Tensioning arrangement for a drive belt, traversing drive arrangement and 3D printing device

Abstract

Tensioning arrangement for a drive belt, characterized in that it comprises: a rotatable element comprising a joint section, a support section and a tensioning section, wherein the joint section is rotatably connected to a base component about an axis of rotation, and wherein the tensioning section is displaceable relative to the base component when the rotatable element is rotated in order to adjust a tension force on the drive belt; an elastic element that is elastically supported between the support section and the base component and whose support direction is offset with respect to the axis of rotation; and a locking element used to lock or release the rotation of the rotatable element.

Description

Technical area

[0001] The present invention relates to the field of 3D printing, in particular to a tensioning arrangement for a drive belt, a travel drive arrangement and a 3D printing device. State of the art

[0002] In some 3D printing devices, such as 3D printing devices based on fused deposition modeling (FDM) technology, 3D printing is performed by moving parts (such as the print head assembly, print platform, etc.) that are moved in the X / Y / Z directions by driving a motor-driven drive belt.

[0003] The drive belt can stretch and relax during use. In this case, it can be tightened using a tensioning mechanism. A problem with some prior art tensioning mechanisms is that they have complicated structures or cause uncomfortable tension. Disclosure of the invention

[0004] The present invention provides a tensioning assembly for a drive belt, a travel drive assembly, and a 3D printing apparatus to solve the problem that some tensioning mechanisms in the prior art have complicated structures or cause uncomfortable tension.

[0005] In a first aspect, the present invention provides a tensioning assembly for a drive belt, comprising a rotatable member, an elastic member, and a locking member. The rotatable member comprises a hinge portion, a support portion, and a tensioning portion, wherein the hinge portion is connected to a base member for rotation about a rotation axis, and wherein the tensioning portion is displaceable relative to the base member upon rotation of the rotatable member to adjust a tensioning force on the drive belt. The elastic member is elastically supported between the support portion and the base member, and its support direction is offset with respect to the rotation axis. The locking member is used to lock or release the rotation of the rotatable member.

[0006] When using the drive belt tensioning assembly of the present invention, the locking element can first be unlocked, and then the rotatable element is rotated about the rotation axis, thereby displacing the tensioning portion and changing its relative position with respect to the drive belt to adjust the pressure and tensioning force on the drive belt. After the tensioning force has been properly adjusted, the locking element is relocked to maintain the rotatable element in the current tensioned state.

[0007] In one possible embodiment, it is provided that the force arm of a supporting force of the elastic element on the rotatable element is greater than the force arm of a counterforce of the drive belt on the supporting section.

[0008] In one possible embodiment, the rotatable element is provided with an arcuate recess whose circular center lies on the axis of rotation. The locking element is a locking screw, whereby the locking element is guided through the arcuate recess and thus locks the rotatable element to the base component to prevent rotation of the rotatable element.

[0009] In one possible embodiment, the support section has a first surface and the base component has a second surface corresponding to the first surface. The first surface is provided with a recessed annular recess. The elastic element is a coil spring, and one end of the elastic element fits into the annular recess.

[0010] In one possible embodiment, the base component has a base plate portion and a step portion protruding from the base plate portion. The tensioning arrangement for a drive belt further comprises a mounting plate, a support wheel, and a rotating shaft. The mounting plate comprises a connecting portion and a projection, wherein the connecting portion serves for fixed connection to the step portion, and wherein the projection protrudes from the step portion and is spaced apart from the base plate portion. One end of the rotating shaft is connected to the base plate portion, and the other end is connected to the projection and penetrates the projection. The joint portion is rotatably connected to a part of the rotating shaft that protrudes from the projection, wherein a central axis of the rotating shaft represents the rotation axis.The support wheel is located between the projection and the base plate section and is mounted on the rotating shaft. The support wheel and the tensioning section are spaced apart in the direction of the drive belt's extension to support different points of the drive belt.

[0011] In one possible embodiment, the connecting portion is provided with a first through-hole, a second through-hole, and a third through-hole. The step portion is provided with a positioning pin, the second through-hole being fitted to the positioning pin, a fixing screw being passed through the first through-hole and thus firmly connecting the connecting portion to the step portion, and the locking element being passed through the rotatable element and then through the third through-hole and thus detachably connected to the step portion. The projection is provided with a fourth through-hole, the rotating shaft being inserted into and fitted to the fourth through-hole.

[0012] In one possible embodiment, the rotatable element is provided with a U-shaped holder, the clamping section being designed as a circular cylinder. The clamping section is rotatably connected to an opening of the U-shaped holder and, together with the U-shaped holder, encloses a closed passage. The drive belt is guided through the passage and is supported on the clamping section in the direction of the opening of the U-shaped holder.

[0013] In a second aspect, the present invention provides a travel drive assembly comprising a rotary motor, a drive belt, and at least one tensioning assembly for a drive belt. The drive belt is fitted to the rotary motor to be set in motion by the rotary motor. The tensioning section is supported on the drive belt to tension the drive belt.

[0014] In one possible embodiment, two rotary motors and two drive belts are provided, each of which is driven by the two rotary motors. The two drive belts are arranged offset from one another in their width directions, and the running sections of the two drive belts have at least a partially overlapping section. Two tensioning arrangements for drive belts are provided, the two tensioning arrangements for drive belts being arranged at a distance from one another in the overlapping section of the running sections of the two drive belts. The tensioning arrangement for one drive belt has a support wheel and an additional support wheel, and the additional support wheel and the support wheel are arranged coaxially and offset from one another in their axial direction.One of the support wheels and one of the additional support wheels form a support wheel set to support two different points of a drive belt in the overlapping section. The other support wheel and the other additional support wheel form another support wheel set to support two different points of the other drive belt in the overlapping section.

[0015] In a third aspect, the present invention provides a 3D printing apparatus comprising a base member, a print head assembly, and a travel drive assembly, wherein a tensioning assembly for a drive belt is mounted on the base member. The print head assembly is connected to the drive belts to be moved by the drive of the drive belt. Short description of the characters

[0016] To clarify the technical solutions of the embodiments of the present invention, the drawings are briefly presented below in the embodiments. It should be understood that the drawings represent only some embodiments of the present invention and should therefore not be considered as limiting the scope. A person of ordinary skill in the art can also derive further drawings based on these drawings without inventive activity. Fig. 1 shows a front view of a 3D printing apparatus in one embodiment of the present invention; Fig. 2 shows a rear view of the 3D printing device from Fig. 1; Fig. 3 shows a schematic structural representation of a travel drive from Fig. 1; Fig. 4 shows an exploded view of the travel drive from Fig. 3; Fig. 5 shows a section of the 3D printing device from Fig. 2; Fig. 6 shows an enlarged view of point D from Fig. 5; Fig. 7 shows an exploded view of Fig. 6; Fig. Fig. 8 is a schematic structural diagram of a drive belt tensioning assembly and a drive belt in a mated state in an embodiment of the present invention; and Fig. 9 shows a front view of the tensioning assembly for a drive belt in one embodiment of the present invention. List of reference symbols: 100 3D printing devices 101 Basics 102 printing platform 103a Basic component 103 Portal 104 Printhead arrangement 110 Travel drive 111 Rotary motor 112 drive belts 113 Synchronous wheel clamping arrangement for 10 a drive belt 11 rotating element 12 elastic element 13 Locking element 14 Joint section 15 support section 16 clamping section 17 Base plate section 18 step section 19 Mounting plate 20 support wheel 21 additional support wheel 22 Rotating shaft 23 connecting section 24 lead 25 Positioning pin 26 Positioning ring 27 U-shaped holder 28 Support shaft 29 Fixing screw S1 overlapping track L1 rotation axis C1 arched recess P1 first surface P2 second surface C2 annular recess K1 first through hole K2 second through hole K3 third through hole K4 fourth through hole K5 passage Detailed description of the preferred embodiment

[0017] The technical solutions of the invention are described clearly and comprehensively below, based on the drawings, in an exemplary embodiment of the invention. Of course, the described exemplary embodiment does not represent all of the exemplary embodiments of the invention, but only a portion.

[0018] It should be noted that when an element is described as being "attached" to another element, it may be directly adjacent to the other element or there may be an element in between. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an element in between. When an element is considered to be "attached" to another element, it may be directly adjacent to the other element or there may be an element in between. The terms "vertical", "horizontal", "left", "right" and similar expressions as used herein are for illustrative purposes only.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention pertains. The terms used in the description of the present invention are intended to describe the purpose of specific embodiments only, without limiting the invention. The term "or / and" as used herein encompasses any combination of one or more of the listed elements.

[0020] Some embodiments of this invention will be described in detail. The following embodiments and features in the embodiments may be combined with each other unless conflicting. Example

[0021] As in Fig. 1 and Fig. 2, in this embodiment, a 3D printing device 100, for example a 3D printing device based on FDM technology, is provided.

[0022] The 3D printing device 100 includes a base 101, a printing platform 102, a gantry 103, a print head assembly 104, and a travel drive assembly 110.

[0023] The print platform 102 is mounted on the base 101 for movement in the Y direction. The gantry 103 is fixedly connected to the base 101 and serves as the base component 103a for mounting the travel drive 110. The travel drive assembly 110 is drive-connected to the print head assembly 104 to move the print head assembly 104 in the X or Z direction.

[0024] Accordingly, relative displacements between the print head assembly 104 and the print platform 102 can occur in the X, Y, and Z directions so that the print head assembly 104 can print a three-dimensional printed part on the print platform 102.

[0025] In other embodiments, the direction of movement of the print platform 102 and the print head assembly 104 may take other forms, but is not limited thereto.

[0026] In this exemplary embodiment, the travel drive arrangement 110 is designed as a bidirectional XZ drive comprising two rotary motors 111 and two drive belts 112. The two rotary motors 111 are each drivingly connected to the two drive belts 112 and are used to set the two drive belts 112 in motion. The drive belt 112 can be a synchronous belt, with the rotary motor 111 setting the synchronous belt into cyclical motion via a synchronous wheel 113. The two drive belts 112 are each connected to the print head arrangement 104, wherein the print head arrangement 104 is driven for displacement in the X direction when the two drive belts 112 drive the print head arrangement 104 in the same direction. When the two drive belts 112 drive the print head assembly 104 in opposite directions and at the same speed, the print head assembly 104 is moved in the Z direction.In order to realize a bidirectional XZ drive, other drive types, such as separate drives in the X direction and in the Z direction, can also be used in this embodiment, although this is not limited thereto.

[0027] The travel drive arrangement 110 in this embodiment further comprises a tensioning arrangement 10 for a drive belt, which may serve to tension the drive belt 112.

[0028] As in Fig. 3 and Fig. 4, in this embodiment, the two drive belts 112 are arranged offset from one another in their width directions and the running paths of the two drive belts 112 have at least a partially overlapping section S1. As shown, for example, in Fig. 3, the two drive belts 112 have a rectangular overlapping section S1 in the upper part and extend in the lower part to the synchronous wheels 113 of the two rotary motors 111 and are connected to them. In this exemplary embodiment, two tensioning assemblies 10 for drive belts are provided, wherein the two tensioning assemblies 10 for drive belts are arranged spaced from one another in the overlapping section S1 of the running paths of the two drive belts 112, for example, distributed at two corners of the rectangular overlapping section S1. Structures for deflecting the drive belt 112 are provided at the other two corners of the rectangle, e.g., guide wheels (not shown).

[0029] As in Fig. 5 to 9, in this embodiment, the drive belt tensioning arrangement 10 comprises a rotatable element 11, an elastic element 12 and a locking element 13.

[0030] The rotatable element 11 comprises a joint section 14, a support section 15, and a tensioning section 16. The joint section 14 is connected to a base member 103a, such as the above-mentioned gantry 103, for rotation about a rotation axis L1. The tensioning section 16 is displaceable relative to the base member 103a upon rotation of the rotatable element 11 to adjust a tensioning force on the drive belt 112. The elastic element 12 is elastically supported between the support section 15 and the base member 103a, and its support direction is offset with respect to the rotation axis L1. The locking element 13 is used to lock or unlock the rotation of the rotatable element 11.

[0031] When using the drive belt tensioning assembly 10 in this embodiment, the locking element 13 can first be unlocked, and then the rotatable element 11 is rotated about the rotation axis L1, so that the tensioning section 16 is displaced and its relative position with respect to the drive belt 112 is changed to adjust a pressure and tensioning force on the drive belt 112. After the tensioning force has been properly adjusted, the locking element 13 is relocked to hold the rotatable element 11 in the current tensioned state.

[0032] The drive belt tensioning assembly 10 has a simple structure and provides comfortable tension.

[0033] Optionally, it is provided that the force arm AB of an elastic supporting force F1 of the elastic element 12 on the rotatable element 11 is greater than the force arm AC of a counterforce F2 of the drive belt 112 on the support section 15. A point A lies on the axis of rotation L1, a point B is a point at which the elastic force of the elastic element 12 acts on the rotatable element 11, and a point C is a point at which the force of the drive belt 112 acts on the rotatable element 11. Because the force arm AB is greater than the force arm AC, the rotatable element 11 can exert a greater tensioning force on the drive belt 112 through a certain size of the elastic supporting force of the elastic element 12. Optionally, it is provided that the force arm AB is 2 to 4 times as long as the force arm AC, so that the elastic supporting force can be increased by a factor of 2 to 4 in order to tension the drive belt 112.

[0034] In this embodiment, the rotatable element 11 is provided with an arcuate recess C1, wherein the center of the circle in which the arcuate recess C1 is located lies on the rotation axis L1. The locking element 13 is a locking screw, wherein the locking element 13 is guided through the arcuate recess C1 and thus locks the rotatable element 11 to the portal 103 to prevent rotation of the rotatable element 11. In the locked state, the rotatable element 11 remains in its current position to stabilize and tension the drive belt 112. The locking element 13 can also be released if the tensioning force needs to be adjusted, and after the tensioning force has been adjusted, the locking element 13 can be locked again.

[0035] The locking member 13 is guided through the arcuate recess C1, and the curvature of the arcuate recess C1 restricts a rotation range of the rotatable member 11 to prevent the rotatable member 11 from colliding with other structures due to excessive rotation or from excessively tightening the drive belt 112.

[0036] In other embodiments, other forms for locking and unlocking the rotatable element 11 are also possible, although this is not limited thereto.

[0037] In this embodiment, the support portion 15 has a first surface P1, and the portal 103 has a second surface P2 corresponding to the first surface P1. The first surface P1 is provided with a recessed annular recess C2. The elastic element 12 is a coil spring, and one end of the elastic element 12 is fitted into the annular recess C2. The elastic element 12 is fitted into the annular recess C2 to position the elastic element 12 and prevent the end of the elastic element 12 from slipping out.

[0038] In this embodiment, the portal 103 includes a base plate portion 17 and a step portion 18 protruding from the base plate portion 17. The drive belt tensioning assembly 10 further includes a mounting plate 19, a support wheel 20, an additional support wheel 21, and a rotating shaft 22.

[0039] The mounting plate 19 includes a connecting portion 23 and a projection 24, wherein the connecting portion 23 serves for fixed connection to the step portion 18, and wherein the projection 24 protrudes from the step portion 18 and is spaced from the base plate portion 17. One end of the rotary shaft 22 is connected to the base plate portion 17, and the other end is connected to the projection 24 and penetrates the projection 24. The joint portion 14 is rotatably connected to a part of the rotary shaft 22 that protrudes from the projection 24, wherein a central axis of the rotary shaft 22 represents the rotation axis L1. The support wheel 20 is located between the projection 24 and the base plate portion 17 and is mounted on the rotary shaft 22. The support wheel 20 and the tensioning portion 16 are spaced from each other in an extension direction of the drive belt 112 to respectively support different locations of the drive belt 112.

[0040] The additional support wheel 21 and the support wheel 20 are coaxially mounted on the rotating shaft 22, and the additional support wheel 21 and the support wheel 20 are arranged offset from each other in their axial directions. The offset direction between the additional support wheel 21 and the support wheel 20 is parallel to the offset direction between the two drive belts 112. One of the support wheels 20 and one of the additional support wheels 21 form a support wheel set to support two different locations of a drive belt 112 in the overlapping section S1 (such as at two upper corners of the above rectangular overlapping section S1). The other support wheel 20 and the other additional support wheel 21 form another support wheel set to support two different locations of the other drive belt 112 in the overlapping section S1 (such as at two upper corners of the above rectangular overlapping section S1).

[0041] The integration of the support wheel 20 and the additional support wheel 21 for supporting the drive belt 112 into the drive belt tensioning assembly 10 results in a compact and practical structure. The fact that the support wheel 20, the additional support wheel 21, and the rotating element 11 of the drive belt 112 all share the same rotating shaft 22 results in a compact and practical structure.

[0042] In this embodiment, it is optionally provided that the connecting portion 23 of the mounting plate 19 is provided with a first through-hole K1, a second through-hole K2, and a third through-hole K3. The step portion 18 is provided with a positioning pin 25, wherein the second through-hole K2 is fitted to the positioning pin 25. A fixing screw 29 is passed through the first through-hole K1, thereby firmly connecting the connecting portion 23 to the step portion 18. The locking element 13 is passed through the rotatable element 11 and then through the third through-hole K3, and is thus detachably connected to the step portion 18. The projection 24 is provided with a fourth through-hole K4, wherein the rotary shaft 22 is inserted into and fitted to the fourth through-hole K4. This construction is compact, practical, and easy to assemble.

[0043] To facilitate the positioning and assembly of the rotary shaft 22, a positioning ring 26 is protrudingly disposed on the base plate portion 17, with one end of the rotary shaft 22 fitting into the positioning ring 26 to establish a connection with the base plate portion 17. For example, a press fit can be created between the rotary shaft 22 and the positioning ring 26 to achieve mutual positioning and connection.

[0044] In this embodiment, it is provided that the rotatable element 11 is provided with a U-shaped holder 27, wherein the clamping section 16 is designed as a circular cylinder, and wherein the clamping section 16 is rotatably connected to an opening of the U-shaped holder 27 and encloses a closed passage K5 with the U-shaped holder 27. The drive belt 112 is guided through the passage K5 and is supported on the clamping section 16 in the direction of the opening of the U-shaped holder 27 (see Fig. 8). The rotatable arrangement of the tensioning section 16 allows the resistance to the movement of the drive belt 112 to be reduced.

[0045] Optionally, it is provided that a support shaft 28 is connected within the opening of the U-shaped holder 27, wherein the clamping section 16 is designed as a hollow circular cylinder which is rotatably mounted on the support shaft 28.

[0046] It should be noted that the above-mentioned use of the drive belt tensioning arrangement 10 is only exemplary and the drive belt tensioning arrangement 10 in this embodiment can be used in all situations in which the drive belt is to be tensioned.

[0047] In summary, the drive belt tensioning arrangement 10 in these embodiments of the present invention can enable the drive belt to be tensioned in a simple manner.

[0048] The above-mentioned embodiments merely illustrate the technical solutions of the present invention and do not limit them. Although the present invention will be explained in more detail in connection with the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions for the technical solutions of the present invention should not deviate from the spirit and scope of the technical solutions of the present invention.

[0049] In summary, the present invention relates to the field of 3D printing and aims to solve the problem that some tensioning mechanisms in the prior art have complicated structures or cause uncomfortable tension. Accordingly, a tensioning assembly for a drive belt, a travel drive assembly, and a 3D printing device are provided. The tensioning assembly for a drive belt comprises a rotatable element, an elastic element, and a locking element. The rotatable element comprises a joint portion, a support portion, and a tensioning portion, wherein the joint portion is connected to a base component for rotation about a rotation axis, and wherein the tensioning portion is displaceable relative to the base component upon rotation of the rotatable element in order to adjust a tensioning force on the drive belt.The elastic element is elastically supported between the support portion and the base member, and its support direction is offset from the rotation axis. The locking element is used to lock or unlock the rotation of the rotatable element. The advantageous effects of the present invention include a simple structure and convenient tensioning.

Claims

[1] Tensioning arrangement for a drive belt, characterized by that it includes: a rotatable member comprising a joint portion, a support portion, and a tensioning portion, wherein the joint portion is connected to a base member for rotation about a rotation axis, and wherein the tensioning portion is displaceable relative to the base member upon rotation of the rotatable member to adjust a tensioning force on the drive belt; an elastic element which is elastically supported between the support section and the base member and whose support direction is offset with respect to the axis of rotation; and a locking element used to lock or unlock the rotation of the rotatable element. [2] Tensioning arrangement for a drive belt according to claim 1, characterized bythat the force arm of a supporting force of the elastic element on the rotatable element is greater than the force arm of a counterforce of the drive belt on the supporting section. [3] Tensioning arrangement for a drive belt according to claim 1, characterized by , that the rotatable element is provided with an arcuate recess whose circle centre lies in the axis of rotation; and that the locking element is a locking screw, wherein the locking element is guided through the arcuate recess and thus locks the rotatable element to the base component in order to block the rotation of the rotatable element. [4] Tensioning arrangement for a drive belt according to claim 1, characterized by , that the support section has a first surface and the base component has a second surface corresponding to the first surface, wherein the first surface is provided with a recessed annular recess, and wherein the elastic member is a coil spring and one end of the elastic member is fitted in the annular recess. [5] Tensioning arrangement for a drive belt according to claim 1, characterized by , that the base component has a base plate portion and a step portion projecting from the base plate portion; and that the tensioning arrangement for a drive belt further comprises a mounting plate, a support wheel and a rotating shaft, wherein the mounting plate comprises a connecting portion and a projection, wherein the connecting portion serves for fixed connection to the step portion, and wherein the projection protrudes from the step portion and is spaced from the base plate portion, wherein one end of the rotary shaft is connected to the base plate portion and the other end is connected to the projection and penetrates the projection, wherein the joint portion is rotatably connected to a part of the rotary shaft protruding from the projection, wherein a central axis of the rotary shaft constitutes the rotation axis, wherein the support wheel is located between the projection and the base plate portion and is mounted on the rotary shaft, and wherein the support wheel and the tensioning portion are spaced apart from each other in an extension direction of the drive belt to respectively support different locations of the drive belt. [6] Tensioning arrangement for a drive belt according to claim 5, characterized by , that the connecting portion is provided with a first through-hole, a second through-hole and a third through-hole; that the step portion is provided with a positioning pin, wherein the second through-hole is fitted to the positioning pin, wherein a fixing screw is passed through the first through-hole and thus firmly connects the connecting portion to the step portion, wherein the locking element is passed through the rotatable element and then the third through-hole and is thus detachably connected to the step portion; and that the projection is provided with a fourth through hole, wherein the rotary shaft is inserted into and fitted to the fourth through hole. [7] Tensioning arrangement for a drive belt according to claim 1, characterized by , that the rotatable element is provided with a U-shaped holder, wherein the clamping section is designed as a circular cylinder, wherein the clamping section is rotatably connected to an opening of the U-shaped holder and encloses a closed passage with the U-shaped holder, and wherein the drive belt is guided through the passage and is supported on the clamping portion in the direction of the opening of the U-shaped holder. [8] Travel drive arrangement, characterized by that it includes: a rotary motor; a drive belt fitted to the rotary motor to be driven by the rotary motor; and at least one drive belt tensioning arrangement according to one of claims 1 to 7, which is supported on the drive belt in order to tension the drive belt. [9] Traversing drive arrangement according to claim 8, characterized by , that two rotary motors and two drive belts are provided, wherein the two drive belts are each driven by the two rotary motors, wherein the two drive belts are arranged offset from one another in their width directions and the running sections of the two drive belts have at least a partially overlapping section, wherein two tensioning arrangements for a drive belt are provided, wherein the two tensioning arrangements for a drive belt are arranged spaced apart from one another in the overlapping section of the running paths of the two drive belts, wherein the tensioning arrangement for a drive belt has a support wheel and an additional support wheel, wherein the additional support wheel and the support wheel are arranged coaxially and offset from one another in their axial direction, wherein one of the support wheels and one of the additional support wheels form a support wheel set to support two different points of a drive belt in the overlapping section, and wherein the other support wheel and the other additional support wheel form another support wheel set to support two different locations of the other drive belt in the overlapping section. [10] 3D printing device, characterized by that it includes: a basic component; a travel drive arrangement according to one of claims 8 and 9, wherein the tensioning arrangement for a drive belt is mounted on the base member; and a print head assembly connected to the drive belts for displacement by drive of the drive belt.

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