Electric cylinder

Abstract

The present disclosure provides an electric cylinder, comprising: a motor and a reverse screw; the reverse screw comprises a nut structure and a screw rod structure, a first push rod and a second push rod are respectively connected to two sides of the screw rod structure and extend in opposite directions along the axial direction; the motor is sleeved on the outer periphery of the nut structure, the motor drives the nut structure to rotate, drives the screw rod structure to move along the axial direction, and in turn drives the first push rod and the second push rod to move along the axial direction. The electric cylinder provided by the embodiment of the present disclosure integrates two push rods extending in opposite directions, is driven by a set of motor and reverse screw, has compact structure, can realize accurate synchronization of the two push rods, does not need to add an additional control system, and is favorable for reducing the failure risk and saving the cost.

Description

Technical Field

[0001] This disclosure relates to the field of linear drive technology, and in particular to an electric cylinder. Background Technology

[0002] An electric cylinder is an electrically driven linear actuator that converts the rotational motion of a motor into the linear motion of a push rod through a lead screw assembly, thereby enabling the movement of a load.

[0003] In traditional structures, a single electric cylinder can only drive one push rod in linear motion. This single-degree-of-freedom output characteristic has significant limitations in applications requiring multi-axis synchronous control. Especially in operating conditions where two or more loads are required to maintain strict synchronous motion, the control accuracy requirements of the control system are high, and this also increases the risk of failure and costs. Utility Model Content

[0004] This disclosure provides an electric cylinder, including a motor and a reverse lead screw; the reverse lead screw includes a nut structure and a lead screw structure, a first push rod and a second push rod are respectively connected to both sides of the lead screw structure and extend in opposite directions along the axial direction; the motor is sleeved on the outer periphery of the nut structure, the motor drives the nut structure to rotate, drives the lead screw structure to move along the axial direction, and then drives the first push rod and the second push rod to move along the axial direction.

[0005] In some embodiments, the lead screw structure includes a first lead screw, a first push rod and a second push rod respectively connected to both ends of the first lead screw, and the first push rod and the second push rod move in the same axial direction under the drive of the first lead screw.

[0006] In some embodiments, the lead screw structure includes a second lead screw and a third lead screw, wherein a first push rod is connected to the end of the second lead screw opposite to the third lead screw, and the second push rod is connected to the end of the third lead screw opposite to the second lead screw; the first push rod moves axially under the drive of the second lead screw, and the second push rod moves axially under the drive of the third lead screw.

[0007] In some embodiments, the nut structure includes a first nut, the internal thread of the first nut including a first thread segment and a second thread segment with opposite helical directions; a second lead screw meshes with the first thread segment, and a third lead screw meshes with the second thread segment; the rotation of the first nut drives the second lead screw and the third lead screw to move in opposite axial directions, thereby driving the first push rod and the second push rod to move in opposite axial directions.

[0008] In some embodiments, the nut structure includes a second nut and a third nut, the second nut engaging with the second lead screw, and the third nut engaging with the third lead screw; the rotation of the second nut causes the second lead screw to move axially, thereby causing the first push rod to move axially; the rotation of the third nut causes the third lead screw to move axially, thereby causing the second push rod to move axially.

[0009] In some embodiments, at least one of the motors is sleeved on the outer periphery of the second nut and the third nut; the helical directions of the internal threads of the second nut and the third nut are opposite; at least one of the motors drives the second nut and the third nut to rotate in the same direction, thereby causing the first push rod and the second push rod to move axially in opposite directions.

[0010] In some embodiments, the second lead screw and the third lead screw have the same lead; or the second lead screw and the third lead screw have different leads.

[0011] In some embodiments, the second lead screw and the third lead screw have the same stroke; or the second lead screw and the third lead screw have different strokes.

[0012] In some embodiments, the electric cylinder further includes a lubrication circuit disposed in at least one of the first push rod, the second push rod, and the lead screw structure, for injecting grease into the interior of the reverse lead screw.

[0013] In some embodiments, the electric cylinder includes a housing, and the motor and the reverse lead screw are disposed inside the housing; the inner rings of two bearings are respectively sleeved on the outer periphery of both ends of the nut structure and are respectively located on both sides of the motor, and the outer rings of the bearings are fixed in the housing.

[0014] In some embodiments, the electric cylinder further includes a bearing retaining ring disposed on the side of the bearing opposite to the motor and sleeved on the outer periphery of the nut structure; a stepped structure is provided on the outer periphery of the nut structure, one side of the inner ring of the bearing abuts against the stepped structure, and the other side abuts against the bearing retaining ring.

[0015] In some embodiments, the housing further includes end caps disposed at both ends in the axial direction, the end caps being provided with guide rings, and the first push rod and the second push rod extending through the guide rings to the outside of the housing.

[0016] In some embodiments, the electric cylinder further includes an encoder that is sleeved around the outer periphery of the nut structure.

[0017] The electric cylinder provided in this embodiment integrates two push rods extending in opposite directions and is driven by a set of motors and a reverse lead screw. The electric cylinder has a compact structure and can achieve precise synchronization of the two push rods without the need for an additional control system, which helps to reduce the risk of failure and save costs. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of an electric cylinder according to an embodiment of this disclosure.

[0019] Figure 2 This is a perspective view of an electric cylinder according to an embodiment of the present disclosure.

[0020] Figure 3 This is a cross-sectional view of another electric cylinder in an embodiment of this disclosure.

[0021] Figure 4 This is a cross-sectional view of another electric cylinder in the embodiments of this disclosure.

[0022] Figure 5 This is a cross-sectional view of another electric cylinder in an embodiment of this disclosure.

[0023] Figure label:

[0024] 1. Motor; 11. First Motor; 12. Second Motor; 2. Reverse Lead Screw; 21. Nut Structure; 211. First Nut; 212. Second Nut; 213. Third Nut; 22. Lead Screw Structure; 221. First Lead Screw; 222. Second Lead Screw; 223. Third Lead Screw; 31. First Push Rod; 32. Second Push Rod; 4. Lubricating Oil Circuit; 41. Oil Inlet; 42. Oil Outlet; 5. Housing; 51. End Cap; 6. Bearing; 7. Bearing Retaining Ring; 8. Encoder. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions of this disclosure, the technical solutions of this disclosure will be described in detail below with reference to the accompanying drawings.

[0026] Exemplary embodiments will be described more fully below with reference to the accompanying drawings; however, these exemplary embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will enable those skilled in the art to fully understand the scope of this disclosure.

[0027] Where there is no conflict, the various embodiments of this disclosure and the features thereof in the embodiments may be combined with each other.

[0028] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0029] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded.

[0030] The embodiments described herein can be described with reference to plan views and / or cross-sectional views using the ideal schematic diagrams of this disclosure. Therefore, the example illustrations can be modified according to manufacturing techniques and / or tolerances. Therefore, the embodiments are not limited to those shown in the drawings, but include modifications to configurations formed based on manufacturing processes. Therefore, the areas illustrated in the drawings are schematic in nature, and the shapes of the areas shown in the figures illustrate specific shapes of areas of an element, but are not intended to be limiting.

[0031] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning, unless expressly so defined herein.

[0032] In traditional electric cylinder structures, it is impossible to achieve synchronous movement of two unconnected or even opposite objects with a single electric cylinder. Two electric cylinders must be used to drive the two objects separately. In order to control the two electric cylinders to move synchronously through electrical signals, the control precision requirements for the two electric cylinders are high. Usually, an additional control system is required, which makes the electric cylinder installation complex, increases the risk of failure, and increases the cost.

[0033] The present disclosure aims to provide a dual-pushrod electric cylinder capable of synchronously moving two or more objects.

[0034] Example 1

[0035] Figure 1 This is a cross-sectional view of an electric cylinder according to an embodiment of this disclosure. Figure 2 This is a perspective view of an electric cylinder according to an embodiment of the present disclosure.

[0036] like Figure 1 , Figure 2As shown, the electric cylinder includes a motor 1 and a reverse lead screw 2; the reverse lead screw 2 includes a nut structure 21 and a lead screw structure 22. In this embodiment, the reverse lead screw 2 refers to a lead screw that drives the lead screw structure 22 to move linearly through the rotation of the nut structure 21. The electric cylinder includes two push rods, a first push rod 31 and a second push rod 32, which are respectively connected to both sides of the lead screw structure 22 and extend in opposite directions along the axial direction.

[0037] In this embodiment, the reverse lead screw 2 can be a ball screw, a roller screw, or a sliding screw. This embodiment does not impose any special limitations on this type of screw.

[0038] like Figure 1 As shown, motor 1 is a frameless motor, and its rotor is sleeved on the outer periphery of nut structure 21. When the rotor of motor 1 rotates under the control of electrical signal, it drives nut structure 21 to rotate. Since nut structure 21 and lead screw structure 22 are engaged by threads or by ball / roller, the rotational motion of nut structure 21 is converted into linear motion of lead screw structure 22 along the axial direction, thereby driving the first push rod 31 and the second push rod 32 to move along the axial direction.

[0039] The electric cylinder provided in this embodiment integrates two push rods extending in opposite directions and is driven by a set of motors and a reverse lead screw. The electric cylinder has a compact structure and can achieve precise synchronization of the two push rods without the need for an additional control system, which helps to reduce the risk of failure and save costs.

[0040] In some embodiments, such as Figure 1 As shown, the lead screw structure 22 is a single lead screw, such as the first lead screw 221. The first push rod 31 and the second push rod 32 are respectively connected to the two ends of the lead screw structure. When the motor 1 rotates, it drives the nut structure 21 to rotate, causing the first lead screw 221 to move axially, which in turn causes the first push rod 31 and the second push rod 32 to move in the same axial direction. For example, under the drive of the motor 1, the first lead screw 221 moves axially towards... Figure 1 When the middle moves to the left, it causes the first push rod 31 to extend to the left, while the second push rod 32 retracts to the left; the first lead screw 221 moves axially towards... Figure 1 When the middle moves to the right, it causes the first push rod 31 to retract to the right, while the second push rod 32 extends to the right. This achieves precise synchronization between the first push rod 31 and the second push rod 32 without the need for an additional control system.

[0041] In some embodiments, such as Figure 3 As shown, the lead screw structure 22 consists of two lead screws, such as the second lead screw 222 and the third lead screw 223. The first push rod 31 is connected to the second lead screw 222. Figure 3 On the left side, the second push rod 32 is connected to the third lead screw 223. Figure 3On the right side of the image. Both the second lead screw 222 and the third lead screw 223 are engaged with the nut structure 21. When the nut structure 21 rotates under the drive of the motor 1, both the second lead screw 222 and the third lead screw 223 can move linearly along the axial direction, thereby causing the first push rod 31 to move axially under the drive of the second lead screw 222, and the second push rod 32 to move axially under the drive of the third lead screw 223.

[0042] In some embodiments, the second lead screw 222 and the third lead screw 223 move axially synchronously. For example, the second lead screw 222 and the third lead screw 223 move simultaneously and in the same direction under the rotational motion of the nut structure 21; or the second lead screw 222 and the third lead screw 223 move simultaneously and in opposite directions under the rotational motion of the nut structure 21. For example, the nut structure 21 is a single nut, and the internal thread of the single nut is a continuous thread structure with a single helical direction (left-hand or right-hand). The second lead screw 222 and the third lead screw 223 are both engaged with the single nut. When the single nut rotates under the drive of the motor 1, it drives the second lead screw 222 and the third lead screw 223 to move simultaneously and in the same direction. For example, the nut structure 21 is a single nut, such as the first nut 211. The internal thread of the first nut 211 is divided into two sections of thread structure with opposite helical directions (one section is left-handed and the other section is right-handed). The second lead screw 222 and the third lead screw 223 respectively mesh with the two sections of thread structure with opposite helical directions. When the first nut 211 rotates under the drive of the motor 1, it drives the second lead screw 222 and the third lead screw 223 to move simultaneously and in opposite directions.

[0043] In some embodiments, the second lead screw 222 and the third lead screw 223 can move axially synchronously or asynchronously. For example, the nut structure 21 can drive the second lead screw 222 or the third lead screw 223 to rotate and convert it into axial movement, thereby causing the second lead screw 222 and the third lead screw 223 to move simultaneously, or causing any one of the second lead screw 222 and the third lead screw 223 to move. Moreover, the directions of movement of the second lead screw 222 and the third lead screw 223 can be the same or different, which is beneficial to improving the flexibility of the dual-push-rod electric cylinder. For example, as Figure 3 As shown, the nut structure 21 consists of two nuts, such as a second nut 212 and a third nut 213. The second nut 212 meshes with the second lead screw 222, and the third nut 213 meshes with the third lead screw 223. The second nut 212 drives the second lead screw 222 to rotate and converts it into axial movement, and the third nut 213 drives the third lead screw 223 to rotate and convert it into axial movement, thereby causing the second lead screw 222 and the third lead screw 223 to move simultaneously, or causing any one of the second lead screw 222 and the third lead screw 223 to move. The second nut 212 and the third nut 213 can be driven by the same motor or by two separate motors; this embodiment does not impose any special limitations on this.

[0044] In some embodiments, the second lead screw 222 and the third lead screw 223 have the same lead.

[0045] In some embodiments, the lead of the second lead screw 222 is different from that of the third lead screw 223.

[0046] In some embodiments, the second lead screw 222 and the third lead screw 223 have the same stroke.

[0047] In some embodiments, the strokes of the second lead screw 222 and the third lead screw 223 are different.

[0048] In some embodiments, such as Figure 1 , Figure 3 As shown, the electric cylinder also includes a lubrication oil passage 4, which is disposed in at least one of the first push rod 31, the second push rod 32, and the lead screw structure 22, for injecting grease into the reverse lead screw 2 to lubricate the reverse lead screw 2.

[0049] For example, in such Figure 1 In the electric cylinder shown, the lead screw structure 22 includes a first lead screw 221. A lubrication oil passage 4 is provided in the second push rod 32 and the first lead screw 221. The lubrication oil passage 4 also includes an oil inlet 41 provided at the end of the second push rod 32 extending to the outside of the electric cylinder, and an oil outlet 42 provided on the first lead screw 221. This allows lubricating oil to be conveniently injected from outside the electric cylinder into the meshing part of the first lead screw 221 and the nut structure 21 to lubricate the reverse lead screw 2.

[0050] For example, in such Figure 5 In the electric cylinder shown, the nut structure 21 includes a second nut 212 and a third nut 213, and the lead screw structure 22 includes a second lead screw 222 and a third lead screw 223. Oil lubrication passages 4 are provided in the first push rod 31 and the second lead screw 222, as well as the second push rod 32 and the third push rod 223, so that lubricating oil can be easily injected from outside the electric cylinder into the meshing part of the second lead screw 222 and the second nut 212, and the meshing part of the third lead screw 223 and the third nut 213 for lubrication.

[0051] In this embodiment, the lubrication oil passage 4 is set inside the push rod and the lead screw, which can lubricate the reverse lead screw 2. There is no need to open a lubrication oil passage on the electric cylinder housing, which makes the axial clearance inside the electric cylinder smaller and the structure more compact.

[0052] In some embodiments, such as Figures 1 to 4As shown, the electric cylinder includes a housing 5, and the motor 1 and the reverse lead screw 2 are both located inside the housing 5. The nut structure 21 is located in the middle of the housing 5, and two bearings 6 are respectively located at both ends of the nut structure 21 and on both sides of the motor 1. The inner rings of the two bearings 6 are respectively sleeved on the outer circumference of both ends of the nut structure 21, and the outer rings of the two bearings 6 are fixed in the housing 5.

[0053] In this embodiment, the outer ring of the bearing 6 is fixed in the housing 5, meaning that the outer ring of the bearing 6 and the housing 5 do not move or rotate relative to each other. This embodiment does not specifically limit how the outer ring of the bearing 6 is fixed in the housing 5. In some embodiments, a stepped structure is provided on the inner wall of the housing 5, the outer ring of the bearing 6 is disposed in the stepped structure, and locked by a lock nut to achieve the purpose of fixation.

[0054] like Figure 1 , Figure 3 As shown, the electric cylinder also includes a bearing retaining ring 7 disposed on the side of the bearing 6 away from the motor 1 and sleeved on the outer periphery of the nut structure 21; a stepped structure is provided on the outer periphery of the nut structure 21, one side of the inner ring of the bearing 6 abuts against the stepped structure, and the other side abuts against the bearing retaining ring 7.

[0055] In this embodiment, placing two bearings 6 at both ends of the nut structure 21 helps to improve the stability of the support for the nut structure 21, while making the structure and weight distribution of the electric cylinder more balanced.

[0056] like Figure 1 , Figure 3 As shown, the housing 5 also includes end caps 51 at both ends in the axial direction. The end caps 51 are provided with guide rings, and the first push rod 31 and the second push rod 32 extend through the guide rings to the outside of the housing 5.

[0057] like Figure 1 , Figure 3 As shown, the electric cylinder also includes an encoder 8, which is sleeved on the outer periphery of the nut structure 21.

[0058] Example 2

[0059] Figure 1 This is a cross-sectional view of a dual-pushrod electric cylinder provided in an embodiment of this disclosure. Figure 1 As shown, the electric cylinder includes a motor 1 and a reverse lead screw 2. In Figure 1 In this embodiment, the reverse lead screw 2 is a planetary ball screw. However, the type of reverse lead screw 2 is not specifically limited in this embodiment; for example, the reverse lead screw 2 can also be a ball screw or a sliding lead screw, etc.

[0060] The reverse lead screw 2 includes a nut structure 21 and a first lead screw 221. A first push rod 31 and a second push rod 32 are respectively connected to the two ends of the first lead screw 221 and extend in opposite directions along the axial direction.

[0061] like Figure 1 As shown, motor 1 is a frameless motor, and its rotor is sleeved on the outer periphery of the nut. When the rotor of motor 1 rotates under the control of the electrical signal, it drives the nut structure 21 to rotate. The rotational motion of the nut structure 21 is converted into the linear motion of the first lead screw 221 along the axial direction, which in turn drives the first push rod 31 and the second push rod 32 to move along the axial direction.

[0062] For example, motor 1 drives nut structure 21 to rotate, and first lead screw 221 moves axially towards... Figure 1 When the middle moves to the left, it causes the first push rod 31 to extend to the left, while the second push rod 32 retracts to the left; the first lead screw 221 moves axially towards... Figure 1 When the middle moves to the right, it causes the first push rod 31 to retract to the right, while the second push rod 32 extends to the right. This achieves precise synchronization between the first push rod 31 and the second push rod 32 without the need for an additional control system.

[0063] like Figure 1 As shown, the electric cylinder also includes a lubrication oil passage 4, which is disposed in the second push rod 32 and the first lead screw 221. The lubrication oil passage 4 also includes an oil inlet 41 disposed at the end of the second push rod 32 extending to the outside of the electric cylinder, and an oil outlet 42 disposed on the first lead screw 221, so that lubricating oil can be conveniently injected from the outside of the electric cylinder into the meshing part of the first lead screw 221 and the nut 21 to lubricate the reverse lead screw 2.

[0064] like Figure 1 The electric cylinder includes a housing 5, and a motor 1 and a reverse lead screw 2 are both located inside the housing 5. A nut structure 21 is located in the middle of the housing 5, and two bearings 6 are respectively located at both ends of the nut structure 21 and on both sides of the motor 1. The inner rings of the two bearings 6 are respectively sleeved on the outer circumference of both ends of the nut structure 21, and the outer rings of the two bearings 6 are fixed in the housing 5.

[0065] In this embodiment, the outer ring of the bearing 6 is fixed in the housing 5, meaning that the outer ring of the bearing 6 and the housing 5 do not move or rotate relative to each other. This embodiment does not specifically limit how the outer ring of the bearing 6 is fixed in the housing 5. In some embodiments, a stepped structure is provided on the inner wall of the housing 5, the outer ring of the bearing 6 is disposed in the stepped structure, and locked by a lock nut to achieve the purpose of fixation.

[0066] like Figure 1As shown, the electric cylinder also includes a bearing retaining ring 7 disposed on the side of the bearing 6 away from the motor 1 and sleeved on the outer periphery of the nut 21; a stepped structure is provided on the outer periphery of the nut structure 21, one side of the inner ring of the bearing 6 abuts against the stepped structure, and the other side abuts against the bearing retaining ring 7.

[0067] like Figure 1 As shown, the housing 5 also includes end caps 51 at both ends in the axial direction. The end caps 51 are provided with guide rings, and the first push rod 31 and the second push rod 32 extend through the guide rings to the outside of the housing 5.

[0068] like Figure 1 As shown, the electric cylinder also includes an encoder 8, which is sleeved on the outer periphery of the nut 21.

[0069] Example 3

[0070] Figure 3 This is a cross-sectional view of another dual-pushrod electric cylinder provided in this embodiment of the present disclosure. Figure 4 This is a cross-sectional view of another dual-pushrod electric cylinder provided in this disclosure embodiment. (See image below.) Figure 3 , Figure 4 As shown, the electric cylinder includes a motor 1 and a reverse lead screw 2. In Figure 3 In this embodiment, the reverse lead screw 2 is a planetary ball screw. However, the type of reverse lead screw 2 is not specifically limited in this embodiment; for example, the reverse lead screw 2 can also be a ball screw or a sliding lead screw, etc.

[0071] The reverse lead screw 2 includes a first nut 211, a second lead screw 222, and a third lead screw 223. A first push rod 31 is connected to the second lead screw 222. Figure 3 On the left side, the second push rod 32 is connected to the third lead screw 223. Figure 3 On the right side of the image. The internal thread of the first nut 211 includes a first thread segment and a second thread segment, with the helical directions of the first thread segment and the second thread segment being opposite. The second lead screw 222 engages with the first thread segment, and the third lead screw 223 engages with the second thread segment.

[0072] like Figure 3 As shown, motor 1 is a frameless motor, and its rotor is sleeved on the outer circumference of the first nut 211. When the rotor of motor 1 rotates under the control of the electrical signal, it drives the first nut 211 to rotate. The rotational motion of the first nut 211 is converted into linear motion of the second lead screw 222 and the third lead screw 223 in opposite axial directions, which in turn drives the first push rod 31 and the second push rod 32 to move in opposite axial directions.

[0073] For example, motor 1 drives the first nut 211 to rotate, and the second lead screw 222 moves axially towards... Figure 3When the screw moves to the left, it causes the first push rod 31 to extend to the left. Simultaneously, because the first and second threaded sections have opposite helical directions, the third lead screw 223 moves axially towards... Figure 3 The movement to the right side causes the second push rod 32 to extend to the right; the second lead screw 222 moves axially towards... Figure 3 When the screw moves to the right, it causes the first push rod 31 to retract to the right. Simultaneously, because the helical directions of the first and second threaded sections are opposite, the third lead screw 223 moves axially towards... Figure 3 When the first push rod 31 moves to the left, the second push rod 32 retracts to the left, achieving precise synchronization between the first push rod 31 and the second push rod 32 without the need for an additional control system.

[0074] like Figure 3 As shown, the electric cylinder also includes a lubrication oil passage 4. The first push rod 31 and the second lead screw 222, as well as the second push rod 32 and the third lead screw 223, are all provided with oil lubrication oil passages 4, which can conveniently inject lubricating oil from outside the electric cylinder into the meshing part of the second lead screw 222 and the second nut 212, and the meshing part of the third lead screw 223 and the third nut 213 for lubrication.

[0075] like Figure 3 The electric cylinder includes a housing 5, and a motor 1 and a reverse lead screw 2 are both located inside the housing 5. A first nut 211 is located in the middle of the housing 5, and two bearings 6 are respectively located at both ends of the first nut 211 and on both sides of the motor 1. The inner rings of the two bearings 6 are respectively sleeved on the outer circumference of both ends of the first nut 211, and the outer rings of the two bearings 6 are fixed in the housing 5.

[0076] In this embodiment, the outer ring of the bearing 6 is fixed in the housing 5, meaning that the outer ring of the bearing 6 and the housing 5 do not move or rotate relative to each other. This embodiment does not specifically limit how the outer ring of the bearing 6 is fixed in the housing 5. In some embodiments, a stepped structure is provided on the inner wall of the housing 5, the outer ring of the bearing 6 is disposed in the stepped structure, and locked by a lock nut to achieve the purpose of fixation.

[0077] like Figure 3 As shown, the electric cylinder also includes a bearing retaining ring 7 disposed on the side of the bearing 6 away from the motor 1 and sleeved on the outer periphery of the first nut 211; a stepped structure is provided on the outer periphery of the first nut 211, one side of the inner ring of the bearing 6 abuts against the stepped structure, and the other side abuts against the bearing retaining ring 7.

[0078] like Figure 3 As shown, the housing 5 also includes end caps 51 at both ends in the axial direction. The end caps 51 are provided with guide rings, and the first push rod 31 and the second push rod 32 extend through the guide rings to the outside of the housing 5.

[0079] like Figure 3As shown, the electric cylinder also includes an encoder 8, which is sleeved on the outer periphery of the first nut 211.

[0080] Example 4

[0081] This embodiment provides a double-push rod electric cylinder, which differs from the double-push rod electric cylinder provided in Embodiment 3 in that the internal thread of the first nut 211 is a single helical direction (left-hand or right-hand) and a continuous thread structure. The second lead screw 222 and the third lead screw 223 mesh with the first nut 211. When the rotor of the motor 1 rotates under the control of the electrical signal, it drives the first nut 211 to rotate. The rotational motion of the first nut 211 is converted into linear motion of the second lead screw 222 and the third lead screw 223 in the same axial direction, thereby driving the first push rod 31 and the second push rod 32 to move in the same axial direction.

[0082] Example 5

[0083] The electric cylinder includes a motor 1 and a reverse lead screw 2. The reverse lead screw 2 is a planetary ball screw. However, in the embodiments disclosed herein, the type of the reverse lead screw 2 is not specifically limited; for example, the reverse lead screw 2 can also be a ball screw or a sliding lead screw, etc.

[0084] The reverse lead screw 2 includes a second nut 212, a third nut 213, a second lead screw 222, and a third lead screw 223. A first push rod 31 is connected to the left side of the second lead screw 222, and a second push rod 32 is connected to the right side of the third lead screw 223. The internal threads of the second nut 212 and the third nut 213 have opposite helical directions. The second lead screw 222 meshes with the second nut 212, and the third lead screw 223 meshes with the third nut 213.

[0085] Motor 1 is a frameless motor, and its rotor is sleeved on the outer circumference of the second nut 212 and the third nut 213. When the rotor of motor 1 rotates under the control of an electrical signal, it drives the second nut 212 and the third nut 213 to rotate in the same direction. The rotational motion of the second nut 212 is converted into the linear motion of the second lead screw 222 along the axial direction, and the rotational motion of the third nut 213 is converted into the linear motion of the third lead screw 223 along the axial direction. Since the helical directions of the internal threads of the second nut 212 and the third nut 213 are opposite, when the second nut 212 and the third nut 213 rotate in the same direction, the second lead screw 222 and the third lead screw 223 move in opposite directions along the axial direction, thereby driving the first push rod 31 and the second push rod 32 to move in opposite directions.

[0086] For example, when motor 1 drives the second nut 212 and the third nut 213 to rotate in the same direction, and the second lead screw 222 moves axially to the left, it drives the first push rod 31 to extend to the left. Simultaneously, because the internal threads of the second nut 212 and the third nut 213 have opposite helical directions, the third lead screw 223 moves axially to the right, driving the second push rod 32 to extend to the right; the second lead screw 222 moves axially to the right... Figure 3 When the middle moves to the right, it drives the first push rod 31 to retract to the right. At the same time, since the internal threads of the second nut 212 and the third nut 213 have opposite helical directions, the third lead screw 223 moves axially to the left, and the second push rod 32 retracts to the left. Precise synchronization of the first push rod 31 and the second push rod 32 is achieved without the need for an additional control system.

[0087] The electric cylinder also includes a lubrication oil passage 4. The first push rod 31 and the second lead screw 222, as well as the second push rod 32 and the third lead screw 223, are all provided with oil lubrication oil passages 4, which can conveniently inject lubricating oil from outside the electric cylinder into the meshing part of the second lead screw 222 and the second nut 212, and the meshing part of the third lead screw 223 and the third nut 213 for lubrication.

[0088] The electric cylinder includes a housing 5, and a motor 1 and a reverse lead screw 2 are both located inside the housing 5. A second nut 212 and a third nut 213 are located in the middle of the housing 5. Two bearings 6 are respectively located at the two ends of the second nut 212 and the third nut 213 that are far apart from each other, on both sides of the motor 1. The inner rings of the two bearings 6 are respectively sleeved on the outer circumference of the second nut 212 and the third nut 213, and the outer rings of the two bearings 6 are fixed in the housing 5.

[0089] In this embodiment, the outer ring of the bearing 6 is fixed in the housing 5, meaning that the outer ring of the bearing 6 and the housing 5 do not move or rotate relative to each other. This embodiment does not specifically limit how the outer ring of the bearing 6 is fixed in the housing 5. In some embodiments, a stepped structure is provided on the inner wall of the housing 5, the outer ring of the bearing 6 is disposed in the stepped structure, and locked by a lock nut to achieve the purpose of fixation.

[0090] The electric cylinder also includes a bearing retaining ring 7 disposed on the side of the bearing 6 away from the motor 1 and fitted around the outer periphery of the first nut 211; the outer periphery of the second nut 212 and the third nut 213 is provided with a stepped structure, one side of the inner ring of the bearing 6 abuts against the stepped structure, and the other side abuts against the bearing retaining ring 7.

[0091] The housing 5 also includes end caps 51 at both ends in the axial direction. The end caps 51 are provided with guide rings, and the first push rod 31 and the second push rod 32 extend through the guide rings to the outside of the housing 5.

[0092] Example 6

[0093] This embodiment provides a double push rod electric cylinder, which differs from the double push rod electric cylinder provided in embodiment 5 in that the internal threads of the second nut 212 and the third nut 213 have the same helical direction. When the rotor of the motor 1 rotates under the control of the electrical signal, it drives the second nut 212 and the third nut 213 to rotate in the same direction. The rotational motion of the second nut 212 and the third nut 213 is converted into the linear motion of the second lead screw 222 and the third lead screw 223 in the same axial direction, thereby driving the first push rod 31 and the second push rod 32 to move in the same axial direction.

[0094] Example 7

[0095] Figure 5 This is a cross-sectional view of another dual-pushrod electric cylinder provided in this disclosure embodiment. (See image below.) Figure 5 As shown, the electric cylinder includes a first motor 11, a second motor 12, and a reverse lead screw 2. Figure 5 In this embodiment, the reverse lead screw 2 is a planetary ball screw. However, the type of reverse lead screw 2 is not specifically limited in this embodiment; for example, the reverse lead screw 2 can also be a ball screw or a sliding lead screw, etc.

[0096] The reverse lead screw 2 includes a second nut 212, a third nut 213, a second lead screw 222, and a third lead screw 223. A first push rod 31 is connected to the second lead screw 222. Figure 5 On the left side, the second push rod 32 is connected to the third lead screw 223. Figure 5 On the right side of the middle. The internal threads of the second nut 212 and the third nut 213 have opposite helical directions. The second lead screw 222 meshes with the second nut 212, and the third lead screw 223 meshes with the third nut 213.

[0097] like Figure 5 As shown, the first motor 11 and the second motor 12 are frameless motors. The rotor of the first motor 11 is sleeved on the outer periphery of the second nut 212, and the rotor of the second motor 12 is sleeved on the outer periphery of the third nut 213. When the rotors of the first motor 11 and the second motor 12 rotate under the control of the electrical signal, they drive the second nut 212 and the third nut 213 to rotate respectively. The rotational motion of the second nut 212 is converted into the linear motion of the second lead screw 222 along the axial direction, and the rotational motion of the third nut 213 is converted into the linear motion of the third lead screw 223 along the axial direction, thereby driving the first push rod 31 and the second push rod 32 to move along the axial direction respectively.

[0098] In this embodiment, the first motor 11 and the second motor 12 can be started synchronously to drive the second nut 212 and the third nut 213 to rotate in the same or opposite directions, thereby driving the second lead screw 222 and the third lead screw 223 to move in the same or opposite directions along the axial direction, and in turn driving the first push rod 31 and the second push rod 32 to move in the same or opposite directions along the axial direction.

[0099] In this embodiment, the first motor 11 and the second motor 12 can also start asynchronously. For example, the first motor 11 starts, driving the second nut 212 to rotate, causing the second lead screw 222 to move axially, thereby causing the first push rod 31 to extend or retract; or the second motor 12 starts, driving the third nut 213 to rotate, causing the third lead screw 223 to move axially, thereby causing the second push rod 32 to extend or retract; or both the first motor 11 and the second motor 12 start, but the rotation speeds of the first motor 11 and the second motor 12 are different, so that the first push rod 31 and the second push rod 32 extend or retract at different rates.

[0100] like Figure 5 As shown, the electric cylinder also includes a lubrication oil passage 4. The first push rod 31 and the second lead screw 222, as well as the second push rod 32 and the third lead screw 223, are all provided with oil lubrication oil passages 4, which can conveniently inject lubricating oil from outside the electric cylinder into the meshing part of the second lead screw 222 and the second nut 212, and the meshing part of the third lead screw 223 and the third nut 213 for lubrication.

[0101] like Figure 5 The electric cylinder includes a housing 5, and a first motor 11, a second motor 12, and a reverse lead screw 2 are all disposed inside the housing 5. A second nut 212 and a third nut 213 are disposed in the middle of the housing 5. Two bearings 6 are respectively disposed at the two ends of the second nut 212 and the third nut 213 that are far apart from each other, located on both sides of the first motor 11 and the second motor 12. The inner rings of the two bearings 6 are respectively sleeved on the outer circumferences of the second nut 212 and the third nut 213, and the outer rings of the two bearings 6 are fixed in the housing 5.

[0102] In this embodiment, the outer ring of the bearing 6 is fixed in the housing 5, meaning that the outer ring of the bearing 6 and the housing 5 do not move or rotate relative to each other. This embodiment does not specifically limit how the outer ring of the bearing 6 is fixed in the housing 5. In some embodiments, a stepped structure is provided on the inner wall of the housing 5, the outer ring of the bearing 6 is disposed in the stepped structure, and locked by a lock nut to achieve the purpose of fixation.

[0103] like Figure 5 As shown, the electric cylinder also includes a bearing retaining ring 7 disposed on the side of the bearing 6 away from the first motor 11 and the second motor 12 and sleeved on the outer periphery of the first nut 211; the outer periphery of the second nut 212 and the third nut 213 is provided with a stepped structure, one side of the inner ring of the bearing 6 abuts against the stepped structure, and the other side abuts against the bearing retaining ring 7.

[0104] like Figure 5As shown, the housing 5 also includes end caps 51 at both ends in the axial direction. The end caps 51 are provided with guide rings, and the first push rod 31 and the second push rod 32 extend through the guide rings to the outside of the housing 5.

[0105] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in connection with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of this disclosure as set forth by the appended claims.

Claims

1. An electric cylinder, characterized in that, include: Motor (1) and reverse lead screw (2); The reverse lead screw (2) includes a nut structure (21) and a lead screw structure (22). The first push rod (31) and the second push rod (32) are respectively connected to the two sides of the lead screw structure (22) and extend in opposite directions along the axial direction. The motor (1) is sleeved on the outer periphery of the nut structure (21). The motor (1) drives the nut structure (21) to rotate, which in turn drives the lead screw structure (22) to move axially, thereby driving the first push rod (31) and the second push rod (32) to move axially.

2. The electric cylinder according to claim 1, characterized in that, The lead screw structure (22) includes a first lead screw (221), a first push rod (31) and a second push rod (32) respectively connected to the two ends of the first lead screw (221), and the first push rod (31) and the second push rod (32) move in the same direction along the axial direction under the drive of the first lead screw (221).

3. The electric cylinder according to claim 1, characterized in that, The lead screw structure (22) includes a second lead screw (222) and a third lead screw (223). The first push rod (31) is connected to the end of the second lead screw (222) away from the third lead screw (223), and the second push rod (32) is connected to the end of the third lead screw (223) away from the second lead screw (222). The first push rod (31) moves axially under the drive of the second lead screw (222), and the second push rod (32) moves axially under the drive of the third lead screw (223).

4. The electric cylinder according to claim 3, characterized in that, The nut structure (21) includes a first nut (211), and the internal thread of the first nut (211) includes a first thread segment and a second thread segment with opposite helical directions; The second lead screw (222) engages with the first threaded section, and the third lead screw (223) engages with the second threaded section; the first nut (211) rotates to drive the second lead screw (222) and the third lead screw (223) to move in opposite directions along the axial direction, thereby driving the first push rod (31) and the second push rod (32) to move in opposite directions along the axial direction.

5. The electric cylinder according to claim 3, characterized in that, The nut structure (21) includes a second nut (212) and a third nut (213), wherein the second nut (212) engages with the second lead screw (222), and the third nut (213) engages with the third lead screw (223); The rotation of the second nut (212) causes the second lead screw (222) to move axially, which in turn causes the first push rod (31) to move axially. The rotation of the third nut (213) causes the third lead screw (223) to move axially, which in turn causes the second push rod (32) to move axially.

6. The electric cylinder according to claim 5, characterized in that, At least one of the motors (1) is sleeved on the outer periphery of the second nut (212) and the third nut (213); the helical directions of the internal threads of the second nut (212) and the third nut (213) are opposite; At least one of the motors (1) drives the second nut (212) and the third nut (213) to rotate in the same direction, thereby causing the first push rod (31) and the second push rod (32) to move in opposite directions along the axial direction.

7. The electric cylinder according to any one of claims 3 to 6, characterized in that, The second lead screw (222) has the same lead as the third lead screw (223); or The second lead screw (222) has a different lead than the third lead screw (223).

8. The electric cylinder according to any one of claims 3 to 6, characterized in that, The second lead screw (222) has the same stroke as the third lead screw (223); or The strokes of the second lead screw (222) and the third lead screw (223) are different.

9. The electric cylinder according to any one of claims 1 to 6, characterized in that, The electric cylinder also includes a lubrication oil passage (4), which is disposed in at least one of the first push rod (31), the second push rod (32), and the lead screw structure (22) for injecting grease into the inside of the reverse lead screw (2).

10. The electric cylinder according to any one of claims 1 to 6, characterized in that, The electric cylinder includes a housing (5), the motor (1) and the reverse lead screw (2) are disposed inside the housing (5); the inner rings of the two bearings (6) are respectively sleeved on the outer periphery of both ends of the nut structure (21) and are respectively located on both sides of the motor (1), and the outer rings of the bearings (6) are fixed in the housing (5).

11. The electric cylinder according to claim 10, characterized in that, The electric cylinder also includes a bearing retainer ring (7) disposed on the side of the bearing (6) away from the motor (1) and sleeved on the outer periphery of the nut structure (21); a stepped structure is provided on the outer periphery of the nut structure (21), one side of the inner ring of the bearing (6) abuts against the stepped structure, and the other side abuts against the bearing retainer ring (7).

12. The electric cylinder according to claim 10, characterized in that, The housing (5) also includes end caps (51) provided at both ends in the axial direction. The end caps (51) are provided with guide rings. The first push rod (31) and the second push rod (32) extend through the guide rings to the outside of the housing (5).

13. The electric cylinder according to claim 10, characterized in that, The electric cylinder also includes an encoder (8), which is sleeved on the outer periphery of the nut structure (21).

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