CN106891322A - A kind of novel six freedom parallel connection platform - Google Patents

Abstract

A kind of novel six freedom parallel connection platform belongs to motion technical field, it is therefore intended that solve the problems, such as many transmission links that prior art is present, transmission accuracy difference and poor structure rigidity.The present invention includes：Silent flatform；The moving platform coaxially being be arranged in parallel with silent flatform；And it is arranged on six linear drives components between silent flatform and moving platform, each linear drives component two ends is connected with moving platform lower surface and silent flatform upper surface respectively by spherical hinge, the piezoelectric linear motor of linear drives component is fixed on motor fixing plate, output shaft is connected through motor fixing plate by shaft coupling and ball spline shaft, ball spline shaft and the female formation ball spline pair of ball spline, motor protecting crust is enclosed within piezoelectric linear motor outside, one end and motor fixing plate are connected, the other end is fixedly connected with end cap, spline set casing one end is enclosed within the female outside of ball spline and is fixedly connected with ball spline mother, the other end is fixedly connected with motor fixing plate.

Description

A New Six Degrees of Freedom Parallel Platform

technical field

The invention belongs to the technical field of kinematics, and in particular relates to a novel six-degree-of-freedom parallel platform.

Background technique

Compared with the series mechanism, the parallel mechanism has the advantages of high precision, high rigidity, small additional inertia, small volume and simple structure, so it has been widely used. The most commonly used six-degree-of-freedom parallel mechanism is the UPS configuration, that is, a single outrigger is composed of the lower Hooker hinge (U), the middle linear drive component (P), and the upper compound ball hinge (S), and then consists of six outriggers and The dynamic and static platforms together constitute a six-degree-of-freedom parallel platform. The six-degree-of-freedom parallel platform of this configuration has the following defects: (1) There are many transmission links. In this configuration, there are 2 shafts and 2 pairs of bearings in the Hooke hinge, 3 shafts and 3 pairs of bearings in the compound ball hinge, and there are motors, reducers, couplings, brakes, encoders, Screws, guide rails and other components have many transmission parts, complex structures, and large cumulative errors, which directly affect the accuracy of the platform. In addition, the transmission link has high requirements on the installation accuracy of each component, and poses a great challenge to the calibration of the later platform. (2) The structural rigidity of the hinge is poor. The Hooke hinge of UPS configuration is composed of a cross shaft and a bearing. The composite ball hinge is based on the Hooke hinge plus another dimension hinge. Due to structural space, processing technology and other reasons, the hinge is often The rigidity is weak and cannot meet the application occasions with high rigidity. These defects greatly affect the accuracy and stiffness of the six-degree-of-freedom parallel platform, which restricts its application in actual production. Therefore, it is urgent to develop a six-degree-of-freedom parallel platform with better performance.

Contents of the invention

The purpose of the present invention is to propose a new six-degree-of-freedom parallel platform to solve the problems of many transmission links, poor transmission precision and poor structural rigidity in the prior art.

To achieve the above object, a novel six-degree-of-freedom parallel platform of the present invention includes:

static platform;

A moving platform arranged coaxially and parallel to the static platform;

And six linear drive assemblies arranged between the static platform and the dynamic platform, the two ends of each linear drive assembly are respectively connected to the lower end surface of the dynamic platform and the upper end surface of the static platform through ball joints, the linear drive assembly includes an end cover, a motor Protective shell, piezoelectric linear motor, motor fixing plate, coupling, ball spline shaft, ball spline nut and spline fixing shell, the piezoelectric linear motor is fixed on the motor fixing plate, and the output shaft is fixed through the motor The plate is connected with the ball spline shaft through a coupling, the ball spline shaft and the ball spline nut form a ball spline pair, the motor protective shell is set on the outside of the piezoelectric linear motor, one end is connected with the motor fixing plate, and the other One end is fixedly connected with the end cover, one end of the spline fixed shell is sleeved on the outside of the ball spline nut and fixedly connected with the ball spline nut, and the other end is fixedly connected with the motor fixing plate.

The two ends of each linear drive assembly are respectively connected to the lower end surface of the moving platform and the upper end surface of the static platform through ball hinges. Specifically: the outer center of the end cover of each linear drive assembly is processed with a threaded hole, and the ball spline shaft protrudes from one end. It is processed with external threads, and is connected with the ball hinges on the static platform and the dynamic platform through threaded holes and external threads respectively.

The ball hinge is a rolling ball hinge.

The ball spline shaft is connected with a set screw and a coupling.

The beneficial effect of the present invention is that: a novel six-degree-of-freedom parallel platform of the present invention adopts the SPS configuration, that is, the upper and lower ball hinges (S) and the middle linear drive assembly (P). Since the present invention adopts a single high-rigidity component ball joint and a high-precision piezoelectric linear motor, the transmission link is greatly reduced compared with the six-degree-of-freedom parallel platform of the traditional UPS configuration, the structure is simple, the cumulative error is small, and the precision is high. In addition, because the rigidity of the ball hinge adopted in the present invention is several times higher than that of the traditional composite ball hinge, the structural rigidity of the whole platform is also significantly increased. The invention is especially suitable for occasions with high precision and high rigidity.

Description of drawings

1 is a schematic diagram of the overall structure of a novel six-degree-of-freedom parallel platform of the present invention;

Fig. 2 is a schematic structural diagram of a linear drive assembly in a novel six-degree-of-freedom parallel platform of the present invention;

Among them: 1. Static platform, 2. Ball hinge, 3. Linear drive assembly, 3-1. End cover, 3-2. Motor protective shell, 3-3. Piezoelectric linear motor, 3-4. Motor fixing plate, 3-5, shaft coupling, 3-6, set screw, 3-7, ball spline shaft, 3-8, ball spline nut, 3-9, spline fixed shell, 4, moving platform.

detailed description

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Referring to accompanying drawing 1 and accompanying drawing 2, a kind of novel six degrees of freedom parallel platform of the present invention comprises:

static platform 1;

A moving platform 4 arranged coaxially and parallel to the static platform 1;

And six linear drive assemblies 3 arranged between the static platform 1 and the dynamic platform 4, the two ends of each linear drive assembly 3 are respectively connected with the lower end surface of the dynamic platform 4 and the upper end surface of the static platform 1 through the ball joint 2, and the straight line The drive assembly 3 includes an end cover 3-1, a motor protective case 3-2, a piezoelectric linear motor 3-3, a motor fixing plate 3-4, a shaft coupling 3-5, a ball spline shaft 3-7, and a ball spline Female 3-8 and spline fixed housing 3-9, the piezoelectric linear motor 3-3 is fixed on the motor fixing plate 3-4, the output shaft passes through the motor fixing plate 3-4 and passes through the shaft coupling 3-5 and The ball spline shaft 3-7 is connected, the ball spline shaft 3-7 and the ball spline nut 3-8 form a ball spline pair, and the motor protective shell 3-2 is set on the outside of the piezoelectric linear motor 3-3 , one end is connected to the motor fixing plate 3-4, and the other end is fixedly connected to the end cover 3-1, and one end of the spline fixing shell 3-9 is set on the outer side of the ball spline nut 3-8 and the ball spline nut 3-8 Fixedly connected, the other end is fixedly connected with the motor fixing plate 3-4.

The two ends of each linear drive assembly 3 are respectively connected to the lower end surface of the moving platform 4 and the upper end surface of the static platform 1 through the ball hinge 2. Specifically: the outer center of the end cover 3-1 of each linear drive assembly 3 is processed with a threaded hole, and the ball Spline shaft 3-7 stretches out one end and is processed with external thread, is connected with ball hinge 2 on static platform 1 and on moving platform 4 by threaded hole and external thread respectively.

The ball spline shaft 3-7 is connected with a set screw 3-6 and a coupling 3-5.

In the parallel platform of the present invention, two ball hinges 2 and a linear drive assembly 3 constitute a leg, a total of six legs, and the entire six-degree-of-freedom parallel platform is formed by connecting the six legs and the dynamic and static platforms 1 . The setting method of the six outriggers between the moving platform 4 and the static platform 1 is the same as that of the existing parallel platform with six degrees of freedom. The static platform 1 is located at the bottom of the entire six-degree-of-freedom parallel platform, and is used to connect the bottom of the six outriggers and fix the entire parallel platform. The moving platform 4 is located on the top of the entire six-degree-of-freedom parallel platform, and is used to connect the tops of the six outriggers and the load. The shapes and interfaces of the dynamic platform 4 and the static platform 1 vary with specific applications. There are twelve ball hinges 2 in total, six of which are installed on the static platform 1, and the remaining six are installed on the moving platform 4. Rolling friction replaces traditional sliding friction between ball head and bowl. The ball hinge 2 of this structural form has mature products and can be directly selected. Its main feature is high precision, which can reach the micron level or higher. In addition, the rigidity of the single ball hinge 2 is many times greater than that of the compound ball hinge 2 . The linear drive assembly 3 is the power source of the six-degree-of-freedom parallel mechanism, and is located in the middle of the entire platform.

The installation process of the linear drive assembly 3 of the present invention is as follows: first, the piezoelectric linear motor 3-3 is connected with the motor fixing plate 3-4, and then the motor fixing plate 3-4, the spline fixing shell 3-9, the motor The protective case 3-2 and the end cover 3-1 are connected with screws to form a whole. The piezoelectric linear motor 3-3 directly outputs linear motion with extremely high precision, which can reach nanoscale resolution. The piezoelectric linear motor 3-3 transmits the linear motion to the ball spline pair through the coupling 3-5. The ball spline pair is composed of a ball spline shaft 3-7 and a ball spline nut 3-8. It has two main functions: One, one is precision guidance, and the other is to bear radial load. The ball spline shaft 3-7 and the shaft coupling 3-5 are locked and positioned through the set screw 3-6. The connection between the linear drive assembly 3 and the ball hinge 2 adopts a threaded connection: the lower ball hinge 2 is connected with the thread processed in the center of the end cover 3-1, and the upper ball hinge 2 is connected with one end of the ball spline shaft 3-7. thread for connection. In this way, adjusting the motion amount of the piezoelectric linear motor 3-3 can change the position and attitude of the moving platform 4, so as to achieve the purpose of precise positioning.

Claims (4)

1. A new six-degree-of-freedom parallel platform, including: static platform (1); A moving platform (4) arranged coaxially and parallel to the static platform (1); And six linear drive components (3) arranged between the static platform (1) and the dynamic platform (4); It is characterized in that, Both ends of each linear drive assembly (3) are respectively connected to the lower end surface of the moving platform (4) and the upper end surface of the static platform (1) through a ball hinge (2); the linear drive assembly (3) includes an end cover (3-1 ), motor protective shell (3-2), piezoelectric linear motor (3-3), motor fixing plate (3-4), coupling (3-5), ball spline shaft (3-7), ball spline nut (3-8) and spline fixed housing (3-9), the piezoelectric linear motor (3-3) is fixed on the motor fixing plate (3-4), and the output shaft passes through the motor fixing plate ( 3-4) Connect the ball spline shaft (3-7) through the coupling (3-5), and the ball spline shaft (3-7) and the ball spline nut (3-8) form a ball spline pair, the motor protective shell (3-2) is set on the outside of the piezoelectric linear motor (3-3), one end is connected to the motor fixing plate (3-4), and the other end is fixedly connected to the end cover (3-1), One end of the spline fixing shell (3-9) is set on the outer side of the ball spline nut (3-8) and fixedly connected with the ball spline nut (3-8), and the other end is fixedly connected with the motor fixing plate (3-4) . 2. A novel six-degree-of-freedom parallel platform according to claim 1, characterized in that the two ends of each linear drive assembly (3) are respectively connected to the lower end surface of the moving platform (4) and the static platform ( 1) The connection of the upper end surface is as follows: the outer center of the end cover (3-1) of each linear drive assembly (3) is processed with a threaded hole, and the protruding end of the ball spline shaft (3-7) is processed with an external thread , are respectively connected with the ball hinges (2) on the static platform (1) and on the dynamic platform (4) through threaded holes and external threads. 3. A novel six-degree-of-freedom parallel platform according to claim 1 or 2, characterized in that the ball joint (2) is a rolling ball joint (2). 4. A novel six-degree-of-freedom parallel platform according to claim 1 or 2, characterized in that the ball spline shaft (3-7) is connected by a set screw (3-6) and a shaft coupling (3). -5) Connect.