CN114198468A - Free push rod multi-stage electric cylinder and design method - Google Patents
Free push rod multi-stage electric cylinder and design method Download PDFInfo
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- CN114198468A CN114198468A CN202210145623.2A CN202210145623A CN114198468A CN 114198468 A CN114198468 A CN 114198468A CN 202210145623 A CN202210145623 A CN 202210145623A CN 114198468 A CN114198468 A CN 114198468A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
- F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
- F16H25/20—Screw mechanisms
- F16H25/2056—Telescopic screws with at least three screw members in coaxial arrangement
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
- F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
- F16H25/20—Screw mechanisms
- F16H25/2015—Means specially adapted for stopping actuators in the end position; Position sensing means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
- F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
- F16H25/20—Screw mechanisms
- F16H25/24—Elements essential to such mechanisms, e.g. screws, nuts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
- F16H37/12—Gearings comprising primarily toothed or friction gearing, links or levers, and cams, or members of at least two of these types
- F16H37/124—Gearings comprising primarily toothed or friction gearing, links or levers, and cams, or members of at least two of these types for interconverting rotary motion and reciprocating motion
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/06—Means for converting reciprocating motion into rotary motion or vice versa
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
- F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
- F16H25/20—Screw mechanisms
- F16H2025/2031—Actuator casings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
- F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
- F16H25/20—Screw mechanisms
- F16H2025/2037—Actuator supports or means for fixing piston end, e.g. flanges
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
- F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
- F16H25/20—Screw mechanisms
- F16H2025/204—Axial sliding means, i.e. for rotary support and axial guiding of nut or screw shaft
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
- F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
- F16H25/20—Screw mechanisms
- F16H2025/2062—Arrangements for driving the actuator
- F16H2025/2081—Parallel arrangement of drive motor to screw axis
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Abstract
The invention discloses a free push rod multistage electric cylinder which comprises a motor, a speed reducer, a transmission case and an electric cylinder body, wherein the electric cylinder body comprises a bearing seat, a main bearing, a main lead screw, two or more stages of nut lead screws, a final stage of nut push rod, other stages of push rods except the final stage, a cylinder barrel, a guiding Z-shaped key, a guiding support, screw plugs, push rod glands and a top connecting hinge. Each level of push rods are in a free assembly relation, namely the push rods are not connected with the screw rod through flanges, and can move freely in the axial direction; the free push rod is designed to be free from axial external load force except for the last push rod, axial load is mainly concentrated on the lead screw nuts and the last push rod nut at each internal stage, stress is concentrated, and bearing performance is good; according to different load sizes and strokes, the design method of the free push rod multi-stage electric cylinder can meet the structural design requirements of two-stage to eight-stage electric cylinders.
Description
Technical Field
The invention belongs to the technical field of electric cylinders, and particularly relates to a free push rod multistage electric cylinder and a design method thereof.
Background
At present, servo electric cylinders are widely applied to various industries, and electric cylinders with various structural forms are developed. The working stroke of the single-stage or two-stage transmission electric cylinder is limited by the size of the cylinder body, so that the requirement of larger working stroke cannot be met. Two or more stages of electric cylinders designed by the traditional method are complex in internal structure and complicated in design, and are difficult to be widely applied.
Disclosure of Invention
The invention aims to provide a free push rod multi-stage electric cylinder and a design method.
The invention has the technical scheme that the free push rod multistage electric cylinder is characterized by comprising a motor, a speed reducer, a transmission case and an electric cylinder body, wherein the electric cylinder body comprises a bearing seat, a main bearing, a main lead screw, a second-stage or more nut lead screw, a last-stage nut push rod, other-stage push rods except for a last stage, a cylinder barrel, a guide Z-shaped key, a guide support, lead screw plugs of all stages, push rod glands of all stages and a top end connecting hinge; each level of push rods are in a free assembly relation, namely the push rods are not connected with the screw rod through flanges, and can move freely in the axial direction; a guiding Z-shaped key is arranged between each level of push rods and used for guiding and preventing rotation of axial movement; meanwhile, polytetrafluoroethylene annular guide supports are arranged among the push rods at all levels and are used for supporting the push rods to move axially, so that the coaxiality of the push rods in the moving process is ensured; the guide Z-shaped key and the annular guide support are respectively positioned at two ends of the push rod; the front ends of the push rods and the cylinder barrel at each stage are provided with push rod glands which are of a stepped structure and are provided with threaded holes, and the guide Z-shaped keys are arranged in the grooves in the push rod glands and are tightly pressed through bolts; the second-stage and the above transmission screw rods are integrated nut screw rods, the nut parts of the second-stage and the above transmission screw rods and the upper-stage screw rods form a nut screw rod pair for transmission, and the screw rod parts and the lower-stage nut parts form a nut screw rod pair for transmission; the last-stage nut push rod is arranged between the screw rod and the push rod, and plays the dual functions of the nut and the push rod; after the motor is decelerated and torque-increased through the speed reducer, power is transmitted to the main lead screw through the transmission box, the main lead screw transmits torque to the second-stage nut lead screw and the nut lead screws above the second-stage nut lead screw step by step, and finally the torque reaches the final-stage nut push rod; under the combined action of nut and screw pair transmission and a guide Z-shaped key, the two-stage and above nut and screw in the electric cylinder sequentially move linearly and extend forwards or retract, the last-stage nut and push rod sequentially drives all stages of push rods to extend after moving linearly, and the reverse motion drives the push rods to retract.
Furthermore, the key groove matched with the guide Z-shaped key is an outer key groove, and the limit of the free push rod is realized through the guide Z-shaped key and the length of the key groove.
Furthermore, the end heads of all levels of lead screws are lead screw plugs with hemispherical end surface appearances, so that the uniformity and stability of pressure between all levels of lead screws during recovery are ensured, and the mechanical limiting effect is achieved.
A design method of a free push rod multistage electric cylinder is characterized in that firstly, the type and the size of each stage of nut-screw pair are selected and configured, the nut-screw pair is arranged in a mode that the higher the transmission stage number is, the smaller the nesting length is, so as to ensure the requirements of axial and radial bearing, and the size of an installation space is reduced; secondly, optimally designing the nesting length between the screw rods at all levels and the nesting length of the push rods at all levels; and finally, designing the total stroke in the design of the free push rod multi-stage electric cylinder.
Further, the total stroke in the design of the free push rod multistage electric cylinder is jointly determined by the effective movement length of each stage of lead screw and the effective movement length of each stage of push rod, and the axial bearing capacity is mainly born by the lead screw and the nut, so that the requirements are met:
the sum of the effective movement length of the main screw and the effective movement length of the nut screw above two levels is larger than the sum of the effective movement lengths of the push rods at all levels, so that the push rods at all levels are not subjected to axial loads except the stress of the push rod at the last level, the free design requirements of the push rods are met, and the extension state of the push rods is determined by the axial movement efficiency of all levels.
Further, the optimal design of the nesting length between the lead screws at all levels and the nesting length of the push rods at all levels meets the overall size planning principle on the basis of meeting the size of single-stage bearing:
the effective movement length of the main screw is more than or equal to that of the second-stage nut screw, the effective movement length of the second-stage nut screw is more than or equal to that of the third-stage nut screw, the effective movement length of the third-stage nut screw is more than or equal to that of the fourth-stage nut screw, and so on;
the effective movement length of the first-stage push rod is greater than or equal to that of the second-stage push rod, the effective movement length of the second-stage push rod is greater than or equal to that of the third-stage push rod, the effective movement length of the third-stage push rod is greater than or equal to that of the fourth-stage push rod, and so on;
the nesting length of the first-stage push rod is more than or equal to that of the second-stage push rod, the nesting length of the second-stage push rod is more than or equal to that of the third-stage push rod, the nesting length of the third-stage push rod is more than or equal to that of the fourth-stage push rod, and so on;
the main screw rod nesting length is more than or equal to the second-stage nut screw rod nesting length, the second-stage nut screw rod nesting length is more than or equal to the third-stage nut screw rod nesting length, the third-stage nut screw rod nesting length is more than or equal to the fourth-stage nut screw rod nesting length, and the rest is done in sequence.
Furthermore, the wall thickness design of the free push rod needs to consider the dead weight and the radial load, and meanwhile, the push rods at all levels are provided with outer key grooves, and the guide Z-shaped keys arranged at the ends of the outer key grooves bear the torque, so that the wall thickness of the push rod needs to ensure the side stress areas of the guide Z-shaped keys and the key grooves.
Further, the free push rods are not subjected to axial external load force except for the final push rod, the axial load is concentrated on the lead screw nuts at each internal stage and the push rod of the final nut, and the stress is concentrated.
The present invention has the following advantageous effects
1. The invention has compact structure and is suitable for the large stroke requirement under the limitation of installation space;
2. the nut and lead screw integrated structure reduces the radial size and does not influence the bearing requirement;
3. each level of push rods is free and has no connecting flange, so that the axial space occupation is reduced;
4. the design of a guide Z-shaped key reduces the cost of the processing technology;
5. the hemispherical end surface lead screw plug ensures the uniformity and stability of pressure between lead screws at all levels during recovery;
6. the screw nut pair can be designed into a trapezoidal screw or a ball screw according to requirements, and is wide in application.
Drawings
FIG. 1 is a block diagram of a free push rod two-stage electric cylinder;
FIG. 2 is a sectional view of an integrated nut-screw structural model;
FIG. 3 is a cut-away view of a nut and pushrod configuration model;
FIG. 4 is a diagram of a model of a guided Z-key configuration;
FIG. 5 is a model view of a hemispherical end screw plug;
FIG. 6 is a model view of the profile structure of the push rod gland;
FIG. 7 is a free push rod four-stage electric cylinder structure;
FIG. 8 is a free push rod four-stage electric cylinder each stage nesting length planning diagram.
The reference numbers illustrate: motor 1, speed reducer 2, transmission case 3, electric cylinder body 4, bearing seat 4.1 for two-stage cylinder, main bearing 4.2 for two-stage cylinder, main screw 4.3 for two-stage cylinder, second nut screw 4.4 for two-stage cylinder, second nut push rod 4.5 for two-stage cylinder, first push rod 4.6 for two-stage cylinder, cylinder 4.7 for two-stage cylinder, guide Z-shaped key 4.8 for two-stage cylinder, guide support 4.9 for two-stage cylinder, screw plug 4.10 for two-stage cylinder, push rod cover 4.11 for two-stage cylinder, top connecting hinge 4.12 for two-stage cylinder, bearing seat 4.1 for two-stage cylinder, main screw 4.2 for two-stage cylinder, guide screw 4.8 for two-stage cylinder, guide support 4.9 for two-stage cylinder, screw plug 4.10 for two-stage cylinder, push rod cover 4.11 for two-stage cylinder, top connecting hinge 4.12 for two-stage cylinder, and screw rod for two-stage cylinder,
The four-stage cylinder main bearing assembly comprises a four-stage cylinder main bearing 5, a four-stage cylinder main screw 6, a four-stage cylinder secondary nut screw 7, a three-stage nut screw 8, a four-stage nut screw 9, a four-stage nut push rod 10, a four-stage cylinder primary push rod 11, a two-stage push rod 12, a three-stage push rod 13, a four-stage cylinder 14, a four-stage cylinder guide Z-shaped key 15, a four-stage cylinder push rod gland 16, a four-stage cylinder lead rod plug 17, a four-stage cylinder guide support 18, a four-stage cylinder top connecting hinge 19 and a four-stage cylinder bearing seat 20.
Detailed Description
As shown in fig. 1 and 7, the free push rod multistage electric cylinder provided by the embodiment of the invention comprises a motor 1, a speed reducer 2, a transmission case 3, an electric cylinder body 4, a four-stage cylinder main bearing 5, a four-stage cylinder main screw 6, a four-stage cylinder secondary nut screw 7, a three-stage nut screw 8, a four-stage nut screw 9, a four-stage nut push rod 10, a four-stage cylinder primary push rod 11, a two-stage push rod 12, a three-stage push rod 13, a four-stage cylinder 14, a four-stage cylinder guiding Z-shaped key 15, a four-stage cylinder push rod gland 16, a four-stage cylinder lead rod plug 17, a four-stage cylinder guiding support 18, a four-stage cylinder top connecting hinge 19 and a four-stage cylinder bearing seat 20.
The electric cylinder body 4 is a core structural component of the invention and mainly comprises a bearing seat 4.1 for a two-stage cylinder, a main bearing 4.2 for the two-stage cylinder, a main screw 4.3 for the two-stage cylinder, a second-stage nut screw 4.4 for the two-stage cylinder, a second-stage nut push rod 4.5 for the two-stage cylinder, a first-stage push rod 4.6 for the two-stage cylinder, a cylinder barrel 4.7 for the two-stage cylinder, a guiding Z-shaped key 4.8 for the two-stage cylinder, a guiding support 4.9 for the two-stage cylinder, a screw rod plug 4.10 for the two-stage cylinder, a push rod gland 4.11 for the two-stage cylinder and a top connecting hinge 4.12 for the two-stage cylinder.
The two-stage cylinder main bearing 4.2 is arranged in the two-stage cylinder bearing seat 4 and is arranged at one end of the two-stage cylinder main screw rod 4.3 to play a role in supporting and rotating; the main screw rod 4.3 for the two-stage cylinder rotates, the screw nut pair drives the screw rod 4.4 for the two-stage nut for the two-stage cylinder to rotate, and the push rod 4.5 for the two-stage nut for the two-stage cylinder is driven to move axially forwards or backwards; after the nut push rod moves in place, the two-stage cylinder is driven by a guide Z-shaped key 4.8 to continue to axially move by a one-stage push rod 4.6; the guide Z-shaped key 4.8 for the two-stage cylinder is fixed at the end part of the cylinder barrel 4.7 for the two-stage cylinder or the first-stage push rod 4.6 for the two-stage cylinder by a push rod gland 4.11 for the two-stage cylinder; the guide support 4.9 for the two-stage cylinder is sleeved at the front end of the screw rod and is tightly pressed on the screw rod through a screw rod plug 4.10 for the two-stage cylinder; the top end connecting hinge 4.12 for the two-stage cylinder is of a fish-ear-shaped structure, one end of the fish-ear-shaped structure is provided with a knuckle bearing which can be assembled according to requirements, and the other end of the fish-ear-shaped structure is provided with a flange spigot and threaded hole structure which can be fixed at the front section of the second-stage push rod through bolts.
Each level of push rods are in a free assembly relation, namely the push rods are not connected with the screw rod through flanges, and can move freely in the axial direction; a guiding Z-shaped key is arranged between each level of push rods and used for guiding and preventing rotation of axial movement; meanwhile, polytetrafluoroethylene annular guide supports are arranged among the push rods at all levels and are used for supporting the push rods to move axially, so that the coaxiality of the push rods in the moving process is ensured; the guide Z-shaped key and the annular guide support are respectively positioned at two ends of the push rod; as shown in fig. 4, the key groove matched with the guiding Z-shaped key is an external key groove, so that compared with an internal key groove process adopted by a common electric cylinder, the processing is easier, and the cost and the working hour are both greatly reduced; the limit of the free push rod is realized by the length of the guide Z-shaped key and the key groove thereof; the front ends of the push rods and the cylinder barrels are provided with push rod gland covers, as shown in figure 6, the push rod gland covers are of a step-shaped structure, threaded holes are formed in the push rod gland covers, the guide Z-shaped keys are arranged in inner grooves of the push rod gland covers, and the guide Z-shaped keys can be tightly pressed through bolts; as shown in fig. 2 and 3, the two-stage or above driving screws are integrated nut screws, the nut portion of the nut screw and the screw of the previous stage form a screw pair for driving, and the screw portion and the nut portion of the next stage form a screw pair for driving; the last-stage nut push rod is arranged between the screw rod and the push rod, and plays the dual functions of the nut and the push rod; as shown in fig. 5, the ends of the lead screws at all levels are lead screw plugs with hemispherical end surface shapes, so that the pressure between the lead screws at all levels is uniform and stable during recovery, and the lead screws at all levels have the function of mechanical limiting; under the combined action of nut and screw pair transmission and a guide Z-shaped key, the two-stage and above nut and screw in the electric cylinder sequentially move linearly and extend forwards or retract, the last-stage nut and push rod sequentially drives all stages of push rods to extend after moving linearly, and the reverse motion drives the push rods to retract.
After power is decelerated and torque-increased by a motor 1 through a speed reducer 2, the power is transmitted to a four-stage cylinder main screw 6 through a transmission case 3, the main screw gradually transmits torque to two-stage and above nut screws, and finally reaches a final-stage nut push rod, namely, the four-stage cylinder main screw 6 drives the four-stage cylinder two-stage nut screw 7 step by step, the three-stage nut screw 8, the four-stage nut screw 9 rotates, the motion conversion effect of the screw nut pair is achieved, all stages of nut screws and four-stage nut push rods 10 axially extend in sequence, and meanwhile, the four-stage nut push rod 10 sequentially drags all stages of push rods axially to extend through a push rod gland to complete the whole stroke.
A design method of a free push rod multi-stage electric cylinder mainly comprises a selection and size configuration method of lead screw nut pairs at each stage and a structure and length optimization method of push rods at each stage. The screw nut pair can be selected according to the load requirement, the nesting length between each stage is adjusted to ensure the requirement of axial and radial bearing, the higher the transmission stage number is, the smaller the nesting length is, and the size of the installation space is reduced; the optimal configuration of the nesting length of each level of push rods is realized by adjusting the axial size and the length of the key slot, so that the requirement of the structure is met and the coordination and unification of the appearance are achieved; the design of the free push rod ensures that other push rods except the final push rod are free from axial external load force, the axial load is mainly concentrated on the lead screw nuts at each internal stage and the push rod of the final nut, the stress is concentrated, and the bearing performance is good; the design of the push rod can reduce the wall thickness and the radial dimension on the premise of meeting the requirement of lateral bearing, thereby meeting the requirements of weight reduction and overall dimension reduction; according to different load sizes and strokes, the design method of the free push rod multi-stage electric cylinder can meet the structural design requirements of two-stage to eight-stage electric cylinders.
As shown in fig. 8, in the embodiment, the total installation length of the four-stage cylinder is H, the effective movement length of the main screw is H1, the effective movement length of the second-stage nut screw is H2, the effective movement length of the third-stage nut screw is H3, the effective movement length of the fourth-stage nut screw is H4, the effective movement length of the first-stage push rod is H1, the effective movement length of the second-stage push rod is H2, the effective movement length of the third-stage push rod is H3, the effective movement length of the fourth-stage nut push rod is H4, the first-stage push rod nesting length M1, the second-stage push rod nesting length M2, the third-stage push rod nesting length M3, the fourth-stage nut push rod nesting length M4, the main screw nesting length n1, the second-stage nut screw nesting length n2, the third-stage nut screw nesting length n3, and the fourth-stage nut screw nesting length n 4.
The total stroke in the design of the free type push rod multistage electric cylinder is jointly determined by the effective movement length of each stage of screw rod and the effective movement length of each stage of push rod, and is mainly born by the screw rod and the nut for ensuring the axial bearing capacity, so that the requirement is met:
h1+h2+h3+h4＞H1+H2+H3+H4
therefore, the push rods of all the stages are not subjected to axial load except the last-stage nut push rod, the free design requirement of the push rods is met, the extending state of the push rods is determined by the axial movement efficiency of all the stages, and the friction resistance is mainly overcome.
The multi-stage cylinder design not only meets the requirements of short installation distance and large stroke, but also needs to ensure structural rigidity and can bear certain radial load, so that the nesting length between lead screws at all stages and the nesting length of push rods at all stages need to be optimally designed. On the basis of meeting the size of single-stage bearing, the general size planning principle needs to meet the following requirements:
h1≥h2≥h3≥h4
H1≥H2≥H3≥H4
M1≥M2≥M3≥M4
n1≥n2≥n3≥n4
dead weight and radial load need be considered in the wall thickness design of free push rod, and the design has outer keyway on the push rod of at all levels simultaneously, and the direction Z shape key of its end installation also bears the moment of torsion, therefore the push rod wall thickness need guarantee to lead the side lifting surface of Z shape key and keyway.
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are intended to be covered by the scope of the present invention.
Claims (8)
1. A free push rod multistage electric cylinder is characterized by comprising a motor, a speed reducer, a transmission case and an electric cylinder body, wherein the electric cylinder body comprises a bearing seat, a main bearing, a main lead screw, two or more stages of transmission lead screws, a final-stage nut push rod, other stages of push rods except for the final stage, a cylinder barrel, a guide Z-shaped key, a guide support, screw plugs at all stages, push rod glands at all stages and a top connecting hinge;
each level of push rods are in a free assembly relation, and the push rods are not connected with the screw rod through flanges and can freely move in the axial direction; a guiding Z-shaped key is arranged between each level of push rods and used for guiding and preventing rotation of axial movement; meanwhile, polytetrafluoroethylene annular guide supports are arranged among the push rods at all levels and are used for supporting the push rods to move axially, so that the coaxiality of the push rods in the moving process is ensured; the guide Z-shaped key and the annular guide support are respectively positioned at two ends of the push rod; the front ends of the push rods and the cylinder barrel at each stage are provided with push rod glands which are of a stepped structure and are provided with threaded holes, and the guide Z-shaped keys are arranged in the grooves in the push rod glands and are tightly pressed through bolts; the second-stage and the above transmission screw rods are integrated nut screw rods, the nut parts of the second-stage and the above transmission screw rods and the upper-stage screw rods form a nut screw rod pair for transmission, and the screw rod parts and the lower-stage nut parts form a nut screw rod pair for transmission; the last-stage nut push rod is arranged between the screw rod and the push rod; after the motor is decelerated and torque-increased through the speed reducer, power is transmitted to the main lead screw through the transmission box, and torque is transmitted to the second-stage and above transmission lead screws step by step through the main lead screw and finally reaches the final-stage nut push rod; under the combined action of nut and screw pair transmission and guide Z-shaped key, the two-stage and above transmission screw in the electric cylinder sequentially linearly moves forwards or recovers, the last-stage nut push rod sequentially drives all stages of push rods to extend after linearly moving, and the reverse motion drives the push rods to recover.
2. The free push rod multistage electric cylinder as claimed in claim 1, wherein the key groove engaged with the guide Z-shaped key is an external key groove, and the limit of the free push rod is realized by the guide Z-shaped key and the length of the key groove.
3. The free push rod multistage electric cylinder as claimed in claim 1, wherein the ends of the lead screws at each stage are lead screw plugs with hemispherical end surface shapes, so that the pressure between the lead screws at each stage is uniform and stable during recovery, and mechanical limiting is realized.
4. A design method of a free push rod multistage electric cylinder is characterized in that firstly, the type and the size of each stage of nut-screw pair are selected and configured, the nut-screw pair is arranged in a mode that the higher the transmission stage number is, the smaller the nesting length is, so as to ensure the requirements of axial and radial bearing, and the size of an installation space is reduced; secondly, optimally designing the nesting length between the screw rods at all levels and the nesting length of the push rods at all levels; and finally, designing the total stroke in the design of the free push rod multi-stage electric cylinder.
5. The design method of the free push rod multi-stage electric cylinder as claimed in claim 4, wherein the total stroke in the design of the free push rod multi-stage electric cylinder is determined by the effective movement length of each stage of lead screw and the effective movement length of each stage of push rod, and in order to ensure that the axial bearing capacity is mainly born by the lead screw and the nut, the following requirements are met: the sum of the effective movement length of the main screw and the effective movement length of the nut screw above two levels is larger than the sum of the effective movement lengths of the push rods at all levels, so that the push rods at all levels are not subjected to axial loads except the stress of the push rod at the last level, the free design requirements of the push rods are met, and the extension state of the push rods is determined by the axial movement efficiency of all levels.
6. The design method of the free push rod multistage electric cylinder as claimed in claim 4, wherein the optimal design of the nesting length between the lead screws of each stage and the nesting length of the push rods of each stage is based on the size of single-stage bearing, and the overall size planning principle needs to be satisfied: the effective movement length of the main screw is more than or equal to that of the second-stage nut screw, the effective movement length of the second-stage nut screw is more than or equal to that of the third-stage nut screw, the effective movement length of the third-stage nut screw is more than or equal to that of the fourth-stage nut screw, and so on; the effective movement length of the first-stage push rod is greater than or equal to that of the second-stage push rod, the effective movement length of the second-stage push rod is greater than or equal to that of the third-stage push rod, the effective movement length of the third-stage push rod is greater than or equal to that of the fourth-stage push rod, and so on; the nesting length of the first-stage push rod is more than or equal to that of the second-stage push rod, the nesting length of the second-stage push rod is more than or equal to that of the third-stage push rod, the nesting length of the third-stage push rod is more than or equal to that of the fourth-stage push rod, and so on; the main screw rod nesting length is more than or equal to the second-stage nut screw rod nesting length, the second-stage nut screw rod nesting length is more than or equal to the third-stage nut screw rod nesting length, the third-stage nut screw rod nesting length is more than or equal to the fourth-stage nut screw rod nesting length, and the rest is done in sequence.
7. The design method of the free push rod multistage electric cylinder as claimed in claim 4, wherein the wall thickness design of the free push rod needs to consider self weight and radial load, and simultaneously, each push rod is provided with an external key slot, and a guide Z-shaped key arranged at the end of the external key slot is also used for bearing torque, so that the wall thickness of the push rod needs to ensure the side stress area of the guide Z-shaped key and the key slot.
8. The design method of the free push rod multistage electric cylinder as claimed in claim 4, wherein the free push rod is designed to be free from axial external load force except for the push rod of the final stage, and the axial load is concentrated on the lead screw nuts of the inner stages and the push rod of the final nut, and the stress is concentrated.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114436149A (en) * | 2022-04-11 | 2022-05-06 | 西安星通通信科技有限公司 | Automatic lifting system for antenna installation |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070137331A1 (en) * | 2005-10-27 | 2007-06-21 | Brose Schliesssysteme Gmbh & Co. Kg | Drive arrangement for motorized actuation of a functional element in a motor vehicle |
| JP2010133519A (en) * | 2008-12-05 | 2010-06-17 | Nsk Ltd | Actuator of multi-stage structure |
| CN102628500A (en) * | 2012-04-19 | 2012-08-08 | 西北工业大学 | Planet roller screw mechanism capable of eliminating axial gaps |
| CN205677854U (en) * | 2016-06-03 | 2016-11-09 | 天津科技大学 | A kind of adjoining spiral oar multistage reverse rotation device |
| CN111237416A (en) * | 2020-03-19 | 2020-06-05 | 常州市凯迪电器股份有限公司 | Intelligent lifting column transmission system assembly |
| CN111859715A (en) * | 2020-08-05 | 2020-10-30 | 西北工业大学 | Secondary planet roller screw optimization design method based on structural parameters |
| CN211901485U (en) * | 2020-03-13 | 2020-11-10 | 力姆泰克（廊坊）传动设备有限公司 | Self-lubricating light multi-section push rod |
-
2022
- 2022-02-17 CN CN202210145623.2A patent/CN114198468B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070137331A1 (en) * | 2005-10-27 | 2007-06-21 | Brose Schliesssysteme Gmbh & Co. Kg | Drive arrangement for motorized actuation of a functional element in a motor vehicle |
| JP2010133519A (en) * | 2008-12-05 | 2010-06-17 | Nsk Ltd | Actuator of multi-stage structure |
| CN102628500A (en) * | 2012-04-19 | 2012-08-08 | 西北工业大学 | Planet roller screw mechanism capable of eliminating axial gaps |
| CN205677854U (en) * | 2016-06-03 | 2016-11-09 | 天津科技大学 | A kind of adjoining spiral oar multistage reverse rotation device |
| CN211901485U (en) * | 2020-03-13 | 2020-11-10 | 力姆泰克（廊坊）传动设备有限公司 | Self-lubricating light multi-section push rod |
| CN111237416A (en) * | 2020-03-19 | 2020-06-05 | 常州市凯迪电器股份有限公司 | Intelligent lifting column transmission system assembly |
| CN111859715A (en) * | 2020-08-05 | 2020-10-30 | 西北工业大学 | Secondary planet roller screw optimization design method based on structural parameters |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114436149A (en) * | 2022-04-11 | 2022-05-06 | 西安星通通信科技有限公司 | Automatic lifting system for antenna installation |
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