Electrically controlled variable-displacement radial piston motor and control method thereof

Abstract

The application discloses an electrically-controlled variable-diameter radial plunger motor and a control method thereof, and relates to the field of hydraulic transmission devices.The technical scheme is characterized in that the motor comprises a shell, a main shaft, a plurality of plunger bodies, a cover, a flow distribution shaft cover, a dynamic flow distribution module, a feedback module and a controller.The rotation speed detection unit of the feedback module is arranged at the end of the main shaft to collect the rotation speed.The dynamic flow distribution module comprises a rotation flow distribution shaft with a circumferential rotation degree of freedom and a flow distribution actuator.The controller instructs the flow distribution actuator to drive the rotation flow distribution shaft to circumferentially deflect based on the rotation speed signal, so that the dynamic adjustment of the flow distribution advance angle is realized.The application increases the flow distribution advance angle to compensate the phase at high speed, suppresses the transient pressure pulsation and cavitation;and reduces the flow distribution advance angle at extremely low speed and heavy load, blocks the oil leakage between the high-pressure cavity and the low-pressure cavity, maintains the smooth torque output, and significantly improves the running stability and efficiency of the motor under variable working conditions.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transmission devices, and in particular to an electrically controlled variable radial piston motor and its control method. Background Technology

[0002] Radial piston hydraulic motors are widely used in the transmission field as low-speed, high-torque power actuators. In the typical internal structure of this type of motor, the periodic distribution and reversal of hydraulic oil are mainly achieved through a distribution shaft. In the prior art, the distribution shaft is usually rigidly mounted on the motor's end cover or housing by fasteners. Throughout the motor's operation, the distribution shaft remains absolutely stationary relative to the external stationary housing. This means that the spatial position and opening angle of the high-pressure and low-pressure distribution windows machined on its surface are completely fixed.

[0003] Under normal steady-state low-speed conditions, this fixed distribution structure can maintain the normal operation of the motor. However, with the increasing demands of modern industrial equipment, hydraulic motors are increasingly being used in specific harsh scenarios, such as travel drive systems that need to balance extremely low-speed heavy-load micro-motion with extremely high-speed no-load transfer, or winch systems that are forced to operate at overspeed due to sudden load release. In these extreme applications, the fixed distribution shaft structure gradually reveals its inherent limitations.

[0004] The working medium of a hydraulic motor is hydraulic oil with a certain degree of compressibility. When the plunger passes the mechanical dead center, the switching of the oil suction and discharge state within the cylinder needs to be precisely matched with the opening timing of the distribution window. Since the geometric position of the existing distribution shaft window is permanently locked, its distribution advance angle can only be optimized and compromised for a specific rated operating point. When the motor is operating at high speed in certain scenarios, the dynamic response time of the fluid becomes extremely short. The fixed distribution window cannot perform dynamic phase compensation, making it difficult for the oil in the cylinder to complete pressure release or build-up before the next distribution window is connected. Forced compression and expansion of the fluid in a very short time can cause hydraulic pulsation and even transient cavitation. Conversely, when the same motor needs to perform extremely low-speed crawling under heavy load, the fixed distribution transition zone originally designed to accommodate high-speed oil discharge may cause oil leakage between the high and low pressure chambers, thus weakening the stability of the motor's torque output at low speeds. Summary of the Invention

[0005] The purpose of this invention is to provide an electronically controlled variable radial piston motor, which has the advantages of dynamic adaptive flow distribution timing, stepless precision adjustment of displacement, smooth operation across the entire speed range, and low mechanical friction loss.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: An electronically controlled variable radial piston motor includes a housing, a main shaft supported within the housing, a plurality of pistons radially distributed within the housing, a cover disposed on the output side of the main shaft, and a distribution shaft cover disposed on the distribution side. The plurality of pistons are respectively connected to the main shaft via connecting rods. It also includes a dynamic flow distribution module, a feedback module, and a controller; The feedback module includes a speed detection unit, which is located at the end of the spindle and is used to collect the speed signal of the spindle. The dynamic distribution module includes a rotating distribution shaft and a distribution actuator; the rotating distribution shaft is inserted into the distribution shaft cover, and there is a clearance fit between the rotating distribution shaft and the distribution shaft cover, so that the rotating distribution shaft has a circumferential rotational degree of freedom; the distribution actuator is drivenly connected to the rotating distribution shaft; The controller is communicatively connected to the speed detection unit and the distribution actuator. The controller receives the speed signal and generates a control command, which is sent to the distribution actuator. The distribution actuator drives the rotating distribution shaft to produce a circumferential angle deflection according to the control command, so as to change the distribution advance angle of the rotating distribution shaft.

[0007] Further configuration: The rotational speed detection unit includes a follower multipole magnetic ring and a magnetic sensing probe; the follower multipole magnetic ring is fixedly installed at the end of the main shaft extending out of the cover and rotates synchronously with the main shaft; the magnetic sensing probe is fixedly installed on the cover, and a physical air gap is provided between the magnetic sensing probe and the follower multipole magnetic ring.

[0008] Further configuration: The housing includes at least a first variable piston and a second variable piston, which are slidably disposed within the housing; the first and second variable pistons are used to change the eccentricity at the connection between the connecting rod and the main shaft transmission; it also includes a hydrostatic suspension control module; the hydrostatic suspension control module further includes a hydrostatic oil chamber disposed on the housing corresponding to the outer cylindrical surface of the first and second variable pistons, and a micro throttling orifice opened within the housing; the micro throttling orifice connects the end face of the first and second variable pistons subjected to controlled high-pressure oil with the corresponding hydrostatic oil chamber, so as to introduce high-pressure oil into the hydrostatic oil chamber and form a hydrostatic support between the outer cylindrical surface of the first and second variable pistons and the housing.

[0009] Further configuration: It also includes an electro-hydraulic proportional actuator module; the electro-hydraulic proportional actuator module includes an integrated valve block and an electro-hydraulic proportional pressure reducing valve; the integrated valve block is fixed to the outside of the housing, and the integrated valve block is provided with a variable control oil passage; the housing is provided with a variable control oil chamber corresponding to the first variable piston, and the output end of the electro-hydraulic proportional pressure reducing valve is connected to the variable control oil chamber through the variable control oil passage; the controller is communicatively connected to the electro-hydraulic proportional pressure reducing valve.

[0010] Further configuration: The feedback module also includes a pressure sensor; the housing also includes a first main working oil port and a second main working oil port located upstream of the dynamic distribution module; a pilot high-pressure extraction oil passage is provided on the path connecting the first main working oil port and the dynamic distribution module, and at least a portion of the pressure sensor is located at the pilot high-pressure extraction oil passage; the pressure sensor is communicatively connected to the controller and is used to collect pressure signals for calculating the output torque.

[0011] Further configuration: The housing has a main internal cavity, and the housing has a closed cavity at the rotating distribution shaft; the distribution shaft cover and the housing are jointly provided with an internal oil drain return channel, which connects the closed cavity and the main internal cavity, and is used to guide the hydraulic oil that has leaked into the closed cavity back to the main internal cavity.

[0012] Another object of the present invention is to provide a control method for an electronically controlled variable radial piston motor, comprising the following steps: S1, Speed ​​Acquisition Steps: The speed detection unit of the feedback module acquires the speed signal of the spindle, and the speed detection unit sends the speed signal to the controller; S2, Command generation steps: The controller receives the speed signal, generates a control command based on the speed signal, and sends the control command to the distribution actuator of the dynamic distribution module; S3, Distribution adjustment steps: The distribution actuator receives the control command, and the distribution actuator drives the rotating distribution shaft to generate a circumferential angle deflection according to the control command. The distribution advance angle of the rotating distribution shaft is changed by the circumferential angle deflection. Specifically, when the rotational speed represented by the rotational speed signal increases, the distribution actuator drives the rotating distribution shaft to deflect in the same direction as the rotation of the main shaft, so as to increase the distribution advance angle.

[0013] Further settings: Also includes S4, the displacement adjustment step. The sub-steps of S4 include: S41, the controller generates a corresponding current proportional control signal according to the preset target displacement, and sends the current proportional control signal to the electro-hydraulic proportional pressure reducing valve of the electro-hydraulic proportional actuator module. S42, the electro-hydraulic proportional pressure reducing valve receives the current proportional control signal and converts the current proportional control signal into a proportional fluid pressure to regulate the high-pressure oil pressure output to the variable control oil chamber. S43, the high-pressure oil in the variable control oil chamber pushes the first variable piston to slide, which in turn drives the second variable piston to move synchronously until the fluid pressure of the high-pressure oil and the mechanical resistance on the side of the second variable piston reach a balance, so as to maintain the eccentricity at the connection between the connecting rod and the main shaft transmission at the position corresponding to the target displacement.

[0014] Further settings: This also includes S5, the torque calculation step. The sub-steps of S5 include: S51, the pressure sensor collects the system's pressure signal at the pilot high-pressure extraction oil passage; S52, the pressure sensor sends the pressure signal to the controller; S53, the controller receives the pressure signal and calculates the output torque of the electronically controlled variable radial piston motor based on the pressure signal.

[0015] Further settings: In S53, the controller synchronously acquires the theoretical eccentricity data corresponding to the currently sent current proportional control signal; the controller calculates the actual output torque of the electronically controlled variable radial piston motor by multiplying the pressure signal, theoretical eccentricity data and preset mechanical efficiency parameters.

[0016] In summary, the present invention has the following beneficial effects: First, in this invention, during motor operation, the speed detection unit in the feedback module collects the spindle speed signal in real time and feeds it back to the controller. The controller generates control commands based on the received speed signals. Since the rotating distribution shaft and the distribution shaft cover have a clearance fit and thus possess circumferential rotational freedom, the distribution actuator can drive the rotating distribution shaft to produce a corresponding circumferential angle deflection according to the control commands, thereby realizing dynamic adjustment of the distribution advance angle.

[0017] When the motor is operating at high or overspeed, the physical response time of fluid exchange is extremely short. At this time, the controller instructs the distribution actuator to drive the rotating distribution shaft to deflect in the same direction as the main shaft, actively increasing the distribution advance angle. This causes the distribution window to open earlier, providing phase compensation for the fluid inertia and compressibility of the hydraulic oil, giving the oil inside the cylinder sufficient time to complete pressure release or build-up before passing the mechanical dead point. This process conforms to the dynamic characteristics of high-speed fluids, effectively smoothing out forced compression and expansion in a short time, and suppressing transient pressure pulsations and cavitation.

[0018] Conversely, when the motor is under extremely low-speed, heavy-load conditions, the fluid exchange rate decreases significantly. The controller then instructs the distribution actuator to adjust in the opposite direction to reduce the distribution advance angle. This action reduces the connection advance of the high and low-pressure distribution windows at slow rotation, making the switching of oil suction and discharge states closer to the physical dead point, thereby blocking the internal leakage path between the high and low-pressure chambers caused by premature opening of the distribution transition zone. This ensures volumetric efficiency at low speeds, reduces torque fluctuations caused by internal leakage, and maintains the stability of the motor's output at low speeds and heavy loads.

[0019] Secondly, in this invention, during the operation of the radial piston motor, obtaining a high-accuracy and stable speed feedback signal is a necessary prerequisite for achieving precise adjustment of the flow advance angle. However, traditional speed acquisition methods often rely on mechanical contact or sensors installed in an internal high-pressure environment. Under the long-term operation of the motor under high pressure, vibration, and periodic impact, mechanical contact is prone to physical wear, and the complex flow of internal high-pressure oil may also interfere with the sensor signal, or even cause oil leakage into electronic components due to seal failure.

[0020] This application provides non-contact signal feedback for the motor through the cooperation of a follower multipole magnetic ring and a magnetic sensing probe. The follower multipole magnetic ring is fixedly installed at the end of the spindle extending from the cover. Because it rotates synchronously with the spindle, it can directly convert the mechanical rotation of the spindle into a periodic change in the spatial magnetic field. The magnetic sensing probe, fixedly installed on the cover, senses the change in the magnetic field through a physical air gap, thereby capturing the rotational speed.

[0021] By utilizing a physical air gap, mechanical friction between measuring elements is eliminated, fundamentally avoiding signal accuracy attenuation caused by contact wear and extending the service life of the detection unit. Simultaneously, the magnetic sensing probe and the follower multi-pole magnetic ring, located at the spindle extension outside the cover, effectively isolate the speed detection unit from the high-pressure oil chamber inside the motor. This avoids direct impact of high-pressure oil flow on the sensing elements and eliminates the need for complex dynamic sealing structures for the sensor leads, thereby reducing the risk of oil leakage and suppressing interference from fluid noise on the signal.

[0022] Third, this invention incorporates a hydrostatic suspension control module. When high-pressure hydraulic fluid acts on the end faces of the first and second variable pistons, a portion of the high-pressure fluid enters the hydrostatic oil chamber through a micro-throttling orifice within the housing. Since the hydrostatic oil chamber is arranged corresponding to the outer cylindrical surface of the variable piston, the fluid entering the chamber forms an oil film with a specific pressure, thereby generating hydrostatic support force between the piston and the housing. This transforms the sliding friction, which might otherwise be in a boundary lubrication state, into a hydrostatic suspension state supported by a liquid film. The hydrostatic support force effectively counteracts the lateral load on the piston, reducing the tendency for direct contact between the piston and the inner wall of the housing. Because the frictional resistance is significantly reduced, the mechanical loss of the variable piston during sliding is greatly reduced. This allows the controller to achieve more precise and rapid adjustment of the eccentricity, significantly improving the sensitivity and dynamic response speed of displacement switching. Simultaneously, the stable existence of the hydrostatic oil film also acts as a buffer and centering agent, reducing mechanical vibration and localized wear during the variable displacement process, ensuring the reliability of the motor operation and the linearity of displacement control under frequent variable displacement conditions.

[0023] Fourth, traditional radial piston motors often rely on simple mechanical switching or constant pressure control when adjusting displacement. This makes it difficult for the motor to achieve precise and continuous displacement adjustment when facing complex and ever-changing load demands, and the adjustment process is prone to sudden pressure changes.

[0024] This application establishes a linear conversion path from electrical signal to fluid pressure through the electro-hydraulic proportional actuator module. The controller, via communication with the electro-hydraulic proportional pressure reducing valve, can output continuously varying electrical signals according to operating instructions. Upon receiving the electrical signal, the electro-hydraulic proportional pressure reducing valve converts it into a proportional hydraulic pressure. Because the integrated valve block is fixed externally to the housing and has an internal variable displacement control oil passage, the regulated pressure oil can be directly guided to the corresponding variable displacement control oil chamber inside the housing.

[0025] This invention transforms the previously discrete displacement switching into a stepless adjustment process driven by a controller. Through dynamic control of the pressure within the variable displacement control chamber via an electro-hydraulic proportional pressure reducing valve, the thrust on the first variable piston smoothly fluctuates with changes in the control current, thereby enabling the variable displacement mechanism to achieve precise compensation for eccentricity. This proportional control method not only reduces hydraulic fluctuations that may arise from traditional switching actions but also ensures that the motor's displacement response is highly synchronized with the electronic control commands, achieving a smooth displacement transition.

[0026] Fifth, in practical applications, especially when dealing with complex operating conditions, radial piston motors often cannot intuitively and accurately grasp the motor's real-time load status simply by setting the displacement.

[0027] This application adds a pressure sensor to the feedback module and sets a pilot high-pressure extraction oil passage on the path connecting the first main working oil port and the dynamic distribution module, so that at least a part of the pressure sensor can directly contact or sense the oil pressure in the path.

[0028] Utilizing the physical mapping relationship between fluid pressure and output torque, pressure changes at key locations are converted into electrical signals and fed back to the controller. Since the pilot high-pressure extraction oil passage is located upstream of the dynamic flow distribution module, the pressure sensor can acquire relatively stable and representative inlet-side pressure data. The controller, combining the real-time acquired pressure signals, can calculate the motor's current output torque, thereby performing a complete power output assessment. Attached Figure Description

[0029] Figure 1 This is a structural cross-sectional view of an electronically controlled variable radial piston motor; Figure 2 This is an end view of an electronically controlled variable radial piston motor; Figure 3 This is a flowchart of the control method for an electronically controlled variable radial piston motor.

[0030] In the diagram, 101 is the housing; 102 is the main shaft; 103 is the connecting rod; and 104 is the plunger body. 105. Cap; 1011. Main body cavity; 1012. Closed cavity; 200. Electro-hydraulic proportional actuator module; 201. Integrated valve block; 202. Electro-hydraulic proportional pressure reducing valve; 300. Static pressure suspension control module; 301. First variable piston; 302. Second variable piston; 303. Static pressure oil chamber; 304. Miniature throttling orifice; 400. Dynamic distribution module; 401. Rotary distribution shaft; 403. Distribution shaft cover; 404. Distribution actuator; 500, Controller; 601. Follow-up multipole magnetic ring; 602. Magnetic sensing probe; 603. Pressure sensor; 701. First main working oil port; 702. Second main working oil port; 703. Pilot high-pressure extraction oil passage; 704. Variable control oil passage; 705. Variable control oil chamber; 707. Internal drain oil return channel. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings.

[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] An electronically controlled variable radial piston motor, such as Figure 1 and Figure 2 As shown, the device includes a housing 101. A main shaft 102 is supported inside the housing 101. Multiple plungers 104 are radially distributed inside the housing 101. The axial ends of the main shaft 102 are defined as an output side and a distribution side, respectively. The output side of the main shaft 102 is provided with a cover 105, and the distribution side of the main shaft 102 is provided with a distribution shaft cover 403. The multiple plungers 104 are respectively connected to the main shaft 102 via corresponding connecting rods 103.

[0034] The electronically controlled variable radial piston motor also includes a dynamic flow distribution module 400, a feedback module, and a controller 500.

[0035] The feedback module includes a speed detection unit. The speed detection unit is located at the end of the spindle 102 and is used to acquire the speed signal of the spindle 102.

[0036] The dynamic distribution module 400 includes a rotating distribution shaft 401 and a distribution actuator 404. The rotating distribution shaft 401 is inserted into the center of the distribution shaft cover 403, and the outer cylindrical surface of the rotating distribution shaft 401 is in clearance fit with the inner wall of the distribution shaft cover 403, so that the rotating distribution shaft 401 has circumferential rotational freedom within the distribution shaft cover 403. The distribution actuator 404 is installed at the distribution shaft cover 403, and the power output end of the distribution actuator 404 is connected to the rotating distribution shaft 401 for transmission.

[0037] The controller 500 is communicatively connected to both the speed detection unit and the distribution actuator 404. The controller 500 receives the speed signal from the speed detection unit and generates control commands, which are then sent to the distribution actuator 404. The distribution actuator 404 drives the rotating distribution shaft 401 to produce a circumferential angle deflection according to the control commands, thereby changing the distribution advance angle of the rotating distribution shaft 401.

[0038] In this embodiment, the current distribution actuator 404 can be a servo motor, a stepper motor, or an electro-hydraulic micro motor; the controller 500 can be a microcontroller, a programmable logic controller (PLC), or a digital signal processor (DSP). The controller settings in the accompanying drawings are for reference only and are actually external controllers.

[0039] The rotational speed detection unit includes a follow-up multipole magnetic ring 601 and a magnetic sensing probe 602.

[0040] The main shaft 102 extends axially and passes through the cover 105. The follower multipole magnetic ring 601 is fixedly installed on the end of the main shaft 102 that extends outside the cover 105. The follower multipole magnetic ring 601 maintains a transmission connection with the main shaft 102 and rotates synchronously with the main shaft 102.

[0041] The magnetic sensing probe 602 is fixedly mounted on the outer surface of the cover 105. The magnetic sensing probe 602 and the follower multipole magnetic ring 601 are arranged opposite each other in space, and a physical air gap is provided between the magnetic sensing probe 602 and the follower multipole magnetic ring 601 to maintain a non-contact assembly relationship between them.

[0042] In this embodiment, the follower multipole magnetic ring 601 can be a radially magnetized multipole magnetic ring or an axially magnetized multipole magnetic ring; the magnetic sensing probe 602 can be a Hall effect sensor probe, an anisotropic magnetoresistive sensor probe, or a giant magnetoresistive sensor probe.

[0043] The housing 101 includes at least a first variable piston 301 and a second variable piston 302. The first variable piston 301 and the second variable piston 302 are arranged radially opposite each other, and both are slidably disposed in guide tracks inside the housing 101. The inner ends of the first variable piston 301 and the second variable piston 302 are connected to an eccentric mechanism. The first variable piston 301 and the second variable piston 302, through linear sliding displacement generated within the housing 101, are used to change the eccentricity at the transmission connection between the connecting rod 103 and the main shaft 102.

[0044] In this embodiment, regarding the specific structure of the eccentric mechanism, a portion of the shaft segment of the main shaft 102 is an eccentric ring. Multiple plunger bodies 104 are rotatably connected to the outer circumference of the eccentric ring via corresponding connecting rods 103. The inner ends of the first variable piston 301 and the second variable piston 302 abut against or are hinged to the outer wall of the eccentric ring, respectively. The first variable piston 301 and the second variable piston 302, through linear sliding displacement generated within the housing 101, directly push the eccentric ring to produce radial translation within the housing 101, thereby physically changing the radial offset of the geometric center of the eccentric ring relative to the axis of the main shaft 102. This radial offset is the actual eccentricity.

[0045] The electronically controlled variable radial piston motor also includes a hydrostatic suspension control module 300.

[0046] The hydrostatic suspension control module 300 includes a hydrostatic oil chamber 303 and a micro throttling orifice 304. The hydrostatic oil chamber 303 is disposed on the inner wall surface of the housing 101, and the position of the hydrostatic oil chamber 303 precisely corresponds to the outer cylindrical surface of the first variable piston 301 and the outer cylindrical surface of the second variable piston 302. The micro throttling orifice 304 is formed inside the solid body of the housing 101.

[0047] The two ends of the micro-throttle orifice 304 form a conductive path. One end of the micro-throttle orifice 304 is connected to the end face region of the first variable piston 301 and the second variable piston 302 under the control of high-pressure oil, and the other end of the micro-throttle orifice 304 is connected to the corresponding hydrostatic oil chamber 303. Through the above-mentioned connection structure, the high-pressure oil at the end face is introduced into the corresponding hydrostatic oil chamber 303 through the physical guidance of the micro-throttle orifice 304. The high-pressure oil fills the hydrostatic oil chamber 303 and forms a hydrostatic support structure between the outer cylindrical surface of the first variable piston 301 and the housing 101, and between the outer cylindrical surface of the second variable piston 302 and the housing 101.

[0048] In this embodiment, the physical form of the first variable piston 301 and the second variable piston 302 can be a cylindrical solid piston or a stepped piston; the geometry of the hydrostatic oil chamber 303 can be an annular groove opened on the inner wall of the housing 101 or a rectangular shallow groove evenly distributed around the circumference; the micro throttling orifice 304 can be a slender straight through hole formed by drilling directly on the housing 101.

[0049] The electronically controlled variable radial piston motor also includes an electro-hydraulic proportional actuator module 200.

[0050] The electro-hydraulic proportional actuator module 200 includes an integrated valve block 201 and an electro-hydraulic proportional pressure reducing valve 202.

[0051] The integrated valve block 201 is fixedly mounted on the outer surface of the housing 101. A variable control oil passage 704 is provided inside the integrated valve block 201. A variable control oil chamber 705 is located inside the housing 101 at the end position of the first variable piston 301.

[0052] The electro-hydraulic proportional pressure reducing valve 202 is installed in the integrated valve block 201. The hydraulic output end of the electro-hydraulic proportional pressure reducing valve 202 is kept in fluid communication with the variable control oil chamber 705 through the variable control oil passage 704 in the integrated valve block 201. The controller 500 establishes a communication connection with the electrical receiving end of the electro-hydraulic proportional pressure reducing valve 202.

[0053] In this embodiment, the integrated valve block 201 can be an aluminum alloy hydraulic valve block, a steel hydraulic valve block, or a cast iron hydraulic valve block; the electro-hydraulic proportional pressure reducing valve 202 can be a direct-acting electro-hydraulic proportional pressure reducing valve or a pilot-operated electro-hydraulic proportional pressure reducing valve.

[0054] The feedback module also includes a pressure sensor 603.

[0055] The housing 101 also includes a first main working oil port 701 and a second main working oil port 702. Both the first main working oil port 701 and the second main working oil port 702 are located upstream of the dynamic flow distribution module 400. A pilot high-pressure extraction oil passage 703 is provided inside the housing 101 along the fluid communication path between the first main working oil port 701 and the dynamic flow distribution module 400. A pressure sensor 603 is fixedly mounted on the wall of the housing 101, and at least a portion of the pressure sensor 603 extends into the housing 101 and is located at the pilot high-pressure extraction oil passage 703, so that the sensing end face of the pressure sensor 603 can directly contact the oil in the pilot high-pressure extraction oil passage 703.

[0056] The signal output terminal of pressure sensor 603 establishes an electrical communication connection with the signal receiving terminal of controller 500. Pressure sensor 603 is used to acquire the pressure signal at the pilot high-pressure extraction oil passage 703 in real time. Controller 500 receives the pressure signal to calculate the output torque of the electronically controlled variable radial piston motor.

[0057] In this embodiment, the pressure sensor 603 can be a thin-film pressure sensor, a piezoresistive pressure sensor, or a strain gauge pressure sensor; the pilot high-pressure extraction oil passage 703 can be an internal concave flow channel integrally formed by the housing 101 during casting.

[0058] The internal space of the housing 101 includes a main inner cavity 1011 and a closed cavity 1012. The main inner cavity 1011 occupies the core area inside the housing 101, and the closed cavity 1012 is located inside the housing 101 at one end corresponding to the rotating distribution shaft 401.

[0059] The distribution shaft cover 403 and the housing 101 both include a shared internal oil drain return channel 707. In terms of pipeline connection and spatial extension, the internal oil drain return channel 707 continuously spans the assembly joint surface between the distribution shaft cover 403 and the housing 101. The first end of the internal oil drain return channel 707 is directly connected to the closed cavity 1012, and the second end of the internal oil drain return channel 707 is connected to the main body cavity 1011, thereby establishing a physical fluid conduction path between the closed cavity 1012 and the main body cavity 1011.

[0060] In this embodiment, the internal oil return channel 707 can be a mechanically drilled inclined through hole penetrating the housing 101 and the distribution shaft cover 403, or it can be an internal flow channel formed by the pre-cast groove on the end face of the distribution shaft cover 403 and the mating surface of the housing 101.

[0061] A control method for an electronically controlled variable radial piston motor, such as Figure 3 As shown, it includes the following steps: S1, Speed ​​Acquisition Steps: The speed detection unit of the feedback module senses the mechanical rotation of the spindle 102 and acquires the speed signal of the spindle 102. The signal output terminal of the speed detection unit establishes electrical communication with the signal input terminal of the controller 500, and the speed detection unit sends the speed signal to the controller 500.

[0062] S2, Command Generation Steps: Controller 500 receives the speed signal. The internal processing unit of controller 500 performs data matching and calculation based on the speed signal, and controller 500 generates corresponding control commands based on the speed signal. The signal output terminal of controller 500 establishes electrical communication with the signal receiving terminal of the current distribution actuator 404 inside the dynamic current distribution module 400, and controller 500 sends the control commands to the current distribution actuator 404 of the dynamic current distribution module 400.

[0063] S3, Distribution Adjustment Step: The distribution actuator 404 receives a control command, and the power output component of the distribution actuator 404 moves according to the control command, thereby driving the rotating distribution shaft 401 to produce a circumferential angle deflection in the internal channel of the distribution shaft cover 403. The spatial phase of the distribution window on the rotating distribution shaft 401 is changed to change the distribution advance angle of the rotating distribution shaft 401.

[0064] In step S3, when the numerical rotational speed of the main shaft 102, as represented by the rotational speed signal, increases, the distribution actuator 404 outputs a corresponding mechanical driving force. The distribution actuator 404 drives the rotating distribution shaft 401 to deflect strictly in the same direction as the current rotational direction of the main shaft 102 in space, thereby increasing the distribution advance angle of the rotating distribution shaft 401 geometrically. The controller 500 has a preset maximum deflection safety threshold. When the distribution advance angle reaches this maximum deflection safety threshold, the controller 500 limits the further driving of the distribution actuator 404 to prevent excessive deflection of the rotating distribution shaft 401 from causing a series short circuit inside the high and low pressure oil ports.

[0065] In this embodiment, the distribution advance angle is the geometrical physical angle by which the phase of the distribution window on the rotating distribution shaft 401 leads the phase of the mechanical dead point inside the main shaft 102. Specifically, in the numerical mapping relationship, when the rotational speed signal indicates that the main shaft 102 is in the low-speed operating range of 0 to 50 revolutions per minute, the controller 500 controls the distribution actuator 404 to remain in place, thus maintaining the distribution advance angle at 0 to 1 degree. When the rotational speed of the main shaft 102 gradually increases to the high-speed operating range of 500 revolutions per minute, the controller 500 generates a control command according to the internal mapping algorithm. The controller 500 controls the distribution actuator 404 to drive the rotating distribution shaft 401 to deflect in the same direction as the rotation of the main shaft 102, thus increasing the distribution advance angle to 5 to 8 degrees.

[0066] The maximum deflection safety threshold is the limit geometric deflection angle boundary at which the high-pressure distribution window and the low-pressure distribution window on the rotating distribution shaft 401 directly short-circuit across the cavity in space. Based on the physical dimension of the sealing layer width between the high and low-pressure distribution windows on the outer cylindrical surface of the rotating distribution shaft 401, the maximum deflection safety threshold is preset to 12 degrees within the controller 500. Under extreme conditions of continuously abnormally increased rotational speed, when the rotational speed represented by the speed signal causes the theoretical distribution advance angle calculated by the controller 500 to reach 12 degrees, the controller 500 triggers the internally preset boundary protection logic. The controller 500 forcibly limits the further drive stroke of the distribution actuator 404, physically locking the actual distribution advance angle of the rotating distribution shaft 401 at 12 degrees to prevent destructive direct internal crossflow caused by the loss of the physical sealing layer between the high and low-pressure ports.

[0067] In this embodiment, the specific form of the speed signal can be a square wave pulse signal, a sine wave signal, or a digitally encoded signal; the specific type of the control command can be an analog voltage command, a PWM duty cycle control command, or a CAN bus data packet command; the internal operation logic of the controller 500 to generate control commands based on the speed signal can be a one-dimensional lookup table algorithm (LUT), a proportional-integral-derivative (PID) algorithm, or a linear mapping function algorithm.

[0068] In this embodiment, the working principle of the electronically controlled variable radial piston motor is as follows: During the continuous operation cycle of the motor, high-pressure oil from the external hydraulic system enters the housing 101 through the first main working port 701 or the second main working port 702. The incoming high-pressure oil is guided to the dynamic distribution module 400 and periodically distributed by the high-pressure distribution window on the rotating distribution shaft 401.

[0069] The high-pressure hydraulic fluid, after being distributed, enters the volumetric chamber containing several plungers 104 in the thrust phase. The fluid pressure of the high-pressure hydraulic fluid acts directly on the ends of these plungers 104, generating a radially inward hydraulic thrust. This hydraulic thrust is transmitted to the eccentric mechanism at the main shaft 102 via the corresponding connecting rod 103. Due to the eccentricity defined by the first variable piston 301 and the second variable piston 302 between the force transmission line of the connecting rod 103 and the actual rotation center of the main shaft 102, the aforementioned radial hydraulic thrust is converted into a rotational torque around the axis of the main shaft 102, thereby driving the main shaft 102 to output mechanical torque and rotational motion outward.

[0070] Simultaneously, as the main shaft 102 rotates continuously, the other plungers 104 in the return phase retract outward under the mechanical limitation of the eccentric mechanism, forcing the low-pressure oil in their chambers to be discharged from the motor through the low-pressure distribution window on the rotating distribution shaft 401. This alternating spatial sequence of oil intake and discharge maintains the continuous mechanical rotation of the motor. When the direction of the external high-pressure oil intake and discharge is changed, the rotational output direction of the motor reverses accordingly.

[0071] The control method for an electronically controlled variable radial piston motor also includes step S4, namely the displacement adjustment step. The sub-steps of step S4 specifically include: S41: The controller 500 has a pre-stored or received externally set target displacement value. The internal processing unit of the controller 500 extracts the target displacement, and the controller 500 generates a corresponding current proportional control signal based on the preset target displacement. Regarding communication and wiring connections, the signal output terminal of the controller 500 establishes a signal connection with the electrical receiving terminal of the electro-hydraulic proportional pressure reducing valve 202 inside the electro-hydraulic proportional actuator module 200. The controller 500 sends the generated current proportional control signal along the wiring path to the electro-hydraulic proportional pressure reducing valve 202 of the electro-hydraulic proportional actuator module 200.

[0072] S42: The electro-hydraulic proportional pressure reducing valve 202 receives a current proportional control signal sent by the controller 500. In the internal physical conversion relationship of the hydraulic components, the electromagnetic proportional iron of the electro-hydraulic proportional pressure reducing valve 202 generates a corresponding electromagnetic thrust based on the current proportional control signal and drives the valve core to move. Thus, the electro-hydraulic proportional pressure reducing valve 202 converts the received purely electrical current proportional control signal into a proportional fluid pressure at the hydraulic level. The electro-hydraulic proportional pressure reducing valve 202 adjusts the high-pressure oil pressure output from its hydraulic output terminal through this fluid pressure. The adjusted high-pressure oil is directly output to the variable control oil chamber 705 connected to it via an internal flow channel.

[0073] S43: In terms of spatial orientation and mechanical transmission, the variable displacement control chamber 705 is located at the outer end of the first variable displacement piston 301, and the second variable displacement piston 302 is located on the opposite side radially opposite to the first variable displacement piston 301. The high-pressure hydraulic fluid continuously supplied to the variable displacement control chamber 705 acts directly on the end face of the first variable displacement piston 301, causing it to slide linearly within the guide rails inside the housing. The inner end of the first variable displacement piston 301 is connected to the second variable displacement piston 302 via an eccentric mechanical structure. The sliding of the first variable displacement piston 301 rigidly drives the second variable displacement piston 302 on the opposite side to produce a synchronous radial displacement. The high-pressure hydraulic fluid continues to push until the fluid pressure generated by the high-pressure hydraulic fluid in the variable displacement control chamber 705 and the mechanical resistance acting on the side of the second variable displacement piston 302 reach numerical equilibrium along the force transmission axis. When force balance is achieved, the first variable piston 301 and the second variable piston 302 stop spatial displacement, so as to physically lock and maintain the spatial eccentricity of the eccentric mechanism at the transmission connection between the connecting rod 103 and the main shaft 102 at the geometric position corresponding to the preset target displacement.

[0074] In this embodiment, the target displacement can be a percentage step value or a continuously varying value based on the maximum theoretical displacement of the motor input from the main control panel of the whole machine; the current proportional control signal can be a PWM pulse width modulation current signal with an amplitude that varies linearly in the range of 0 to 800mA; the mechanical resistance present on the side of the second variable piston 302 can come from the reverse elastic restoring force generated after the metal helical spring coaxially mounted on the outer end of the second variable piston 302 is compressed, or from the hydraulic resistance generated by the constant low-pressure fluid introduced into the sealed cavity outside the second variable piston 302.

[0075] The electronically controlled variable radial piston motor control method also includes step S5, namely the torque calculation step. The sub-steps of step S5 specifically include: S51, Pressure Acquisition Step: Pressure sensor 603 is installed in the pilot high-pressure extraction oil passage 703 of housing 101. The sensing end of pressure sensor 603 extends into the pilot high-pressure extraction oil passage 703 and contacts the oil. Pressure sensor 603 acquires the pressure signal of the system.

[0076] S52, Signal transmission steps: The signal output terminal of the pressure sensor 603 is connected to the controller 500 via an electrical line or wireless network. The pressure sensor 603 sends the collected pressure signal to the controller 500.

[0077] S53, Torque Calculation Steps: Controller 500 receives the pressure signal transmitted back by pressure sensor 603. Within the data synchronization logic of controller 500, controller 500 acquires the current proportional control signal currently sent to electro-hydraulic proportional pressure reducing valve 202 in real time, and retrieves the corresponding theoretical eccentricity data based on the current proportional control signal.

[0078] The controller 500 extracts the mechanical efficiency parameters preset in the internal storage unit. The controller 500 uses the torque calculation formula T=(P·V) / (2π)×η for calculation, where T is the actual output torque, P is the pressure value corresponding to the pressure signal, V is the real-time displacement data, and η is the mechanical efficiency parameter. Through the above multiplication calculation process, the controller 500 finally obtains the actual output torque value of the electronically controlled variable radial piston motor. The physical quantities and their calibrated dimensions are as follows: T is the actual output torque, in N·m; P is the pressure value corresponding to the pressure signal, in MPa; V is the real-time displacement data, in mL / r; and η is the mechanical efficiency parameter.

[0079] In this embodiment, the pressure signal can be a 4-20mA current signal or a CAN bus pressure data packet; the theoretical eccentricity data can be represented as a current-displacement mapping curve stored in the controller 500; the preset mechanical efficiency parameter can be a constant or a variable efficiency coefficient obtained by real-time lookup of tables based on rotational speed and pressure.

[0080] The above embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. An electrically controlled variable radial piston motor, comprising a housing (101), a main shaft (102) supported within the housing (101), a plurality of piston bodies (104) radially distributed within the housing (101), a cover (105) respectively disposed on the output side of the main shaft (102), and a distribution shaft cover (403) disposed on the distribution side, wherein the plurality of piston bodies (104) are respectively connected to the main shaft (102) via connecting rods (103); Its features are, It also includes a dynamic flow distribution module (400), a feedback module, and a controller (500); The feedback module includes a speed detection unit, which is located at the end of the spindle (102) and is used to collect the speed signal of the spindle (102). The dynamic distribution module (400) includes a rotating distribution shaft (401) and a distribution actuator (404); the rotating distribution shaft (401) is inserted into the distribution shaft cover (403), and there is a clearance fit between the rotating distribution shaft (401) and the distribution shaft cover (403), so that the rotating distribution shaft (401) has circumferential rotational freedom; the distribution actuator (404) is connected to the rotating distribution shaft (401) in a driving connection; The controller (500) is connected to the speed detection unit and the distribution actuator (404) respectively. The controller (500) receives the speed signal and generates a control command to send to the distribution actuator (404). The distribution actuator (404) drives the rotating distribution shaft (401) to generate a circumferential angle deflection according to the control command, so as to change the distribution advance angle of the rotating distribution shaft (401).

2. The electronically controlled variable radial piston motor according to claim 1, characterized in that: The rotational speed detection unit includes a follower multipole magnetic ring (601) and a magnetic sensing probe (602); the follower multipole magnetic ring (601) is fixedly installed at the end of the main shaft (102) extending out of the cover (105) and rotates synchronously with the main shaft (102); the magnetic sensing probe (602) is fixedly installed on the cover (105), and a physical air gap is provided between the magnetic sensing probe (602) and the follower multipole magnetic ring (601).

3. The electronically controlled variable radial piston motor according to claim 1, characterized in that: The housing (101) includes at least a first variable piston (301) and a second variable piston (302), which are slidably disposed within the housing (101); the first variable piston (301) and the second variable piston (302) are used to change the eccentricity at the transmission connection between the connecting rod (103) and the main shaft (102); It also includes a hydrostatic suspension control module (300); the hydrostatic suspension control module (300) further includes a hydrostatic oil chamber (303) disposed on the housing (101) corresponding to the outer cylindrical surface of the first variable piston (301) and the second variable piston (302) and a micro throttling orifice (304) opened in the housing (101); the micro throttling orifice (304) connects the end face of the first variable piston (301) and the second variable piston (302) under the action of controlled high pressure oil with the corresponding hydrostatic oil chamber (303) so as to introduce high pressure oil into the hydrostatic oil chamber (303) and form a hydrostatic support between the outer cylindrical surface of the first variable piston (301) and the second variable piston (302) and the housing (101).

4. The electronically controlled variable radial piston motor according to claim 3, characterized in that: It also includes an electro-hydraulic proportional actuator module (200); the electro-hydraulic proportional actuator module (200) includes an integrated valve block (201) and an electro-hydraulic proportional pressure reducing valve (202); the integrated valve block (201) is fixed outside the housing (101), and the integrated valve block (201) is provided with a variable control oil passage (704); the housing (101) is provided with a variable control oil chamber (705) corresponding to the first variable piston (301), and the output end of the electro-hydraulic proportional pressure reducing valve (202) is connected to the variable control oil chamber (705) through the variable control oil passage (704); the controller (500) is communicatively connected to the electro-hydraulic proportional pressure reducing valve (202).

5. The electronically controlled variable radial piston motor according to claim 1, characterized in that: The feedback module further includes a pressure sensor (603); the housing (101) further includes a first main working oil port (701) and a second main working oil port (702) located upstream of the dynamic flow distribution module (400); a pilot high-pressure extraction oil passage (703) is provided on the path connecting the first main working oil port (701) and the dynamic flow distribution module (400), and at least a portion of the pressure sensor (603) is located at the pilot high-pressure extraction oil passage (703); the pressure sensor (603) is communicatively connected to the controller (500) and is used to collect pressure signals for calculating the output torque.

6. The electronically controlled variable radial piston motor according to claim 1, characterized in that: The housing (101) has a main body cavity (1011) inside, and the housing (101) has a closed cavity (1012) at the rotating distribution shaft (401); the distribution shaft cover (403) and the housing (101) are jointly provided with an internal oil drain return channel (707), the internal oil drain return channel (707) connects the closed cavity (1012) and the main body cavity (1011), and is used to guide the hydraulic oil that has leaked into the closed cavity (1012) back to the main body cavity (1011).

7. A control method for an electronically controlled variable radial piston motor as described in any one of claims 1-6, characterized in that, Includes the following steps: S1, Speed ​​acquisition steps: The speed detection unit of the feedback module acquires the speed signal of the spindle, and the speed detection unit sends the speed signal to the controller (500). S2, instruction generation steps: The controller (500) receives the speed signal, the controller (500) generates a control instruction based on the speed signal, and the controller (500) sends the control instruction to the distribution actuator (404) of the dynamic distribution module (400). S3, Distribution adjustment steps: The distribution actuator (404) receives the control command and drives the rotating distribution shaft (401) to generate a circumferential angle deflection according to the control command. The distribution advance angle of the rotating distribution shaft (401) is changed by the circumferential angle deflection. When the rotation speed represented by the speed signal increases, the distribution actuator (404) drives the rotating distribution shaft (401) to deflect in the same direction as the rotation direction of the main shaft (102) to increase the distribution advance angle.

8. The control method according to claim 7, characterized in that: It also includes S4, the displacement adjustment step, whose sub-steps include: S41, the controller (500) generates a corresponding current proportional control signal according to the preset target displacement, and the controller (500) sends the current proportional control signal to the electro-hydraulic proportional pressure reducing valve (202) of the electro-hydraulic proportional execution module (200). S42, the electro-hydraulic proportional pressure reducing valve (202) receives the current proportional control signal and converts the current proportional control signal into a proportional fluid pressure to regulate the high-pressure oil pressure output to the variable control oil chamber (705). S43, the high-pressure oil in the variable control oil chamber (705) pushes the first variable piston (301) to slide, thereby driving the second variable piston (302) to move synchronously until the fluid pressure of the high-pressure oil and the mechanical resistance on the side of the second variable piston (302) reach a balance, so as to maintain the eccentricity at the transmission connection between the connecting rod (103) and the main shaft (102) at the position corresponding to the target displacement.

9. The control method according to claim 8, characterized in that: It also includes S5, the torque estimation step, whose sub-steps include: S51, the pressure sensor (603) collects the system pressure signal at the pilot high-pressure extraction oil passage (703); S52, the pressure sensor (603) sends the pressure signal to the controller (500). S53, the controller (500) receives the pressure signal and calculates the output torque of the electronically controlled variable radial piston motor based on the pressure signal.

10. The control method according to claim 9, characterized in that: In S53, the controller (500) synchronously acquires the theoretical eccentricity data corresponding to the currently sent current proportional control signal; the controller (500) calculates the actual output torque of the electronically controlled variable radial piston motor by multiplying the pressure signal, theoretical eccentricity data and preset mechanical efficiency parameters.

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