Drive shaft braking apparatus

Abstract

The driving shaft braking apparatus according to an embodiment of the present invention is a braking apparatus for braking a driving shaft used for an arm of a robot. The driving shaft braking apparatus comprises: a ring-shaped brake outer to which a brake ring is coupled so as to apply braking or release the braking by means of an interaction with a brake wing; and a ring-shaped brake pad coupled to the inside of the brake outer, the driving shaft being positioned inside the brake pad. The inner surface of the brake pad and the outer surface of the driving shaft partially contact each other such that impacts occurring when the brake ring engages with the brake wing are reduce and then transferred to the driving shaft through the brake outer and the brake pad.

Description

Drive shaft braking device

[0001] The present invention relates to a drive shaft braking device, and more particularly, to a drive shaft braking device that can accurately perform braking while reducing the shock generated at the time from being transmitted to the drive shaft, thereby maintaining the durability of the drive shaft and the brake pad surrounding the drive shaft.

[0002] Due to recent advancements in robotics technology, the need for intelligent robots that can perform various tasks in place of humans, in addition to industrial robots, is increasing, and research and development in this area is actively being conducted.

[0003] Developing intelligent robots requires advanced technologies such as new materials, semiconductors, artificial intelligence, and sensor software, along with technologies in machinery and electronics. Unlike existing industrial robots, intelligent robots can be said to be robots that possess the functions and performance demanded by the future market.

[0004] Meanwhile, industrial robots and service robots have been developed and are being used for various purposes in various fields, and their use is increasing as they can perform not only simple tasks but also advanced tasks accurately and quickly.

[0005] In this way, the joint module of a robot used in various industrial and service fields includes a motor, a torque sensor for stably driving the motor, a braking device, etc., and among these, the braking device is essential for controlling the acceleration and deceleration of a moving object or maintaining the position of the robot arm when stopped.

[0006] Conventional braking devices perform a braking action on an object by using friction-type brake pads, mechanically bringing the brake pads into contact with the object requiring the braking action, and using the frictional force generated at this time to perform the braking action on the object.

[0007] However, in the case of conventional braking devices, slipping may occur during the process of performing mechanical braking operation by the brake pad, so there were limitations in using them in areas where relatively precise braking force control was required, such as the joints of robots.

[0008] In addition, in conventional braking devices, the entire inner surface area of ​​the brake pad has a structure that wraps around the drive shaft while making full contact with it. In this case, if an impact occurs on the brake ring, the impact is transmitted to the drive shaft, which may reduce the durability of the drive shaft and cause wear to the brake pad wrapping the drive shaft.

[0009] Accordingly, there is a need for the development of a new configuration of a braking device that can accurately perform braking when braking the brake ring while reducing the shock transmitted to the drive shaft, thereby maintaining the durability of the drive shaft and the brake pad surrounding it.

[0010] An embodiment of the present invention provides a drive shaft braking device that can reduce the shock generated at the time of braking from being transmitted to the drive shaft while accurately performing braking, thereby maintaining the durability of the drive shaft and the brake pad surrounding the drive shaft.

[0011] The problems to be solved by the present invention are not limited to the problem(s) mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0012] A drive shaft braking device according to an embodiment of the present invention is a braking device for braking a drive shaft used in an arm of a robot, comprising: a ring-shaped brake outer to which a brake ring is coupled to perform braking or release of the brake by mutual operation with a brake wing; and a ring-shaped brake pad coupled to the inner side of the brake outer and having the drive shaft positioned on the inner side, wherein the inner surface of the brake pad and the outer surface of the drive shaft are in partial contact so that an impact generated by the brake ring being caught by the brake wing is reduced and transmitted to the drive shaft through the brake outer and the brake pad.

[0013] According to one side, the brake outer is formed in a circular shape and has a disconnected section, and the disconnected section is connected by a connecting portion, and the diameter of the brake outer and the brake pad can be adjusted by adjusting the interval of the disconnected section by the connecting portion.

[0014] According to one side, the connecting part is provided with a preload wrench bolt, and the head part of the connecting part is rotatably coupled to one side of the brake outer forming the disconnected section, and the leg part of the connecting part is rotatably coupled to the other side of the brake outer forming the disconnected section, so that the gap of the disconnected section can be adjusted by rotation of the connecting part.

[0015] According to one side, the brake pad is provided with a pad disconnection section that matches the disconnection section of the brake outer, so that when the gap of the brake outer is adjusted by the connecting portion, the gap of the pad disconnection section and the diameter of the brake pad can be adjusted.

[0016] According to one aspect, a pair of contact portions are provided to protrude symmetrically from the inner surface of the brake pad, and one of the pair of contact portions is provided in the pad disconnection section, and the other contact portion may be provided symmetrically on the opposite side of the one contact portion.

[0017] According to one side, the area of ​​the contact portion provided on the brake pad may be 1 / 6 to 1 / 4 of the area of ​​the inner circumference of the brake pad.

[0018] According to one side, when the connecting part is rotated so that the gap of the disconnected section becomes smaller, a preload is applied to the brake outer, thereby generating a fastening torque, and the diameter of the brake outer and the brake pad is reduced within the elastic limit by the fastening torque, and a load is generated in the radial direction between the brake pad and the driving shaft, so that a friction torque can be generated when the brake ring is braked by the brake wing.

[0019] According to one aspect, the brake ring is provided with one or more catch pieces, and the brake wing is rotatably coupled to the brake axis of the support frame fixed to the robot arm, and the braking of the brake ring is performed by physical interference between the catch pieces of the brake ring and the catch projection provided on one side of the brake wing, thereby stopping the rotation of the drive shaft.

[0020] According to one aspect, the brake wing may further include a position adjusting unit that adjusts the position of the catch by rotating the brake wing to adjust the catch or release of the catch piece of the braking ring with respect to the catch; and an elastic unit that provides elasticity to the rotation of the brake wing.

[0021] According to one side, the end of the engaging piece of the brake ring includes a triangular portion in the shape of an isosceles triangle whose width decreases as it goes outward and a rectangular square portion located at the vertex area of ​​the triangular portion, and the engaging projection of the brake wing may be provided in a groove shape in which the square portion of the engaging piece is engaged or released.

[0022] According to one aspect, the position control unit may be a solenoid that pressurizes or depressurizes the other side of the braking wing to rotate the braking wing about its axis.

[0023] According to an embodiment of the present invention, while braking is performed accurately, the shock generated at the time can be reduced from being transmitted to the drive shaft, thereby maintaining the durability of the drive shaft and the brake pad surrounding the drive shaft.

[0024] FIG. 1 is a perspective view of a drive shaft braking device according to one embodiment of the present invention.

[0025] Fig. 2 is a vertical cross-sectional view of the drive shaft braking device of Fig. 1.

[0026] Fig. 3 is a schematic drawing of the combined structure of the brake ring and the drive shaft illustrated in Fig. 1.

[0027] Figure 4 is a drawing for explaining the configuration of the brake outer, brake pad, and drive shaft in Figure 1.

[0028] Fig. 5 is a drawing schematically illustrating the contact state between the contact portion of the brake pad and the outer surface of the drive shaft in Fig. 4.

[0029] The advantages and / or features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

[0030]

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0032] FIG. 1 is a perspective view of a drive shaft braking device according to one embodiment of the present invention, FIG. 2 is a cross-sectional view taken vertically through the drive shaft braking device of FIG. 1, FIG. 3 is a drawing schematically illustrating a joint structure of a brake ring and a drive shaft illustrated in FIG. 1, FIG. 4 is a drawing for explaining the configuration of a brake outer, a brake pad, and a drive shaft in FIG. 1, and FIG. 5 is a drawing schematically illustrating a contact state between a contact portion of a brake pad and an outer surface of a drive shaft in FIG. 4.

[0033] Although not illustrated in detail, a drive shaft braking device (100) according to one embodiment of the present invention may be a device that is coupled to a drive shaft (110) of a motor together with a reducer and an encoder inside a joint, for example, of a robot arm, and that allows the rotation of the joint to be stopped and maintained at an accurate position when the motor stops.

[0034] For example, the joint can be equipped in various robots such as collaborative robots, industrial robots, humanoid robots, and robot manipulators, but the present invention is not limited thereto, and can be applied as a braking mechanism coupled to the drive shaft (110) of various devices other than robots.

[0035] As illustrated in FIGS. 1 and 2, a drive shaft braking device (100) according to one embodiment of the present invention may include a brake wing (130) mounted on a support frame (105), a ring-shaped brake outer (160) to which a brake ring (120) is coupled to perform braking or release braking by mutual operation with the brake wing (130), and a ring-shaped brake pad (150) coupled to the inside of the brake outer (160) and on which a drive shaft (110) of a robot arm is positioned.

[0036] Below, the braking structure of the brake ring (120) and the brake wing (130) will first be described, and then the structure in which the shock generated in the brake ring (120) is transmitted to the drive shaft (110) will be described in detail.

[0037] Referring to FIGS. 1 and 2, the brake ring (120) is coupled to the brake outer (160), and the brake outer (160) has a structure in which it is coupled to the drive shaft (110) with the brake pad (150) therebetween, so that when the drive shaft (110) rotates, the brake ring (120) also rotates, and the brake wing (130) whose position is adjusted by the position adjustment unit (180) can be braked or released.

[0038] For example, the brake ring (120) may have an overall circular ring shape, as shown in FIGS. 1 to 3, and may have four catch pieces (121) protruding in a radial direction.

[0039] The end of the catch piece (121) may include a triangular portion (122) in the shape of an isosceles triangle whose width decreases as it goes outward, as shown in FIG. 3, and a rectangular square portion (123) located at the vertex area of ​​the triangular portion (122), and the square portion (123) may be caught or released from the brake wing (130).

[0040] In addition, referring to FIG. 3, a total of four protruding portions are provided on the inside of the brake ring (120), so that the protruding portions (125) can be supported on the drive shaft (110). A cushioning material made of, for example, silicone can be provided at the end of the protruding portions (125), thereby reducing the impact applied to the drive shaft (110), etc.

[0041] In addition, a catch (131) is formed on a brake wing (130) that rotates around the brake axis of a support frame (105) fixed to a robot arm, so that the drive shaft (110) can be rotated or stopped by physical interference with the end of the catch piece (121), thereby implementing a braking device (100) capable of bidirectional braking with a small clearance.

[0042] In detail, the catch (131) of the brake wing (130) is provided in a groove shape in which the square part (123) of the catch piece (121) is caught or released, so that the square part (123) of the catch piece (121) can be caught by the catch piece (131) and firmly maintained in that state, and when the brake wing (130) is rotated by the position adjusting part (180) described later, the square part (123) of the catch piece (121) can be smoothly released from the catch piece (131).

[0043] The brake wings (130) may be provided one on each side of the support frame (105), as shown in FIGS. 1 and 2, and each brake wing (130) may be rotated by a position adjusting member (180) provided on each side of the support frame (105).

[0044] In detail, the catch (131) can move between a catch position located within the rotation radius of the end of the catch piece (121) formed on the brake ring (120) and a catch release position located outside the rotation radius of the end according to the rotation of the brake wing (130) by the position adjusting unit (180).

[0045] Through this, when the catch (131) of the brake wing (130) moves to the catch position, the rotation of the drive shaft (110) is stopped due to physical interference with the square portion (123) provided at the end of the catch piece (121) formed on the brake ring (120), and when the catch (131) moves to the catch release position, physical interference with the square portion (123) does not occur, so the rotation is not affected.

[0046] Meanwhile, the position control unit (180) of the present embodiment may be provided with a solenoid that can rotate the brake wing (130) depending on the presence or direction of the input current to move the engaging projection (131) to either the engaging position or the releasing position.

[0047] Referring to FIGS. 1 and 2, the brake wing (130) may be provided with an elastic member (140) that provides elasticity. A spring-type elastic member (140) may be provided on the axis of the brake wing (130), and through this, when the other side of the brake wing (130), i.e., a part adjacent to the position adjusting member (180), is not pushed by the position adjusting member (180), the brake wing (130) may be in an unlocked position that does not engage the engaging piece (121) of the brake ring (120).

[0048] Conversely, when the other side of the brake wing (130) is pushed through the position adjustment unit (180), the brake wing (130) can be rotated in the opposite direction of the direction in which the elastic force is provided and positioned in the engaging position, and the engaging piece (121) of the brake ring (120) can be engaged with the engaging projection (131) of the brake wing (130).

[0049] In this embodiment, using FIGS. 1 and 2, the brake wing (130) is provided on each side of the support frame (105) and the position adjusting unit (180) is provided correspondingly. However, the present invention is not limited thereto, and although not illustrated, one brake wing may be provided and one position adjusting unit for rotating the brake wing may also be provided. However, in this case, the engaging projection of the brake wing may have a groove structure that allows the engaging piece of the brake ring to move in both directions.

[0050] In this way, in the present embodiment, braking and braking release of the brake ring (120) can be performed by the brake wing (130) whose position is adjusted by the position adjustment unit (180).

[0051] However, during the process of braking the brake ring (120) through the brake wing (130), an impact may occur, and the impact may be transmitted to the brake outer (160), brake pad (150), and drive shaft (110) to which the brake ring (120) is coupled. If the impact is transmitted as is, the durability of the drive shaft (110) may be weakened, and wear may occur on the brake pad (150).

[0052] Accordingly, the drive shaft braking device (100) of the present embodiment has a contact structure of a brake pad (150) and a drive shaft (110) to prevent this.

[0053] As described above, the drive shaft braking device (100) of the present embodiment may include a brake outer (160) and a ring-shaped brake pad (150) coupled to the inside of the brake outer (160) and on which the drive shaft (110) of the robot arm is positioned.

[0054] Here, the inner surface of the brake pad (150) and the outer surface of the drive shaft (110) are not in full contact as shown in FIGS. 4 and 5, but are partially in contact, so that the shock generated when the brake ring (120) is caught on the brake wing (130) is not directly transmitted to the drive shaft (110), but the shock can be reduced and transmitted in proportion to the contact area.

[0055] In other words, the shock generated by the catch piece (121) of the brake ring (120) being caught on the catch protrusion (131) of the brake wing (130) can be reduced and transmitted to the drive shaft (110) due to the partial contact structure of the brake pad (150) and the drive shaft (110), thereby not only maintaining the durability of the drive shaft (110), but also minimizing wear of the brake pad (150).

[0056] The brake outer (160) of the present embodiment has an overall ring shape, as illustrated in FIGS. 1 and 4, and a brake ring (120) can be fixed to the front by a fixing bolt (124). A total of four fixing bolts (124) can pass through the brake ring (120) and be coupled to the brake outer (160), thereby firmly maintaining the position of the brake ring (120) with respect to the brake outer (160).

[0057] This brake outer (160), as schematically illustrated in FIG. 4, is provided in a circular shape and has a disconnection section (160S), and the interval of the disconnection section (160S) can be adjusted by connecting the disconnection section (160S) with a connecting portion (170).

[0058] This connecting portion (170) can be provided with a preload wrench bolt, as illustrated in FIGS. 1 and 4. That is, the head portion (171) of the connecting portion (170) is coupled to one side of the brake outer (160) forming the disconnected section (160S), and the leg portion (175) of the connecting portion (170) having a thread formed thereon is coupled to the other side of the brake outer (160) forming the disconnected section (160S), and through this, when the connecting portion (170) is rotated, the other side of the disconnected section (160S) can be brought closer to or separated from one side of the disconnected section (160S) by the screw movement principle.

[0059] This allows the spacing of the disconnection section (160S) to be adjusted, thereby allowing the diameter of the brake outer (160) and the brake pad (150) therein to be adjusted.

[0060] Precise control is possible by utilizing a high reduction ratio through the connecting portion (170), and through this, the diameter of the brake outer (160) can be adjusted in micrometer units. Therefore, as will be described later, the initial preload required to generate friction torque between the brake pad (150) and the drive shaft (110) can be sensitively controlled.

[0061] In addition, the brake pad (150) of the present embodiment, as illustrated in FIG. 4, is provided in an overall ring shape and is positioned within the brake outer (160), and may be provided with a pad disconnection section (150S) that matches the disconnection section (160S) of the brake outer (160). Accordingly, when the disconnection section (160S) of the brake outer (160) is adjusted in interval by the connecting portion (170), the pad disconnection section (150S) of the brake pad (150) is also adjusted in interval, thereby allowing the diameter of the brake pad (150) to be adjusted.

[0062] As described above, in the case of the present embodiment, the shock transmission amount can be reduced by having a structure in which the inner surface of the brake pad (150) and the outer surface of the drive shaft (110) are partially in contact rather than completely in contact.

[0063] As illustrated in FIG. 4 and exaggeratedly illustrated in FIG. 5 for ease of understanding, a pair of contact portions (155) having a symmetrical structure may be provided protrudingly on the inner surface of a brake pad (150). One of the pair of contact portions (155) may be provided in a pad disconnection section (150S), and the other contact portion (155) may be provided symmetrically on the opposite side.

[0064] The contact portion (155) may be, for example, 1 / 6 to 1 / 4 of the inner circumference of the brake pad (150), so that the brake pad (150) and the drive shaft (110) are kept in a non-contact state in the remaining portion (151) except for the contact portion (155).

[0065] Referring to Fig. 4, the friction coefficient (M) of the brake pad (150) of the present embodiment p ) can be obtained by the following equation.

[0066] ...Formula 1

[0067] ...Formula 2

[0068] ...Formula 3

[0069] ...Formula 4

[0070] ...Formula 5

[0071] (Here, M p is the friction torque of the brake pad (150), μ p is the coefficient of friction, N p is the vertical load applied to the brake pad (150), D0 is the initial contact diameter, D1 is the changed contact diameter, and Kpn is the vertical stiffness coefficient of the brake pad (150), and δ pn is the change in diameter of the brake pad (150), and A p m is the contact area of ​​the brake pad (150), m is the contact area number, α is the contact area angle, and E p is the elastic modulus of the brake pad (150), and L p is the thickness of the brake pad (150), and d c is the diameter of the drive shaft (110), and d h is the height of the brake pad (150))

[0072] Through this, when the contact area between the brake pad (150) and the drive shaft (110) is small, the frictional torque is generated small, so that the durability of the drive shaft (110) can be maintained while minimizing wear of the brake pad (150).

[0073] As the contact area between the brake pad (150) and the drive shaft (110) becomes smaller, the vertical stiffness coefficient (K) of the brake pad (150) pn ) is lowered, and the stiffness coefficient and elastic modulus (E p ) are proportional, the strain for the same vertical load may increase when the elastic modulus decreases within the elastic limit.

[0074] That is, by reducing the contact area between the brake pad (150) and the drive shaft (110), the sensitivity to changes in the diameter of the brake pad (150) can be reduced.

[0075] In detail, as described above, by rotating the connecting portion (170) provided with a wrench bolt, a preload is applied to the brake outer (160), thereby generating a fastening torque, and the diameter of the brake outer (160) and the brake pad (150) is reduced within the elastic limit due to the fastening torque, and as a result, a load is generated in the radial direction between the brake pad (150) and the drive shaft (110), so that a friction torque may be generated when braking the brake ring (120).

[0076] In this way, according to the present embodiment, while braking is performed accurately, the shock generated at the time can be reduced from being transmitted to the drive shaft (110), thereby maintaining the durability of the drive shaft (110) and the brake pad (150) surrounding it.

[0077]

[0078] While specific embodiments of the present invention have been described so far, it is clear that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the claims set forth below, but also by equivalents thereof.

[0079] Although the present invention has been described with reference to limited embodiments and drawings, it is not limited to the above-described embodiments. Those skilled in the art will appreciate that various modifications and variations are possible based on this disclosure. Therefore, the scope of the present invention should be understood solely by the scope of the claims set forth below, and all equivalent or equivalent modifications thereof are deemed to fall within the scope of the present invention.

Claims

1. In a braking device for breaking a drive shaft used in a robot arm, A ring-shaped brake outer to which a brake ring is coupled to enable braking or release of the brake by interaction with the brake wing; and A ring-shaped brake pad coupled to the inner side of the brake outer, the drive shaft being positioned on the inner side; Including, A drive shaft braking device characterized in that the inner surface of the brake pad and the outer surface of the drive shaft are in partial contact so that the shock generated by the brake ring being caught by the brake wing is reduced and transmitted to the drive shaft through the brake outer surface and the brake pad.

2. In paragraph 1, A drive shaft braking device characterized in that the brake outer is formed in a circular shape and has a disconnected section, the disconnected section is connected by a connecting portion, and the diameter of the brake outer and the brake pad is adjusted by adjusting the gap of the disconnected section by the connecting portion.

3. In paragraph 2, The above connection is provided with a preload wrench bolt, A drive shaft braking device characterized in that the head portion of the connecting portion is rotatably connected to one side of the brake outer forming the disconnected section, and the leg portion of the connecting portion is rotatably connected to the other side of the brake outer forming the disconnected section, such that the gap of the disconnected section is adjusted by the rotation of the connecting portion.

4. In paragraph 3, A drive shaft brake device, characterized in that the brake pad has a pad disconnection section that matches the disconnection section of the brake outer, and when the gap of the brake outer is adjusted by the connecting portion, the gap of the pad disconnection section and the diameter of the brake pad are adjusted.

5. In paragraph 4, A pair of contact portions are provided to protrude symmetrically from the inner surface of the above brake pad, A drive shaft braking device, characterized in that one of the pair of contact portions is provided in the pad disconnection section and the other contact portion is provided symmetrically on the opposite side of the one contact portion.

6. In paragraph 5, A drive shaft braking device, characterized in that the area of ​​the contact portion provided on the brake pad is 1 / 6 to 1 / 4 of the area of ​​the inner circumference of the brake pad.

7. In paragraph 4, A drive shaft brake device characterized in that when the connecting part is rotated so that the gap of the above-mentioned disconnected section becomes smaller, a preload is applied to the brake outer, a fastening torque is generated, the diameter of the brake outer and the brake pad is reduced within the elastic limit by the fastening torque, and a load is generated in the radial direction between the brake pad and the drive shaft, so that a friction torque is generated when the brake ring is braked by the brake wing.

8. In paragraph 1, The above brake ring is provided with one or more catches, The brake wing is rotatably connected to the brake axis of the support frame fixed to the robot arm. A drive shaft braking device characterized in that the rotation of the drive shaft is stopped by braking the brake ring through physical interference between the engaging piece of the brake ring and the engaging projection provided on one side of the brake wing.

9. In paragraph 8, A position adjusting unit that adjusts the position of the catch by rotating the brake wing to adjust the catch or release of the catch piece of the braking ring with respect to the catch; and A drive shaft braking device characterized in that it further includes an elastic member that provides elasticity to the rotation of the brake wing.

10. In paragraph 9, The end of the engaging piece of the above brake ring includes a triangular portion in the shape of an isosceles triangle whose width decreases as it goes outward, and a rectangular square portion located at the vertex area of ​​the triangular portion, A drive shaft braking device, characterized in that the engaging projection of the brake wing is provided in a groove shape in which the square portion of the engaging piece is engaged or released.

11. In paragraph 10, A drive shaft braking device characterized in that the above position adjusting member is a solenoid that pressurizes or releases the other side of the braking wing to rotate the braking wing about the axis.

Images