Patent Description:
A traditional hydraulic system has a motor to drive a pump, where the pump outputs fluid in response to being driven by the motor. Traditional hydraulic systems use motors that take a significant amount of time and energy to spin up from a stopped state, so motors are run continuously. Therefore, these traditional systems include valves to control the flow rate and pressure of the fluid out of the system. Traditional systems have separate motors and pumps, which requires interfaces that reduce the efficiency of the system. The systems with separate motors and pumps have more components, which tends to add to the system cost. The system setup and upkeep may also be higher in terms of labor with more independent parts that need separate maintenance and configuration to work together. Even with these inefficiencies, the least efficient part of the system is the valves, where a significant amount of energy loss occurs, considering the amount of work output from the valves relative to the energy input into the motor.

Additionally, with traditional systems, capabilities such as end of stroke detection, leak detection, or other capabilities required external sensors. Such sensors can add significant cost and size to the overall hydraulic system. The sensor inputs are fed back into the motor controller for control of the motor. It will be understood that the sensors provide useful information for the system but cannot overcome inherent inefficiencies of the traditional system design.

As described herein a hydraulic system has an integrated motor and pump. Integration of the motor and pump allows for elimination of certain interface components, which can increase the pump system efficiency. As described herein, the integrated pump system can eliminate the need for valves by directly driving the work function fluid from the integrated motor and pump. Elimination of the valves can remove the greatest inefficiency from the hydraulic system and enable more power delivery into the work function relative to energy inputted into the motor.

Direct driving of the fluid flow from the integrated motor and pump is possible with a motor that provides power on demand. A power-on-demand motor refers to a motor that can spin up and spin down on demand. The motor can operate on demand instead of needing to be constantly spinning as with traditional systems. Electronically controlled electric motors can allow for the operation needed by a motor to provide the direct hydraulic control.

In a traditional hydraulic system, the motor operates continuously to maintain fluid pressure, which is then regulated to the work function through high pressure output by the switching of valves. Such a system has been improved over the years by increasing the sensitivity and operation of the valves, as well as increasing the precision of the motor and the pump. However, with the system herein, such precision features added to traditional systems are unnecessary, while the system can still offer the same or improved precision operation.

Prior art which is deemed relevant for the present patent application, and which is hereby referred to as such, includes in particular the patent documents <CIT>, <CIT>, and <CIT>, which documents disclose hydraulic systems which are provided with an integrated pump system. These documents do not disclose a cooling fluid channel configured to cool a controller and a motor which is part of a low pressure path for returning hydraulic fluid from a work function to a reservoir.

The present invention relates to an integrated pump system as defined by the appended claim <NUM>. An integrated pump system as described herein can allow various implementations. In one example, an integrated pump system enables a valveless hydraulic system. In one example, an integrated pump system enables pressure detection and pressure control through directly driving the hydraulic fluid with the integrated pump system. In one example, an integrated pump system enables flow rate detection and control through directly driving the hydraulic fluid with the integrated pump system. In one example, an integrated system enables pumping post-work fluid as a coolant. The example provided in this paragraph can have multiple variations. The examples in this paragraph can be combined in any combination of features.

A hydraulic system provides fluid to a work function, which is typically one of two types. One type of work function is linear displacement. The linear displacement can be displacement of a rod, or displacement of an assembly with reference to a rod or other fixed reference mechanism. Another type of work function is rotary actuation. Rotary actuation refers to causing an assembly to rotate around an axis. The work function can be an axle itself, or an axle can be fixed as rotary actuation causes an assembly to rotate around the axle.

In one example, an integrated system includes a permanent magnet motor that provides power on demand. The motor can be driven by an inverter or other controller hardware. The controller hardware can include an encoder that controls the switching of power to the motor to cause the motor to spin. In one example, the controller will know the speed and torque of the motor. Thus, the integrated system can include information on speed and torque of the motor, which can directly inform the system on pump operation. The system can monitor and control the pressure of fluid output by the pump, which is changed directly by operation of the motor. The system can monitor and control the flow rate of the hydraulic fluid, which is changed directly by operation of the motor. The pressure or the flow rate, or both, can be considered the load on the integrated pump system. The controller can monitor load on the pump system and change operation of the motor based on reference setpoints or threshold of operation, as set by an administrator for the particular system implementation. It will be understood that different system implementations will have different requirements and different operating parameters.

In one example, the motor control can act as a proxy for fluid control. The control can be related to flow rate, or to pressure, or to both flow rate and pressure. The motor controller can calculate flow rate or pressure or both based on motor speed and torque of the motor. Such calculations may involve calibration by operating the integrated pump system and determining its operating parameters. An electronic circuit can store configuration information for a specific pump system, which enables the calculations to be specific to a device. In one example, a motor and controller that enables reversible motor operation can enable a bidirectional pump design. The use of a bidirectional pump can enable an implementation of a bidirectional, valveless pump system for implementations where bi-directionality is a factor.

The integration of the motor and pump together can reduce the cost, size, and weight of a hydraulic system. Additionally, the design can be made to include the motor controller directly integrated in the pump system, in one example. The integration of the pump system and power on demand enables the use of smaller motors relative to traditional designs. Additionally, rather than complicated and expensive designs for variable displacement pumps and high precision control valves, the system can use relatively simpler components and achieve precision through motor control based on feedback from measuring motor and pump performance and fluid flow. Use of the simpler components allows for more tolerance to impurities in the hydraulic fluid, which is projected to extend the operating time (time between maintenance) and the overall lifecycle (life of the pump system) as compared to traditional systems.

Integration of the pump system enables pumping the work fluid past the motor to cool the motor. Integration of the pump system can enable pumping the work fluid past the electronics to cool the motor controller circuitry. It will be understood that the hydraulic fluid heats up relative to the surrounding environment when put under pressure to convey to the work function. It is true that the post-work fluid returned through the low-pressure port of the pump system will be higher temperature than the surrounding environment, while cooling fluid traditionally starts out at the temperature of the environment. However, even heated for conveyance to the work function, the temperature of the post-work fluid is significantly cooler than the temperature of the motor components, or the temperature of the motor control electronics. Thus, the post-work fluid can still be effective at cooling the motor or the electronics, or both.

In one example, knowing the speed and operational parameters of the motor, directly controlling the high pressure output, the system can perform stall detection based on monitoring the operational states of the motor. For example, knowing a reference speed for a given pressure or flow rate, the system can detect deviation from the reference speed for an associated pressure or flow rate. In one example, if the motor has an expected pressure, PEXP, for a reference motor speed, VELREF, the system can identify a stall if PEXP becomes some value greater than <NUM>. 0xPEXP at constant VELREF. Similarly, in one example, if the motor has an expected pressure, PEXP, for a reference motor speed, VELREF, the system can identify a leak if PEXP becomes less than <NUM>. 0xPEXP at constant VELREF. Similar calculations can be performed for flow rate.

In one example, if the torque increases, the motor speed will slow down. For example, motor position detection can identify a slowdown in the motor speed and determine that a slow down or stall of the motor indicates an end of stroke detection for the work function. In response to such a condition, the controller can slow down or shut off the motor. Motor encoders typically have information on very fine resolution of the motor, for example, having a value greater than <NUM> to represent a single rotation of the motor. Thus, even slowdowns of the motor can be precisely detected or other changes of motor speed.

More specific descriptions for various implementations of the invention are provided below, unless it is explicitly stated that an example is not part of the invention.

The invention according to the appended claims comprises a hydraulic system which includes a housing with channels for fluid flow, including a high-pressure path. The housing includes an electronically controlled motor. The system includes a high pressure port to convey fluid from the housing to a work function, where the fluid is conveyed based on operation of the motor. The system includes a pressure sensor to detect pressure of the fluid flow for the high pressure port. The system includes a controller to adjust operation of the motor based on deviation of the pressure from a reference setpoint. The reference setpoint can indicate a high pressure reference. The high pressure reference can indicate a maximum pressure desired, or a minimum pressure to trigger the need to increase the pressure.

In one example, the pressure sensor is a motor position sensor to determine a rotational speed of the motor based on rotational position and torque of the motor. The rotational position and the torque of the motor can be known from a motor controller, and the rotational speed computed from the information. The controller can be or include a motor encoder, where the encoder generates commands to position the motor. In one example, the controller computes an estimated deviation of the pressure based on the speed and torque of the motor as computed from detected rotational position and energy input into the motor.

In one example, the controller reduces the spin velocity of the motor in response to detection that the pressure has increased beyond a specified threshold. For example, the controller may spin down the motor completely. The controller may partially spin down the motor. For example, where the pressure reaches a maximum point, it can indicate an end of stroke.

In one example, the controller generates an error indication in response to detection of the pressure lower than expected for a given speed of the motor. For example, when the hydraulic system springs a leak, the pressure will be lower than expected for the given speed of the motor. The error indication can include an indication to a user or administrator of the system.

In one example, the controller is, or the controller includes, a motor encoder. in one example, the motor is a linear displacement motor. In one example, the linear displacement motor is a fixed displacement motor.

In one example, the system includes a pump. The pump is disposed in the housing to directly control the fluid flow through the channels. The pump is controlled by the motor. In one example, the pump is part of the channels, and is integrated directly into the channels in the housing surrounding the components of the motor.

The invention according to the appended claims comprises a hydraulic system which includes a housing with channels for fluid flow, which include a high-pressure path. The system includes an electronically controlled motor mounted in the housing and a high pressure port to convey fluid from the housing to a work function. The fluid is conveyed based on operation of the motor. In one example, the system does not include fluid control valves, but the fluid control is controlled directly from the motor operation. The system includes flow rate sensor to detect flow rate of the fluid for the high pressure port. The system includes a controller to adjust operation of the motor in response to detection of deviation of the flow rate from a reference setpoint. The reference setpoint can indicate a flow rate reference. The reference can indicate a maximum pressure desired, or a minimum pressure to trigger the need to increase the flow rate.

In one example, the flow rate sensor is or includes a motor position sensor to determine a rotational speed of the motor based on rotational position of the motor. In one example, the controller computes an estimated flow rate deviation. The flow rate deviation can be computed based on the speed of the motor as computed from detected rotational position.

In one example, the controller reduces the spin velocity of the motor in response to detection that the flow rate has stalled. For example, the controller may spin down the motor completely. The controller may partially spin down the motor. For example, when the flow rate stalls can be an indication of end of stroke.

In one example, the controller generates an error indication in response to detection of the pressure lower than expected for a given speed of the motor. For example, when the hydraulic system springs a leak, the flow rate will be higher than expected for the given speed of the motor. The error indication can include an indication to a user or administrator of the system.

The invention according to the appended claims comprises a hydraulic system which includes a housing with channels for fluid flow. The channels include a high-pressure path and a low pressure return path. The low pressure return path conveys post-work fluid. The system includes an electronically controlled motor mounted in the housing. The system includes a pump mounted in the housing and an electronic circuit to control the motor. The electronic circuit is coupled with the housing and can be integrated into the housing with the motor. The low pressure return path includes a path to convey the post-work fluid past the electronic circuit for removal of heat from the electronic circuit.

In one example, the electronic circuit is an inverter or includes inverter circuitry. In one example, the electronic circuit is or includes a motor position encoder. In one example, the hydraulic system lacks a fluid control valve between the pump and a work function to which the system pumps fluid. In one example, the low pressure return path includes a path to convey the post-work fluid past the motor.

The invention further comprises: a fluid reservoir coupled to housing, wherein the pump is to pull the fluid from the fluid reservoir, and return the post-work fluid to the fluid reservoir. According to the invention, the housing includes a path from a low pressure input port to a low pressure output port to the fluid reservoir.

In one example, a system includes a power-on-demand pump system with an electronically controlled motor. The electronically controlled motor will selectively be on or off, or selectively be at very low RPM (rotations per minute) and high RPM. The motor can be made to spin fast for hydraulic pumping and then be turned off when the fluid flow is not needed, or a desired pressure applied by operation of the pump is no longer needed. In one example, the integrated system has a high-pressure fluid port to deliver hydraulic fluid from the pump system directly to the work function, without a fluid control valve. As stated above, the operation of the motor can directly drive the fluid with the pump, eliminating the need for a fluid control valve. The integrated motor and pump system includes a controller to selectively control the RPMs of the motor to directly control flow rate or pressure at the port, or to control both flow rate and pressure at the port.

In one example, the work function is linear displacement of a piston. Thus, the operation of the motor can spin up or spin down to cause the pump to increase or decrease flow rate or pressure or both, causing a piston to be extended or retracted relative to a starting point.

In one example, the work function is rotary actuation of a rotor. Thus, the operation of the motor can spin up or spin down to cause the pump to increase or decrease flow rate or pressure or both, causing a rotor to rotate differently in response to the change in hydraulic fluid.

In one example, the electronically controlled motor is a permanent magnet motor. In one example, the motor is an induction motor, although permanent magnet motors are typically more efficient and faster for power on demand than induction motors. However, proper motor design can still be effective in a valveless system.

In one example, control of the RPMs of the motor can refer to stopping the motor from spinning in response to detection of a target pressure for hydraulic fluid at the high-pressure port. In one example, control of the RPMs of the motor can refer to spinning up the motor from spinning in response to detection that a target pressure for hydraulic fluid at the high-pressure port is below a desired threshold. For spin up, spin down, or stopping the motor, the direct control of the hydraulic fluid at the high pressure port can be in place of traditional control valve operation.

In one example, the pump system is a fixed displacement pump. With the on demand pumping to directly control the hydraulic fluid, the traditional variable displacement pumps are not needed. Fixed displacement pumps deliver a fixed amount of hydraulic fluid during every operating cycle, where the cycle is dependent on the type of pump used (e.g., rotary, axial flow, piston, centrifugal, or other). Variable displacement pumps include either mechanical or electrical controller (or both in some designs) to alter the amount of fluid provided in a single cycle. Typically, the control changes the speed or rate of the cycle, which can be referred to as the rate of actuation, and the fluid displacement changes proportionally to the change in actuation time. The use of a fixed displacement pump allows for a simpler pump in the system, and the operation of the pump changes as the motor operation changes, instead of having to separately control the flow in the pump.

In one example, multiple integrated motor and pump systems are ganged together. The combining or ganging of multiple integrated motor and pump systems can be in place of multi-valve systems. For example, in a system where a large motor delivers hydraulic fluid that is controlled by selective actuation of multiple parallel valves, instead multiple integrated motor and pump systems can replace the valve. As the integrated systems already have a motor and pump, the large motor and pump can be eliminated. Multiple small, more efficient systems can be combined to replace a large system that has many inefficiencies. Thus, in place of one integrated motor and pump system with a high pressure port, there will be multiple such systems each with a separate high pressure port. The ports can be coupled to a common line to deliver to a work function, in a similar way currently done with multiple valves.

The accompanying drawings provide certain examples that are applicable to one or more of the implementations described above. The drawings can be briefly described as follows:.

<FIG> illustrates an example of a control loop that monitors and controls pressure. Pressure control system <NUM> provides an example of various elements that can be either hardware elements, or software control elements, or a combination of hardware elements that provide data to be used for calculation or the calculation engines. All computations are implemented in electronic components.

RPRES refers to a reference pressure for the specific implementation. For example, perhaps a pump system is to convey hydraulic fluid at <NUM> bar (<NUM> PSI; pounds per square inch), or some other setpoint, for a specific work function. In one example, the reference pressure is configurable. An electronic controller can take the reference pressure and control operation of a motor in an integrated pump system to provide the desired pressure.

Combiner <NUM> represents a computational element to compare the reference pressure to a feedback pressure, FBPRES. EPRES represents an error signal or difference between the reference signal and the feedback signal. The feedback signal comes from other components in the integrated pump system, as described below.

In one example, pressure filter <NUM> receives the error signal. Pressure filter <NUM> can be, or include, for example, a PID (proportional-integral-derivative) or other error compensation component. A PID device receives an error and generates an output to reduce the error. Another error compensation component can be used. In one example, pressure filter <NUM> generates a reference velocity signal, which indicates a motor speed that should provide the desired pressure. The correlation between motor speed and desired pressure is a metric that can be measured before implantation of the integrated pump system and stored in the memory of the controller. Then, at regular intervals, the integrated pump system can be retested or recalibrated to account for wear of the pump and or motor of the integrated pump system.

In one example, pressure filter <NUM> receives position feedback, FBPOS, from a motor encoder that acts as a position sensor to indicate the position of the motor. The position information typically includes a sequence of motor position and timing information to indicate where the motor was at a given time, which can be used to compute the velocity or rotational speed of the motor (e.g., RPMs or rotations per minute).

Pressure filter <NUM> provides a reference command, RCMD, to a motor controller. The motor command can be with reference to a current used to drive the motor itself. Thus, pressure filter <NUM> can provide the reference command to a Hall effect sensor state filter. In one example, pressure filter <NUM> provides the reference command to an inverter (not specifically shown). In one example, pressure filter <NUM> provides the reference command to an amplifier (not specifically shown). The motor control circuitry uses the command to create a driving current to operate the motor <NUM>.

Hall state sensor <NUM> represents a logic component to determine and perform a computation based on a Hall effect sensor information from Hall effect sensors <NUM>. In one example, motor <NUM> has multiple different branches of conductors (e.g., a three-phase motor, or separately controllable groups of windings/conductor in the motor). Hall sensors <NUM> can indicate where current is flowing in the motor <NUM> to indicate what branch of the motor is currently active. With different branches of the motor <NUM> active at different times, currents induced in the rotor cause magnetic fields that can attract or repel magnets of the stator. The differences in magnetic fields cause the stator and rotor to move relative to each other, where typically one is fixed and the other rotates relative to the fixed component. Whether the rotor or stator is the fixed element depends on the motor design, and either design can be implemented with what is described herein.

Hall state sensor <NUM> can provide a reference current, RCURR, to combiner or summer <NUM>. Summer <NUM> can combine reference current with a feedback current, FBCURR, from a current sensor of the motor. The summer <NUM> can generate an error current, ECURR, to indicate a deviation of a current being used to what should be used to provide the desired pressure output.

In one example, the system includes current filter <NUM> to receive the current adjustment information of ECURR. In one example, current filter <NUM> is or includes a PI (proportional-integral) filter or other error compensation filter component. In one example, current filter <NUM> generates a PWM (pulse width modulator) output, VPWM. The PWM output can indicate a duty cycle to use to drive the motor <NUM> to adjust the current driving the motor. The adjusted current (and more specifically, the on/off rate of the current used to drive the motor) can cause the motor to operate differently to adjust for the given conditions to cause the desired pressure.

Motor (M) <NUM> represents the motor or the motor controller, which operates based on the current signal. In one example, current sensor <NUM> represents one or more current sensors to monitor one or more currents of the motor. The current sensors can provide the feedback current signal FBCURR to summer <NUM>.

Position sensor <NUM> monitors a position sensor for motor <NUM>. The position sensor <NUM> can determine the precise motor location and be used to determine motor velocity. In one example, position sensor <NUM> provides position feedback FBPOS.

Plant <NUM> represents a gear the motor drives. Plant <NUM> represents a gear within the integrated pump system driven by the motor <NUM> to cause the pump to pump the hydraulic fluid. Pressure sensor <NUM> represents one or more sensor components of the integrated system to provide pressure feedback to combiner <NUM>.

In one example, the system computes pressure sensor state information without needing discrete pressure sensor hardware. This can be accomplished by monitoring the current going into the motor and knowing the specific geometry of the pump that would relate the input torque and output pressure (i.e., mapping the pump). These quantities can be related by the formula Pressure output = (Torque x constant)/Displacement.

<FIG> illustrates an example of a flow rate control loop <NUM> that control flow rate, whereas pressure control system <NUM> of <FIG> controls pressure. There are many similarities between system <NUM> and system <NUM>, and many components operate the same.

Flow rate control system <NUM> provides an example of various elements that can be either hardware elements, or software control elements, or a combination of hardware elements that provide data to be used for calculation or the calculation engines. All computations are implemented in electronic components.

RVEL refers to a reference velocity for the motor <NUM> to operate for the specific implementation of the integrated pump system. When the motor directly drives the pump to provide the fluid to the work function, the velocity of the motor <NUM> can act as a proxy for the flow rate of the hydraulic fluid (i.e., the correlation is known in advance by the controller of motor <NUM>). Thus, for example, perhaps a pump system is to convey hydraulic fluid having a specific setpoint for a specific work function. In one example, the reference velocity is configurable to set different target flow rates. An electronic controller can take the reference velocity and control operation of a motor in an integrated pump system to provide the desired flow rate.

Combiner or summer <NUM> represents a computational element to compare the reference velocity to a feedback velocity, MVEL, which is the velocity of the motor <NUM>. EVEL represents an error signal or difference between the reference signal and the feedback signal. The feedback signal comes from other components in the integrated pump system, as described below.

Motion control filter <NUM> provides an example of motion control for an integrated motor <NUM>. The motion control filter <NUM> includes hardware components to control the operation of the motor <NUM>. Motion control filter <NUM> represents control of the hardware components to achieve the desired motor operation. In one example, motion control filter <NUM> receives position feedback, FBPOS, from motor position sensor <NUM> that monitors the position of the motor <NUM>. In one example, the motor position sensor <NUM> is a sensor separate from the motor encoder. The position information typically includes a sequence of motor position and timing information to indicate where the motor <NUM> was at a given time, which can be used to compute the velocity or rotational speed of the motor (e.g., RPMs or rotations per minute).

Motion control filter <NUM> provides a reference command, RCMD, to a motor controller. The motor command can be with reference to a current used to drive the motor itself. Thus, motion control filter <NUM> can provide the reference command to a Hall effect sensor <NUM>. In one example, motion control filter <NUM> provides the reference command to an inverter (not specifically shown). In one example, motion control filter <NUM> provides the reference command to an amplifier (not specifically shown). The motor control circuitry uses the command to create a driving current to operate the motor <NUM>.

Hall state sensor <NUM> represents a logic component to determine and perform a computation based on a Hall effect sensor information from Hall effect sensors <NUM>. In one example, motor <NUM> has multiple different branches of conductors (e.g., a three-phase motor, or separately controllable groups of windings/conductor in the motor). Hall sensors <NUM> can indicate where current is flowing in the motor <NUM> to indicate what branch of the motor <NUM> is currently active. With different branches of the motor <NUM> active at different times, currents induced in the rotor cause magnetic fields that can attract or repel magnets of the stator. The differences in magnetic fields cause the stator and rotor to move relative to each other, where typically one is fixed and the other rotates relative to the fixed component. Whether the rotor or stator is the fixed element depends on the motor design, and either design can be implemented with what is described herein.

Hall state sensor <NUM> can provide a reference current, RCURR, to summer <NUM>. Summer <NUM> can combine reference current, RCURR, with a feedback current, FBCURR, from current sensor <NUM> of the motor <NUM>. Summer <NUM> can generate an error current, ECURR, to indicate a deviation of a current being used to what should be used to provide the desired pressure output.

In one example, flow rate control loop <NUM> includes current filter <NUM> to receive the current adjustment information of ECURR. In one example, current filter <NUM> is or includes a PI (proportional-integral) filter or other error compensation filter component. In one example, current filter <NUM> generates a PWM (pulse width modulator) output, VPWM. The PWM output can indicate a duty cycle to use to drive the motor <NUM> to adjust the current driving the motor. The adjusted current (and more specifically, the on/off rate of the current used to drive the motor) can cause the motor <NUM> to operate differently to adjust for the given conditions to cause the desired pressure.

Motor (M) <NUM> represents the motor or the motor controller, which operates based on the current signal VPWM. In one example, current sensor <NUM> represents one or more current sensors to monitor one or more currents of the motor <NUM>. The current sensors <NUM> can provide the feedback current signal FBCURR.

Position sensor <NUM> represents a position sensor for motor <NUM>. The encoder can determine the precise motor location and be used to determine motor velocity. In one example, position sensor <NUM> provides position feedback. Based on the position feedback, the controller can compute the rotational velocity of the motor <NUM>.

Plant <NUM> represents a gear the motor drives. Plant <NUM> represents a gear within the integrated pump system driven by the motor <NUM> to cause the pump to pump the hydraulic fluid. Motor velocity <NUM> represents a present velocity of the motor, MVEL, which is a state of the motor to provide to combiner <NUM>.

<FIG> represents an example of an integrated pump system <NUM>. It will be understood that the shape and configuration of the integrated pump system <NUM> can be different than shown. The illustration is a non-limiting example, and one skilled in the art will understand that the possible configurations are too numerous to illustrate.

The integrated motor and pump can be referred to as an integrated pump system. Integrated pump system <NUM> can replace a traditional pump and the motor to drive the pump. In one example, integrated pump system <NUM> can directly control the hydraulic fluid output based on operation of the motor <NUM>, eliminating the need for a flow control valve. In one example, an integrated pump system <NUM> can be a replacement for a valve, while also replacing the motor and pump that would traditionally provide the fluid that the valve controls.

In one example, integrated pump system <NUM> includes a housing <NUM> that includes the pump <NUM> and the motor <NUM>. In one example, the housing <NUM> includes one or more components that have fluid channels within the housing itself, to convey fluid from the pump <NUM> to the high pressure output port <NUM>. The high pressure output port <NUM> allows system <NUM> to provide work fluid to a work function.

In one example, integrated pump system <NUM> includes a low pressure input port <NUM> as a return path for the work fluid from the work function. The low pressure input port <NUM> receives post-work fluid. In one example, the low pressure input port <NUM> couples to a low pressure path inside the housing that conveys the post-work fluid past either the motor, or past the electronics, or past both the motor and the electronics. In such an implementation, integrated pump system <NUM> can enable use of the post-work fluid for cooling integrated pump system <NUM>. The integrated pump system <NUM> can also include a input/output port <NUM> for coupling the integrated pump system <NUM> to a hydraulic fluid reservoir <NUM>. The hydraulic fluid reservoir <NUM> can receive the post-work fluid and provide a path back to where the integrated pump system <NUM> pumps the hydraulic fluid from the hydraulic fluid reservoir <NUM>.

<FIG> represents an example of two integrated pump systems <NUM> coupled in a cooperating system <NUM>. When the integrated pump system <NUM> is used as a replacement for a valve (e.g., a valveless hydraulic system), multiple integrated pump systems <NUM> can be used in parallel to provide hydraulic fluid to a common work function <NUM>, similar to how multiple valves would couple to a command work function. It should be obvious to one of ordinary skill in the art that up to N integrated pump systems <NUM> can be joined together in parallel depending upon the hydraulic requirements of the work function(s) <NUM>.

The work function <NUM> can be either a linear work function as illustrated (the arrow indicates the linear displacement), or can be a rotary actuator. In one example, cooperating system <NUM> combines the output of high pressure lines <NUM> of multiple integrated pump systems <NUM> to drive the work function <NUM>.

<FIG> depicts a schematic diagram an integrated pump system <NUM> that accesses hydraulic fluid from a hydraulic fluid reservoir <NUM> and provides high pressure fluid to a work function <NUM> via high pressure port <NUM>. Integrated pump system <NUM> functions as a power-on-demand pump system, which includes an integrated motor <NUM> and pump <NUM> in one housing <NUM>. In the illustrated embodiment, the housing <NUM> also includes a controller <NUM> for driving the motor <NUM> and for monitoring the operation of the integrated pump system <NUM>. For example, controller <NUM> may function as the electronics receives the various outputs of the sensors of pressure control system <NUM> or flow rate control system <NUM> and determines VPWM for driving the motor <NUM>.

The motor <NUM> is an electric motor and controller <NUM> represents the control circuitry or electronics that control the operation of the motor <NUM>. The motor <NUM> drives the operation of the pump <NUM>. Based on how the motor drives the pump <NUM>, the pump <NUM> directly outputs the hydraulic fluid from the high pressure port <NUM> to the work function <NUM>. Thus, control over the output of the high pressure port depends <NUM> on the operation of the motor <NUM>, controlling the operation of the pump <NUM>. The hydraulic fluid reservoir <NUM> represents a holding container or other source of the hydraulic fluid.

<FIG> depicts a schematic diagram of integrated pump system <NUM> that accesses hydraulic fluid from a hydraulic fluid reservoir <NUM> and includes feedback <NUM> from a pressure sensor <NUM> which measures the pressure of the hydraulic fluid leaving high pressure output port <NUM>. Integrated pump system <NUM> is a power-on-demand pump system, which includes an integrated motor <NUM> and pump <NUM> in one housing <NUM>. In one example, as illustrated, the housing <NUM> also includes controller <NUM> for the motor <NUM>. In one example, the housing <NUM> includes pressure sensor <NUM> to provide pressure feedback to the controller <NUM>. For example, integrated pump system <NUM> may be used to implement the pressure control system <NUM> depicted and described with respect to <FIG>.

The motor <NUM> is an electric motor and controller <NUM> is the control circuitry or electronics that control the operation of the motor <NUM>. The motor <NUM> drives the operation of the pump <NUM>. Based on how the motor <NUM> drives the pump <NUM>, the pump <NUM> will directly output the fluid from the high pressure port <NUM> to the work function <NUM>. Thus, control over the output of the high pressure port <NUM> depends on the operation of the motor <NUM>, controlling the operation of the pump <NUM>. The hydraulic fluid reservoir <NUM> is a holding container or other source of the hydraulic fluid.

In one example, the pressure sensor <NUM> provides feedback <NUM> (FBPRES of <FIG>) to the controller <NUM>. The pressure sensor <NUM> may be any type of pressure sensor <NUM>. Examples of pressure sensors <NUM> can include discrete sensor components or can include electronics and mechanical components within the pump to provide pressure feedback. The pressure sensor <NUM> can provide feedback about the pressure of hydraulic fluid exiting high pressure port <NUM>. In one example, when the detected pressure is above a threshold pressure, the controller <NUM> can slow the operation of the motor <NUM> to reduce the operation of the pump. In one example, when the pressure is lower than a threshold pressure, the controller <NUM> can increase the operation of the motor <NUM> to increase the operation of the pump <NUM>. In this manner, constant pressure output of hydraulic through high pressure output port <NUM> can be maintained within a selected tolerance (i.e., between an upper pressure threshold and a lower pressure threshold).

<FIG> represents an example of an integrated pump system <NUM> that accesses hydraulic fluid from hydraulic fluid reservoir <NUM> reservoir and receives motor feedback <NUM> directly from motor <NUM>. Integrated pump system <NUM> is a power-on-demand pump system, which includes an integrated motor <NUM> and pump <NUM> in one housing <NUM>. In one example, as illustrated, the housing <NUM> also includes controller <NUM> for the motor <NUM>. In one example, the housing <NUM> includes a pressure sensor <NUM> to monitor a pressure of the fluid from the pump <NUM> to the high pressure port <NUM>.

The motor <NUM> is an electric motor and controller <NUM> provides the control circuitry or electronics that control the operation of the motor <NUM>. The motor <NUM> drives the operation of the pump <NUM>. Based on how the motor <NUM> drives the pump <NUM>, the pump <NUM> directly outputs hydraulic fluid from the high pressure port <NUM> to the work function <NUM>. Thus, control over the output of the high pressure port <NUM> depends on the operation of the motor <NUM>, controlling the operation of the pump <NUM>. The hydraulic fluid reservoir <NUM> is a holding container or other source of the hydraulic fluid.

In one example, the pressure sensor <NUM> represents sensor hardware that may be integrated into the pump <NUM>, motor <NUM>, or both. The pressure sensor <NUM> can thus provide feedback to the controller <NUM> via a connection of the motor <NUM> with the controller <NUM>. The controller <NUM> provides motor control to the motor <NUM>, and the motor <NUM> can provide motor feedback <NUM>, such as motor position and speed of the motor, to the controller <NUM>. In one example, the controller <NUM> computes pressure information based on the motor feedback <NUM> through the motor <NUM>. In one example, when the detected pressure is above a threshold pressure, the controller <NUM> can slow the operation of the motor <NUM> to reduce the operation of the pump. In one example, when the pressure is lower than a threshold pressure, the controller <NUM> can increase the operation of the motor <NUM> to increase the operation of the pump <NUM>.

<FIG> represents an integrated pump system according to the claimed invention, which accesses fluid from a reservoir and includes feedback through the motor. System <NUM> includes a power on demand pump system, which includes an integrated motor and pump in one housing. As illustrated, the housing also includes a controller for the motor. The housing includes a pressure sensor to monitor a pressure of the fluid from the pump to the high pressure port. The system provides a low pressure fluid return path to cool the electronics and motor.

The motor represents an electric motor and controller represents the control circuitry or electronics that control the operation of the motor. The motor drives the operation of the pump. Based on how the motor drives the pump, the pump will directly output the fluid from the high pressure port to the work function. Thus, control over the output of the high pressure port depends on the operation of the motor, controlling the operation of the pump. The reservoir represents a holding container or other source of the hydraulic fluid.

In one example, the pressure sensor represents sensor hardware that can be integrated into the pump or motor or both. The pressure sensor can thus provide feedback to the controller via a connection of the motor with the controller. The controller provides motor control to the motor, and the motor can provide feedback, such as motor position and speed of the motor, to the controller. In one example, the controller computes pressure information based on the feedback through the motor. In one example, when the pressure is above a threshold pressure, the controller can slow the operation of the motor to reduce the operation of the pump. In one example, when the pressure is lower than a threshold pressure, the controller can increase the operation of the motor to increase the operation of the pump.

Typically, after the work is performed in a hydraulic system, the hydraulic fluid is returned to the hydraulic fluid reservoir. This returned hydraulic fluid is at a lower than the supply line due to the work being performed at the work function. In an embodiment of the invention, the returned hydraulic fluid is used to cool controller <NUM>, motor <NUM>, and the shaft coupling <NUM> before the hydraulic fluid is return to hydraulic reservoir <NUM>. A schematic diagram showing this feature is depicted in <FIG> using integrated pump system <NUM>.

The hydraulic fluid exits through high pressure port <NUM> and is used to perform linear work or rotary work at work function <NUM>. This causes the hydraulic fluid to decrease in pressure. The low pressure hydraulic fluid is generally at a maximum temperature of <NUM>-<NUM>° F. This temperature is still much cooler than the temperature that the electronics of controller <NUM> operate or the temperature at which motor <NUM> and/or the shaft coupler operates.

The low pressure hydraulic fluid enters integrated pump system <NUM> via low pressure return line <NUM>. The hydraulic fluid is guided through a cooling fluid channel <NUM> passing through/over the electronics of controller <NUM> and motor <NUM> as depicted, after which it returns to hydraulic fluid reservoir <NUM>. The controller <NUM> preferable comprises a heat sink coupled to the electronics. The cooling fluid channel <NUM> preferably passes through or over the heat sink to provide effective cooling as is known in the fluid cooling arts. For example, cooling fluid channel <NUM> preferably comprises a section which coils around motor <NUM> to increase the surface area engagement and to spread the heat transfer over the surface equally.

Optionally, or in addition, the low pressure hydraulic fluid (oil) may be passed directly over the shaft coupling <NUM> to provide lubrication in a continuous oil bath. The mating of the motor shaft and the pump shaft may either be direct or through the use of a coupling to connect the two shafts. The coupling of the cooling fluid channel <NUM> to the shaft coupling <NUM> is preferably sealed with o-rings or gaskets to prevent any leakage of the hydraulic fluid. Baffles may also be employed to create a slight back pressure to force the hydraulic fluid through shaft coupling <NUM>.

The hydraulic fluid that is moved by pump <NUM> is forced into the area that the motor shaft and pump shaft mate after it is used to cool the motor <NUM> and controller <NUM> as depicted in <FIG>. The hydraulic fluid thus provides both lubrication and cooling to the motor <NUM> and pump <NUM>. This guarantees that the motor and pump shafts are continuously lubricated with oil any time the motor <NUM> is spinning. Using the hydraulic oil for cooling and lubrication also allows for the elimination of a dedicated cooling system that may normally be present on a piece of hydraulic equipment.

When integrated pump system <NUM> is operating in a standard pump mode and providing uni-directional flow to a valve bank like any traditional electronic system, the heat generated by integrated pump system <NUM> can be reduced by over <NUM>%. However, if integrated pump system <NUM> is utilized as depicted in <FIG> and directly provides/return hydraulic fluid from work function <NUM>, the heat generated can be reduced by over <NUM>% when compared with a traditional HPU with direction, pressure, and control valves. This leads to an overall efficiency of <NUM>-<NUM>% when compared with other hydraulic systems (e.g., servo driven HPU, induction motor driven, or combustion engine driven).

<FIG> depicts an embodiment of integrated pump system <NUM> according to the claimed invention, which is capable of bi-directional pumping the hydraulic fluid. In this embodiment, motor <NUM> is preferably a permanent magnet motor. This type of motor has the advantage that it is highly efficient, can be revved up quickly, and is reversible. High pressure output port <NUM> and low output pressure port <NUM> are replaced by bi-directional ports <NUM> which are each configured to output high pressure hydraulic fluid to work function <NUM> depending upon the direction of the operation of motor <NUM>.

The output of the pump is routed through a check valve <NUM> which can be switched such that the high pressure hydraulic fluid is routed from reservoir <NUM> through either port, depending upon the current pumping direction. Another output of the check valve <NUM> is coupled to cooling fluid channel <NUM> to ensure that the low pressure hydraulic fluid always flows in the same direction, namely, first past controller <NUM>, past motor <NUM>, and then through shaft coupling <NUM> to provide lubrication as already described. Through use of the check valve <NUM>, bi-directional flow of the hydraulic fluid is achieved without requiring the motor <NUM> to reverse direction.

As previously described, the integrated pump systems depicted in <FIG> incorporated a plurality of sensors (motor velocity sensor, motor position sensor, current sensor, Hall state sensors, etc.). The motor <NUM> is initially calibrated so that a known motor velocity produces a known pressure or flow output. However, as the motor <NUM> and pump <NUM> degrade over time, the same motor velocity will naturally create a lower pressure or flow output. In some configurations, controller <NUM> includes an auto calibration in which the motor <NUM> is run at a plurality of different speeds and the resulting flow or output pressure is recorded. This allows controller <NUM> to create a new output model for the integrated pump system which can then be used to update the control algorithms utilized by controller <NUM> in controlling motor <NUM>.

Controller <NUM> is able to accurately control the torque and RPM of motor <NUM> in order to drive pump <NUM>. If pump <NUM> is a fixed displacement pump, the output pressure and flow depend on the input torque and RPM of motor <NUM>. The exact relationship between the inputs, torque and rpm, and the outputs, pressure and flow, depend on a combination of both the geometry of the pump <NUM> and the various inefficiencies that hinder the pumping action such as friction and leakage.

By using the integrated pressure sensors and flow sensors in the device in integrated pump system <NUM> or integrated pump system <NUM>, the pressure and flow rate produced by driving the pump with a known torque and RPM can be measured. These measurements can then be used to accurately predict the output pressure and flow rate of the pump <NUM> if it is driven with a similar known torque and RPM.

As the pump <NUM> wears over time, the relationship between input torque and speed relative to the output pressure and flow will change and become less efficient. As the pump <NUM> becomes less efficient, it will require higher torques and speeds to produce the same pressure and flow output. The auto calibration described above can function as a diagnostic routine that could be run either automatically or by request from a user to assess the state of the pump <NUM>. This information is used to effectively choose a target torque or RPM to reach a commanded pressure or flow rate. For example, the motor <NUM> may have initially spun at <NUM> rpm to achieve a target flow rate of <NUM>/s (<NUM> gpm), but over time the pump <NUM> has worn so that <NUM> rpm achieves only <NUM>/s (<NUM> gpm). After calibration, the device would be able to determine that a target of <NUM>/s (<NUM> gpm) should be obtained by driving the pump <NUM> at perhaps <NUM> rpm.

After performing a significant number of diagnostics on a wide sample of pumps <NUM>, it is possible to preemptively predict when a pump <NUM> is going to wear to the point that it no longer satisfies the requirements of the given work function <NUM>. This information could be used to notify the user to replace the pump <NUM> at a non-critical work time. This greatly increases the chance that a pump <NUM> does not fail catastrophically while performing a critical function, generally increasing the "up time" of the integrated pump system.

As previously explained, the integrated pump systems of <FIG> utilize a single housing <NUM> in which a motor <NUM> and pump <NUM> are co-located. However, in some embodiments, the motor <NUM> and pump <NUM> may be manufactured as separate "wet" and "dry" units which can be coupled together in a modular fashion. For example, <FIG> depicts a modular integrated pump system <NUM> comprising dry side <NUM> and wet side <NUM>. Dry side <NUM> incorporates the elements of modular integrated pump system <NUM> where electronic connections are made, including the connection between motor <NUM> and controller <NUM>. Wet side <NUM> incorporates pump <NUM> and all the hydraulic hose connections, such as high pressure output port <NUM> and low pressure output port <NUM>. This is achieved by using a self-aligning mechanical spline shaft coupler which is mechanically affixed to the splined shaft of the motor <NUM>. That is, the dry side <NUM> comprises an external male shaft having gears which couples with a receiving spline hub on the wet side <NUM>. One of ordinary skill in the art would recognize that any type of spline shat coupling <NUM> would be compatible with the present invention for allowing motor <NUM> to be coupled to pump <NUM>. A set of four retaining clamps <NUM> are used to releasably couple dry side <NUM> to wet side <NUM>.

This modularity allows dry side <NUM> to easily be removed away from wet side <NUM> for inspection and/or replacement. If the controller of dry side <NUM> reaches end of life, a new dry side <NUM> can be installed in its place without the cumbersome practice of needing to remove and cap/cover exposed hydraulic hose ends. This minimizes opportunities for oil contamination or hazardous spills.

Claim 1:
An integrated pump system (<NUM>) comprising:
an electronically controlled motor (<NUM>);
a controller (<NUM>) for controlling a speed and a torque of the motor;
a pump (<NUM>) directly coupled to the electronically controlled motor for pumping high pressure hydraulic fluid through a first output port (<NUM>) to a work function (<NUM>); and
a cooling fluid channel (<NUM>) interfaced with electronics of the controller (<NUM>) and the motor (<NUM>),
wherein low pressure hydraulic fluid returning from the work function (<NUM>) is conveyed through the cooling fluid channel (<NUM>) to cool the electronics of the controller (<NUM>) and the motor (<NUM>),
a housing having channels for hydraulic fluid which define a high pressure path for supply of hydraulic fluid to the work function (<NUM>) and a low pressure path for returning hydraulic fluid from the work function (<NUM>),
and a hydraulic fluid reservoir (<NUM>) from which hydraulic fluid is pumped via the high pressure path, and to which hydraulic fluid is returned via the low pressure path,
wherein a part of the low pressure path is composed by the cooling fluid channel (<NUM>), such that hydraulic fluid is led from the work function (<NUM>) through the cooling fluid channel (<NUM>), and hydraulic fluid exiting the cooling fluid channel (<NUM>) is led towards the hydraulic fluid reservoir (<NUM>), wherein the low pressure path is designed to allow the hydraulic fluid to directly flow from the work function (<NUM>) towards the hydraulic fluid reservoir (<NUM>).