and the compressor 120, and may be configured to selectively direct the oil flow from the oil sump to the oil cooler 140 (e.g., Figure 1 ) or by directing the oil flow from the oil sump to the compressor 120 by bypassing the oil cooler 140 (as shown in the solid line in FIG. Figure 1138). In this case, the thermal control valve 142 may be mechanically operated (e.g., a sliding valve with a wax plug) or electronically controlled to selectively direct the flow to the oil inlet 138. In some cases, the pressure of the air within the separator tank 132 may drive the oil flow along the return path to the compressor 120. In some cases, an oil pump (not shown) may be provided. Further, in some cases, an oil pump 144 may be provided upstream of the oil inlet 138 between the separator tank 132 and the compressor 120 to provide enhanced oil circulation to or within the compressor 120, which may provide enhanced lubrication, cooling, and sealing for the components of the compressor 120. In this case, the oil pump 144 may be powered directly by the engine 108, by the rotation of the compressor 120, or by an external power source (not shown).

[0045] In some embodiments, the separator tank can also serve as a storage tank, which can store pressurized air from the compressor for use when the supply line needs it. In this regard, the separator tank 132 can serve as a buffer for storing the amount of pressurized air, thereby allowing the compressor system 100 to provide an air flow with a flow rate greater than the flow rate provided by the compressor 120 alone. Therefore, in some cases, the air in the separator tank 132 can be maintained at a pressure higher than the pressure supplied at the supply line 104. In order to maintain the pressure in the separator tank 132, the compressor system 100 may include a minimum pressure valve 146, which is coupled to the air outlet 148 of the separator tank 132. For example, the minimum pressure valve 146 may be configured as a normally closed spring biased check valve, which is opened only when the pressure of the air passing through the air outlet 148 is large enough to overcome the force of a spring or other biasing element. In some cases, the minimum pressure valve 146 may be an adjustable pressure valve. In addition, the minimum pressure valve 146 can also inhibit or prevent air or other substances from changing their flow direction and entering the separator tank 132, the oil cooler 140, and the compressor 120 from the downstream (e.g., supply line 104) side of the system. In other embodiments, the minimum pressure valve 146 can be set at other points along the flow path between the separator tank 132 and the supply line 104.

[0046] In some cases, the compressor system may include additional components disposed between the compressor and the supply line to remove additional contaminants (e.g., water and oil) from the air flow. Figure 1As shown, the compressor system 100 includes an aftercooler 152 coupled to an outlet 150 of the minimum pressure valve 146. The aftercooler 152 is a heat exchanger that cools the air to remove heat generated during compression. Therefore, as the air cools within the aftercooler 152, the air approaches its dew point, which can cause moisture to condense out of the air. In addition, the compressor system 100 can also include an oil separator 154 (e.g., a filter) and a water separator 156 for further removing oil and water from the service air flow. Figure 1 As shown, service air may flow from outlet 158 ​​of aftercooler 152 to oil separator 154, and then from outlet 160 of oil separator 154 to water separator 156. In other embodiments, aftercooler 152, oil separator 154, and water separator 156 may be arranged differently or in other combinations.

[0047] Before exiting the compressor system 100 at the supply line 104, air may flow from the outlet 162 of the water separator 156 through the pressure control assembly 164. The pressure control assembly 164 may be configured to control the pressure of the air flow (e.g., the supply pressure of the compressor system 100) provided to the supply line 104 at a connection point 166 (e.g., a hose connector or other structure). Thus, when the supply line 104 is coupled to the connection point 166, pressurized air from the compressor system 100 may be transferred from the compressor 120 to the supply line 104 via the outlet 168 of the pressure control assembly 164. The pressure control assembly 164 may be an adjustable pressure control assembly that may be manipulated by a user to supply a desired air pressure at the supply line 104.

[0048] In some cases, it may be beneficial to reduce the flow rate of the compressed air or to stop compressing the air altogether. For example, it may be beneficial to reduce the flow rate of the compressed air when air flow is not needed at the supply line 104 or at other times. However, running the compressor at a reduced speed may result in lower compressor temperatures, which in turn may result in increased condensation within the compressor 120 and other components located downstream of the compressor 120. For example, condensed water may accumulate within the separator tank 132 (where it mixes with the oil in the tank), thereby shortening the life of the oil, increasing the risk of rust and other corrosion, and increasing maintenance costs.

[0049] Relatedly, when compressed air flow is not needed, some systems can be configured to close the air inlet valve of the compressor to stop air from flowing into the compressor, thereby reducing the load on the power source. For example, when air flow is not needed at the supply line 104 and the separator tank 132 is at maximum pressure, the air inlet valve 128 can be configured to close to prevent the compressor 120 from sucking additional air from the atmosphere. Therefore, a vacuum can be formed in the compressor 120, which can reduce the load on the engine 108 and further reduce fuel consumption. However, since the mechanical rotation of the compressor 120 is still powered by the engine 108, there will still be some load on the engine 108.

[0050] To further reduce fuel consumption and condensation rates within the compressor system, it is beneficial to decouple the driven components of the compressor from the associated power source. For example, according to some embodiments of the technology disclosed herein, the compressor 120 can be selectively decoupled from the engine 108 so that the inertial load of the compressor 120 is completely removed from the engine 108. For example, when air flow is not required at the supply line 104, or during engine startup, the compressor 120 can be decoupled from the engine 108, as this can generally allow the use of a smaller engine than used in conventional systems for a similarly sized compressor.

[0051] For example, continue to refer to Figure 1 , the compressor system 100 can include a coupling device configured as a clutch 170 that is mechanically disposed between the engine 108 and the compressor 120. Specifically, the clutch 170 is coupled to both the engine 108 (e.g., at the output shaft 112) and the compressor 120 (e.g., at the input shaft 124), and is configured by the controller 180 to move between a disengaged configuration and an engaged configuration, as discussed further below. In the disengaged configuration, the output shaft 112 and the input shaft 124 are decoupled from each other, so that the engine 108 does not provide power for the rotation of the compressor 120 (e.g., no torque is transmitted between the output shaft 112 and the input shaft 124, and the shafts 112, 124 can rotate independently of each other). Therefore, the inertial load of the compressor 120 can be completely removed from the engine 108, which is beneficial during engine startup and when compressed air flow is not required. Specifically, decoupling the compressor 120 from the engine 108 may reduce peak inertial load application on the engine 108 during startup and may allow for lower engine speeds when the compressor system 100 is not required to provide compressed air without the same potential for condensation accumulation as with conventional systems.

[0052] The clutch can be configured as any of a variety of known coupling devices, which can selectively couple two rotating bodies together to achieve the operation transmission of rotational power. For example, in the illustrated embodiment, the clutch 170 is configured as an electromagnetic friction clutch having a driving member 172, which is configured to selectively couple with a driven member 174 and provide power for the rotation of the driven member 174. More specifically, in the illustrated embodiment, the driving member 172 is configured as a friction plate, which is coupled to the output shaft 112 of the engine 108 (e.g., via direct coupling or indirect coupling), and the driven member 174 is configured as a pressure plate, which is coupled to the input shaft 124 of the compressor 120 (e.g., via direct coupling or indirect coupling). Therefore, when the driving member 172 and the driven member 174 are moved to the engagement configuration, the output shaft 112 can rotate the input shaft 124 via the frictional engagement between the driving member 172 and the driven member 174. However, in other embodiments, other clutch configurations can be used. For example, the clutch may be configured as a radial clutch, wherein the driving member or the driven member moves in a radial direction relative to each other to move between a disengaged configuration and an engaged configuration.

[0053] In some cases, in order to provide a smoother, more efficient transition between the disengaged configuration and the engaged configuration, the clutch may include a damper (not shown). For example, an elastic bushing, spring, or other elastic member acting as a torsional damper may be arranged to provide cushioning when the clutch is engaged. In some cases, in order to reduce wear on the driving member and the driven member, the clutch may also include a locking mechanism (not shown) configured to mechanically lock the driving member and the driven member together so that they rotate together in the engaged configuration, rather than relying solely on frictional contact. In this regard, a controller (e.g., controller 180, also discussed below) may sometimes be configured to control the locking mechanism.

[0054] In some cases, it may be advantageous to place the drive member and the driven member in a partially engaged configuration, wherein the drive member and the driven member are in contact with each other, but the normal force is insufficient to lock the drive member and the driven member so that they rotate in unison. For example, with respect to the illustrated embodiment, while there may be frictional contact between the drive member 172 and the driven member 174 in the partially engaged configuration, the drive member 172 and the driven member 174 may slide past each other such that they rotate at different speeds (e.g., the drive member 172 may rotate faster than the driven member 174).

[0055] The compressor system may also include a controller (e.g., a control device or system) that may be configured to control one or more operating parameters of the compressor system. For example, the controller 180 of the compressor system 100 may be configured to control the rotational speed of the output shaft 112 (e.g., via electronic control of the speed of the engine 108), the engagement and disengagement of the engine 108 from the compressor 120 (e.g., via electronic control of the clutch 170), and the opening and closing of the air inlet valve 128 of the compressor 120 (e.g., via control of an on-off valve or a proportional valve).

[0056] The controller 180 may be implemented as one or more known types of processor devices (e.g., microcontrollers, field programmable gate arrays, programmable logic controllers, logic gates, etc.), including as part of a general purpose or special purpose computer. In addition, the controller 180 may also appropriately include other generally known computing components, including memory, input devices, output devices, etc. (not shown). Therefore, the controller 180 may be configured to implement some or all of the operations of the control process described herein, which operations may be appropriately performed based on instructions or other data retrieved from the memory. In some embodiments, the controller 180 may include multiple control devices (or modules), which may be integrated into a single component or arranged as multiple separate components. In some embodiments, the controller 180 may be part of a larger control system and may therefore include various control modules (e.g., engine controller, clutch controller, compressor controller, wheel hub controller, etc.) or communicate electronically with various control modules. For example, as Figure 1 As shown, the controller 180 may include one or more of a dedicated engine controller 182 , a dedicated clutch controller 184 , a dedicated compressor controller 186 , or various other control modules.

[0057] In general, the controller may be configured to control the compressor system in response to user input, or in response to or otherwise based on one or more operating parameters of the compressor system (e.g., one or more operating parameters sensed by various sensors on or around the compressor system or one or more operating parameters that are predetermined and stored in memory). Thus, as also described above, the controller 180 may operate to monitor or control the speed of the power source 108, monitor or control the state of the air inlet valve 128, or monitor or control the state of the clutch 170. For example, the controller 180 may be configured to increase the engine speed to maintain the supply pressure at the supply line 104. Conversely, when a lower air flow is required to maintain the supply pressure at the supply line 104 (e.g., when no air is flowing from the supply line, but the separator tank 132 is not at maximum pressure (e.g., the compressor system 100 is filling the separator tank 132)), the controller 180 may reduce the engine speed.

[0058] As another example, when the engine is started or when the separator tank 132 is at maximum pressure and no air is flowing out of the system at the supply line 104, the controller 180 can be configured to move the clutch 170 from the engaged configuration to the disengaged configuration to decouple the engine 108 from the compressor 120, thereby stopping the compressor 120 from providing a flow of compressed air. Relatedly, once the system pressure is reduced to a minimum system pressure (e.g., a threshold), or after the engine 108 reaches a minimum operating temperature after starting, the controller 180 can be configured to move the clutch 170 from the disengaged configuration to the engaged configuration so that the engine 108 can power the compressor 120 to provide a flow of compressed air.

[0059] As another example, the controller may be configured to control engagement and disengagement of the clutch to help manage moisture accumulation within the compressor system. For example, clutch control may be associated with helping to maintain a specific temperature or pressure of the compressor system to avoid problems associated with condensation of moisture (e.g., water) in the compressed air flow. Thus, Figure 1 As shown, the controller 180 can communicate with a humidity sensor 190 that is configured to sense the moisture level of the compressed air flow. The humidity sensor can typically be a humidity sensor (which can be used to measure the humidity level in the ambient intake or compressed air in the tank), a water contact sensor, or any other known sensor type configured to measure the moisture content. In some cases, the sensor signal corresponding to the moisture content of the compressor system can therefore be evaluated to control the operation of the clutch of the compressor. For example, when operating at idle speed, when a predetermined humidity level is sensed, the controller 180 can command the clutch 170 to disengage, thereby stopping the compressor 120 and preventing additional water vapor from being introduced into the system 100. In other embodiments, other criteria for determining the clutch command based on the sensed humidity (e.g., internal humidity) can also be appropriately adopted.

[0060] In some cases, the controller can be configured to control the clutch to provide a soft start or other soft engagement of the compressor and the power source. That is, the controller can be configured to regulate the engagement of the compressor with the power source during startup of the compressor system or at other times. This approach can, for example, reduce noise, vibration, and harshness during the transition of the system from a disengaged configuration to an engaged configuration, and can generally improve system reliability (e.g., by preventing stalling) and efficiency (e.g., via improved fuel economy). As an example, refer to Figure 2, a method 200 of operating the compressor system 100 to provide a soft start function when engaging the engine 108 with the compressor 120 according to some aspects of the present disclosure is shown. Although the method 200 is described with reference to the compressor system 100 discussed above, the method may also be used for other types of rotating machines. In addition, the operation of the method 200 does not necessarily have to be performed in the specific order discussed below, and in some cases, it may be implemented using other control devices and systems not explicitly described herein. Generally, the method 200 can be implemented using various known general-purpose control devices (e.g., the controller 180), or it can be implemented using a dedicated control device constructed according to known principles to implement the concepts disclosed herein.

[0061] At box 204, method 200 may include: reducing the engine speed from the first engine speed to the second engine speed to reduce the rotational speed of the output shaft from the first rotational speed to the second rotational speed. Therefore, generally, before the clutch is engaged, the rotational speed of the engine can be controlled to a relatively low value. In some cases, the engine speed of the compressor system 100, the engine 108, and the rotational speed of the output shaft 112 can be the same. However, in other cases, they can be different (e.g., the engine speed can be greater than or less than the rotational speed of the output shaft), and the speed of the engine can be selected to achieve the desired output shaft speed.

[0062] Generally, the operation at box 204 can help reduce the engine speed to a lower relative value so that the engagement of the clutch can be smoother and more efficient. In some embodiments, the first engine speed can be a high idle speed of the engine, which can be suitable for initially warming up the engine at startup, and the second engine speed can be a low idle speed that is significantly lower than the first engine speed. For example, additional reference Figures 3 to 5 , at the start of method 200 (i.e., at Figures 3 to 5 ), the engine 108 may be controlled to operate at a first engine speed between 1250 RPM and 1750 RPM, or more specifically, approximately 1500 RPM, which may correspond to a high idle speed of the engine 108. The engine 108 may then receive a first engine speed (change) command signal 310 from a controller 180 (e.g., the engine controller 182) to reduce the engine speed to a lower second engine speed, for example, between 500 RPM and 1200 RPM.

[0063] In some cases, the second engine speed may be selected depending on whether the clutch is provided with a separate soft engagement function. Typically, the separate soft engagement function of the clutch allows the clutch to engage gradually over a longer period of time (e.g., 2 to 3 seconds) and may be used in conjunction with controlling the speed of the power source to further reduce noise, vibration, and harshness (e.g., by preventing the driving member and the driven member from immediately locking together, but rather allowing some slip between them before locking). For example, if Figure 3 and Figure 4 As shown, when the clutch (eg, clutch 170) is provided with a separate soft engagement function, the second engine speed may be approximately 1000 RPM. As another example, Figure 5 As shown, when the clutch (e.g., clutch 170) does not have a separate soft engagement function, the second engine speed can be lower (e.g., as low as the lowest speed that the engine can reach without stalling), specifically, between 500RPM and 900RPM, or about 800RPM. However, in other embodiments, other RPM settings can be used appropriately. In this way, for example, in the case where the engagement of the clutch with the compressor may be relatively sudden, the second engine speed can be reduced to reduce the kinetic energy of the engine output shaft when the clutch is engaged.

[0064] In some embodiments, the method 200 may include preventing the clutch from moving from the disengaged configuration to the engaged configuration until the engine 108 has risen to at least a minimum operating temperature (e.g., a coolant temperature of the engine 108 is greater than or equal to 80 degrees Fahrenheit, such as Figure 4 330 in the example). However, in some cases, a manual override may be provided to allow an operator to move the clutch 170 from a disengaged configuration to an engaged configuration (e.g., via the controller 180) so that air flow can be provided in the supply line 104 before the engine 108 reaches the minimum operating temperature. In some embodiments, the method 200 may include: the engine speed is not reduced from the first speed to the second speed until the engine 108 has been raised to at least the minimum operating temperature. In some embodiments, the amount of time after the initial start of the engine can be measured as a proxy for the operating temperature. In other words, the controller can make a reasonable approximation to the operating temperature (i.e., whether it is above a minimum threshold) based on the length of time the compressor has been running. This approximation may or may not include information about the ambient temperature. Alternatively, the controller may obtain actual temperature information from a sensor that communicates with the controller.

[0065] At block 208, method 200 may include increasing the engine speed from the second engine speed to a third engine speed. Figure 3 and Figure 5In the example shown, the third engine speed is caused by the second engine speed (change) command signal 320 and can be the same as the first engine speed. However, in other embodiments, other command signals can be used, or the first engine speed and the third engine speed can be different. In some embodiments, such as Figure 4 As shown, the third engine speed can be greater than the first engine speed. For example, the first engine speed can be an idle speed, and the third engine speed can be an operating speed or can be higher than the operating speed. As used herein, the operating speed indicates the speed of a power source (e.g., an engine) operably coupled to a compressor when the compressor is operating to provide service air in response to an operator request. Therefore, in some cases, an engine or other power source can have multiple predetermined (or other) operating speeds, which can be a function of the amount of compressed air requested by the customer.

[0066] In various embodiments, the controller may be configured to command the power source to reach the third speed depending on various operating parameters. For example, in the illustrated embodiment, the controller 180 may be configured to: command the power source to reach the third speed a predetermined time after the speed of the engine 108 reaches a predetermined value (e.g., Figure 3 About 3 seconds in Figure 4 About 2.3 seconds in Figure 5 For example, the command signal 320 to operate the engine at an increased (third) speed may be sent at a predetermined time after the engine speed reaches the lower threshold. In some cases, such a threshold may correspond to a speed that is slightly offset from the second engine speed (e.g., Figure 3 About 1020RPM, or Figure 5 about 815RPM in ).

[0067] In other embodiments, the second engine speed signal may be sent depending on other parameters or combinations of parameters, including, for example, when the engine 108 reaches the second engine speed (e.g., a minimum commanded speed), a predetermined amount of time after sending the clutch engagement signal (as discussed in more detail below), or a predetermined amount of time after sending the first engine speed signal. In the latter case, for example, the predetermined amount of time may be selected to ensure that the engine is moving toward a speed (e.g., a third speed, as the operating speed, as discussed above) that can provide appropriate torque capacity to power the compressor when the compressor is coupled to the power source. As discussed below with respect to Figure 4 As will be discussed, there may be circumstances where additional adjustments to the engine speed are made to obtain the final operating speed.

[0068] Still reference Figure 2At block 212 , method 200 may include operating a clutch (or other coupling device) to move the clutch from a disengaged configuration to an engaged configuration. Figures 3 to 5 As shown, the controller 180 (eg, the clutch controller 184) may send an engagement signal 340 to the clutch 170 to initiate movement of the driven member 174 toward the driving member 172 (see Figure 1 ) to move the clutch 170 from the disengaged configuration to the engaged configuration.

[0069] Method 200 may include commanding engagement of the clutch based on various operating parameters. In some embodiments, the timing of the commanded clutch engagement may correspond to a current engine speed, a current commanded engine speed, or a predetermined time interval between certain engine speed commands or other events. For example, where clutch 170 is provided with an independent soft start function (see Figure 3 ), the controller 180 may send the engagement signal 340 at a predetermined time (e.g., about one second) after the engine 108 reaches a predetermined speed (or another threshold, such as a second speed). As another example, Figure 4 As shown, the controller 180 may send the engagement signal 340 when the engine 108 reaches a predetermined speed to move from the first engine speed to the second engine speed, or at a predetermined time before sending the second engine speed signal. Figure 5 As shown, the controller 180 may send the engage signal 340 at another time after sending the command to increase the engine speed.

[0070] Generally, the time at which the controller sends the engagement signal may be selected to ensure that the engine (e.g., engine 108) is at or above a minimum engagement speed when the clutch reaches the engaged configuration to prevent the engine 108 from stalling due to the increased inertial load caused by the initial engagement with the compressor 120. More specifically, when the clutch 170 couples the engine 108 to the compressor 120, the compressor will begin to compress air, thereby generating an inertial load applied to the engine 108. This inertial load may cause a brief drop in the speed of the engine 108, which may cause the engine 108 to stall if the rotating components of the engine 108 do not have enough power to overcome the inertial load of the compressor 120. For example, when the clutch 170 is moved to the engaged configuration, the speed of the engine 108 may need to be at or above 1000 RPM to avoid stalling.

[0071] In some embodiments, the timing of clutch engagement can be determined to optimize the balance between the challenge of engaging the clutch during high speed rotation and the challenge of the engine speed decreasing upon initial engagement. In some embodiments, the clutch can be controlled so that the clutch reaches the engaged configuration after the engine speed has begun to increase from the commanded speed but before the engine speed has increased significantly (or otherwise) relative to the starting (e.g., second or minimum) speed. In some embodiments, for example, Figure 3 As shown, by comparing the dashed line 302 to the local peak of the engine speed after the clutch engagement signal 340 (i.e., the actual clutch engagement), the clutch command can be timed so that the clutch reaches the engaged configuration before the engine speed exceeds the second speed by less than 25% of the difference between the second speed and the third speed (or in some cases, between the second speed and the first speed). Figure 4 As shown, by comparing the dotted line 402 with the local peak of the engine speed after the clutch engagement signal 340 (i.e., the actual clutch engagement), the clutch command can be timed so that the clutch reaches the engaged configuration when the engine speed exceeds the second speed by more than 25% of the difference between the second speed and the third speed (or in some cases, between the second speed and the first speed). In addition, in some cases, the clutch command can be timed so that the clutch reaches the engaged configuration when the engine speed is within 25% of the fourth engine speed or the final engine speed.

[0072] In some cases, when the compressor 120 is coupled to the engine 108, the air inlet valve 128 of the compressor 120 may be closed to further minimize the inertial load on the engine 108. Therefore, in order to provide flow to the supply line 104 as needed, at box 216, the controller 180 may be configured to open the air inlet valve 128 of the compressor 120. For example, in the illustrated embodiment, the controller 180 is configured to open the air inlet valve 128 once the clutch 170 has been moved from the disengaged configuration to the engaged configuration and the engine 108 has recovered from any resulting engine speed drop (see, e.g., Figure 3 and Figure 4 In some embodiments, for example, the air inlet valve 128 may be opened when the engine speed and the compressor speed begin to increase together. In some embodiments, the air inlet valve 128 may be opened when the engine speed has increased to a level significantly above the start-up (e.g., minimum or second) speed but has not yet reached the target (e.g., third or operating) speed. Figure 3 The dotted line 304 and Figure 4As shown by the dotted line 402 in FIG. 1 , the command to open the air inlet valve 128 may be timed such that the air inlet valve 128 opens after the difference between the engine speed and the third speed is less than 25% of the difference between the second speed and the third speed (or in some cases, between the second speed and the first speed) but when the engine speed is still below the third (e.g., operating) speed.

[0073] In various embodiments, the controller may be configured to command the power source to reach the third speed depending on various operating parameters. In various embodiments, the controller 180 may be configured to send an air inlet opening signal to the air inlet valve 128 based on various operating parameters. For example, Figure 3 and Figure 4 As shown, the clutch 170 includes a soft engagement function, and the controller 180 (eg, the compressor controller 186) can be configured to: after commanding the engine speed to increase to a third (eg, running) speed, after the engine 108 reaches a specific engine speed (eg, Figure 3 About 1480RPM or Figure 4 After the engine 108 reaches a certain engine speed (e.g., about 1980 RPM in the example above), or before the engine 108 reaches a certain engine speed (e.g., a third speed), the air inlet valve 128 is commanded to open for at least a threshold amount of time (e.g., one second). Thus, for example, although the load application associated with opening the air inlet valve 128 may cause another brief drop in engine speed (see, e.g., Figure 3 ), but the engine may be able to quickly recover and advance (or return) to the target (e.g., third) speed. In some cases (including cases where the clutch 170 does not include an independent soft engagement function, such as Figure 5 As shown, the controller 180 may be configured to send the inlet opening signal at a predetermined time (e.g., at least one second) after the engagement signal is sent to the clutch 170 once the engine 108 reaches a certain engine speed (e.g., approximately 1475 RPM) or based on other parameters.

[0074] In the event that the third engine speed exceeds the operating speed or other desired final speed of the engine, the method 200 may also include, at block 218, reducing the engine speed to a fourth engine speed. Figure 4 As shown, the controller 180 may also be configured to send a third engine speed signal to command the engine 108 to decrease from the third engine speed to a fourth engine speed. Figure 4 As shown, the fourth engine speed is the same as the first engine speed (eg, 1500 RPM), however, it may be greater than or less than the first engine speed (and typically between the second engine speed and the third engine speed).

[0075] In various embodiments, the controller may be configured to command the power source to reach the fourth speed depending on various operating parameters. Figure 4 As shown, the controller 180 may send a command signal 360 to the engine 108 to reduce from the third engine speed to the fourth engine speed at a predetermined time (e.g., greater than 0.5 seconds) after commanding the inlet valve to open. Thus, the air inlet valve may be opened while the engine 108 is reducing from the third engine speed to the fourth engine speed. However, in other embodiments, other timing or criteria (e.g., pressure criteria) may be used.

[0076] Reference now Figure 6 , another method 500 for operating a compressor system 100 to provide a soft start function when an engine 108 is engaged with a compressor 120 according to some aspects of the present disclosure is shown. The method 500 can be used for a compressor system having a clutch with or without an independent soft engagement function, and may be particularly useful for engaging the clutch during a startup sequence of the compressor system (e.g., when starting the engine or compressor from a cold shutdown state). Although the method 500 is described with reference to the compressor system 100 discussed above, the method may also be used for other types of rotating machines. In addition, the operation of the method 500 does not necessarily have to be performed in the specific order discussed below, and in some cases, it may be implemented using other control devices and systems not explicitly described herein. Generally, the method 500 can be implemented using various known general control devices (e.g., the controller 180), or can be implemented using a dedicated control device constructed according to known principles to implement the concepts disclosed herein.

[0077] At box 504, method 500 may include increasing the engine speed from a first engine speed to a second engine speed to increase the rotational speed of the output shaft from the first rotational speed to the second rotational speed. Typically, the operation at box 204 can therefore help increase the engine speed to a higher value so that engagement with the clutch does not reduce the engine speed below a minimum allowable engine speed, or so that engagement of the clutch does not cause the engine speed to drop below another relevant threshold (e.g., the first engine speed). Therefore, when using a downsized engine, increasing the engine speed at box 504 may be particularly useful because increasing the rotational inertia of the engine can help overcome the increased load caused by engaging the clutch to operate the compressor. Therefore, by using a starting process similar to the starting process disclosed herein, a compressor system according to some embodiments can be more reliably cold started to provide service air and significantly reduce the engine size compared to conventional systems.

[0078] As an example, additional reference Figure 7 , at the start of method 500 (i.e., at Figure 7), the engine 108 may be controlled to operate at a first engine speed of approximately 1500 RPM, which may correspond to the operating speed of the engine 108. Then, the controller 180 (e.g., the engine controller 182) may provide a first engine speed signal 310 to increase the engine speed to a second, higher engine speed (e.g., approximately 2000 RPM or at least 20% higher than the operating speed). Figure 7 As shown and described above, some embodiments may operate at a first engine speed that is equal to the operating speed of the engine (e.g., low idle or high idle). In other embodiments, the first engine speed may be different from the operating speed of the engine (e.g., may be a lower starting speed).

[0079] In various embodiments, the controller 180 may be configured to command the power source 108 to reach the second speed depending on various operating parameters. For example, as similarly discussed above with respect to block 204, the controller 180 may be configured to command the engine 108 to increase from the first engine speed to the second engine speed once the engine 108 has risen to at least the minimum operating temperature or upon receipt of a manual override signal. Thus, for example, at block 504, the controller 180 may command an increase to the second speed based on a signal received from an internal or external temperature sensor or based on an elapsed time corresponding to a predetermined warm-up interval.

[0080] Still reference Figure 6 and Figure 7 At block 508, the method 500 may include, once the engine 108 reaches the second engine speed, operating a clutch (e.g., clutch 170) or another coupling device to move the coupling device from the disengaged configuration to the engaged configuration. In some embodiments, the controller 180 may send the engagement signal 340 based on one or more operating parameters. For example, Figure 7 As shown, the engagement signal 340 may be sent approximately simultaneously with sending the first engine speed signal 310 (or generally before the engine 108 reaches the second engine speed). In other embodiments, the engagement signal may be sent once the engine 108 reaches the second engine speed (e.g., for a clutch without an independent soft start function).

[0081] At block 512, and similarly as discussed above with respect to block 216, the controller 180 is configured to open the air inlet valve 128. In some embodiments, the controller 180 may open the air inlet valve 128 in response to the clutch 170 having moved from the disengaged configuration to the engaged configuration and sensing that the engine 108 has recovered from any resulting engine speed drop (e.g., as described above). Figure 7In some embodiments, controller 180 may open air inlet valve 128 a predetermined amount of time (eg, approximately 3 seconds) after controller 180 sends the first engine speed signal or after controller 180 commands the clutch to engage.

[0082] At block 516, the controller 180 may provide a second engine speed signal to the engine 108 to reduce the engine speed to a lower third engine speed (e.g., Figure 7 320 in the command signal). Figure 7 In the example shown, the third engine speed may be the operating speed of the engine 108 and thus may be approximately the same as the first speed. In other embodiments, the third speed may be greater than or less than the first engine speed. In some embodiments, as similarly discussed above with respect to block 218, the controller 180 may be configured to initiate a first engine speed signal at a predetermined time (e.g., approximately 4 seconds after the controller sends the first engine speed signal, e.g., approximately 15 seconds after the controller sends the first engine speed signal). Figure 7 ), including causing the air inlet valve to open when the engine 108 decreases from the second engine speed to the third engine speed.

[0083] Reference now Figure 8 , another method 600 for operating a compressor system 100 to provide a soft start function when an engine 108 is engaged with a compressor 120 according to some aspects of the present disclosure is shown. The method 600 can be used for a compressor system having a clutch with or without an independent soft engagement function, and may be particularly useful for engaging the clutch during a startup sequence of the compressor system (e.g., when starting the engine or compressor from a cold shutdown state). Although the method 600 is described with reference to the compressor system 100 discussed above, the method may also be used for other types of rotating machines. In addition, the operation of the method 600 does not necessarily have to be performed in the specific order discussed below, and in some cases, it may be implemented using other control devices and systems not explicitly described herein. Generally, the method 500 can be implemented using various known general control devices (e.g., the controller 180), or can be implemented using a dedicated control device constructed according to known principles to implement the concepts disclosed herein.

[0084] At block 604, Fig. 9 As shown in the example of , method 600 may include: once the engine 108 reaches a minimum operating temperature (eg, when the engine coolant reaches a minimum threshold temperature, such as Fig. 9330 in FIG. 1 ), or another operating parameter satisfies a corresponding criterion (e.g., the operating time or time period after the initial start sequence has exceeded a time threshold), then a clutch (e.g., clutch 170) or another coupling device is operated to move the coupling device from a disengaged configuration to an engaged configuration. Thus, the controller 180 may be configured to send an engagement signal 340 based on engine temperature or other operating parameters (e.g., which may indirectly indicate temperature).

[0085] At block 604, the engine 108 may be at a first engine speed sufficient to allow the clutch 170 to move from the disengaged configuration to the engaged configuration without causing the engine speed to drop below a minimum allowable speed or another related threshold. For example, in some implementations, the engine 108 may be at a warm-up speed of approximately 1500 RPM. Relatedly, the clutch 170 may include an independent soft engagement function, but this is not required.

[0086] At block 608, and similarly as discussed above with respect to blocks 216 and 512, the controller 180 is configured to open the air inlet valve 128. In some embodiments, the controller 180 may open the air inlet valve 128 in response to the clutch 170 having moved from the disengaged configuration to the engaged configuration and the controller having sensed that the engine 108 has properly (e.g., fully) recovered from any resulting engine speed drop. In some embodiments, the controller 180 may open the air inlet valve 128 a predetermined amount of time (e.g., approximately 4 seconds, e.g., after the controller 180 commands the clutch to engage). Fig. 9 The air inlet valve 128 is opened at 20° (as shown in FIG. 1 ) relative to the command signal 350, which may similarly allow a certain degree of engine speed recovery before the inlet valve opens.

[0087] Reference now Fig.10 , another method 700 is shown for operating the compressor system 100 to provide a startup function during a startup sequence (e.g., a startup strategy) to remove any existing waxy oil within the compressor 120 (e.g., an oil film covering the screws of the compressor 120) and further reduce the load on the engine 108, according to some aspects of the present disclosure. That is, due to previous operation of the compressor system 100, the oil within the compressor 120 may become waxy (e.g., the viscosity may increase), especially in cold environments, which may increase the load applied to the engine 108. By removing this waxy oil from the compressor 120, the load imposed by the compressor 120 on the engine 108 during startup of the compressor 120 may be reduced.

[0088] Method 700 may be used with a compressor system having a clutch with or without an independent soft engagement function, and may be particularly useful for engaging the clutch during a startup sequence of the compressor system (e.g., when starting the engine or compressor from a cold shutdown state). Although method 700 is described with reference to the compressor system 100 discussed above, the method may also be used with other types of rotating machines. In addition, the operation of method 700 does not necessarily have to be performed in the specific order discussed below, and in some cases, may be implemented using other control devices and systems not explicitly described herein. Generally, method 700 may be implemented using various known general control devices (e.g., controller 180), or may be implemented using a dedicated control device constructed according to known principles to implement the concepts disclosed herein.

[0089] At block 704, method 700 may include operating the auxiliary compressor to pressurize the chamber that closes the inlet valve of the air compressor. Fig.11 In response to receiving a start signal (eg, the on signal 702 ) and the engine 108 being in an “off” state such that the output shaft 112 is at a first speed of 0 RPM, the controller 180 may be configured to close the air inlet valve 128 (see Figure 1 ) to prevent air from entering or leaving the compressor system 100 (eg, the compressor 120), thereby minimizing the load on the engine 108 during startup. More specifically, the controller 180 may be configured to operate an auxiliary compressor 192 (eg, an electric compressor receiving power from the battery 110, see Figure 1 ) to increase the pressure at the inlet valve 128. The increase in pressure at the inlet valve 128 may cause the inlet valve 128 to close, which blocks air from entering the compressor 120, causing a vacuum to form within the compressor 120. This may help minimize any parasitic loads on the engine 108 during the startup process by alleviating the load associated with air compression. In this regard, the controller 180 may be configured to operate the auxiliary compressor 192 (e.g., within a time interval 720) until the compressor system 100 reaches a predetermined minimum threshold pressure (e.g., approximately 55 psi) at the inlet valve 128, at which point the pressure causes the inlet valve 128 to close. In some cases, the controller 180 may be configured to operate the auxiliary compressor 192 for a predetermined period of time (e.g., approximately 10 seconds). The particular period of time may be selected to achieve a desired minimum threshold pressure within the compressor system 100, and may therefore vary depending on the flow rate of the auxiliary compressor 192, the volume to be pressurized, and the desired minimum threshold pressure.

[0090] At box 708, the method 700 may include operating a clutch (e.g., clutch 170) or another coupling device to move the coupling device from a disengaged configuration to an engaged configuration. For example, the controller 180 may be configured to send an engagement signal 340 to the clutch 170 once the pressure of the compressor system 100 at the inlet valve 128 is equal to or higher than the minimum threshold pressure (e.g., at the end of the time interval 720), thereby operably coupling the output shaft 112 of the engine 108 to the compressor 120. The engagement signal 340 may be sent automatically when the minimum threshold pressure is reached or based on other criteria, or manually by an operator (e.g., via a button press). However, as also discussed generally above, due to the inherent (or other) delay between the commanded clutch engagement and the actual clutch engagement, the actual clutch engagement may not occur within the time interval 730 thereafter.

[0091] At block 712, the method 700 may include operating (e.g., starting) a power source (e.g., the engine 108) to increase the speed of the output shaft from a first speed of 0 RPM to a second speed. For example, at time 740, when the clutch 170 is in an engaged configuration, the controller 180 may be configured to start the engine 108 by commanding the starter motor 194 to engage the engine 108 and increase the speed of the output shaft 112 from 0 RPM to a non-zero speed (e.g., about 600 RPM). Thus, starting the engine 108 may include the controller 180 sending the first engine speed signal 310 to the engine to increase the speed of the output shaft 112 to the second speed. Once the clutch 170 is fully engaged, or after a predetermined amount of time (e.g., about 4 seconds) after the engagement signal at block 708, the operation at block 712 may begin. Thus, as the starter motor 194 increases the speed of the engine 108 and, therefore, the speed of the output shaft 112, the speed of the compressor 120 will increase with the output shaft 112 during the time interval 750. In other words, the output shaft 112 provides operating power to increase the rotation speed of the compressor 120 .

[0092] At block 716, the method 700 may include operating a clutch (e.g., clutch 170) or another coupling device to move the coupling device from an engaged configuration to a disengaged configuration, including doing so after (e.g., immediately after) the operation at block 712. For example, the controller 180 may be configured to send a disengagement signal 760 to the clutch 170 to move the clutch 170 from the engaged configuration to the disengaged configuration, thereby decoupling the compressor 120 from the output shaft 112. Fig.11 As shown, operations at block 716 may begin in response to the output shaft 112 increasing to the second speed.

[0093] More specifically, the controller 180 may be configured to send the disengagement signal 760 once the output shaft 112 reaches a predetermined speed (e.g., 150 RPM) or after the power source is operated for a predetermined period of time according to block 712 (i.e., the clutch is engaged and the power source is operated during the time interval 750). In addition, the predetermined speed or predetermined period of time may be selected so that the compressor 120 completes a minimum number of revolutions sufficient to remove substantially all of the waxy oil from the compressor 120 before the clutch is disengaged (and thus power is removed from the compressor). In some cases, the compressor 120 may be rotated to complete at least two revolutions to remove any waxy oil from the compressor 120 (for one or more specific engine speeds, the associated shortest clutch engagement time length corresponds to at least two revolutions).

[0094] Since the output shaft 112 is thus decoupled from the compressor 120, the output shaft 112 will continue to increase speed to the second speed independently of the compressor. Thus, at block 718, after a brief operation to remove oil from the compressor, the engine 108 can continue to operate to warm up the engine 108 during startup (e.g., at the second speed or another speed) without increasing the load on the compressor 120 (e.g., during Fig.11 770). Subsequently, after an appropriate engine warm-up or other operating period, compressor 120 may be reengaged with engine 108 (eg, using any of the previously described methods for operating a coupling arrangement).

[0095] Reference now Fig.12 , another method 800 for operating the compressor system 100 (including for operation in a disengaged mode after a startup sequence or otherwise) is shown. For example, after the compressor system 100 was previously operating in an engaged mode (e.g., the clutch was engaged following a correlation mode of engine speed and other commands, as discussed with respect to any of the methods above), it may be useful to disengage the clutch during a period of reduced (e.g., zero) compressed air demand. For example, when service air is not needed, this method can significantly reduce fuel consumption without having to stop the engine and then restart the engine.

[0096] Method 800 can be used for compressor systems having a clutch with or without an independent soft engagement function. Although method 800 is described with reference to the compressor system 100 discussed above, the method can also be used for other types of rotating machines. In addition, the operation of method 800 does not have to be performed in the specific order discussed below, and in some cases, other control devices and systems not explicitly described herein can be used to implement it. Generally, method 800 can be implemented using various known general control devices (e.g., controller 180), or it can be implemented using a dedicated control device constructed according to known principles to implement the concepts disclosed herein.

[0097] At box 804, method 800 may include operating a clutch (e.g., clutch 170) or another coupling device to move the coupling device from an engaged configuration to a disengaged configuration. Thus, although the associated power source (e.g., engine 108) may continue to operate, the power source may not be loaded by the operational coupling with the compressor. In some examples, controller 180 may be configured to send a disengagement signal to clutch 170 in response to an operator input (e.g., pressing a button to begin operating in a disengaged mode). In other examples, other inputs or conditions may result in automatic (or other) disengagement of the coupling device.

[0098] At block 808, typically after the coupling device is disengaged at block 804, the valve may be closed to prevent pressurized air in the tank of the compressor system from pushing oil into the rotor of the compressor. Figure 1 , the valve 196 can be controlled to prevent oil from flowing into the oil filling port of the compressor 120. The valve 196 is Figure 1 Schematically represented in the figure, but in some cases, it can be an electronically controlled solenoid valve, or it can be another type of controllable valve. In addition, those skilled in the art will recognize that such a valve can be arranged in other positions and have similar effects. In some examples, the valve can be commanded to close to prevent oil from flowing into the compressor at the same time or substantially at the same time (i.e., within 0.25 seconds) as the signal to disengage the clutch is sent.

[0099] Other valves may also operate to prevent oil from flowing into the compressor in the disengaged mode, including check valves (not shown) of various generally known configurations that may be disposed between the separator canister 132 and the discharge port of the compressor 120. Thus, for example, during implementation of the method 800, oil may be prevented from accumulating in the compressor 120, thereby avoiding any corresponding increase in electrical power required to restart the compressor 120 when the clutch 170 is reengaged (i.e., when exiting the disengaged mode).

[0100] At block 812, when the coupling device is disengaged (e.g., at block 804), method 800 may include reducing the speed of the power source. Fig.13 As shown, the engine 108 may receive a first engine speed (change) command signal 310 from the controller 180 (e.g., the engine controller 182) to reduce the engine speed to a lower (e.g., second or fourth) engine speed, such as between 500 RPM and 1200 RPM. In some examples, the reduced speed of the power source may be the same as the reduced speed under the various methods discussed above (e.g., 1000 RPM). For example, the engine 108 may be in accordance with Figure 3 , Figure 4 , Figure 5 , Figure 7 or Fig. 9The sequence shown runs at a first (or third) speed of 1500 RPM, and then the command signal 310 (or other signal) may reduce the engine speed to a second (or fourth) speed of 1000 RPM.

[0101] In addition, the method 800 may include, at box 816, operating the compressor system to reduce the pressure within a tank arranged to contain pressurized air from the compressor. For example, one or more additional valves (not shown) may be operated according to various known methods to reduce the pressure within the separator tank 132. Thus, in some examples, when the clutch 170 reengages the compressor 120, the compressor 120 may see a relatively low back pressure from the separator tank 132, and the initial load on the engine 108 may be correspondingly low. In some examples, the tank pressure may be reduced to an intermediate non-zero value (e.g., 50 psi), which may allow for faster re-pressurization in response to a demand for service air. In some examples, the tank pressure may be reduced to zero psi (e.g., in order to operate in a split mode for a longer period of time).

[0102] After operating in the separated mode for a period of time, method 800 may include operating the compressor system to enter an engaged operating mode. In some examples, the transition to the engaged mode may be triggered by an operator input (e.g., another button press), or may be automatically achieved based on detecting an increased demand for pressurized air (e.g., detected via monitoring the pressure between the separator tank 132 and the supply line 104). Thus, at box 818, the compressor system may be operated to move the coupling device (e.g., clutch 170) to an engaged configuration so that the compressor may be powered by the power source. In this regard, any valves that may have been operated to prevent oil from flowing to the compressor (e.g., at box 808) may be operated to allow oil to flow to the rotors so that the compressor may function normally once it is again powered by the power source. For example, as part of the transition from the separated mode to the engaged mode, valve 196 (see Figure 1 ) can be reopened so that oil can flow to the rotor of compressor 120 again.

[0103] Generally, the above discussion (including with respect to Fig.13 The engine and clutch signals 320, 340 shown and discussed with respect to Figure 4(and other figures) discussed in detail) engage (or re-engage) the clutch to exit the disengaged mode. However, in some examples, the compressor system may be operating at a reduced engine speed (e.g., 1000 RPM) for a longer period of time, and therefore the clutch engagement signal may be provided while the compressor system is operating at this reduced speed. Thus, for example, in some cases, the clutch engagement signal 340' may be provided when the engine is at a lower speed in a steady state, rather than when the engine is being reduced to this lower speed. Generally, in this regard, it may be useful to provide the clutch engagement signal 340 (or 340') a predetermined period of time before the engine speed command signal 320, so that the clutch 170 is not actually engaged until the engine speed has increased sufficiently (e.g., the time between the expected engagement command and the actual clutch engagement is 2.6 seconds to 3 seconds, as shown in Figures 1 and 2). Fig.13 as shown).

[0104] In some examples, the valve supplying oil to the compressor may be commanded to open simultaneously or substantially simultaneously (ie, within 0.25 seconds) with the command to increase engine speed to reengage the coupling. Fig.13 As shown, the valve opening signal 820 may be provided simultaneously with the engine speed signal 320 (and, for example, after the clutch engagement signals 340, 340') so that the compressor 120 is fully supplied with oil flow when the compressor 120 begins to be powered by the engine 108 again. However, in other examples, other timings may be used for each of the command signals discussed. For example, if the pressure of the tank is significantly reduced (e.g., to 0 psi) during operation in the split mode, the oil flow valve may be opened earlier because it may take longer for the pressure in the tank to reach a level at which oil can begin to flow into the compressor.

[0105] In some examples, such as the above Figure 4 As discussed, once the engine speed has stabilized at the increased speed (e.g., after the inlet valve is opened via the inlet opening signal 350), the engine speed may be reduced to the idle (or other) speed. In some examples, the engine speed may instead be increased (e.g., via the command signal 830) to the operating speed (e.g., as Fig.13 2400RPM shown).

[0106] In some embodiments, the devices or systems disclosed herein may be utilized, manufactured, installed, etc. using methods that embody aspects of the present invention. Thus, any description herein of a particular feature, capability, or intended use of a device or system is generally intended to include disclosure of methods of using such a device for its intended use, methods of otherwise achieving such capability, methods of manufacturing related components of such a device or system (or the entire device or system), and methods of installing disclosed (or otherwise known) components to support such purpose or capability. Similarly, unless otherwise indicated or limited, discussion herein of any method of manufacturing or using a particular device or system (including installing the device or system) is intended to inherently include disclosure of the utilized features and enabled capabilities of such a device or system as embodiments of the present invention.

[0107] In some embodiments, aspects of the present invention (including computerized implementations of methods according to the present invention) may be implemented as systems, methods, devices, or articles of manufacture that use standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof to control a processor device (e.g., serial or parallel general or dedicated processor chips, single-core or multi-core chips, microprocessors, field programmable gate arrays, control units, any combination of arithmetic logic units and processor registers, etc.), a computer (e.g., a processor device operably coupled to a memory) or another electronically operated controller to implement the aspects detailed herein. Thus, for example, embodiments of the present invention may be implemented as a set of commands tangibly embodied on a non-transitory computer-readable medium, such that a processor device can execute the commands based on reading the commands from the computer-readable medium. Some embodiments of the present invention may include (or utilize) a control device consistent with the following discussion, such as an automation device, a dedicated or general-purpose computer (including various computer hardware, software, firmware, etc.). As a specific example, the control device may include a processor, a microcontroller, a field programmable gate array, a programmable logic controller, logic gates, etc., as well as other typical components known in the art for implementing appropriate functions (e.g., memory, communication system, power source, user interface and other inputs, etc.). In some embodiments, the control device may include a centralized hub controller that receives, processes and (re)transmits control signals and other data to other distributed control devices (e.g., engine controllers, implement controllers, drive controllers, etc.), including as part of a hub-and-spoke architecture or otherwise.

[0108] The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier (e.g., non-transitory signal), or medium (e.g., non-transitory medium). For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips, etc.), optical disks (e.g., compact disks (CDs), digital versatile disks (DVDs), etc.), smart cards, and flash memory devices (e.g., cards, sticks, etc.). In addition, it should be understood that a carrier wave may be used to carry computer-readable electronic data, such as computer-readable electronic data used to send and receive e-mail or access a network (such as the Internet or a local area network (LAN)). Those skilled in the art will recognize that many modifications may be made to these configurations without departing from the scope or spirit of the claimed subject matter.

[0109] Certain operations of the methods of the present invention or systems for performing these methods may be schematically represented in the accompanying drawings or otherwise discussed herein. Unless otherwise specified or limited, specific operations represented in a particular spatial order in the accompanying drawings do not necessarily require that these operations be performed in a particular order corresponding to the particular spatial order. Therefore, certain operations represented in the accompanying drawings or otherwise disclosed herein may be performed in an order different from the order explicitly shown or described to suit a particular embodiment of the present invention. In addition, in some embodiments, certain operations may be performed in parallel, including by dedicated parallel processing devices or separate computing devices configured to interoperate as part of a larger system.

[0110] As used herein in the context of computer implementation, unless otherwise specified or limited, the terms "component", "system", "module", "block", etc. are intended to cover part or all of a computer-related system including hardware, software, a combination of hardware and software, or software in execution. For example, a component can be, but is not limited to, a processor device, a process executed (or executable) by a processor device, an object, an executable code, an execution thread, a computer program, or a computer. For example, both an application running on a computer and the computer can be components. One or more components (or systems, modules, etc.) can reside within a process or execution thread, can be located on one computer, can be distributed between two or more computers or other processor devices, or can be included in another component (or system, module, etc.).

[0111] In addition, as used herein, unless otherwise limited or qualified, "or" indicates a non-exclusive list of components or operations that can exist in any combination, rather than an exclusive list of components that can exist only as alternatives to each other. For example, a list of "A, B, or C" indicates the following options: A; B; C; A and B; A and C; B and C; and A, B, and C. Therefore, the term "or" as used herein is intended to indicate exclusive alternatives only when it is followed by an exclusive term (such as "any," "one of," "only one of," or "exactly one of"). For example, a list of "one of A, B, or C" indicates the following options: A, but not B and C; B, but not A and C; C, but not A and B. A list that begins with "one or more" (and variations thereof) and includes "or" to separate the listed elements indicates an option of one or more of any or all of the listed elements. For example, the phrases "one or more of A, B, or C" and "at least one of A, B, or C" indicate the following options: one or more A; one or more B; one or more C; one or more A and one or more B; one or more B and one or more C; one or more A and one or more C; and one or more A, one or more B, and one or more C. Similarly, a list beginning with "plurality" (and variations thereof) and including "or" to separate the listed elements indicates the option of multiple instances of any or all of the listed elements. For example, the phrases "plurality of A, B, or C" and "two or more A, B, or C" indicate the following options: A and B; B and C; A and C; and A, B, and C.

[0112] The foregoing description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A compressor system (100), include: Power Source (108); Compressor (120); A coupling device (170) is disposed between the power source and the compressor to selectively couple the power source to the compressor; as well as A control device (180) is configured to move the coupling device between a disengaged configuration and an engaged configuration, wherein in the disengaged configuration, the power source is decoupled from the compressor, and in the engaged configuration, the power source is coupled to the compressor via the coupling device.

2. The compressor system according to claim 1, in, The control device is configured to: during a startup sequence of the compressor system, after the control device increases the speed of the power source from a startup speed to a minimum engagement speed, move the coupling device from the disengaged configuration to the engaged configuration, and optionally or preferably, wherein the control device is configured to: after the coupling device reaches the engaged configuration, reduce the speed of the power source from the minimum engagement speed to an operating speed to provide service air using the compressor.

3. A compressor system according to any one of the preceding claims, in, The control device is configured to move the coupling device from the disengaged configuration to the engaged configuration in response to engine coolant exceeding a minimum threshold temperature during a startup sequence of the compressor system.

4. A compressor system according to any one of the preceding claims, in, the control device being configured to: move the coupling device from the disengaged configuration to the engaged configuration after the control device reduces the speed of the power source from the first speed to the second speed; as well as Wherein, the control device is configured to move the coupling device from the disengaged configuration to the engaged configuration when the control device increases the speed of the power source from the second speed to a third speed.

5. The compressor system according to claim 4, in, The control device is configured to perform one or more of the following: providing an engagement signal to the coupling device after reducing the speed of the power source to the second speed and before increasing the speed of the power source to the third speed so that the coupling device is moved to the engaged configuration after the control device increases the speed of the power source from the second speed; or When the speed of the power source moves from the second speed to the third speed, an inlet valve of the compressor is opened.

6. A compressor system according to any one of the preceding claims, in, The control device is configured to maintain the coupling device in the disengaged configuration during a startup sequence of the power source and to move the coupling device from the disengaged configuration to the engaged configuration in response to the power source reaching a minimum operating temperature.

7. The compressor system according to claim 1, in, One or more of the following exists: The power source is an internal combustion engine; or The coupling device is an electromagnetic clutch.

8. A method (200; 800) of operating a compressor system (100), the method include: Using one or more electronic control devices, when the coupling device (170) is in a disconnect configuration that decouples the power source from the compressor (120), reducing (310) the speed of the power source (108) from a first speed to a second speed; utilizing the one or more electronic control devices, after reducing the speed of the power source (108) to the second speed, increasing (320) the speed of the power source (108) from the second speed to a third speed; and Utilizing the one or more electronic control devices, when the speed of the power source is increased from the second speed, the coupling device (170) is controlled to move from the disengaged configuration to the engaged configuration (340) to couple the power source (108) to the compressor (120) so that the output shaft of the power source rotates the input shaft of the compressor.

9. The method according to claim 8, in, The coupling device is controlled to reach the engaged configuration when the speed of the power source exceeds the second speed by less than 25% of the difference between the third speed and the second speed.

10. The method according to claim 9, further comprising: include: When increasing the speed of the power source from the second speed, using the one or more electronic control devices, the inlet valve of the compressor is opened after the coupling device reaches the engaged configuration and before the speed of the power source reaches the third speed.

11. The method according to claim 10, in, When the difference between the speed of the power source and the third speed is less than 25% of the difference between the third speed and the second speed, the inlet valve is controlled to open.

12. The method (800) according to any one of claims 8 to 11, further comprising: include: After controlling the coupling device to move from the disengaged configuration to the engaged configuration (340), controlling the compressor system to operate in a disengaged mode comprises: utilizing the one or more electronic control devices, controlling the coupling device (170) to move from the engaged configuration to the disengaged configuration; closing the first valve (196) to prevent oil from flowing to the rotor of the compressor (120); reducing (310) the speed of the power source to a fourth speed; and reducing the pressure of a tank arranged to receive pressurized air from the rotor, Wherein, optionally or preferably, the fourth speed is equal to the second speed.

13. The method according to claim 12, further comprising: include: Utilizing the one or more electronic control devices, after operating in the split mode, opening the first valve (196) to allow oil to flow to the rotor; increasing (320) the speed of the power source to a fifth speed; as well as When the speed of the power source increases to the fifth speed, controlling (340; 340') the coupling device to move from the disengaged configuration to the engaged configuration to recouple the power source to the compressor so that the output shaft of the power source rotates the input shaft of the compressor, Wherein, optionally or preferably, the fifth speed is equal to the third speed.

14. A method (700) for starting a compressor system (100), the method include: During the startup sequence of the compressor system, When the power source is at a first speed, controlling the coupling device to operably couple the power source to the compressor (340); When the coupling device is operably coupled to the power source, increasing (310) the speed of the power source from the first speed to a second speed to cause the power of the compressor to rotate; as well as When the compressor is in power rotation: controlling the coupling device to decouple the power source from the compressor (760); and Further increasing the rotation speed of the power source towards the operating speed, Wherein, optionally or preferably, the first rotational speed is zero.

15. The method according to claim 14, in, Controlling the coupling device to decouple the power source from the compressor (760) after at least one of the following: The compressor completes a predetermined number of rotations; the amount of time scheduled; or The output of the power source to the coupling device reaches a predetermined speed, Wherein, optionally or preferably, the method further comprises: before controlling the coupling device to couple the power source to the compressor (340), closing an air inlet valve of the compressor.

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