KR102203728B1 - Apparatus for variable gravity compensation for rotation and linear motion joint - Google Patents

Abstract

The present invention relates to a gravity compensating device for rotating and linear motion joints capable of compensating for changing gravity torque according to rotation and linear motion joint manipulation. According to the present invention, the gravity compensating deice for rotating and linear motion joints may comprise: a housing; a joint member rotatably and linearly installed in the housing; a cam profile rotated in association with the rotation of the joint member; a cam follower installed in the housing to move up and down along the cam profile; a spring presser installed in the housing to move together with the cam follower; and a torsion spring installed in the housing so as to be directly moved in conjunction with the linear movement of the joint member, and providing an elastic force in a direction opposite to the rotational direction of the joint member by one end thereof being pressed by the spring presser when the joint member is rotated and moves linearly.

Description

Gravity compensation device for rotary and linear joints {APPARATUS FOR VARIABLE GRAVITY COMPENSATION FOR ROTATION AND LINEAR MOTION JOINT}

The present invention relates to a gravity compensation device for rotational and linear joints, and more particularly, to a gravity compensation device for rotational and linear joints capable of compensating for gravity torque even during linear movement (direct movement) as well as rotational movement.

The gravity compensation device refers to a mechanism that compensates the gravitational torque acting on the joint through passive mechanical elements such as corresponding mass and spring to reduce the energy consumption of manipulator robots used in various fields.

Manipulators composed only of rotating joints are widely used because their work area is wider than the installation area. However, when implementing linear motion, there is a disadvantage in that a lot of torque must be generated due to unnecessary motion. Therefore, a manipulator including a linear motion (linear motion) joint is used in a surgical robot or a Stewart platform. Manipulators including linear joints likewise consume power continuously to support the load and gravity torque applied to the joint.

This problem can be improved by applying a gravity compensation device, but studies on the gravity compensation device of such a manipulator are hardly in progress. Therefore, there is a need for research on a gravity compensation device for a manipulator for a rotating linear joint.

Korean Registered Patent Publication No. 10-1790863 (2017.10.20)

The present invention is to provide a gravity compensation device for rotational and linear joints capable of compensating for gravity torque that changes according to rotation and linear joint manipulation.

According to an embodiment of the present invention, the present invention includes a housing; A joint member that is rotatably and directly installed in the housing; A cam profile rotated in association with the rotation of the joint member; A cam follower installed in the housing to move up and down along the cam profile; A spring pressure installed in the housing so as to move together with the cam follower; And a torsion installed in the housing so as to be directly driven in connection with the direct motion of the joint member, and when the joint member rotates and moves directly, one end is pressed against the spring pressure to provide an elastic force in a direction opposite to the rotational direction of the joint member. It may contain springs.

The housing is formed in a cylindrical shape and the cam profile is formed in a circular surface, and the cam profile may be formed to be eccentric with respect to the rotation center of the joint member.

The cam follower block on which the cam follower and the spring pressure are installed may be installed in the housing.

The cam follower may be installed on a front surface of the cam follower block, and the spring pressure may be installed on a rear surface of the cam follower block.

A through hole through which one end of the torsion spring passes may be formed in the spring pressure.

A belt member on which a conversion belt is installed is rotatably installed on one surface of the housing, and the conversion belt is installed to be interlocked with the joint member to convert a linear motion of the joint member into a rotational motion.

One side of the conversion belt may be connected by the joint member and the fastener.

A central shaft serving as a rotation center of the belt member may be installed in the housing, and a gear portion installed on the central shaft may be provided on one side of the belt member, and a pulley on which the belt member is wound may be provided on the other side.

A sliding yoke interlocked with the central axis is installed in the housing, and the sliding yoke may be directly driven in association with the rotation of the central axis.

An extension part extending in a vertical direction may be provided at one end of the central axis, and a yoke protrusion inserted into a long hole formed in the sliding yoke may be provided at an end of the extension part.

The sliding yoke may be provided with a fixed shaft into which the fixed end of the torsion spring is inserted.

According to an embodiment of the present invention, it is possible to compensate for the gravity torque that changes according to rotation and manipulation of the linear joint. In particular, it is possible to compensate for the changed gravity torque for rotation and the amplified gravity torque for linear motion. In this way, when the gravity torque is compensated for the rotational and linear joints, energy efficiency can be increased, and thus, it can be used in various equipment such as rehabilitation equipment, flight simulation equipment, and medical surgical robots.

1 is a perspective view of a gravity compensation device for rotation and direct motion joint according to an embodiment of the present invention.
Figure 2 is a view showing the configuration of the joint member side of the gravity compensation device for rotation and direct motion joint according to an embodiment of the present invention.
Figure 3 is a view schematically showing the initial state of the gravity compensation device for rotation and direct motion joint.
Figure 4 is a view schematically showing the gravity compensation when the joint member is rotated by 90 °.
Figure 5 is a view schematically showing the gravity compensation when the joint member is moved directly.
Figure 6 is a view schematically showing the gravity compensation when the joint member is rotated by 180 °.

In the present invention, various transformations may be applied and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it is to be understood to include all conversions, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are used only for the purpose of distinguishing one component from another component.

The terms used in the present application are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprises" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

Hereinafter, an embodiment of the gravity compensation device according to the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are assigned the same reference numbers and overlapped therewith. Description will be omitted.

1 is a perspective view of a gravity compensation device for a rotational and linear joint according to an embodiment of the present invention, and FIG. 2 is a view showing the configuration of a joint member side of a gravity compensation device for a rotational and linear joint according to an embodiment of the present invention. It is a drawing.

As shown, the gravity compensation device for rotation and direct motion joint according to an embodiment of the present invention includes a housing 10; A joint member 60 that is installed to be rotatable and directly moveable to the housing 10; A cam profile 12 rotated in association with the rotation of the joint member 60; A cam follower 22 installed in the housing 10 to move up and down along the cam profile 12; A spring pressure 24 installed in the housing 10 to move together with the cam follower 22; And the joint member 60 is installed in the housing 10 so as to be directly moved together with the joint member 60, and when the joint member 60 is rotated and moved directly, one end is pressed against the spring pressure 24 so that the joint member 60 It may include a torsion spring 30 that provides an elastic force in the direction opposite to the rotation direction of.

The housing 10 is made in a substantially cylindrical shape, which is only presented as an example, and the housing 10 may be made in various shapes. Inside the housing 10, a cam profile 12 having a circular surface is formed. The cam profile 12 is substantially formed inside the housing 10 so as to be operated in conjunction with the rotation and direct motion of the joint member 60, and the cam profile 12 is eccentric with respect to the rotation center of the housing 10. Are arranged. Accordingly, the cam follower 22 positioned on the cam profile 12 moves up and down in association with the cam profile 12 when the joint member 60 rotates and moves directly. This is well illustrated in FIGS. 3 to 6 which will be described below.

A cover 14 is coupled to one side of the housing 10, and the cover 14 covers the configuration of a cam follower block 20, a torsion spring 30, and a sliding yoke 40 installed on the housing 10. Plays a role.

The cam follower block 20 is installed to be movable in the vertical direction inside the housing 10. The cam follower block 20 moves in the vertical direction along the guide shaft 28 installed in parallel in the vertical direction.

Then, the cam follower 22 is installed on the front side of the cam follower block 20, and the spring pressure 24 is installed on the rear side. In FIG. 1, the cam follower 22 is illustrated as being installed on the rear side, but hereinafter, the side close to the joint member 60 is defined as the front side and will be described.

The cam follower 22 is a portion protruding from the front surface of the cam follower block 20 like a protrusion, and is disposed on the cam profile 12 to move in association with the rotation and linear motion of the cam profile 12. Since the cam follower 22 is installed on the cam follower block 20, when the cam follower 22 moves along the cam profile 12, it will move together with the cam follower block 20. That is, the cam follower block 20 may be moved up and down in the housing 10 in association with the rotation and direct motion of the cam profile 12.

Since the spring pressure 24 is also installed on the cam follower block 20, when the cam follower block 20 is moved, it interlocks with it and moves in the vertical direction. One side of the spring pressure 24 is formed with a through hole 26 through which one end 34 of the torsion spring 30 passes. Therefore, when the spring pressure 24 is moved downward in association with the cam follower block 20, the fixed end 32 provides an elastic force by pressing the one end 34 of the torsion spring 30 in this process.

The torsion spring 30 includes a circular fixed end 32 providing a substantially elastic force, and an end 34 extending from one side of the fixed end 32 by a predetermined length. The circular fixed end 32 is inserted and fixed to the fixed shaft 46 of the sliding yoke 40 to be described below. In addition, the one end portion 34 extending in the horizontal direction penetrates the through hole 26 of the spring pressure 24 and is pressed in association with the spring pressure 24. When the one end 34 of the torsion spring 30 is pressed in this way (in conjunction with the rotation of the joint member 60), the torsion spring 30 provides an elastic force in the opposite direction to the rotational direction of the joint member 60 Therefore, it compensates the torque for the changed gravity.

Next, the sliding yoke 40 is installed to be movable in the horizontal direction inside the housing 10. The sliding yoke 40 is linearly moved in the horizontal direction in conjunction with the linear motion of the joint member 60. An important function of the sliding yoke 40 in this embodiment is to change the position of the fixed end 32 of the torsion spring 30 by being directly moved according to the direct motion of the joint member 60. When the position of the fixed end 32 of the torsion spring 30 is changed by moving, the ratio at which the one end 34 of the torsion spring 30 is pressed is amplified, so that the torque against the amplified gravity can be compensated. This occurs as the torsion spring 30 moves directly toward the spring pressure 24, and in this process, the one end 34 of the torsion spring 30 is pressed relatively a lot.

The sliding yoke 40 is directly driven along the yoke guide 42 installed in the horizontal direction inside the housing 10, and the long hole 44 into which the yoke protrusion 74 of the central shaft 70 is inserted into the sliding yoke 40. ) Is formed. The long hole 44 is formed long in the vertical direction, and when the central shaft 70 is rotated, the yoke protrusion 74 is rotated and moves along the long hole 44, and in conjunction with this, the sliding yoke 40 is moved in the horizontal direction. It is directly driven.

The central shaft 70 is installed through the interior of the housing 10 and serves as a center through which the belt member 50 to be described below rotates. At the end of the central axis 70 (the side close to the sliding yoke 40), the extension 72 extends in a vertical direction, and a yoke protrusion 74 is formed at the end of the extension 72. Since the central shaft 70 has the configuration of the extension 72 and the yoke protrusion 74 as described above, when the central shaft 70 is rotated, the sliding yoke 40 may be directly moved in the horizontal direction in association with it. .

Referring to FIG. 2, a belt member 50 on which a conversion belt 54 is installed is rotatably installed on one surface of the housing 10. Since the belt member 50 is connected to the central shaft 70 through a gear portion 52 (eg, a planetary gear), the belt member 50 rotates the central shaft 70. On the other hand, since the conversion belt 54 is connected through the joint member 60 and the fastener 62, when the joint member 60 is directly moved, the conversion belt 54 rotates in connection with it, and the gear unit 52 It is converted so that the central axis 70 is rotated by. In other words, the linear motion of the joint member 60 is converted into a rotational motion of the central shaft 70 through the configuration of the conversion belt 54 and the gear unit 52. On the other hand, one side of the conversion belt 54 is wound around the gear unit 52 and the other side is wound around the pulley 56.

The mechanism for converting the linear motion of the joint member 60 described above is only an example, and a mechanism capable of changing the position of the fixed end 32 of the torsion spring 30 for the linear motion of the joint member 60 is implemented. If this is possible, any configuration could be employed.

Hereinafter, a gravity compensation process of the gravity compensation device for a rotational and linear joint according to an embodiment of the present invention will be described with reference to FIGS. 3 to 6. 3 is a view schematically showing the initial state of the gravity compensation device for rotation and direct motion joint, Figure 4 is a view schematically showing the gravity compensation when the joint member is rotated by 90 °, Figure 5 is a joint member is a direct motion It is a view schematically showing the compensation of gravity when the joint member is rotated by 180°, and FIG. 6 is a view schematically showing the compensation of gravity when the joint member is rotated by 180°. For reference, FIGS. 3 to 6 illustrate a gravity compensation mechanism by simplifying the complex configuration shown in FIGS. 1 and 2.

Referring to FIG. 3, in the initial state of the gravity compensation device, the joint member 60 is in an upward state and the cam follower 22 is located at the top end of the cam profile 12. In fact, the cam follower 22 may be located at the lowest end on the cam profile 12, which can be changed according to the design of the gravity compensation device. In this drawing, the cam follower 22 is located at the top of the cam profile 12 for convenience. It is shown as being located.

In this state, when the joint member 60 is rotated by 90° in the clockwise direction, it becomes the position shown in FIG. 4. At this time, the cam profile 12 is rotated together in association with the rotation of the joint member 60, and the cam follower 22 is moved downward in association with the cam profile 12. This is because the cam profile 12 is eccentric with respect to the rotation center (central shaft 70) of the joint member 60, the cam follower 22 is moved. When the cam follower 22 is moved downward in this way, the spring pressure 24 presses the one end 34 of the torsion spring 30. At this time, since the torsion spring 30 provides an elastic force in a direction opposite to the rotation direction of the joint member 60, the changed gravity torque can be compensated.

Next, when the joint member 60 is directly moved to the right by a predetermined distance in the state shown in FIG. 4, the state shown in FIG. 5 is achieved. At this time, the rotation angle of the joint member 60 is maintained as it is, and the position of the fixed end 32 of the torsion spring 30 moves to the right in connection with the movement of the joint member 60. Then, since the ratio of the one end 34 of the torsion spring 30 pressed by the spring pressure 24 is amplified, the amplified gravity torque can be compensated. Meanwhile, the movement of the torsion spring 30 described above is performed by the movement of the sliding yoke 40 described above.

Finally, when the joint member 60 is rotated by 90° in the clockwise direction in the state shown in FIG. 5 (maintaining the linear length), the position of the cam follower 22 moves further downward by interlocking with the cam profile 12 Is done. That is, since the one end 34 of the torsion spring 30 is pressed by the displacement of the cam follower 22, the amplified and changed gravity torque can be compensated.

Although the above has been described with reference to specific embodiments of the present invention, those of ordinary skill in the relevant technical field may vary the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You will understand that it can be modified and changed.

10: housing 12: cam profile
14: cover 20: cam follower block
22: cam follower 24: spring pressure
26: through hole 28: guide shaft
30: torsion spring 32: fixed end
34: one end 40: sliding yoke
42: yoke guide 44: long hole
46: fixed shaft 50: belt member
52: gear part 54: conversion belt
56: pulley 60: joint member
62: fastener 70: central axis
72: extension 74: yoke protrusion

Claims (11)

housing;
A joint member that is rotatably and directly installed in the housing;
A cam profile rotated in association with the rotation of the joint member;
A cam follower installed in the housing and moved up and down along the cam profile;
A spring pressure installed in the housing so as to move together with the cam follower; And
A torsion spring that is installed in the housing so as to be directly driven by interlocking with the linear motion of the joint member, and provides an elastic force in a direction opposite to the rotation direction of the joint member by pressing one end of the spring pressure when the joint member is rotated and moved Gravity compensation device for rotation and direct motion joints comprising a. The method of claim 1,
The housing is shaped in a cylindrical shape and the cam profile is formed in a circular surface,
The cam profile is formed to be eccentric with respect to the rotation center of the joint member. The method of claim 1,
In the housing, the cam follower and a cam follower block on which the spring pressure is installed are installed. The method of claim 3,
The cam follower is installed on the front side of the cam follower block, and the spring pressure is installed on the rear side of the cam follower block. The method of claim 1,
Gravity compensation device for rotational and linear joints, characterized in that the spring pressure has a through hole through which one end of the torsion spring passes. The method of claim 1,
A belt member on which a conversion belt is installed is rotatably installed on one surface of the housing, and the conversion belt is installed to rotate in association with the linear motion of the joint member, thereby converting the linear motion of the joint member into a rotational motion. Gravity compensation device for rotary and linear joints. The method of claim 6,
One side of the conversion belt is a gravity compensation device for rotation and direct motion joint, characterized in that connected by the joint member and fastener. The method of claim 6,
The housing is provided with a central axis serving as the center of rotation of the belt member,
One side of the belt member is provided with a gear unit installed on the central shaft, and the other side is provided with a pulley on which the belt member is wound. The method of claim 8,
The housing is provided with a sliding yoke for linear motion in association with the central axis, wherein the sliding yoke linearly moves in association with the rotational motion of the central axis. The method of claim 9,
An extension portion extending in a vertical direction is provided at one end of the central axis, and a yoke protrusion inserted into a long hole formed in the sliding yoke is provided at an end of the extension portion. The method of claim 10,
Gravity compensation device for rotating and linear joints, characterized in that the sliding yoke is provided with a fixed shaft into which the fixed end of the torsion spring is inserted.

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