A multi-stage braking slewing power assembly for an engineering machine

Abstract

The utility model discloses an engineering machinery line stays integrated multistage braking slewing power assembly belongs to engineering machinery technical field. The slewing power assembly includes slewing motor, wet type multi -disc brake, hydraulic rotary damper, speed reducer, power output shaft, valve group, energy accumulator, low pressure electronic pump and power battery, and one end of slewing motor is connected with wet type multi -disc brake, and the other end of wet type multi -disc brake is connected with one end of hydraulic rotary damper, and the other end of hydraulic rotary damper is connected with speed reducer, and speed reducer is connected slewing platform through power output shaft machine, and the oil inlet of valve group is connected with hydraulic oil tank through low pressure electronic pump, and the oil outlet of valve group is connected with energy accumulator, wet type multi -disc brake, hydraulic rotary damper and power battery respectively. The utility model can realize the free switching of various braking modes, and solve the problems such as low temperature energy recovery, inconvenient storage of braking recovery energy, braking impact inhibition, non -inductive switching of braking mode etc.

Description

Technical Field

[0001] This utility model relates to a multi-stage braking and turning power assembly that integrates travel and parking functions in engineering machinery, belonging to the field of engineering machinery technology. Background Technology

[0002] Excavators, as multi-purpose construction machinery, are commonly used for digging, leveling, and loading operations. Their work is characterized by strong cyclical nature, frequent slewing movements, and complex and variable external loads. During slewing, excavators are prone to speed fluctuations, causing the motor to frequently switch between high-efficiency and low-efficiency zones. Under these transient conditions, not only does energy consumption increase significantly, but the driver's comfort also deteriorates.

[0003] Excavator electric slewing drives often employ a single braking source (such as pure electric braking or pure friction braking). A single braking source cannot simultaneously meet the braking performance requirements under all working conditions. Pure electric braking experiences rapid torque decay at low speeds, making reliable parking impossible; energy recovery is limited at low temperatures or when the battery is fully charged. Pure friction braking suffers from large braking impacts and poor ride smoothness at high speeds, and is also subject to continuous wear and thermal fade issues.

[0004] Furthermore, excavators need to operate in extremely low-temperature environments. Below -10°C, the motor braking energy can only be dissipated because the battery cannot be charged, thus requiring the installation of additional dissipation resistor grids. When the excavator battery is at full SOC, the power battery also cannot be charged, making it inconvenient to store the energy recovered from braking by the swing motor. Utility Model Content

[0005] The purpose of this utility model is to provide a multi-stage braking and slewing powertrain for engineering machinery that integrates travel and parking. It realizes the slewing transmission control of excavators through a three-stage braking structure of electric braking, friction braking, and hydraulic damping, and solves problems such as low-temperature energy recovery, inconvenient storage of brake recovery energy, brake impact suppression, and seamless switching of braking modes.

[0006] To achieve the above objectives / to solve the above technical problems, this utility model adopts the following technical solution:

[0007] This utility model provides a multi-stage braking and slewing power assembly for engineering machinery, including a slewing motor, a wet multi-disc brake, a hydraulic rotary damper, a reducer, a power output shaft, a valve group, an accumulator, a low-pressure electronic pump, and a power battery. The slewing motor is connected to one end of the wet multi-disc brake, the other end of the wet multi-disc brake is connected to one end of the hydraulic rotary damper, the other end of the hydraulic rotary damper is connected to the reducer, and the reducer is connected to the slewing platform via the power output shaft. The oil inlet of the valve group is connected to the hydraulic oil tank via the low-pressure electronic pump, and the oil outlet of the valve group is connected to the accumulator, the wet multi-disc brake, the hydraulic rotary damper, and the power battery, respectively.

[0008] Furthermore, the wet multi-disc brake includes a spring, multiple sets of dynamic and static friction discs, a hydraulic cylinder, bearings, splines, and a housing;

[0009] The spline includes external and internal splines. Multiple sets of moving and stationary friction plates include moving friction plates and external friction plates. The external spline is located on the extension of the rotary motor's output shaft, and the internal spline is located in the inner hole of the moving friction plate. The moving friction plate meshes with the external spline on the motor shaft via the internal spline, thus rotating with the motor shaft. The stationary friction plate meshes with the internal spline on the housing via the external spline. The hydraulic cylinder is located in the annular piston cavity within the housing, and the spring is mounted on the piston or pressure plate of the hydraulic cylinder. The bearing is located between the housing and the rotary motor's motor shaft or the hydraulic cylinder's pressure plate.

[0010] The braking chambers of the hydraulic cylinder and the moving and stationary friction plates are respectively connected to the valve assembly.

[0011] Furthermore, the hydraulic rotary damper includes a planetary gear, an internal gear pump, and an electro-proportional relief valve;

[0012] The planetary gear mechanism includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the internal gear pump. The planet carrier is fixed to the housing of the rotary power assembly via bearings. The ring gear is connected to the housing of the wet multi-disc brake. The internal gear pump includes a pump shaft, a pinion, and an internal ring gear. The pump shaft is coaxially connected to the sun gear. The pinion is mounted on the pump shaft and rotates at high speed with the pump shaft. The internal ring gear is fixed in the pump body of the internal gear pump and forms an internal meshing relationship with the pinion. The inlet of the electro-proportional relief valve is connected to the outlet of the internal gear pump via a high-pressure oil pipe. The return port of the electro-proportional relief valve is connected to the inlet of the internal gear pump.

[0013] When the pump shaft is driven, the internal gear pump converts the mechanical energy of rotation into hydraulic energy, drawing in oil from the inlet and discharging pressurized oil from the outlet.

[0014] Furthermore, the hydraulic oil in the hydraulic tank enters the valve assembly through a low-pressure electronic pump. The oil then flows through the valve assembly into the accumulator, the hydraulic cylinder of the wet multi-disc brake, and the braking chamber of the moving and stationary friction pads. The oil supplies oil to the hydraulic cylinder, which then actuates to brake or release the brake. The oil also supplies oil to the braking chambers of the moving and stationary friction pads, cooling them. The hot oil flowing out of the accumulator, hydraulic cylinder, and braking chambers of the moving and stationary friction pads flows through the valve assembly to the power battery. After heating the power battery, the cold oil flows back to the hydraulic tank.

[0015] Furthermore, the internal gear pump of the hydraulic rotary damper draws oil from the hydraulic oil tank, and the oil flows into the electro-proportional relief valve to realize hydraulic rotary damping braking. The hot oil flows back to the hydraulic oil tank through the valve group.

[0016] Furthermore, the slewing powertrain also includes a motor controller, a vehicle controller, and an operating handle. The operating handle is electrically connected to one end of the vehicle controller, and the other end of the vehicle controller is connected to the slewing motor through the motor controller.

[0017] Furthermore, it also includes a pressure sensor, one end of which is connected to an energy storage device, and the other end of which is connected to the vehicle controller.

[0018] Furthermore, it also includes a DC-DC converter, one end of which is connected to the power battery, and the other end of which is connected to a low-voltage electronic pump.

[0019] Compared with the prior art, the beneficial effects achieved by this utility model are as follows:

[0020] This invention proposes a multi-stage braking and slewing power assembly integrating travel and parking functions for engineering machinery. The system is equipped with a slewing motor, a wet multi-disc brake, and a hydraulic rotary damper. It can achieve motor braking, friction braking (mechanical braking), and hydraulic damping braking according to actual braking needs, allowing for free switching between multiple braking modes to improve braking effect and avoid braking shock. This invention connects the power battery to a valve assembly. When the power battery temperature is too low, the valve assembly can transfer heat from the motor braking, brake, and hydraulic damping to the power battery, accelerating the battery temperature recovery. Attached Figure Description

[0021] Figure 1 The diagram shown is a structural schematic of a multi-stage braking and slewing power assembly for engineering machinery that integrates travel and parking functions, according to an embodiment of this utility model.

[0022] Figure 2 The diagram shown is a structural schematic of the wet multi-plate brake in an embodiment of this utility model;

[0023] Figure 3 The diagram shown is a structural schematic of the hydraulic rotary damper in an embodiment of this utility model.

[0024] Figure 4 The diagram shown is a schematic diagram of the hydraulic circuit of the rotary power assembly in an embodiment of this utility model;

[0025] In the diagram, 1-rotary motor, 2-wet multi-disc brake, 3-hydraulic rotary damper, 4-reducer, 5-power output shaft, 6-valve group, 7-accumulator, 8-low-pressure electronic pump, 9-motor controller, 10-vehicle controller, 11-operating handle, 12-pressure sensor, 13-power battery, 14-DC-DC converter, 15-hydraulic tank, 21-spring, 22-multiple sets of dynamic and static friction plates, 23-hydraulic cylinder, 24-bearing, 25-spline, 26-housing, 31-planetary gear, 32-internal gear pump, 33-electro-proportional relief valve. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features therein are detailed descriptions of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features therein can be combined with each other.

[0027] This embodiment introduces a multi-stage braking and slewing powertrain integrating travel and parking functions for engineering machinery, such as... Figure 1 As shown, it mainly includes a rotary motor 1, a wet multi-disc brake 2, a hydraulic rotary damper 3, a reducer 4, a power output shaft 5, a valve group 6, an accumulator 7, a low-pressure electronic pump 8, a motor controller 9, a vehicle controller 10, and an operating handle 11.

[0028] The slewing motor, wet multi-disc brake, hydraulic rotary damper, reducer, and power take-off shaft are mainly used to achieve slewing and braking. The slewing motor is connected to the vehicle control unit (VCU) via a motor controller and performs slewing or braking according to the control commands issued. The wet multi-disc brake is mechanically connected to the slewing motor and is mainly used to achieve power slewing braking or, in conjunction with the slewing motor's electric braking and the hydraulic rotary damper, to achieve combined braking. The hydraulic rotary damper is mechanically connected to the wet multi-disc brake and is mainly used to reduce slewing impact and decelerate slewing, or, in conjunction with the slewing motor's electric braking and the wet multi-disc brake, to achieve combined braking. The power take-off shaft is mechanically connected to the hydraulic rotary damper via a reducer. The reducer reduces speed and increases torque, and the power take-off shaft can output power to the slewing platform.

[0029] The valve group is connected to the wet multi-disc brake, hydraulic rotary damper, accumulator and low-pressure electronic pump respectively. By adjusting the valves in the valve group, the oil in the oil circuit of the wet multi-disc brake, hydraulic rotary damper, accumulator, electronic pump and power battery cooling is distributed.

[0030] The low-pressure electronic pump is used to power the wet multi-disc brake. At the start-up time, the pressure sensor 12 detects the accumulator pressure value. If the lower limit of the pressure setting value is reached, the low-pressure electronic pump starts to replenish the accumulator and meet the working requirements of the wet multi-disc brake. If the upper limit of the pressure setting value is reached, the low-pressure electronic pump stops.

[0031] The driver outputs control signals to the vehicle controller (VCU) via the operating handle. The VCU processes the control signals, and the motor controller receives the control commands output by the VCU to control the rotary motor to operate (rotate or brake).

[0032] The power battery 13 supplies power to the various components inside the device; the power battery is connected to the DC-DC converter (DCDC) 14, and the output voltage of the power battery can be adjusted through the DCDC.

[0033] like Figure 2 As shown, the wet multi-disc brake mainly includes a spring 21, multiple sets of dynamic and static friction discs 22, a hydraulic cylinder 23, a bearing 24, a spline 25, and a housing 26.

[0034] The housing is the basic structural and load-bearing component of the entire brake. The two ends of the housing are rigidly connected to the output end of the rotary motor and the input end of the reducer through flanges and bolts, respectively, thus forming a coaxial transmission power assembly.

[0035] The spline includes an external spline and an internal spline. The external spline is machined on the extension of the output shaft of the rotary motor, and the internal spline is located in the inner hole of a set of moving friction plates. The moving friction plates mesh with the external spline on the motor shaft through the internal spline, so that they rotate together with the motor shaft.

[0036] The system comprises multiple sets of dynamic and static friction plates. The dynamic friction plates are connected to the motor shaft via splines and rotate with the shaft. The outer edges of the static friction plates engage with the inner splines on the housing via external splines, meaning the static friction plates are fixed to the housing and only slide axially without rotating. The dynamic and static friction plates are alternately stacked together to form a friction pair. In the non-braking state, there is a slight gap between them.

[0037] A hydraulic cylinder is an annular piston cavity machined inside a housing. When pressurized oil enters the cylinder, it pushes the annular piston inside. This piston directly or through a set of pressure plates axially pushes all the stacked moving and stationary friction plates together, pressing them together. This converts the rotational kinetic energy of the motor into heat energy through friction, thus achieving braking.

[0038] The springs are a set of circumferentially distributed return springs, installed on the piston or pressure plate of the hydraulic cylinder. When the oil pressure in the hydraulic cylinder is unloaded, the spring force pushes the piston back to its original position, thereby releasing the clamping force on the moving and stationary friction plates, causing the friction plates to separate, and the braking state is released.

[0039] The bearing is located between the housing and the motor shaft or pressure plate. Its function is to support and position the internal moving parts (such as pistons and pressure plates) to move smoothly in the axial direction, while preventing them from shifting radially or rotating with the housing, thus ensuring the accuracy of the braking action.

[0040] The hydraulic connections of a wet multi-disc brake include:

[0041] Brake chamber oil circuit: The oil inlet of the hydraulic cylinder is connected to the brake oil inlet of the valve assembly on the housing through an internal oil passage. When the valve assembly supplies pressurized oil, the brake applies the braking force.

[0042] Cooling / Separation Chamber Oil Circuit: A dedicated cooling oil passage is located inside the housing. Its inlet is connected to the cooling oil inlet of the valve assembly on the housing. It can directly spray or flow through the gap between the moving and stationary friction plates in the separated state, serving to cool (remove heat generated during braking), lubricate (reduce wear on the friction plates in the initial engagement stage), and clean and separate (the flow of oil helps separate the friction plates and remove wear debris). Figure 3 As shown, the hydraulic rotary damper mainly includes a planetary gear 31, an internal gear pump 32, and an electro-proportional relief valve 33.

[0043] The planetary gear mechanism further includes a sun gear 311, a planet carrier 312, and a ring gear 313. The ring gear is the input end of the planetary gear mechanism; its outer edge is rigidly connected to the housing of the wet multi-disc brake via splines or bolts, thus the rotational motion of the brake housing is directly transmitted to the ring gear. The planet carrier is the fixed end of the planetary gear mechanism; it is supported on the assembly housing by bearings and is circumferentially fixed (e.g., connected to the housing by pins or keys), preventing it from rotating and allowing it to withstand torque. The sun gear is the output end of the planetary gear mechanism, and its rotational speed is amplified by the planetary mechanism. The sun gear output shaft is directly connected to the pump shaft of the internal gear pump via splines or a coupling.

[0044] The internal gear pump further includes a pump shaft 321, a pinion 322, and an internal gear ring 323. The pump shaft is coaxially connected to the sun gear (311) of the planetary mechanism and receives the accelerated input. The pinion is mounted on the pump shaft and rotates at high speed with the pump shaft. The internal gear ring is fixed in the pump body and forms an internal meshing relationship with the pinion.

[0045] The transmission relationship from planetary gears to the internal gear pump is as follows: power flow is brake housing -> gear ring -> planetary gears -> sun gear -> pump shaft.

[0046] When the pump shaft is driven, the internal gear pump begins to work, converting the mechanical energy of rotation into hydraulic energy, drawing in oil from the inlet (P1) and discharging pressurized oil from the outlet (P2). At this point, it is no longer used as a power element, but as a damping element.

[0047] The inlet of the electro-proportional relief valve is connected to the outlet (P2) of the internal gear pump via a high-pressure oil pipe, and its return port is connected to the inlet (P1) of the internal gear pump, thus forming a closed hydraulic circulation loop.

[0048] The electro-proportional relief valve is used to set and regulate the system pressure of the aforementioned hydraulic circuit. Its set pressure value is proportional to the received control current.

[0049] In the rotary power assembly of this utility model, the hydraulic circuit connection is as follows: Figure 4 As shown, the low-pressure electronic pump draws oil from the hydraulic tank, and the oil enters the valve assembly. Firstly, the oil flows through the valve assembly to the accumulator. Secondly, the oil supplies oil to the hydraulic cylinder of the wet multi-disc brake, supporting the cylinder's action to achieve braking or releasing the brake. Thirdly, the oil supplies oil to the braking chambers of the wet multi-disc brake's moving and stationary friction plates, supporting the braking and cooling of the moving and stationary friction plates. The hot oil flowing out of the accumulator, the hydraulic cylinder of the wet multi-disc brake, and the braking chambers of the moving and stationary friction plates flows back to the hydraulic tank through the valve assembly. The internal gear pump of the hydraulic rotary damper draws oil from the hydraulic tank and flows into the electro-proportional relief valve, achieving hydraulic rotary damping braking. The hot oil flows back to the hydraulic tank through the valve assembly. When the power battery temperature is too low, the control valve assembly directs the hydraulic oil flowing from the braking chambers of the wet multi-disc brake's moving and stationary friction plates and the electro-proportional relief valve to the power battery, heating the battery pack. The cold oil finally flows back to the hydraulic tank.

[0050] This utility model provides a rotary power assembly with multi-stage braking capability. The system is equipped with a rotary motor, a wet multi-disc brake and a hydraulic rotary damper. It can realize motor braking, friction braking (mechanical braking) and hydraulic damping braking according to actual braking needs, and freely switch between multiple braking modes to improve braking effect and avoid braking impact.

[0051] This invention connects the power battery to the valve assembly. When the power battery temperature is too low, the valve assembly can transfer heat from the motor braking, brake, and hydraulic damping to the power battery, accelerating the battery temperature recovery. To address the problem of inability to regenerate braking at low temperatures, this invention adopts an integrated design of the hydraulic damping system and wet brake circuit, and adds a copper-loss braking mode for the motor. This mode introduces heat into the battery cooling system through a cooling circuit, avoiding energy waste at low temperatures and improving energy utilization. The copper-loss braking mode expands the effective operating range of the system in extremely cold environments. This invention also uses a planetary gear coaxially driven internal gear pump, and the hydraulic damping system and wet brake circuit share the same oil source to avoid system bulkiness. This invention reduces the application of friction braking in high-speed areas, reduces wear and heat load, and extends the service life of the brake.

[0052] This utility model structure can fully leverage the advantages of electric braking (high efficiency, recyclable), friction braking (reliable, high torque), and hydraulic braking (smooth, buffered), achieving functional complementarity, smooth switching between multiple braking modes, significantly improving operational comfort and structural reliability, and solving problems such as low-temperature energy recovery, inconvenient storage of regenerated braking energy, braking impact suppression, and seamless switching of braking modes.

[0053] The embodiments of the present utility model have been described above with reference to the accompanying drawings. However, the present utility model is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present utility model without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present utility model.

Claims

1. A multi-stage braking and slewing power assembly integrating travel and parking functions for engineering machinery, characterized in that, It includes a rotary motor, a wet multi-disc brake, a hydraulic rotary damper, a reducer, a power output shaft, a valve group, an accumulator, a low-pressure electronic pump, and a power battery. The rotary motor is connected to one end of the wet multi-disc brake, the other end of the wet multi-disc brake is connected to one end of the hydraulic rotary damper, the other end of the hydraulic rotary damper is connected to the reducer, and the reducer is connected to the rotary platform via the power output shaft. The oil inlet of the valve group is connected to the hydraulic oil tank via the low-pressure electronic pump, and the oil outlet of the valve group is connected to the accumulator, the wet multi-disc brake, the hydraulic rotary damper, and the power battery, respectively.

2. The rotary power assembly according to claim 1, characterized in that, The wet multi-disc brake includes a spring, multiple sets of dynamic and static friction discs, a hydraulic cylinder, bearings, splines, and a housing; The spline includes external and internal splines. Multiple sets of moving and stationary friction plates include moving friction plates and external friction plates. The external spline is located on the extension of the rotary motor's output shaft, and the internal spline is located in the inner hole of the moving friction plate. The moving friction plate meshes with the external spline on the motor shaft via the internal spline, thus rotating with the motor shaft. The stationary friction plate meshes with the internal spline on the housing via the external spline. The hydraulic cylinder is located in the annular piston cavity within the housing, and the spring is mounted on the piston or pressure plate of the hydraulic cylinder. The bearing is located between the housing and the rotary motor's motor shaft or the hydraulic cylinder's pressure plate. The braking chambers of the hydraulic cylinder and the moving and stationary friction plates are respectively connected to the valve assembly.

3. The rotary power assembly according to claim 1, characterized in that, The hydraulic rotary damper includes a planetary gear, an internal gear pump, and an electro-proportional relief valve. The planetary gear mechanism includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the internal gear pump. The planet carrier is fixed to the housing of the rotary power assembly via bearings. The ring gear is connected to the housing of the wet multi-disc brake. The internal gear pump includes a pump shaft, a pinion, and an internal ring gear. The pump shaft is coaxially connected to the sun gear. The pinion is mounted on the pump shaft and rotates at high speed with the pump shaft. The internal ring gear is fixed in the pump body of the internal gear pump and forms an internal meshing relationship with the pinion. The inlet of the electro-proportional relief valve is connected to the outlet of the internal gear pump via a high-pressure oil pipe. The return port of the electro-proportional relief valve is connected to the inlet of the internal gear pump. When the pump shaft is driven, the internal gear pump converts the mechanical energy of rotation into hydraulic energy, drawing in oil from the inlet and discharging pressurized oil from the outlet.

4. The rotary power assembly according to claim 2, characterized in that, The hydraulic oil in the tank enters the valve assembly through a low-pressure electronic pump. The oil then flows through the valve assembly into the accumulator, the hydraulic cylinder of the wet multi-disc brake, and the braking chamber of the moving and stationary friction pads. The oil supplies oil to the hydraulic cylinder, which then actuates to brake or release the brake. The oil also supplies oil to the braking chambers of the moving and stationary friction pads, cooling them. The hot oil flowing out of the accumulator, hydraulic cylinder, and braking chambers of the moving and stationary friction pads flows through the valve assembly to the power battery. After heating the power battery, the cold oil flows back to the hydraulic oil tank.

5. The rotary power assembly according to claim 3, characterized in that, The internal gear pump of the hydraulic rotary damper draws oil from the hydraulic oil tank, and the oil flows into the electro-proportional relief valve to realize hydraulic rotary damping braking. The hot oil flows back to the hydraulic oil tank through the valve group.

6. The rotary power assembly according to claim 1, characterized in that, The slewing powertrain also includes a motor controller, a vehicle controller, and an operating handle. The operating handle is electrically connected to one end of the vehicle controller, and the other end of the vehicle controller is connected to the slewing motor through the motor controller.

7. The rotary power assembly according to claim 6, characterized in that, It also includes a pressure sensor, one end of which is connected to an energy storage device, and the other end of which is connected to a vehicle controller.

8. The rotary power assembly according to claim 1, characterized in that, It also includes a DC-DC converter, one end of which is connected to the power battery and the other end of which is connected to a low-voltage electronic pump.

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