阅读说明：本技术 一种基于磁力丝杆的液-电混合动力系统 (Liquid-electricity hybrid power system based on magnetic force lead screw ) 是由 张丽慧 夏永明 方攸同 卢琴芬 颜文俊 郑军 袁国堂 于 2020-05-06 设计创作，主要内容包括：本发明公开了一种基于磁力丝杆的液-电混合动力系统,包括液压缸和电动机；所述液压缸包括缸体和活塞杆；所述活塞杆包覆有动子永磁体并定义为磁力丝杆动子,所述动子永磁体呈螺旋形；所述磁力丝杆动子外可转动地套设有磁力丝杆转子,所述磁力丝杆转子包括转子永磁体,所述转子永磁体呈螺旋形；所述电动机用于驱动所述转子永磁体转动。本发明一方面通过液-电混合的驱动方式提升了驱动效率,另一方面提升了节能回收的效率。(The invention discloses a magnetic lead screw-based hydraulic-electric hybrid power system, which comprises a hydraulic cylinder and a motor, wherein the hydraulic cylinder is connected with the motor through a hydraulic cylinder; the hydraulic cylinder comprises a cylinder body and a piston rod; the piston rod is coated with a rotor permanent magnet and defined as a magnetic lead screw rotor, and the rotor permanent magnet is spiral; the magnetic screw rotor comprises a rotor permanent magnet, and the rotor permanent magnet is spiral; the motor is used for driving the rotor permanent magnet to rotate. According to the invention, on one hand, the driving efficiency is improved through a liquid-electricity hybrid driving mode, and on the other hand, the energy-saving recovery efficiency is improved.)

1. A liquid-electricity hybrid power system based on a magnetic screw rod is characterized by comprising a hydraulic cylinder and a motor;

the hydraulic cylinder comprises a cylinder body and a piston rod;

the piston rod is coated with a rotor permanent magnet and defined as a magnetic lead screw rotor, and the rotor permanent magnet is spiral;

the magnetic screw rotor comprises a rotor permanent magnet, and the rotor permanent magnet is spiral;

the motor is used for driving the rotor permanent magnet to rotate.

2. The hydraulic-electric hybrid power system based on the magnetic screw according to claim 1, wherein any position of the inner surface of the rotor permanent magnet axially comprises at least one N pole and at least one S pole.

3. The hydraulic-electric hybrid power system based on the magnetic screw according to claim 1 or 2, wherein when the rotor permanent magnet and the mover permanent magnet are in the equilibrium position, the N poles of the inner surface of the rotor permanent magnet correspond to the S poles of the mover permanent magnet one to one; and the S poles on the inner surface of the rotor permanent magnet correspond to the N poles of the rotor permanent magnet one by one.

4. The hydraulic-electric hybrid power system based on the magnetic lead screw according to claim 1, wherein the magnetic lead screw rotor further comprises a rotor housing, the rotor housing is annular, and the rotor permanent magnet is arranged on the inner wall of the rotor housing.

5. The magnetic screw-based hydro-electric hybrid system according to claim 4, wherein the rotor housing is made of a magnetically conductive material.

6. The hybrid power system as claimed in claim 4, wherein the rotor housing is rotatably disposed at an end of the cylinder body near the piston rod via a bearing, such that the magnetic screw rotor is sleeved outside the magnetic screw mover.

7. The hybrid hydraulic-electric system based on a magnetic screw as set forth in claim 4 or 6, wherein the output end of the electric motor is in belt or gear transmission with the magnetic screw rotor.

8. The magnetic screw-based hydraulic-electric hybrid system as recited in claim 7, wherein the electric motor is fixedly disposed outside the cylinder.

9. The magnetic screw-based hydraulic-electric hybrid power system as claimed in claim 1, wherein the piston rod is made of solid magnetic conductive material.

10. The hydraulic-electric hybrid power system based on a magnetic screw rod as claimed in claim 1, wherein the magnetic screw rod mover is sleeved with a stainless steel tube.

Technical Field

The invention relates to the technical field of excavator power, in particular to a magnetic lead screw-based hydraulic-electric hybrid power system.

Background

China belongs to the major country of capital construction, excavators are used in large quantities, and the energy efficiency of the excavators is directly related to energy utilization rate and environmental protection, so that the energy-saving research of the excavators always belongs to the key point of industrial research.

The traditional hydraulic cylinder excavator adopts a potential energy recovery mode to improve energy-saving efficiency, if potential energy recovery is not adopted, in the falling process of an excavator arm, the potential energy is reduced in the falling process of a heavy object in an excavator bucket, the potential energy is converted into the heat energy of oil in a hydraulic cylinder, so that the temperature is increased, specifically, in the falling process of the heavy object in the excavator bucket, in order to control the falling speed, the hydraulic cylinder must generate a force opposite to the gravity direction, the heavy object falls to press the oil out of the oil cylinder, the size of a pressing valve is controlled, the pressing flow is controlled, and the oil temperature in the pressing process is increased. The potential energy is recovered and converted into electric energy in the excavator with potential energy recovery, and the electric energy can be reused; the oil outlet control valve can be opened to the maximum in the downward moving process of the piston rod of the hydraulic cylinder, the resistance of oil outlet comes from the hydraulic generator, the larger the generating current is, the larger the resistance is, and the process can convert the potential energy of heavy objects into electric energy.

The energy-saving method of the hybrid excavator comprises the following steps: the rotary motor replaces a hydraulic pump to recover rotary kinetic energy; recovering the potential energy of the movable arm for energy storage and recycling; a high-efficiency engine is adopted; improved energy distribution management, reduced hydraulic losses, etc.

However, only electric power is currently available on the slewing mechanism, and the excavator arm is still hydraulically driven. The further improvement of the efficiency of the excavator is greatly limited by the low efficiency of hydraulic driving, and the problem that the hybrid excavator is urgently required to be solved because the excavator arm cannot use hybrid power for energy saving is solved.

At present, the problem that an excavator arm cannot adopt electric or hybrid drive to save energy is urgently needed to be solved, and the bottleneck of saving energy by 30% is broken through. Although electric cylinders are increasingly replacing hydraulic cylinders, for example Volvo also employs electric cylinders in its conceptual machine EX2, current electric cylinder technology has proven to be incompatible with the harsh working environment of excavators.

Although electric cylinders have tended to replace hydraulic cylinders in many applications, they have not been able to replace hydraulic cylinders in excavators. The main reasons are: 1. the ball screw is easy to damage, and the ball screw is easy to damage under the load blocking working condition; 2. the spiral groove of the ball screw cannot be integrated with a piston rod of a hydraulic cylinder meeting the sealing requirement; 3. the recovery efficiency is low, and the high-efficient conversion from linear motion to rotary motion cannot be realized to the small-pitch lead screw in the high-load electric cylinder, namely if the electric cylinder is adopted, the high-efficient conversion from potential energy to electric energy cannot be realized in the descending process of the power arm.

Disclosure of Invention

The invention aims to provide a magnetic lead screw-based hydraulic-electric hybrid power system to realize a hybrid power driving mode under heavy load or severe working conditions and solve the problem that a hybrid power excavator cannot realize high efficiency and energy conservation.

In order to achieve the above purpose, the invention provides the following technical scheme: a hydraulic-electric hybrid power system based on a magnetic lead screw comprises a hydraulic cylinder and a motor;

the hydraulic cylinder comprises a cylinder body and a piston rod;

the piston rod is coated with a rotor permanent magnet and defined as a magnetic lead screw rotor, and the rotor permanent magnet is spiral;

the magnetic screw rotor comprises a rotor permanent magnet, and the rotor permanent magnet is spiral;

the motor is used for driving the rotor permanent magnet to rotate.

Further, the inner surface of the rotor permanent magnet comprises at least one N pole and at least one S pole at any position along the axial direction.

Further, when the rotor permanent magnet and the rotor permanent magnet are in a balance position, the N poles on the inner surface of the rotor permanent magnet correspond to the S poles of the rotor permanent magnet one by one; and the S poles on the inner surface of the rotor permanent magnet correspond to the N poles of the rotor permanent magnet one by one.

Further, the magnetic screw rotor further comprises a rotor shell, the rotor shell is in a circular ring shape, and the rotor permanent magnet is arranged on the inner wall of the rotor shell.

Further, the rotor shell is made of a magnetic conductive material.

Further, the rotor housing is rotatably disposed at one end of the cylinder body close to the piston rod through a bearing, so that the magnetic screw rotor is sleeved outside the magnetic screw rotor.

Further, the output end of the motor and the magnetic screw rotor are in transmission through a belt or a gear.

Further, the motor is fixedly arranged on the outer side of the cylinder body.

Further, the piston rod is made of solid magnetic materials.

Furthermore, a stainless steel pipe is sleeved outside the magnetic lead screw rotor.

Compared with the prior art, the invention has the advantages that:

1. the invention realizes the driving mode of liquid-electricity mixing in the excavator through the structure of the magnetic lead screw, overcomes the difficult problem that the mechanical lead screw and hydraulic power are difficult to mix, the mechanical lead screw passes through mechanical rigid contact in the power transmission process, and the electric power and the hydraulic pressure are difficult to be respectively controlled in the power process; the mechanical screw rod is easy to damage under heavy load and is not suitable for the severe working condition of the excavator; the mechanical screw rod cannot realize conversion from linear motion to rotary motion under a small polar distance. The magnetic screw rod adopts non-mechanical contact magnetic transmission, so that the magnetic screw rod is more stable under the load blocking working condition; and easy integration, magnetic force lead screw does not have the helicla flute, easily integrates with the pneumatic cylinder piston rod mutually.

2. The invention has high safety, and can be driven by another power source under the condition of failure of one power source by combining two different power sources.

3. The magnetic lead screw is introduced, so that the energy efficiency recoverability which is not possessed by a mechanical lead screw is possessed, and the magnetic lead screw still has high efficiency of converting linear motion into rotary motion under a small lead.

4. The invention can solve the bottleneck problem that the excavator arm which restricts the excavator efficiency to be further improved cannot use hybrid power to save energy through the double energy conservation of the hydraulic cylinder and the motor.

Drawings

Fig. 1 is a schematic structural view of the present invention.

In the figure: 1. a cylinder body; 2. an electric motor; 3. a magnetic lead screw rotor; 4. a magnetic screw rotor; 5. a mover permanent magnet; 6. a rotor permanent magnet; 7. and a bearing.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further specifically described below by way of embodiments in combination with the accompanying drawings.