Multi-motor heavy-load electric cylinder for crane

Abstract

The present invention relates to the technical field of electric cylinders. Disclosed is a multi-motor heavy-load electric cylinder for a crane, aiming to solve the problem in the prior art that a conventional electric cylinder having a gear reduction mechanism driven by a single motor cannot meet heavy load and long stroke requirements of a crane. The multi-motor heavy-load electric cylinder for a crane comprises multiple driving assemblies, a reduction gearbox housing, and a cylinder barrel; the cylinder barrel is connected to one side of the reduction gearbox housing; the multiple driving assemblies are evenly arranged on the reduction gearbox housing around a rod barrel; a lead screw is arranged in the rod barrel; the rod barrel is sleeved with the cylinder barrel, and has one end provided with a lead screw nut, and the other end extending to the outside of the cylinder barrel to be connected to a rod head; the lead screw nut is threadedly connected to the lead screw. The present invention can use a multi-motor driving mechanism, thereby meeting heavy load and long stroke requirements of the electric cylinder for a crane.

Description

A multi-motor large-load electric cylinder for cranes Technical Field

[0001] The invention relates to a multi-motor large-load electric cylinder for a crane, belonging to the technical field of electric cylinder machinery. Background Art

[0002] Electric cylinders generally consist of a linear actuator, a transmission mechanism, and a motor. They are characterized by low noise and zero leakage. They are being used in many applications to replace traditional hydraulic cylinders, and their application is becoming increasingly widespread in industry. Currently, commonly used electric cylinders use a single motor to drive a gear reduction or a synchronous belt or chain reduction to drive a ball screw to control the extension and retraction of the cylinder barrel. This structure is generally used under low-load conditions. Synchronous belts and chains have low load-bearing capacity, reduced transmission efficiency, and short lifespans, which limit the product's range of use. They are only suitable for low-end equipment with light loads, low control accuracy requirements, and short travel strokes. However, for high-load, long-stroke, and high-precision electric cylinders, a single motor-driven gear reduction, synchronous belt, or chain structure cannot meet the requirements, resulting in large structural dimensions and high costs.

[0003] Electric cylinders used in cranes typically handle heavy loads and long travels, placing stringent requirements on their mounting location and space. While traditional electric cylinders with a single motor driving a gear reduction mechanism can meet the load requirements, the drive motor and reduction mechanism are often too large to meet crane installation requirements. Furthermore, the specialized operating conditions of crane electric cylinders make it difficult for a single motor drive mechanism to achieve both speed and efficiency. Therefore, the drive mechanism for high-load electric cylinders used in cranes requires a redesigned design.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a multi-motor large-load electric cylinder for cranes, which can adopt a multi-motor drive mechanism to meet the requirements of large load and long stroke of the electric cylinder for cranes.

[0006] To achieve the above-mentioned purpose, the present invention is implemented by adopting the following technical solution: a multi-motor large-load electric cylinder for a crane, comprising multiple groups of drive components, a reduction gear housing and a cylinder barrel, wherein the cylinder barrel is connected to the side of the reduction gear housing, and multiple groups of the drive components are evenly arranged on the reduction gear housing around the cylinder barrel.

[0007] The drive assembly includes a drive motor, an input shaft and an intermediate shaft. The drive motor is connected to the input shaft. The input shaft is provided with an input shaft driving gear. The intermediate shaft is provided with an intermediate shaft primary driven gear and an intermediate shaft secondary driving gear. The intermediate shaft primary driven gear is meshed with the input shaft driving gear. An output shaft is provided in the middle of the reduction gear box housing. The output shaft extends into the cylinder and is connected to the lead screw. The output shaft is provided with an output shaft gear, which is meshed with the intermediate shaft secondary driving gear.

[0008] The lead screw is arranged in the rod barrel, and the rod barrel is sleeved in the cylinder barrel. One end of the lead screw is provided with a lead screw nut, and the other end extends to the outside of the cylinder barrel and is connected to the rod head. The lead screw nut is threadedly connected to the lead screw.

[0009] Optionally, the input shaft, intermediate shaft and output shaft are all connected to the reduction gearbox housing via bearings.

[0010] Optionally, the bearing includes a left bearing and a right bearing, and the input shaft, the intermediate shaft and the output shaft are all arranged inside the reduction gearbox housing and are respectively connected to both sides of the reduction gearbox housing through the left bearing and the right bearing.

[0011] Optionally, a base is connected to the opposite side of the reduction gearbox housing from which the cylinder is connected, the base and the cylinder are on the same axis, the base is used to be connected to the turntable of the crane, and the rod head is used to be connected to the boom of the crane.

[0012] Optionally, the lead screw nut is connected to the interior of the cylinder in a sliding fit.

[0013] Optionally, the end of the cylinder and the rod are connected in a sliding fit, so that the rod can be extended and retracted in the cylinder.

[0014] Optionally, a screw guide sleeve is further included, which is arranged at one end of the screw away from the screw nut and is slidably connected to the inner wall of the rod barrel. The screw guide sleeve is used to guide and limit the rod barrel when it is extended and retracted.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention is provided with multiple sets of drive assemblies, the number of which can be increased or decreased according to the load and power output requirements of the crane. The use of multiple sets of drive assemblies can reduce the volume of the motor and the reduction gearbox, facilitate installation and reduce costs.

[0017] The present invention can select the driving motor working mode according to the load conditions, so that the driving motor always works in a high-efficiency state, has a high load-bearing capacity and a long transmission stroke, and meets the requirements of the large-load electric cylinder required by the crane. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic structural diagram of a multi-motor, high-load electric cylinder for a crane using a dual-drive assembly in one embodiment of the present invention;

[0019] FIG2 is a schematic diagram of the installation structure of a multi-motor, high-load electric cylinder for a crane using a dual-drive assembly in one embodiment of the present invention;

[0020] FIG3 is a schematic structural diagram of a multi-motor, high-load electric cylinder for a crane using three drive assemblies in one embodiment of the present invention;

[0021] FIG4 is a schematic diagram of the installation structure of a multi-motor, high-load electric cylinder for a crane using three drive assemblies in one embodiment of the present invention;

[0022] FIG5 is a schematic structural diagram of a multi-motor, high-load electric cylinder for a crane using a four-drive assembly in one embodiment of the present invention;

[0023] FIG6 is a schematic diagram of the installation structure of a multi-motor, high-load electric cylinder for a crane using four drive assemblies in one embodiment of the present invention;

[0024] In the figure: 1 drive assembly, 2 drive motor, 3 input shaft, 4 intermediate shaft, 5 reduction gearbox housing, 6 input shaft driving gear, 7 intermediate shaft first-stage driven gear, 8 intermediate shaft second-stage driving gear, 9 output shaft, 10 output shaft gear, 11 bearing, 12 base, 13 lead screw, 14 lead screw nut, 15 cylinder, 16 rod barrel, 17 rod head, 18 lead screw guide sleeve, 19 upper arm, 20 turntable. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0027] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] Example 1:

[0029] As shown in Figure 1, an embodiment of the present invention provides a multi-motor, high-load electric cylinder for cranes. The cylinder comprises two drive assemblies and a reduction gearbox housing 5. A cylinder barrel 15 and a base 12 are connected to the reduction gearbox housing 5 on either side. The base 12 and cylinder barrel 15 are coaxial. The two drive assemblies are located on either side of the cylinder barrel 15 and connected to the reduction gearbox housing 5.

[0030] An output shaft 9 is located in the middle of the reduction gearbox housing 5 and extends into the cylinder 15 to connect to the lead screw 13. The drive assembly includes a drive motor 2, an input shaft 3, and an intermediate shaft 4. The input shaft 3, intermediate shaft 4, and output shaft 9 are all disposed within the reduction gearbox housing 5 and connected to the reduction gearbox housing 5 on both sides via a left bearing and a right bearing, respectively.

[0031] The driving motor 2 is connected to the input shaft 3, the input shaft 3 is provided with an input shaft driving gear 6, the intermediate shaft 4 is provided with an intermediate shaft first-level driven gear 7 and an intermediate shaft second-level driving gear 8, and the output shaft 9 is provided with an output shaft gear 10. The input shaft driving gear 6 is meshed with the intermediate shaft first-level driven gear 7, and the intermediate shaft second-level driving gear 8 is meshed with the output shaft gear 10.

[0032] A rod barrel 16 is sleeved within the cylinder barrel 15, and the lead screw 13 is disposed within the rod barrel 16. One end of the rod barrel 16 is connected to the lead screw nut 14, and the other end extends outside the cylinder barrel 15 and is connected to the rod head 17. The lead screw nut 14 is slidably engaged with the inner bore of the cylinder barrel 15 and is threadedly engaged with the lead screw 13. A lead screw guide sleeve 18 is also provided at the end of the lead screw 13 near the rod head 17. The lead screw guide sleeve 18 is slidably engaged with the inner bore of the rod barrel 16 and can serve as a guide and limiter when the rod barrel 16 is extended and retracted.

[0033] The screw 13 of this embodiment can be a planetary roller screw or a ball screw, and the input shaft driving gear 6, the intermediate shaft first-stage driving gear 7, the intermediate shaft second-stage driving gear 8 and the output shaft gear 10 can be parallel axis gears or planetary gears.

[0034] As shown in FIG2 , the electric cylinder using the dual-drive assembly is used as a crane luffing cylinder. During installation, the base 12 is connected to the pin hole on the turntable 20 of the crane via a fixing pin, and the rod head 17 is connected to the pin hole on the crane's boom 19 via a fixing pin.

[0035] The working principle of the electric cylinder of the dual drive assembly is as follows:

[0036] When the electric cylinder is in medium or heavy load conditions, the two drive motors 2 output power simultaneously.

[0037] Specifically, under medium and heavy load extension conditions: the two drive motors 2 rotate forward at the same time, and the power of the drive motors 2 passes through the input shaft 3, the input shaft driving gear 6, the intermediate shaft first-level driven gear 7, the intermediate shaft 4, the intermediate shaft second-level driving gear 8 and the output shaft gear 10 in sequence. At this point, the power of the two drive motors 2 is coupled at the output shaft gear 10 and transmitted to the screw 13 through the output shaft 9, thereby driving the screw nut 14 to move axially in the extension direction, driving the rod barrel 16 to extend out of the cylinder barrel 15 until it reaches the limit position of the screw guide sleeve 18.

[0038] Under medium and heavy load retraction conditions, the two drive motors 2 rotate in opposite directions at the same time. The power transmission of the drive motor 2 is the same as that under the extension condition. Both are coupled at the output shaft gear 10 and transmitted to the screw 13 through the output shaft 9, thereby driving the screw nut 14 to move axially in the retraction direction, driving the rod barrel 16 to retract into the cylinder barrel 15 until it reaches the limit position of the screw guide sleeve 18.

[0039] When the electric cylinder is in a light-load condition, one of the drive motors 2 is selected to output power, and the other does not work. Its extension and retraction conditions are the same as those in medium and heavy-load conditions.

[0040] Dual motor drive is selected under low-speed and medium-heavy load conditions, and single motor drive is selected under high-speed and light-load conditions. This can not only meet the load requirements but also ensure that the drive motor operates in a high-efficiency area.

[0041] Example 2:

[0042] As shown in FIG3 , based on Example 1, this embodiment is modified to provide three sets of drive components, and the added third set of drive components is provided above the cylinder.

[0043] 4 , an electric cylinder with three drive components is used as a luffing cylinder of a crane. During installation, the base 12 is connected to the pin hole on the turntable 20 of the crane through a fixing pin, and the rod head 17 is connected to the pin hole on the boom 19 of the crane through a fixing pin.

[0044] The working principle of the electric cylinder of the three-drive component is as follows:

[0045] When the electric cylinder is in a heavy-load condition, the three drive motors 2 output power simultaneously.

[0046] When the electric cylinder is in a light-load condition, the third drive motor 2 outputs power, while the other two drive motors 2 do not work.

[0047] Three motors are used for driving under heavy load conditions, single motor is used for driving under light load conditions, and dual motors are used for driving under medium load conditions, which can not only meet the load requirements but also ensure that the drive motor operates in a high efficiency area.

[0048] Example 3:

[0049] As shown in FIG5 , based on Example 2, this example is modified to provide four drive assemblies. The added fourth drive assembly is provided below the cylinder 15 , and its position is symmetrical to the third drive assembly.

[0050] 6 , an electric cylinder with three drive components is used as a luffing cylinder of a crane. During installation, the base 12 is connected to the pin hole on the turntable 20 of the crane through a fixing pin, and the rod head 17 is connected to the pin hole on the boom 19 of the crane through a fixing pin.

[0051] The working principle of the electric cylinder of the four-drive assembly is as follows:

[0052] When the electric cylinder is in a heavy-load condition, the four drive motors 2 output power simultaneously.

[0053] When the electric cylinder is in a light-load condition, two symmetrical drive motors 2 are selected to output power, and the other two drive motors 2 do not work.

[0054] When the electric cylinder is in a medium-load condition, any three drive motors 2 are selected to output power, and the other drive motor 2 does not work.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-motor large-load electric cylinder for a crane, characterized in that: It includes multiple sets of driving components, a reduction box housing and a cylinder barrel, wherein the cylinder barrel is connected to the side of the reduction box housing, and multiple sets of driving components are evenly arranged on the reduction box housing around the cylinder barrel; The driving assembly includes a driving motor, an input shaft and an intermediate shaft, wherein the driving motor is connected to the input shaft, an input shaft driving gear is arranged on the input shaft, a first-level intermediate shaft driven gear and a second-level intermediate shaft driving gear are arranged on the intermediate shaft, the first-level intermediate shaft driven gear is meshed with the input shaft driving gear, an output shaft is arranged in the middle of the reduction box housing, the output shaft extends into the cylinder barrel and is connected to the lead screw, and an output shaft gear is arranged on the output shaft, the output shaft gear is meshed with the second-level intermediate shaft driving gear; The lead screw is arranged in a rod barrel, and the rod barrel is sleeved in the cylinder barrel. A lead screw nut is arranged at one end of the lead screw, and the other end extends to the outside of the cylinder barrel and is connected to the rod head. The lead screw nut is threadedly connected to the lead screw.

2. The multi-motor large-load electric cylinder for crane according to claim 1, characterized in that: The input shaft, the intermediate shaft and the output shaft are all connected to the reduction box housing through bearings.

3. The multi-motor large-load electric cylinder for crane according to claim 2, characterized in that: The bearings include a left bearing and a right bearing. The input shaft, the intermediate shaft and the output shaft are all passed through the interior of the reduction gearbox housing and are connected to both sides of the reduction gearbox housing through the left bearing and the right bearing respectively.

4. The multi-motor large-load electric cylinder for crane according to claim 1, characterized in that: A base is connected to the opposite side of the reduction box housing where it is connected to the cylinder. The base and the cylinder are on the same axis. The base is used to be connected to the turntable of the crane, and the rod head is used to be connected to the boom of the crane.

5. The multi-motor large-load electric cylinder for crane according to claim 1, characterized in that: The lead screw nut is connected with the inside of the cylinder in a sliding fit.

6. The multi-motor large-load electric cylinder for crane according to claim 1, characterized in that: The end of the cylinder barrel and the rod barrel are connected in a sliding fit, so that the rod barrel can be extended and retracted in the cylinder barrel.

7. The multi-motor large-load electric cylinder for crane according to claim 1, characterized in that: It also includes a screw guide sleeve, which is arranged at one end of the screw away from the screw nut and is slidably connected to the inner wall of the rod barrel. The screw guide sleeve is used to guide and limit the rod barrel when it is extended and retracted.

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