Winding drum and spring device

Abstract

The invention provides a winding drum and a spring device, the winding drum comprises a body, and on the cross section perpendicular to the axis of the body, the outer contour of the body comprises a first contour line and a second contour line. The first contour line is configured as an Archimedes spiral. The first contour line is provided with a head end point and a tail end point which are spaced in the extending direction of the first contour line. The radius of the end point of the head end is smaller than that of the end point of the tail end. The second contour line is connected between the head end point and the tail end point so as to seal the first contour line. The part of the body corresponding to the second contour line is used for connecting the end of the spring belt. According to the spring belt, the local arching phenomenon cannot occur at the junction of the second winding ring and the first winding ring, and the curvature of the spring belt is more uniformly increased along with the rotation angle from the second winding ring, so that the rigidity of the spring belt can be controlled within a very small range, and the service life of the spring belt is prolonged. And the fluctuation of the pulling force of the spring belt is effectively reduced.

Description

Technical Field

[0001] The present application generally relates to the technical field of medical devices, and more particularly to a reel and spring device. Background Art

[0002] Constant force spring is a kind of spring with small volume, constant load and low friction loss, which is widely used in electronic products, medical equipment, instrumentation, aerospace and other fields. Constant force spring device is a special tension spring, which is formed by winding one or more layers of thin metal elastic sheets on a reel. The metal elastic sheet is in a dense coil shape in the free state. By pulling the outermost end to unfold the spring, a restoring force will be generated in the transition area between winding and unfolding to restore the winding.

[0003] As the metal elastic sheet is gradually pulled out from the reel, the radius of curvature at the position where the metal elastic sheet generates elastic force gradually decreases, and the tension is negatively correlated with the radius of curvature and gradually increases. Especially for multi-layer constant force springs, after the multi-layer metal elastic sheet is wound on the reel for the first circle, its winding radius will increase, and the increase will be at least the total thickness of the multi-layer metal elastic sheet. At the junction of the first circle and the second circle, local arching is prone to occur, resulting in fluctuations in the radius of curvature at the junction of each previous circle and the next circle. Since the tension is negatively correlated with the radius of curvature, the tension will also fluctuate accordingly. Summary of the invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description of the Invention section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0005] In order to at least partially solve the above problems, the first aspect of the present application provides a reel for winding a spring strip, the reel comprising a body, and in a cross section perpendicular to the axis of the body, the outer profile of the body comprises:

[0006] A first contour line, wherein the first contour line is configured as an Archimedean spiral line, the first contour line having a head end point and a tail end point spaced apart along its own extension direction, and a radius at the head end point is smaller than a radius at the tail end end point; and

[0007] a second contour line, the second contour line being connected between the first end point and the tail end point to close the first contour line,

[0008] The portion of the main body corresponding to the second contour line is used to connect the end of the spring band.

[0009] According to the reel of the first aspect of the present application, the outer contour of the reel includes a first contour line configured as an Archimedean spiral and a second contour line connected between the head end point and the tail end point of the Archimedean spiral. Wherein, the radius at the head end point of the Archimedean spiral is smaller than the radius at the tail end point, that is, the radius of curvature of the Archimedean spiral gradually increases. The part corresponding to the second contour line is used to connect the end of the spring band. Since there is a radius difference between the head end point and the tail end point of the Archimedean spiral, the radius difference between the head end point and the tail end point of the Archimedean spiral can be reasonably set according to the thickness of the spring band to be wound. When the reel of the present application is used to wind the spring band, the spring band can be prevented from having a local bulge at the junction of the second winding and the first winding, and since the second winding, the curvature of the spring band increases more evenly with the turning angle, thereby helping to control the rigidity of the spring band within a very small range, effectively reducing the fluctuation of the tension of the spring band.

[0010] Optionally, the number of turns of the Archimedean spiral is equal to one turn, and the second contour line at least partially overlaps with the straight line where the radius of the first end point is located.

[0011] Optionally, the number of turns of the Archimedean spiral is less than one turn.

[0012] Optionally, the tail end point of the Archimedean spiral is set to any point between a first point and a second point of a preset Archimedean spiral, and the tail end point does not overlap with the first point and the second point, the preset Archimedean spiral takes the head end point as a starting point and has a number of turns of not less than one, the number of turns of the preset Archimedean spiral between the first point and the head end point is equal to one, and the straight line between the second point and the head end point is perpendicular to the tangent of the head end point and the tangent of the second point.

[0013] Optionally, the straight line on which the head end endpoint and the tail end endpoint are located is perpendicular to the tangent direction of the head end endpoint and the tangent direction of the tail end endpoint.

[0014] Optionally, the reel also includes two limit baffles, which are relatively arranged at the two ends of the main body along the axial direction, and a groove is formed between the two limit baffles and the outer circumferential surface of the main body. Along the radial direction of the reel, the width of the groove gradually increases from the inside to the outside, and the groove is used to allow N layers of the spring strip to be wound in the groove after stacking, where N is a positive integer greater than or equal to 1.

[0015] Optionally, the main body and the limit baffle are constructed as an integrated structure.

[0016] Optionally, the body is provided with a center hole, the center hole extends along the axial direction of the body and penetrates the body, and the center line of the center hole coincides with the axis of the body and the center of a circle corresponding to the end point of the head end.

[0017] A second aspect of the present application provides a spring device, the spring device comprising:

[0018] A reel according to above; and

[0019] A constant force spring, comprising N layers of spring strips, which are stacked in a thickness direction and wound on the drum, wherein N is a positive integer greater than or equal to 1, and wherein at least one of the width, thickness and natural curvature of at least one layer of the spring strip gradually decreases from the outer circle to the inner circle along the length of the spring strip.

[0020] According to the spring device of the second aspect of the present application, by using the above-mentioned reel to adapt to the winding spring strip, when N layers of spring strips are stacked in the thickness direction and wound on the reel, the spring strip will not have a local arching phenomenon at the junction of the second winding circle and the first winding circle, and starting from the second winding circle, the curvature of the spring strip increases more evenly with the turning angle, thereby helping to control the stiffness of the spring strip within a very small range, effectively reducing the fluctuation of the tension of the spring strip. Since at least one of the width, thickness and natural curvature of at least one layer of the spring strip gradually decreases from the outer circle to the inner circle along the length of the spring strip, corresponding compensation is made for the change in the actual curvature of the spring strip gradually increasing from the outer circle to the inner circle, so that the output force value fluctuation of the constant force spring is further reduced or substantially zero.

[0021] Optionally, the Archimedean spiral is according to the following formula

[0022] get:

[0023]

[0024] Wherein, N is the number of layers of the spring strip stacked in the thickness direction, t is the thickness of the spring strip, R is the radius at the end point, θ∈[0, 2π].

[0025] Optionally, the number of turns of the Archimedean spiral is equal to one turn, and the second contour line is obtained according to the following formula:

[0026]

[0027] Wherein, N is the number of layers of the spring strip stacked in the thickness direction, t is the thickness of the spring strip, and R is the radius at the end point of the head end.

[0028] Optionally, the number of turns of the Archimedean spiral is equal to one turn;

[0029] A first angle is formed between the first end surface of the first turn of the N-layer spring strip wound on the reel and the second contour line.

[0030] Optionally, the number of turns of the Archimedean spiral is less than one turn;

[0031] The first end face of the first coil of the N-layer spring strip wound on the reel coincides with the second contour line, and the second contour line is obtained according to the following formula:

[0032]

[0033] Wherein, N is the number of layers of the spring strip stacked in the thickness direction, t is the thickness of the spring strip, and R is the radius at the end point of the head end.

[0034] Optionally, the number of turns of the Archimedean spiral is less than one turn;

[0035] The first end face of the first coil of the N-layer spring strip wound on the reel does not overlap or intersect with the second contour line, and the second contour line is obtained according to the following formula:

[0036]

[0037] Wherein, N is the number of layers of the spring strip stacked in the thickness direction, t is the thickness of the spring strip, and R is the radius at the end point of the head end.

[0038] Optionally, the number of turns of the Archimedean spiral is less than one turn;

[0039] A second angle is formed between the first end surface of the first turn of the N-layer spring strip wound on the reel and the second contour line.

[0040] Optionally, the at least one layer of spring strip has a first position and a second position spaced apart along its length, and between the first position and the second position, at least one of the width, thickness and natural curvature of the at least one layer of spring strip changes linearly along its length.

[0041] Optionally, the first position and the second position are respectively located at two ends of the at least one layer of spring strip along its length.

[0042] Optionally, the at least one layer of spring band includes M sections along the length of the spring band, and within each section, at least one of the width, thickness and natural curvature of the at least one layer of spring band changes linearly along its length, where M is a positive integer greater than or equal to 2.

[0043] Optionally, N is greater than or equal to 2, and the width, thickness and natural curvature of the N layers of spring strips at the ends of the outermost circles are all the same.

[0044] Optionally, N is greater than or equal to 2, and the constant force spring is constructed so that the restoring elastic forces of the N layers of spring strips at the ends of the outermost circles are all the same.

[0045] Optionally, the curvature of the first end point is smaller than the natural curvature of the constant force spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The following drawings of the embodiments of the present application are hereby used as part of the present application for understanding the present application. The drawings show the embodiments of the present application and their descriptions, and are used to explain the principles of the present application. In the drawings,

[0047] Figure 1 is a schematic diagram of a medical system according to an embodiment of the present application;

[0048] Figure 2 is a schematic diagram of a robotic arm system according to an embodiment of the present application;

[0049] Figure 3 A three-dimensional view of a reel according to a preferred embodiment of the present application;

[0050] Figure 4 for Figure 3 A schematic cross-sectional view of the body of the reel in FIG.

[0051] Figure 5 for Figure 4 A schematic cross-sectional view of the body of the reel shown in the state of winding the spring strip;

[0052] Figure 6 for Figure 4 Another schematic cross-sectional view of the body of the reel shown in the state of winding the spring strip;

[0053] Figure 7 is a three-dimensional view of a constant force spring according to a preferred embodiment of the present application;

[0054] Figure 8 for Figure 7 A front view of a constant force spring is shown;

[0055] Fig. 9 A three-dimensional schematic diagram of an application scenario of a constant force spring according to a specific embodiment of the present application; and

[0056] Fig.10 It is a three-dimensional schematic diagram of another application scenario of the constant force spring according to the specific embodiment of the present application.

[0057] Description of reference numerals:

[0058] 100: reel 110: body

[0059] 110a: center hole 111: first contour line

[0060] 111a: Heading endpoint 111b: Tail endpoint

[0061] 112: second contour line 120: limit baffle

[0062] 130: groove 200: constant force spring

[0063] 200a: head end surface 201: outer spring strip

[0064] 202: Inner spring belt 203: Expanded part

[0065] 204: output part 205: winding part

[0066] 206: First position 207: Second position

[0067] 208: Spring belt 260: Heavy object

[0068] 270: Heavy Objects

[0069] 300: Surgical Robot 310: Control System

[0070] 320: Imaging system 330: Robotic arm system

[0071] 331: Adjustment arm 332: Operation arm

[0072] 333: Arm 334: Column

[0073] 335: handle 336: base DETAILED DESCRIPTION

[0074] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is obvious to those skilled in the art that the present application embodiments can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application embodiments, some technical features well known in the art are not described.

[0075] In order to fully understand the implementation of the present application, a detailed structure will be presented in the following description. Obviously, the implementation of the implementation of the present application is not limited to the specific details familiar to those skilled in the art.

[0076] It should be understood that the purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present application, and the singular forms "a", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. When the terms "comprise" and / or "include" are used in this specification, they indicate the presence of the features, integral bodies, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integral bodies, steps, operations, elements, components and / or combinations thereof.

[0077] Ordinal numbers such as "first" and "second" cited in this application are merely identifiers and do not have any other meaning, such as a specific order. Moreover, for example, the term "first component" itself does not imply the existence of a "second component", and the term "second component" itself does not imply the existence of a "first component". It should be noted that the terms "upper", "lower", "front", "back", "left", "right", "inner", "outer" and similar expressions used in this application are for illustrative purposes only and are not limiting.

[0078] Hereinafter, specific embodiments of the present application will be described in more detail with reference to the accompanying drawings. These drawings show representative embodiments of the present application and do not limit the present application.

[0079] like Figure 1 and Figure 2 As shown, the present invention provides a surgical robot 300 for remotely controlling a surgery. The surgical robot 300 may include a control system 310, an imaging system 320 and a robotic arm system 330, which may communicate with each other.

[0080] The control system 310 is also called the doctor's console. The control system 310 has a display unit for displaying surgical instruments or endoscope environments, a control mechanism for doctors to operate, and armrests. The display unit is provided with an observation window for doctors to observe. The control mechanism is configured to perform various actions corresponding to the actions of surgical instruments or endoscopes. The armrests are used to place the doctor's arms. In addition, the doctor's console also has other control switches that are convenient for hands or feet to touch or press, which are used to perform various functional operations and complete human-computer interaction.

[0081] The imaging system 320 has a display screen, an endoscope controller, system electronics, an image processor, etc. Thus, the patient's internal organs can be presented to the operator more clearly.

[0082] The robotic arm system 330 is arranged beside the patient, and a surgical instrument or an endoscope is arranged at its distal end for performing various surgical operations on the patient. The robotic arm system 330 may include at least one robotic arm. The robotic arm has a plurality of connecting arms, and two adjacent connecting arms are connected by joints and move relative to each other with specific degrees of freedom, so that the end of the robotic arm can achieve multiple degrees of freedom. An instrument support frame is installed at the end of the robotic arm, and the surgical instrument is detachably mounted on the instrument support frame. An instrument drive module is arranged on the instrument support frame to drive the surgical instrument to perform actions such as insertion, clamping, hooking, shearing, and shoveling.

[0083] In some cases, reference Figure 2 , a single robotic arm may include an adjustment arm 331, an operating arm 332 and a holding arm 333. The surgical instrument or endoscope is detachably mounted on the holding arm 333. During surgery, part of the main channel and wrist mechanism of the surgical instrument are passed through tissues such as the chest and abdominal wall to replace human hands for surgery. The two adjacent connecting rods in the adjustment arm 331 are pivotally connected through a rotating joint. In addition, a rotating joint is also provided between the adjustment arm 331 and the operating arm 332 to achieve a pivotable connection. Before operating the robotic arm system 330 for surgery, it is necessary to first operate the adjustment arm 331 to make the holding arm 333 reach the specified position, and then lock the rotating joint of the adjustment arm 331. During surgery, the surgical operation is completed by remotely controlling the operating arm 332, while keeping the rotating joint of the adjustment arm 331 locked to prevent relative rotation between the connecting rods of the adjustment arm 331 during surgery.

[0084] In one example, reference Figure 2 , the robot arm system 330 includes a base 336. A column 334 and a handle 335 are provided on the base 336. The column 334 includes at least one set of lifting mechanisms (not shown). For example, the column 334 includes four sets of lifting mechanisms, and each set of lifting mechanisms corresponds to a robot arm. The operator can assist in completing the movement of the base 336 through the handle 335. In the lifting mechanism (not shown), in order to provide a substantially constant elastic force, a constant force spring is usually provided in the lifting mechanism (not shown), and the output end of the constant force spring is connected to the movable mechanism moving along a straight line, so that the constant force spring can apply the output force to the movable mechanism, thereby outputting a substantially constant elastic force.

[0085] The embodiment of the first aspect of the present application provides a reel 100, which is used to wind a spring strip 208, such as Figures 3 to 10 shown.

[0086] The reel 100 according to the present application may include a body 110. On a cross section perpendicular to the axis of the body 110, the outer contour of the body 110 may include a first contour line 111 and a second contour line 112. The first contour line 111 is configured as an Archimedean spiral. The first contour line 111 has a head end point 111a and a tail end point 111b spaced apart along its own extension direction. The radius at the head end point 111a is smaller than the radius at the tail end point 111b. The second contour line 112 is connected between the head end point 111a and the tail end point 111b to close the first contour line 111, wherein the portion of the body 110 corresponding to the second contour line 112 is used to connect the end of the spring strip 208. That is, the surface of the body 110 corresponding to the second contour line 112 is used to connect the end of the spring strip 208, and the connection here may be any one of a surface contact, a line contact and a point contact, or may be a fixed connection or a detachable connection.

[0087] According to the reel 100 of the present application, the outer contour of the reel 100 includes a first contour line 111 configured as an Archimedean spiral and a second contour line 112 connected between the head end endpoint 111a and the tail end endpoint 111b of the Archimedean spiral. Among them, the radius at the head end endpoint 111a of the Archimedean spiral is smaller than the radius at the tail end endpoint 111b, that is, the curvature radius of the Archimedean spiral gradually increases. The portion corresponding to the second contour line 112 is used to connect the end of the spring strip 208. Since there is a radius difference between the head end endpoint 111a and the tail end endpoint 111b of the Archimedean spiral, the radius difference between the head end endpoint 111a and the tail end endpoint 111b of the Archimedean spiral can be reasonably set according to the thickness of the spring strip 208 to be wound. When the reel 100 of the present application is used to wind the spring strip 208, the spring strip 208 will not have local arching at the junction of the second winding circle and the first winding circle, and starting from the second winding circle, the curvature of the spring strip 208 increases more evenly with the turning angle, thereby helping to control the stiffness of the spring strip 208 within a very small range, effectively reducing the fluctuation of the tension of the spring strip 208.

[0088] In one example, the number of turns of the Archimedean spiral is equal to one turn. The second contour line 112 at least partially coincides with the straight line where the radius of the first end point 111 a is located.

[0089] In another example, the number of turns of the Archimedean spiral is less than one turn. Here, the number of turns less than one turn can be understood as slightly less than one turn. At this time, except for the end of the second contour line 112 near the center of the reel 100 coinciding with the straight line where the radius of the head end point 111a is located, the rest of the second contour line 112 is located outside the straight line where the radius of the head end point 111a is located. The plane formed by the second contour line 112 overlaps with at least a part of the head end face 200a of the spring band 208, such as line contact. The plane formed by the second contour line 112 here can be understood as the surface facing the outside of the part of the second contour line 112 corresponding to the body 110, that is, the transition surface between the head and tail ends of the outer peripheral surface of the Archimedean spiral on the reel 100.

[0090] In a further example, the tail end point 111b of the Archimedean spiral is set to any point between the first point (not shown) and the second point (not shown) of the preset Archimedean spiral. And the tail end point 111b does not overlap the first point and the second point. The preset Archimedean spiral here is an Archimedean spiral with the head end point 111a as the starting point and the number of turns being not less than one turn. The number of turns of the preset Archimedean spiral between the first point and the head end point is equal to one turn, and the straight line where the second point and the head end point 111a are located is perpendicular to the tangent of the head end point 111a and the tangent of the second point. The embodiment here provides an Archimedean spiral that is less than one turn and within a certain range.

[0091] In a further example, the straight line where the head end point 111a and the tail end point 111b are located is perpendicular to the tangent direction of the head end point 111a and the tangent direction of the tail end point 111b. Here, an Archimedean spiral of a certain shape is provided.

[0092] See also Figure 3In addition, the reel 100 may further include two limit baffles 120. The two limit baffles 120 are arranged oppositely at the two ends of the body 110 in the axial direction. A groove 130 is formed between the two limit baffles 120 and the outer peripheral surface of the body 110. Along the radial direction of the reel 100. The width of the groove 130 gradually increases from the inside to the outside. The groove 130 is used to allow N layers of spring strips 208 to be wound in the groove 130 after stacking. Wherein, N is a positive integer greater than or equal to 1. Since the width of the groove 130 gradually increases from the inside to the outside, the reel 100 is applied to the spring strip 208 that gradually increases from the inner circle to the outer circle. That is, when the spring strip 208 is wound on the reel 100, the width of the spring strip 208 can be gradually reduced from the outer circle to the inner circle along the length direction of the spring strip 208. The width of the spring strip 208 is positively correlated with the output force value, and the reduction in the width of the spring strip 208 has an effect on the output force value, which is to reduce the output force value. Therefore, on the basis that the actual curvature of the spring strip 208 is reduced, resulting in an increase in the output force value, it is equivalent to using the change in width to compensate for the change in the actual curvature, so that the output force value at all locations along the entire length tends to be stable. The reel 100 is designed in accordance with the feature that the width of the spring strip 208 gradually decreases from the outer circle to the inner circle along its length, and is also conducive to realizing the axial and radial limitation of the spring strip 208 when the spring strip 208 is wound in the application state.

[0093] For example, the body 110 and the limiting baffle 120 may be constructed as an integrated structure, which is convenient for processing, helps to improve the structural strength of the reel 100, and reduces the number of parts.

[0094] Furthermore, the body 110 is provided with a center hole 110a. The center hole 110a extends along the axial direction of the body 110 and penetrates the body 110. The center line of the center hole 110a coincides with the axis of the body 110 and the center of the circle corresponding to the head end point 111a. By providing the center hole 110a, it is convenient to assemble the reel 100 on the corresponding shaft, so that when the spring belt 208 is acted by the pulling force, the reel 100 can adaptively rotate relative to the corresponding shaft.

[0095] The embodiment of the second aspect of the present application provides a spring device. The spring device according to the present application may include the reel 100 and the constant force spring 200 according to the above. The constant force spring 200 may include N layers of spring strips 208. The N layers of spring strips 208 are stacked along the thickness direction and wound on the reel 100. Wherein, N is a positive integer greater than or equal to 1. Wherein, at least one of the width, thickness and natural curvature of at least one layer of spring strip 208 gradually decreases from the outer circle to the inner circle along the length of the spring strip 208.

[0096] According to the spring device of the present application, by applying the above-mentioned reel 100 to adapt to the wound spring strip 208, when N layers of spring strips 208 are stacked in the thickness direction and wound on the reel 100, the spring strip 208 will not have local arching at the junction of the second circle and the first circle of winding, and starting from the second circle of winding, the curvature of the spring strip 208 increases more evenly with the turning angle, thereby helping to control the stiffness of the spring strip 208 within a very small range, effectively reducing the fluctuation of the tension of the spring strip 208.

[0097] The Archimedean spiral can be obtained according to the following formula (1):

[0098]

[0099] Wherein, N is the number of layers of the spring strip 208 stacked in the thickness direction, t is the thickness of the spring strip 208, R is the radius at the end point 111a of the head end, and θ∈[0, 2π]. Here, θ can be understood as the range of the central angle corresponding to each layer of the spring strip 208. Wherein, R should generally be greater than the radius of the spring strip 208 in a free state.

[0100] In one example, the number of turns of the Archimedean spiral is equal to one turn. The second contour line 112 can be obtained according to the following formula (2):

[0101]

[0102] Wherein, N is the number of layers of the spring strip 208 in the thickness direction, t is the thickness of the spring strip 208, and R is the radius of the head end 111a. It can be understood that the second contour line 112 here is on the straight line where the radius of the head end 111a is located.

[0103] When the N-layer spring strip 208 starts to be wound from the second contour line 112 of the reel 100, the spring strip 208 is wound on the reel 100 in the form of an Archimedean spiral due to the support of the reel 100. The front end of the second turn of the spring strip 208 wound on the reel 100 can just smoothly transition to the radially outer side of the front end of the first turn. In this way, the spring strip 208 will not have a local arch, bulge or bulge phenomenon, so that the curvature radius of the entire spring strip 208 increases uniformly with the turning angle, and the stiffness of the spring strip 208 is controlled within a very small range.

[0104] See also Figure 5 Further, when the number of turns of the Archimedean spiral is equal to one turn, a first angle is formed between the first end face 200a of the first turn of the N-layer spring strip 208 wound on the reel 100 and the second contour line 112. The first angle is denoted as α, where α can be calculated by the following formula (3):

[0105]

[0106] Wherein, N is the number of layers of the spring strip 208 stacked in the thickness direction, t is the thickness of the spring strip 208, and R is the radius at the head end 111a.

[0107] In another example, the number of turns of the Archimedean spiral is less than one turn. Here and below, the number of turns less than one turn can be understood as slightly less than one turn. The head end face 200a of the first turn of the N-layer spring strip 208 wound on the reel 100 coincides with the second contour line 112. At this time, the tangents at the head end and the tail end of the Archimedean spiral are both perpendicular to the second contour line 112. The second contour line 112 can be obtained according to the following formula (4):

[0108]

[0109] Wherein, N is the number of layers of the spring strip 208 stacked in the thickness direction, t is the thickness of the spring strip 208, and R is the radius at the head end 111a. The intersection of formula (4) and the above formula (1) is the two end points of the second contour line, that is, the two end points of the Archimedean spiral line, the head end 111a and the tail end 111b.

[0110] Furthermore, when the number of turns of the Archimedean spiral is less than one turn, the head end surface 200a of the first turn of the N-layer spring strip 208 wound on the reel 100 does not overlap or intersect with the second contour line 112. The second contour line 112 can be obtained according to the following formula (5):

[0111]

[0112] Wherein, N is the number of layers of the spring strip 208 stacked in the thickness direction, t is the thickness of the spring strip 208, and R is the radius at the head end 111a.

[0113] See also Figure 6 , further, when the second contour line satisfies the above formula (5), a second angle is formed between the first end face 200a of the first coil of the N-layer spring strip 208 wound on the reel 100 and the second contour line 112. The second angle is denoted as β, where β can be calculated by the following formula (6):

[0114]

[0115] Wherein, N is the number of layers of the spring strip 208 stacked in the thickness direction, t is the thickness of the spring strip 208, and R is the radius at the head end 111a.

[0116] It is understandable that the second contour line 112 may also be an arbitrary curve, for example, an inwardly concave curve, as long as the second contour line 112 does not interfere with the front end surface of the first coil of the spring strip.

[0117] In the vicinity of the head end 111 a and the tail end 111 b , grooves or chamfers (rounded) may be added based on considerations such as strength or manufacturability.

[0118] See also Figures 5 to 8 For example, at least one layer of spring strip 208 has a first position 206 and a second position 207 spaced apart along its length. Between the first position 206 and the second position 207, at least one of the width, thickness and natural curvature of at least one layer of spring strip 208 changes linearly along its length. By adopting this technical means, the design and processing of the spring strip 208 is simplified while ensuring the stability of the output force provided by the spring device.

[0119] Optionally, the outer spring band 208 of the spring device has a first position 206 and a second position 207 along its length. Within the range from the first position 206 to the second position 207, the width of the outer spring band 208 gradually decreases linearly from the outer circle to the inner circle along the length direction of the outer spring band 208, thereby reducing the difficulty of processing the spring band 208 and reducing the fluctuation of the output force of the constant force spring 200 to no more than 0.5%.

[0120] Furthermore, the first position 206 and the second position 207 are respectively located at two ends along the length of at least one layer of spring strip 208. By adopting this technical means, the structure of the spring device is further simplified, thereby reducing the difficulty of processing.

[0121] Continue reading Figures 5 to 8 For example, the first position 206 is located at the end of the outermost circle along the length, and the second position 207 is located at the end of the innermost circle along the length. This can further reduce the difficulty of processing the outer spring band 208, and at the same time ensure that the fluctuation of the output force of the spring device is no more than 0.5%. And / or, the thickness of the outer spring band 208 can be gradually reduced linearly from the outer circle to the inner circle along the length of the outer spring band 208 between the first position 206 and the second position 207. And / or, the natural curvature of the outer spring band 208 can be gradually reduced linearly from the outer circle to the inner circle along the length direction of the outer spring band 208 between the first position 206 and the second position 207.

[0122] Such a construction is also applicable to the inner layer spring belt 208. Moreover, the positions of the linear size change intervals of the inner layer spring belt 208 and the outer layer spring belt 208 can be the same (corresponding along the length) or different, and the linear size change dimension of the inner layer spring belt 208 can be the same as or different from that of the outer layer spring belt 208.

[0123] Optionally, each layer of spring strip 208 has a first position 206 and a second position 207 spaced apart along its length, and the width of each layer of spring strip 208 varies linearly along its length between the first position 206 and the second position 207. The first position 206 and the second position 207 between each spring strip 208 may be disposed at the same or different positions, and the slopes of their linear variations may be the same or different.

[0124] Continue reading Figures 5 to 8 For example, at least one layer of spring strip 208 includes M sections along the length of spring strip 208. In each section, at least one of the width, thickness and natural curvature of at least one layer of spring strip 208 changes linearly along its length. Wherein M is a positive integer greater than or equal to 2. In this way, the intervals of linear change of the size of spring strip 208 increase, and the linear change of the size dimension in each interval can be the same or different, which increases the design flexibility of constant force spring 200. Similarly, the number M of sections between each (each layer) spring strip 208 can be the same or different, the division method of the section (such as the position of the section) can be the same or different, and the linear change of the size dimension in each section can be the same or different. In the present application, the sum of the above-mentioned M sections can be the entire spring strip 208, or only a part of the spring strip 208. The above-mentioned M sections can be sections arranged continuously along the length direction, or sections that are intermittent or spaced along the length direction. By adopting this technical means, different processing methods can be used in different sections while ensuring the stability of the output force provided by the spring device, thereby improving the flexibility of design and processing.

[0125] Optionally, each layer of spring strip 208 is divided into M sections (M is an integer greater than or equal to 2), and in each section, the width of each layer of spring strip 208 changes linearly along its length. Similarly, the positions of the M sections between each spring strip 208 can be the same or different, and the slopes of the linear changes in each section can be the same or different. The sum of the M sections can be the entire spring strip 208, or only a part of the spring strip 208. The M sections can be sections that are continuously arranged along the length direction, or sections that are intermittent or spaced along the length direction.

[0126] When designing the spring belt 208, a person skilled in the art may first determine a number of position points along the length direction of the spring belt 208, so that the output force values ​​at the several position points (these several positions are used as the output parts 204) are equal or approximately equal. Then, for the portion between the several position points, the size dimensions (such as thickness, width, natural curvature) of the spring belt 208 are linearly changed. This can simplify the design and processing of the spring belt 208. It can be understood that the more position points are selected, that is, the more sections the spring belt 208 is divided into along the length, the more stable the output force of the spring belt 208 along the entire length.

[0127] Continue reading Figures 5 to 8 , for example, the above-mentioned N is greater than or equal to 2. The width, thickness and natural curvature of the N-layer spring belt 208 at the end of the outermost circle are the same. For example, the outer spring belt 208 and the inner spring belt 208 have the same width, thickness and natural curvature at the end of the outermost circle. It can be understood that the end of the spring belt 208 at the outermost circle is used to directly or indirectly connect the component to be compensated, such as the weight 270. When the shape and size of the N-layer spring belt 208 at the end of the outermost circle are the same, the design and processing difficulty can be reduced to a certain extent, and the production cost can be reduced. At the same time, the spring device has a regular shape at this part, which is conducive to the connection between the spring device and the external components, reducing the difficulty of assembly. By adopting this technical means, the design and processing difficulty can be reduced to a certain extent, while improving the consistency of the structure at the interface of the spring device, improving the adaptability of the end of the spring device and the external connection structure, and reducing the difficulty of assembly.

[0128] For example, N is greater than or equal to 2. The spring device is constructed so that the restoring elastic forces at the ends of the outermost circles of the N layers of spring strips 208 are all the same. This makes the forces between the layers of spring strips 208 more uniform, which helps to extend the overall service life of the spring device. By adopting this technical means, another spring design method is proposed, which makes the forces between the layers of spring strips 208 more uniform, which helps to extend the overall service life of the spring device.

[0129] Optionally, the curvature of the head end point 111a is smaller than the natural curvature of the spring device.

[0130] See below Figures 5 to 10 The constant force spring 200 provided according to the embodiment of the present application is further described in detail.

[0131] The constant force spring 200 according to the present application includes N layers of spring strips 208, which are stacked along the thickness direction of the spring strips 208, and the N layers of spring strips 208 are in a coiled state. Wherein, N is a positive integer greater than or equal to 1. For example, N is 1, 2, 3, 4, etc. Since the N layers of spring strips 208 are in a coiled state, the thickness direction of the single layer of spring strips 208 corresponds to the radial direction of the constant force spring 200, the length direction of the single layer of spring strips 208 corresponds to the circumferential direction of the constant force spring 200, and the width direction of the single layer of spring strips 208 corresponds to the axial direction of the constant force spring 200. For example, when N=2, the constant force spring 200 has an outer layer of spring strips 208 and an inner layer of spring strips 208 from the outside to the inside in the radial direction of the constant force spring 200. The outer layer of spring strips 208 and the inner layer of spring strips 208 are stacked along their own thickness direction and are in a coiled state.

[0132] In the present application, the number of turns of the N-layer spring strip 208 may not be an integer.

[0133] The output force F of the constant force spring 200 is calculated according to the following formula (7):

[0134]

[0135] In formula (7), E is the elastic modulus of the material of the constant force spring 200, ν is the Poisson's ratio of the material, b is the width of the constant force spring 200, t is the thickness of the constant force spring 200, r is the radius of the constant force spring 200 in the free state, and R is the actual radius at the output point.

[0136] Since the constant force spring 200 usually needs to be wound on the drum 100 to achieve connection with other components when in use, the actual radius R of the constant force spring 200 usually refers to the radius of the constant force spring 200 after being wound on the drum 100 .

[0137] As pointed out in the background technology, due to the thickness of the spring band 208, the actual curvature R of the constant force spring 200 cannot remain constant, and the actual curvature R at each location gradually decreases from the inner circle to the outer circle, causing the output force F to gradually increase from the inner circle to the outer circle.

[0138] To solve this problem, in certain embodiments of the present application, the width of at least one (one) of the N layers of spring strips 208 of the constant force spring 200 gradually decreases from the outer circle to the inner circle along the length of the spring strip 208. For example, in the illustrated example, the widths of the two spring strips 208 and gradually decrease from the outer circle to the inner circle along the length direction. According to formula (7), the width of the spring strip 208 is positively correlated with the output force value, and the reduction in the width of the spring strip 208 has an effect on the output force value that the output force value is reduced. Therefore, on the basis that the actual curvature of the spring strip 208 is reduced, resulting in an increase in the output force value, it is equivalent to using the change in width to compensate for the change in the actual curvature, so that the output force value at all locations along the entire length tends to be stable.

[0139] Alternatively, a constant force spring 200 may be used in which the thickness t of the spring strip 208 gradually decreases from the outer circle to the inner circle along the length of the spring strip 208 to compensate for the change in the actual curvature.

[0140] Alternatively, a constant force spring 200 may be used in which the natural curvature of the spring strip 208 gradually decreases from the outer circle to the inner circle along the length of the spring strip 208 to compensate for the change in the actual curvature.

[0141] Reference Figure 7 and Figure 8 , each layer of spring strip 208 includes a winding portion 205, an output portion 204 and an unfolding portion 203. The output portion 204 of the spring strip 208 is located / connected between the unfolding portion 203 and the winding portion 205, and is used to provide a restoring elastic force, that is, to provide the force F in the output formula (7). In addition, the position of the output portion 204 changes with the change of the degree of unfolding or winding of the spring strip 208. In the application scenario of the constant force spring 200 of the embodiment of the present application, the constant force spring 200 can be used to balance the forces or moments in various directions.

[0142] In an exemplary application scenario, the constant force spring 200 is used to balance the tension in the horizontal direction, and the constant force spring 200 is deployed in the horizontal direction. In this application scenario, at least one of the width, thickness, and natural curvature of at least one layer of the spring strips 208 in the N layers of spring strips 208 gradually decreases from the outer circle to the inside along its length direction, so that the sum of the restoring elastic forces provided by the output parts 204 of each layer of the spring strips 208 is constant or approximately constant. In other words, at least one of the width, thickness, and natural curvature of at least one layer of the spring strips 208 in the N layers of spring strips 208 gradually decreases from the outer circle to the inside along the length direction of the coil spring strips 208, so that the restoring elastic forces of the constant force spring 200 at any two positions (any two different processing positions) along the length direction are equal or approximately equal.

[0143] It can be understood that the output force of the constant force spring 200 is the resultant force of the output force of the N-layer spring belt 208, that is, the sum of the output force of the N-layer spring belt 208, that is, the sum of the restoring elastic force provided by the output portion 204 of the N-layer spring belt 208. Therefore, the constant force spring 200 according to the present application can provide a constant or approximately constant output force. The "approximately constant output force" mentioned here means that the fluctuation of the output force value of the constant force spring 200 does not exceed 0.5%, which can be understood as the absolute value of the difference between any two of the maximum output force, minimum output force and average output force of the constant force spring 200 and any one of the maximum output force, minimum output force and average output force of the constant force spring 200. The ratio is less than or equal to 0.5%.

[0144] In the present application, the technical solution of compensating the influence of actual curvature on output force by width, thickness or natural curvature can be implemented separately or in combination, any two of them can be combined, or all three can be adopted at the same time.

[0145] In an exemplary example, when N=2, at least one of the width, thickness and natural curvature of one layer of spring strips 208 changes along its length direction, and the other layer of spring strips 208 does not change, so that the sum of the restoring elastic forces provided by the output portions 204 of the two layers of spring strips 208 is constant or approximately constant. That is, in the example of multiple layers of spring strips 208, the change in the width, thickness or natural curvature of a portion of the spring strips 208 can be used to compensate for the sum of the effects of the actual curvatures of the spring strips 208 of each layer on the output force.

[0146] In an exemplary example, when N=2, at least one of the width, thickness and natural curvature of each of the two layers of spring strips 208 varies along its length direction, so that the sum of the restoring elastic forces provided by the output portion 204 of the two layers of spring strips 208 is constant or approximately constant. That is to say, in the example of multiple layers of spring strips 208, the change in the width, thickness or natural curvature of each layer of spring strips 208 can be used to compensate for the effect of the actual curvature of each layer of spring strips 208 on the output force. Among them, the change parameters of each layer can be the same or different; when the change parameters are the same, the change rate can be the same or different; as long as it can compensate for the effect of the actual curvature of the two layers of spring strips 208 on the output force.

[0147] Optionally, when N is greater than or equal to 2, the width of each layer of spring belt 208 varies along its length direction, so that the sum of the restoring elastic forces provided by the output portion 204 of each layer of spring belt 208 is constant or approximately constant. Wherein, at the same length position, the width of each layer of spring belt 208 is equal, that is, the shape and size of each layer of spring belt 208 are the same. Each layer of spring belt 208 has the same variation parameter (width in this example), and each layer of variation parameter has the same variation rate, so that each layer of spring belt 208 has the same shape and size, which facilitates the design of the constant force spring 200, is conducive to the mass production of the spring belt 208, and reduces the fluctuation of the output force of the constant force spring 200 caused by production errors. The variation parameter is not limited to the width described in this example, and can also be thickness, natural curvature, or any combination of the three.

[0148] In an exemplary example, N=4, the thickness and natural curvature of each layer of spring strip 208 are the same and constant along the length direction, and the width gradually decreases along the length direction. At the same length position, the widths of each layer of spring strip 208 are equal. In the constant force spring 200 thus obtained, the restoring elastic force of each layer of spring strip 208 at each position along the length is approximately equal, and the sum of the restoring elastic force provided by the output portion 204 of each layer of spring strip 208 is constant or approximately constant.

[0149] In another application scenario, the constant force spring 200 is used for pulling force in the vertical direction, and the constant force spring 200 is deployed in the vertical direction. For example, the constant force spring 200 is applied to a gravity balance device, which can be used to balance a component that rises or falls or swings in a vertical plane. In this application scenario, the constant force spring 200 is set at a fixed position relative to the frame / ground above the component to be compensated (such as Fig. 9 and Fig.10 The constant force spring 200 may be arranged below the component to be compensated (not shown), so that the constant force spring 200 is pulled downward. It may also be arranged below the component to be compensated (not shown), in which case the pulley assembly is required to redirect the force so that the constant force spring 200 is pulled upward. In the field of medical robots, the constant force spring 200 is usually used to provide gravity compensation in the lifting joint of the robot arm, gravity torque compensation in the rotating joint of the robot arm, and other scenarios.

[0150] In an exemplary embodiment, the fixed position of the constant force spring 200 relative to the frame / ground is set above the component to be compensated, and the end of the outermost circle of the constant force spring 200 moves with the component to be compensated, such as Fig. 9As shown. The load of the output part 204 of the constant force spring 200 includes the gravity of the unfolded part 203 in addition to the gravity of the weight 260. When the position of the weight 260 changes, the stretching degree of the spring belt 208 changes, so that the length distribution of the unfolded part 203 and the winding part 205 changes, that is, the load of the output part 204 changes. In order to ensure that the restoring elastic force provided by the output part 204 at any position can fully balance the gravity of the weight 260, the change of the spring's own weight can be taken into account when adjusting the width, thickness, natural curvature and other parameters of the spring belt 208, so that the difference between the sum of the restoring elastic forces provided by the output parts 204 of each layer of spring belts 208 and the sum of the gravity of the unfolded parts 203 of each layer of spring belts 208 is constant or approximately constant. Among them, the measurement standard of constant or approximately constant is as described above.

[0151] In an exemplary embodiment, the fixed position of the constant force spring 200 relative to the frame / ground is set above the component to be compensated, and the end of the outermost circle of the constant force spring 200 is fixed relative to the frame / ground, such as Fig.10 As shown. The load of the output part 204 of the constant force spring 200 includes the gravity of the winding part 205 in addition to the gravity of the weight 270. When the position of the weight 270 changes, the stretching degree of the spring belt 208 changes, so that the length distribution of the unfolded part 203 and the winding part 205 changes, that is, the load of the output part 204 also changes. In order to ensure that the restoring elastic force provided by the output part 204 at any position can fully balance the gravity of the weight 270, the change of the spring's own weight can be taken into account when adjusting the width, thickness, natural curvature and other parameters of the spring belt 208, so that the difference between the sum of the restoring elastic force provided by the output part 204 of each layer of the spring belt 208 and the sum of the gravity of the winding part 205 of each layer of the spring belt 208 is constant or approximately constant. Among them, the measurement standard of constant or approximately constant is as described above.

[0152] For the application scenarios of the above two examples, it is not necessary to take the change of the spring's own weight into consideration. The constant force spring 200 can still be constructed so that the sum of the restoring elastic forces provided by the output parts 204 of each layer of spring strips 208 is constant or approximately constant, while the influence of the change of the spring's own weight can be offset by other means.

[0153] It can be understood that the spring device according to the present application includes all the features and effects of the reel 100 according to the present application and the constant force spring 200 according to the present application.

[0154] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art in the technical field of this application. The terms used herein are only for describing specific implementation purposes and are not intended to limit this application. Terms such as "setting" appearing in this article can mean that one component is directly attached to another component, or that one component is attached to another component through an intermediate. Features described in this article in one embodiment may be applied to another embodiment alone or in combination with other features, unless the feature is not applicable in the other embodiment or otherwise specified.

[0155] The present application has been described through the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of example and description, and are not intended to limit the present application to the described embodiments. It can be understood by those skilled in the art that more variations and modifications can be made according to the teachings of the present application, and these variations and modifications all fall within the scope of protection claimed in the present application.

Claims

1. A reel for winding a spring strip, characterized in that: The reel comprises a body, and in a cross section perpendicular to the axis of the body, the outer contour of the body comprises: A first contour line, wherein the first contour line is configured as an Archimedean spiral line, the first contour line having a head end point and a tail end point spaced apart along its length direction, the radius at the head end point being smaller than the radius at the tail end end point; and a second contour line, the second contour line being connected between the first end point and the tail end point to close the first contour line, The portion of the main body corresponding to the second contour line is used to connect the end of the spring band.

2. The reel according to claim 1, characterized in that The number of turns of the Archimedean spiral is equal to one turn, and the second contour line at least partially overlaps with the straight line where the radius of the first end point is located.

3. The reel according to claim 1, characterized in that: The number of turns of the Archimedean spiral is less than one turn.

4. The reel according to claim 3, characterized in that: The tail end point of the Archimedean spiral is set to any point between a first point and a second point of a preset Archimedean spiral, and the tail end point does not overlap with the first point and the second point, the preset Archimedean spiral takes the head end point as a starting point and has a number of turns of not less than one, the number of turns of the preset Archimedean spiral between the first point and the head end point is equal to one, and the straight line between the second point and the head end point is perpendicular to the tangent of the head end point and the tangent of the second point.

5. The reel according to claim 3, characterized in that: The straight line on which the head end point and the tail end point are located is perpendicular to the tangent direction of the head end point and the tangent direction of the tail end point.

6. The reel according to any one of claims 1 to 5, characterized in that The reel also includes two limit baffles, which are relatively arranged at the two ends of the main body along the axial direction, and a groove is formed between the two limit baffles and the outer circumferential surface of the main body. Along the radial direction of the reel, the width of the groove gradually increases from the inside to the outside, and the groove is used to allow N layers of the spring strip to be wound in the groove after stacking, where N is a positive integer greater than or equal to 1.

7. The reel according to claim 6, characterized in that The body and the limit baffle are constructed as an integrated structure.

8. The reel according to any one of claims 1 to 5, characterized in that The body is provided with a center hole, which extends along the axial direction of the body and penetrates the body, and the center line of the center hole coincides with the axis of the body and the center of the circle corresponding to the end point of the head end.

9. A spring device, characterized in that: The spring device comprises: A reel according to any one of claims 1 to 8; and A constant force spring, comprising N layers of spring strips, which are stacked in a thickness direction and wound on the drum, wherein N is a positive integer greater than or equal to 1, and wherein at least one of the width, thickness and natural curvature of at least one layer of the spring strip gradually decreases from the outer circle to the inner circle along the length of the spring strip.

10. The spring device according to claim 9, characterized in that The Archimedean spiral is obtained according to the following formula: Wherein, N is the number of layers of the spring strip stacked in the thickness direction, t is the thickness of the spring strip, R is the radius at the end point, θ∈[0, 2π].

11. The spring device according to claim 10, characterized in that The number of turns of the Archimedean spiral is equal to one turn, and the second contour line is obtained according to the following formula: Wherein, N is the number of layers of the spring strip stacked in the thickness direction, t is the thickness of the spring strip, and R is the radius at the end point of the head end.

12. The spring device according to claim 11, characterized in that The number of turns of the Archimedean spiral is equal to one turn; A first angle is formed between the first end surface of the first turn of the N-layer spring strip wound on the reel and the second contour line.

13. The spring device according to claim 10, characterized in that The number of turns of the Archimedean spiral is less than one turn; The first end face of the first coil of the N-layer spring strip wound on the reel coincides with the second contour line, and the second contour line is obtained according to the following formula: Wherein, N is the number of layers of the spring strip stacked in the thickness direction, t is the thickness of the spring strip, and R is the radius at the end point of the head end.

14. The spring device according to claim 10, characterized in that The number of turns of the Archimedean spiral is less than one turn; The first end face of the first coil of the N-layer spring strip wound on the reel does not overlap or intersect with the second contour line, and the second contour line is obtained according to the following formula: Wherein, N is the number of layers of the spring strip stacked in the thickness direction, t is the thickness of the spring strip, and R is the radius at the end point of the head end.

15. The spring device according to claim 14, characterized in that The number of turns of the Archimedean spiral is less than one turn; A second angle is formed between the first end surface of the first turn of the N-layer spring strip wound on the reel and the second contour line.

16. The spring device according to claim 9, characterized in that The at least one layer of spring strip has first and second positions spaced apart along its length, between which at least one of a width, a thickness and a natural curvature of the at least one layer of spring strip varies linearly along its length.

17. The spring device according to claim 16, characterized in that The first position and the second position are respectively located at two ends of the at least one layer of spring strip along the length thereof.

18. The spring device according to claim 9, characterized in that The at least one layer of spring band includes M sections along the length of the spring band, and within each section, at least one of the width, thickness and natural curvature of the at least one layer of spring band changes linearly along its length, where M is a positive integer greater than or equal to 2.

19. A spring device according to any one of claims 9, 16 to 18, characterized in that N is greater than or equal to 2, and the width, thickness and natural curvature of the N layers of spring strips at the ends of the outermost circles are all the same.

20. A spring device according to any one of claims 9, 16 to 18, characterized in that N is greater than or equal to 2, and the constant force spring is configured such that the restoring elastic forces of the N layers of spring strips at the ends of the outermost circles are all the same.

21. A spring device according to any one of claims 8 to 18, characterised in that The curvature of the first end point is smaller than the natural curvature of the constant force spring.

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