TWI477706B - Differential-velocity driving device and mechanical arm applying thereof - Google Patents

Description

Differential drive device and robot arm applying the same

The present disclosure relates to a driving device and a robot arm using the same, and more particularly to a differential driving device and a robot arm using the differential driving device.

In 2010, the number of global smart mobile devices has exceeded 1.35 billion. In the manufacturing process of these electronic products, the demand for human assembly is over 90%. However, in recent years, the basic salary of assembly manpower has grown significantly, seriously eroding the assembly of electronic components. In addition, with the aging of the population and the impact of declining population, most countries are also facing the problem of lack of labor. Therefore, the electronic component assembly industry has always had the need to introduce automated assembly technology to overcome the above problems and face electronic products. Increasingly complex assembly characteristics, such as the compliant properties required for polishing or deburring.

Due to the requirements of the aforementioned automated assembly technology, the electronic component assembly industry has greatly increased its investment in multi-axis robot arms. Among them, due to the light weight and high speed of the parallel mechanical arm, combined with visual feature recognition technology, It has a competitive advantage in the assembly of electronic components, so it is often used in odd-form assembly, and even has a tendency to gradually replace horizontal multi-joint robots.

At present, the parallel type mechanical arm still has vibration problems to be overcome under high-speed operation. If the vibration can be further improved to reduce the cycle time, the production efficiency and application range can be greatly improved, and the development of electronic products tends to be light and delicate. , electronic substrate is multi-layer design, various Connectors are also more difficult to assemble, so when the assembly line has been gradually automated, the assembly of electronic components must still be carried out manually. The main reason is that the robot arm lacks human compliance.

Those skilled in the art have proposed a dual drive joint mechanism that can simultaneously achieve position and stiffness control. The mechanism has dual drive components and a planetary gear set. The main drive components are low speed and high torque motors for position control. The sub-driving element is a high-speed and low-torque motor for rigid modulation, and the main driving element and the sub-driving element drive the mechanical joint in series by the planetary gear set, thereby driving a mechanical arm and transmitting Control motor speed to achieve position control and change the rigidity of the arm.

However, the prior art still has a backlash problem, and the planetary gear set has a reduction ratio, and it is necessary to select a properly matched driving component, so that the design of the controller will be inconvenient.

Therefore, how to avoid various problems in the above-mentioned prior art has become a problem that is currently being solved.

The present disclosure provides a differential drive device comprising: a first rotary drive component; a first drive gear coupled to the first rotary drive component and rotationally driven by the first rotary drive component; a second rotary drive component; a second transmission gear is coupled to the second rotary drive component and is rotationally driven by the second rotary drive component, the first transmission gear has the same number of teeth as the second transmission gear train; the fixing member is coupled to the first rotary drive An element and a second rotary drive element, and the first rotary drive element and the second rotation The drive elements do not move or rotate relative to each other; the power output gears simultaneously engage the first transfer gear and the second transfer gear; and the output shaft passes through the axis of the power output gear and is coaxial with the shaft.

The disclosure provides a mechanical arm, comprising: a fixed platform; at least one differential driving device, each of the differential driving devices includes: a first rotating driving component; and a first transmission gear coupled to the first rotating driving component, And being driven by the first rotation driving element; the second rotation driving element; the second transmission gear is connected to the second rotation driving element, and is driven by the second rotation driving element, the first transmission gear and the second The transmission gear train has the same number of teeth; the fixing member connects the first rotation driving element and the second rotation driving element, and the first rotation driving element and the second rotation driving element do not move or rotate relative to each other, and the difference The speed drive device is disposed on the fixed platform by the fixing member; the power output gear meshes with the first transmission gear and the second transmission gear; the output shaft passes through the axis of the power output gear, and a coaxial axis; a restraining member is disposed on the output shaft and connected to at least two of the output shafts, and the at least two portions are respectively located at the power output The inner side and the outer side of the wheel are configured to prevent the power output gear from being disengaged from the first transmission gear and the second transmission gear, and prevent the output shaft from being disengaged from the power output gear; the swing arm is connected to the restraint member at one end thereof And a rod member having one end pivotally connected to the other end of the swing arm; and a moving platform pivotally connected to the other end of the rod of each of the differential driving devices.

As can be seen from the above, the differential driving device of the present disclosure is a differential joint that is simultaneously driven by two sets of rotary driving elements, that is, the speed of the joint is driven by two sets of rotations. The moving elements are matched, and only the speed of the rotating driving element needs to be changed during the reciprocating motion of the joint without stopping and reversing, so that the vibration problem caused by the inertia when the rotating driving element is stopped can be reduced, thereby achieving high speed. Round-trip motion and reduce cycle time, and can eliminate backlash problems.

The embodiments of the present disclosure are described below by way of specific embodiments, and those skilled in the art can readily understand other features and functions of the present disclosure.

It is to be understood that the structure, the proportions, the size and the like of the present invention are only used to clarify the disclosure of the specification for the understanding and reading of those skilled in the art, and are not intended to limit the disclosure. The conditions are limited, so it is not technically meaningful. Any modification of the structure, change of the proportional relationship or adjustment of the size should remain in this book without affecting the effectiveness and the purpose of the disclosure. It is disclosed that the disclosed technical content can be covered. In the meantime, the terms "upper", "inside", "outside", "one" and "two" are used in this description for convenience of description and are not intended to limit the disclosure. The scope, the change or adjustment of its relative relationship, is also considered to be within the scope of this disclosure if it is not materially changed.

1A and 1B are perspective views of the differential drive device disclosed herein, wherein FIG. 1B is a subsequent actuation state of FIG. 1A.

As shown, the differential drive device of the present disclosure includes: a first rotary drive element 11a; a first transfer gear 12a coupled to the first rotary drive element 11a and rotatably driven by the first rotary drive element 11a; second a rotary drive element 11b; the second transfer gear 12b is connected to the second rotary drive element 11b and is rotationally driven by the second rotary drive element 11b; and the fixing member 13 (shown only in FIGS. 2A and 2B described later) Connecting the first rotational driving element 11a and the second rotational driving element 11b, and the first rotating driving element 11a and the second rotating driving element 11b are not moved or rotated relative to each other; the power output gear 14 simultaneously meshes the first The transmission gear 12a and the second transmission gear 12b; and the output shaft 15 pass through the axis of the power output gear 14 and are coaxial with the shaft center.

In the differential drive device described above, the restraining member 16 (shown only in FIGS. 2A to 2C to be described later) is provided on the output shaft 15 and connected to at least two of the output shafts 15, and the at least two The two parts are respectively located inside and outside of the power output gear 14; the restraining member 16 is for preventing the power output gear 14 from being disengaged from the first transmission gear 12a and the second transmission gear 12b, and preventing the output shaft 15 from coming off the Power output gear 14.

The differential driving device may include an angle sensor 17 having a pulley 171 (shown only in FIGS. 2A to 2C, which will be described later), and is disposed on the second rotary driving element 11b, and the restraining member 16 has The outer frame of the ring, the pulley 171 is rotated simultaneously with the outer ring frame of the restraining member 16 through the belt 172; the angle sensor 17 is used for measuring the rotation angle of the restraining member 16, thereby obtaining the output shaft 15 The angle of rotation.

The first transmission gear 12a, the second transmission gear 12b and the power output gear 14 of the differential drive device of this embodiment may be a bevel gear or a friction wheel, and the first transmission gear 12a and the second transmission gear 12b have the same number of teeth. And the first transmission gear 12a and the power output gear 14 may have the same Or different numbers of teeth.

It should be noted that although the present embodiment shows two power output gears 14, the number of the power output gears 14 is not limited to two, and only a single power output gear 14 can complete the disclosure. Differential drive.

Referring to the rotation direction arrows of FIGS. 1A and 1B at the same time, assuming that the first transmission gear 12a and the second transmission gear 12b respectively have the rotation speed ω ₁ and the rotation speed ω _2, the power output gear 14 will be driven to have the rotation speed ω ₃ , and The output shaft 15 is also driven by the power output gear 14, and has a rotational speed Ω. The relationship between the rotational speeds ω _{1 ,} ω _{2 ,} ω ₃ and Ω will be as follows: ω ₃ = (ω ₂ + ω ₁ ) /2 Ω=(ω ₂ -ω ₁ )/2

2A to 2C are schematic views of a mechanical arm to which the differential driving device is applied, wherein FIG. 2B is an exploded view of a partial member of FIG. 2A, and FIG. 2C is a partial member of FIG. 2B. Floor plan.

Referring to FIGS. 1A and 1B and FIGS. 2A to 2C simultaneously, the present disclosure may further apply a differential driving device to complete a robot arm, including: a fixed platform 20, a moving platform 23, and at least one differential driving device; The composition of the differential driving device further includes a swing arm 21 and a rod member 22, and each of the differential driving devices is pivotally connected to the moving platform 23 by the swing arm 21 and the rod member 22; each of the differential speeds The driving device includes: a first rotation driving element 11a; a first transmission gear 12a coupled to the first rotation driving element 11a and rotatably driven by the first rotation driving element 11a; a second rotation driving element 11b; a gear 12b connected to the second rotary drive The movable element 11b is rotatably driven by the second rotary drive element 11b; the fixing member 13 is connected to the first rotary drive element 11a and the second rotary drive element 11b, and the first rotary drive element 11a and the second rotation The driving elements 11b are not moved or rotated relative to each other, and the differential driving device is disposed on the fixed platform 20 by the fixing member 13; the power output gear 14 simultaneously meshes the first transmission gear 12a and the second transmission gear 12b. The output shaft 15 is passed through the axis of the power output gear 14 and coaxial with the shaft; the restraining member 16 is disposed on the output shaft 15 and connected to at least two of the output shafts 15, and The at least two portions are respectively located inside and outside the power output gear 14; the restraining member 16 is configured to prevent the power output gear 14 from being disengaged from the first transmission gear 12a and the second transmission gear 12b, and prevent the output shaft 15 from being disengaged The power output gear 14 is connected to the restraining member 16 at one end of the swing arm 21, and the other end of the swing arm 21 is pivotally connected to one end of the rod member 22. The moving platform 23 is pivotally connected to each of the differential drives. The other end of the rod 22 of the device .

The mechanical arm includes an angle sensor 17 having a pulley 171 disposed on the second rotary driving element 11b, and the restraining member 16 has a circular outer frame, and the pulley 171 is transmitted through the belt 172. The annular frame of the restraining member 16 is simultaneously rotated; the angle sensor 17 is for measuring the angle of rotation of the restraining member 16.

The first transmission gear 12a, the second transmission gear 12b and the power output gear 14 of the robot arm of the embodiment may be a bevel gear or a friction wheel, and the first transmission gear 12a and the second transmission gear 12b have the same number of teeth, and The first transmission gear 12a and the power output gear 14 may have the same or different The number of teeth.

It can be seen from FIG. 2A that three differential driving devices of the present disclosure can be combined in parallel to form a mechanical arm having three degrees of freedom. However, the number of differential driving devices constituting the mechanical arm is not limited thereto. For example, The differential driving device can be combined into a mechanical arm having one degree of freedom, or the four differential arms can be combined in parallel to form a mechanical arm having four degrees of freedom, but the above disclosure is changed in the technical field. Generally, the knowledgeable person can understand according to the present specification, and therefore will not be illustrated and described herein.

In summary, the differential driving device of the present disclosure is a differential joint that is driven by two sets of rotating driving elements at the same time, that is, the speed of the joint is matched by two sets of rotating driving elements, and only needs to be performed during the reciprocating motion of the joint. The speed of the rotary drive element is changed without stopping and reversing, so that the vibration caused by the inertia when the rotary drive element is stopped can be reduced, thereby enabling high-speed reciprocating motion, reducing cycle time, and eliminating backlash problems. .

In addition, in terms of compliance, when the two rotational driving elements maintain the same rotational speed and the steering is reversed, the power output gear in the differential driving device is idling in place, and the output shaft is in a stationary state, at this time, as long as the synchronous rotation is increased by two rotational driving The speed of the component and the same speed, the output shaft is still at rest, but the rigidity of the output shaft will decrease with the increase of the speed. Conversely, the rigidity of the output shaft will increase with the decrease of the speed, that is, at the same output shaft speed output. It has a variable rigidity effect, because when a single DC motor is driven, the speed output is inversely proportional to the torque output, that is, the rigidity of the output shaft is related to the speed output, and the differential driving method disclosed in the present invention uses two rotary drives. The rotational speed of the components constitutes the output of an output shaft, so the output shaft can have different torque outputs at the same speed output. For example, when the rotational speeds of two rotary drive components are simultaneously increased, the torque and rigidity of the single motor and the output shaft are reduced. , but the speed of the output shaft does not change. In addition, when the two rotational driving elements have a speed difference, the output shaft can achieve a fretting effect by a small speed difference between the two rotating driving elements. Therefore, the disclosed robot arm has the characteristics of high torque output, high speed round trip, compliant motion and micro motion.

The above embodiments are intended to illustrate the principles of the disclosure and its functions, and are not intended to limit the disclosure. Any person skilled in the art can modify the above embodiments without departing from the spirit and scope of the disclosure. Therefore, the scope of protection of the present disclosure should be as set forth in the scope of the patent application described later.

11a‧‧‧First rotary drive element

11b‧‧‧second rotary drive element

12a‧‧‧First transmission gear

12b‧‧‧second transmission gear

13‧‧‧Fixed parts

14‧‧‧Power output gear

15‧‧‧ Output shaft

16‧‧‧ restraint

17‧‧‧ Angle Sensor

171‧‧‧ Pulley

172‧‧‧Land

20‧‧‧Fixed platform

21‧‧‧ swing arm

22‧‧‧ rods

23‧‧‧Mobile platform

ω _1, ω _2, ω ₃ , Ω‧‧‧ rpm

1A and 1B are perspective views of the differential drive device of the present disclosure, wherein FIG. 1B is a subsequent actuation state of FIG. 1A; and FIGS. 2A to 2C are for application of the differential drive of the present disclosure. A schematic view of a mechanical arm of the device, wherein FIG. 2B is an exploded view of a partial member of FIG. 2A, and FIG. 2C is a plan view of a partial member of FIG. 2B.

11a‧‧‧First rotary drive element

11b‧‧‧second rotary drive element

12a‧‧‧First transmission gear

12b‧‧‧second transmission gear

14‧‧‧Power output gear

15‧‧‧ Output shaft

ω _1, ω _2, ω ₃ , Ω‧‧‧ rpm

Claims (6)

A differential drive device includes: a first rotary drive component; a first drive gear coupled to the first rotary drive component and rotationally driven by the first rotary drive component; a second rotary drive component; a second drive gear Connecting the second rotary drive component and being rotationally driven by the second rotary drive component, the first drive gear and the second drive gear train having the same number of teeth; the fixing member connecting the first rotary drive component and the first Rotating the driving element and causing the first rotating driving element and the second rotating driving element not to move or rotate relative to each other; the power output gear simultaneously meshes the first transmission gear and the second transmission gear; the output shaft passes through The shaft of the power output gear is coaxial with the shaft; the restraining member is disposed on the output shaft and connected to at least two of the output shafts, and the at least two portions are respectively located at the power output gear The inner side and the outer side, the restraining member is configured to prevent the power output gear from being disengaged from the first transmission gear and the second transmission gear, and preventing the output shaft from being separated from the power transmission a gear; and an angle sensor having a pulley disposed on the second rotary driving member, wherein the restraining member has a ring outer frame, and the pulley rotates through the belt and the annular outer frame of the restraining member simultaneously, Angle sensing The device is used to measure the rotation angle of the restraint member. The differential drive device of claim 1, wherein the first transmission gear, the second transmission gear, and the power output gear train are a bevel gear or a friction wheel. The differential drive device of claim 1, wherein the first transmission gear has the same or different number of teeth as the power output gear train. A mechanical arm includes: a fixed platform; at least one differential drive device, each of the differential drive devices includes: a first rotary drive component; a first drive gear coupled to the first rotary drive component, and the first drive gear a rotary drive element is rotationally driven; a second rotary drive element; a second drive gear coupled to the second rotary drive element and rotatably driven by the second rotary drive element, the first drive gear and the second drive gear train having The same number of teeth; the fixing member connects the first rotating driving element and the second rotating driving element, and the first rotating driving element and the second rotating driving element do not move or rotate relative to each other, and each of the differential driving devices The fixing member is disposed on the fixed platform; the power output gear simultaneously meshes the first transmission gear and the second transmission gear; the output shaft passes through the axis of the power output gear, and Coaxial with the axis; the restraining member is disposed on the output shaft and connected to at least two of the output shafts, and the at least two portions are respectively located on the inner side and the outer side of the power output gear, and the restraining member is used Preventing the power output gear from being disengaged from the first transmission gear and the second transmission gear, and preventing the output shaft from being disengaged from the power output gear; an angle sensor having a pulley is disposed on the second rotary driving element, and the The restraining member has a ring outer frame, and the pulley wheel rotates simultaneously with the outer ring frame of the restraining member through the belt, the angle sensor is used for measuring the rotation angle of the restraining member; the swing arm is connected at one end thereof a restraining member; and a rod member pivotally connected to the other end of the swing arm; and a moving platform pivotally connected to the other end of the rod of each of the differential driving devices. The robot arm of claim 4, wherein the first transmission gear, the second transmission gear and the power output gear train are a bevel gear or a friction wheel. The robot arm of claim 4, wherein the first transmission gear has the same or different number of teeth as the power output gear train.