WO2018006693A1

WO2018006693A1 - Rotating machine frame and transmission mechanism thereof for aerospace storage box and particle treatment instrument

Info

Publication number: WO2018006693A1
Application number: PCT/CN2017/088400
Authority: WO
Inventors: 华庆强
Original assignee: 上海格昆机电科技有限公司
Priority date: 2016-07-07
Filing date: 2017-06-15
Publication date: 2018-01-11
Also published as: CN106051058A

Abstract

Disclosed is a transmission mechanism, comprising a rotating bearing sleeved on a rotator (1), wherein an outer ring of the rotating bearing is fastened to a pin wheel (3); at least two gears (4-1, 4-2) engage with pin teeth of the pin wheel (3) to form a pin tooth transmission; the gears (4-1, 4-2) are connected to a zero backlash speed reducer; and the zero backlash speed reducer is directly connected to output shafts of two alternating-current servomotors controlled by a numerical control system with a double-servomotor driving anti-backlash technology. The transmission mechanism may be used in a rotating machine frame for an aerospace storage box and a particle treatment instrument, the rotating machine frame comprising the rotator (1), wherein the transmission mechanism drives the rotator (1) to rotate, and the front and rear ends of the rotator (1) are respectively provided with a front rotation power base (6) and a rear rotation bracket base (7). The rotating machine frame uses a circle of large-load-bearing rollers to form a load bearing machine base for supporting the rotating machine frame, non-sliding driving and positioning are achieved under the cooperation of the gears or the pin teeth, and the value of a rotation angle is also obtained in a non-sliding manner according to a certain speed ratio of the gears or the pin teeth at the same time.

Description

Rotating frame for aerospace tank and particle therapy instrument and its transmission mechanism

Technical field

The invention relates to a rotating frame which can be used for aerospace tank and particle therapeutic instrument, can carry components of 10 to 1000 tons of magnets, and is capable of 360° multi-turn rotation, high-precision positioning and extremely low noise. component. The invention also relates to a transmission mechanism of the above rotating frame.

Background technique

Aerospace tanks and other structures belong to aluminum alloy thin-walled grid welded structures. Structural welds exist in various shapes and sizes, such as straight longitudinal joints, curved longitudinal joints, spatial secondary curved welds, butt joints and flanges. Through-line welds, etc. The joints are complicated in force. For example, the longitudinal section of the cylinder section and the butt joint are only subjected to uniaxial tensile stress, and the curved weld of the bottom of the box is subjected to complex biaxial tensile stress, and the closer to the top of the tank, the greater the magnitude of the stress, the resistance to the joint. The requirements for tensile strength and toughness (ie, elongation) are higher. At the same time, since the tank, the node tank and the function tank belong to the pressure vessel structure, it is very sensitive to the residual stress and deformation of the structural weld. The application of the new solid phase welding technology of high quality, low stress and no deformation - friction stir welding Demand is urgent. The use of CNC friction stir welding technology also has an inherent process advantage: it can realize the seamless integration of precision CNC turning and milling and precision CNC welding, and its versatility and interchangeability are optimal.

The proton and heavy ion therapy device is the most advanced and expensive ultra-large-scale medical equipment in the world. Its advantage is that it is a kind of stereotactic blasting radiotherapy technology. Proton therapy is different from conventional radiotherapy. When protons and heavy ions enter the human body, their energy is gradually lost due to ionization. At the beginning of the range, due to its high speed, the opportunity to interact with normal tissues or cells in the body is low. The loss is small, so that damage to tissues or cells is small. When protons and heavy ions reach the end of their range, the velocity suddenly drops and stops, releasing the maximum energy, forming a sharp dose peak called the Bragg peak, which produces the strongest killing effect on the tissue or cells at the end of the range.

As shown in Fig. 1, it is a block diagram of the proton and heavy ion therapeutic apparatus. From this block diagram, it can be seen that the rotating frame is a beam transport system (transportation) installed in the rotating frame at the center of the entire therapeutic apparatus. Protons from 10 tons to 250 tons, transporting heavy ions from 100 tons to 1000 tons) Send protons or heavy ions to the treatment head, and then hit the needed place to achieve the purpose of treatment. The rotating gantry is actually the treatment room where the doctor treats the patient.

Summary of the invention

It is an object of the present invention to provide a rotating gantry that can be used in aerospace tanks and particle therapy devices. Another object of the present invention is to provide a transmission mechanism for the above rotating frame.

In order to achieve the above object, an aspect of the present invention provides a transmission mechanism including a slewing sleeve sleeved on a rotating body, and a pin wheel fastened to the outer ring of the slewing ring, at least two The gear meshes with the pin teeth of the pin wheel to form a pin gear transmission, the gear is coupled with the zero backlash reducer, and the zero backlash reducer and two AC servo motors controlled by a numerical control system with a dual servo motor drive backlash reduction technology The output shafts are directly connected.

Preferably, the rotating body is integral with the slewing ring.

Preferably, a raceway structure is designed as an inner ring of the slewing bearing in the outer circle of the main rotating body, and a cylindrical roller is mounted between the inner ring and the outer ring to form a complete slewing bearing.

Another technical solution of the present invention provides a rotating frame for an aerospace tank and a particle therapeutic apparatus, comprising a rotating body, wherein the rotating body is driven by the above-mentioned transmission mechanism to rotate before and after the rotating body. The front end is respectively provided with a front rotating power base and a rear rotating bracket base. The front rotating power base and the rear rotating bracket base form a front and rear double-slewing slewing support structure for the rotating body, and the rear end of the rotating body is supported by the tail center bracket.

Preferably, a section of the shoulder is formed on the front and rear ends of the rotating body, and inner holes, inner holes and corresponding positions are respectively formed on the inner circumferential surfaces of the front rotating power base and the rear rotating bracket base The shoulders are matched to form an inner embrace structure.

Preferably, a film ring is disposed between the rear rotating bracket base and the rotating body, and an inflatable hole communicating with the film ring is disposed on the rotating body, and the rotating body and the working body are normally operated. After the rotating bracket base is not in contact, it can rotate with each other. When braking, the external device inflates the film ring through the inflation hole on the rotating body, and the inflated film ring expands and deforms, so that the rear rotating bracket The base or the front rotary power base is in contact with the rotating body such that the rotating body stops rotating.

Preferably, the tail center bracket has a cylindrical mechanism for cable retracting inside.

The invention can be used not only for proton and heavy ion therapeutic instruments, but also for welding of structures such as aerospace tanks. Through the development of the universal spindle interface, the smooth machining of the structural weld bevel precision machining and the precision numerical control friction stir welding can be realized, and the structural weld bead processing and welding can be sequentially realized in one working position.

There are three main control functions of the rotating frame provided by the present invention:

1. Control of the beam optical section, at the entrance of the beam of the rotating frame, at the two beam cross-section position probes at the entrance of the 135° deflection magnet B2G1, and by the beam position probe at the entrance of the treatment head The beam current parameter signal is automatically controlled by a beam adjustment algorithm of the control computer to be within the allowable collimation error.

2. CT pre-scan positioning.

3. Rotation control of the rotating frame. At present, the rotating frame in the world is based on "the circular orbit with eight load-bearing cylinders to support the rotating frame" (such as the products of Belgian IBA), or "two large load-bearing rollers to support the circular orbit of the rotating frame. (For example, Mitsubishi Corporation of Japan is a product built in Japan’s Hyogo, Shizuoka and Gunma), which relies on friction (with slip) to drive the rotation and positioning of the entire rotating bracket, and also relies on friction (with slip). Get the angle value of the rotation.

The rotating frame designed by the invention "takes a large load-bearing roller to form a load-bearing machine seat supporting the rotating frame" cooperates with the gear or the pin gear to drive and position without slip, and also has a certain speed ratio by gear or pin tooth. The slip takes the angle value of the rotation. The load-bearing base is connected to the numerical control system and is used not only for the measurement of working conditions (rotation angle, rotational speed, rotational acceleration, braking stop, etc.) but also for deceleration braking and "safe braking" in emergency situations.

DRAWINGS

Figure 1 is a block diagram showing the composition of a proton and heavy ion therapeutic apparatus;

2 is a schematic structural view of the present invention applied to a proton and heavy ion therapeutic apparatus;

3 is a schematic view showing the internal structure of the present invention applied to a proton and heavy ion therapeutic apparatus;

Figure 4 is a schematic view of the transmission mechanism of the present invention;

Figure 5 is a schematic view of the transmission mechanism of the present invention;

6A is a schematic view showing the installation of a ring portion of a film in the present invention;

Fig. 6B is a partially enlarged schematic view showing a portion I of Fig. 6A.

detailed description

The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation procedures are given. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the inventive concept. These are all within the scope of protection of the present invention.

Hereinafter, the present invention will be further described by applying the present invention to a proton therapeutic apparatus or a heavy ion therapeutic apparatus.

It is an object of the present invention to provide a high load bearing, high precision rotation and positioning, low noise rotary component that can be used in a rotating gantry of a proton therapy device or a heavy ion therapy device.

The principle of the proton and heavy ion therapy device is shown in Figure 1. The beam is accelerated by the accelerator and then enters the rotating frame. It is deflected and focused by a number of magnets and hit the tumor through the treatment head. In order to maintain the required characteristics of the passing beam, a coordinated control of the treatment planning system, the treatment control system, and the positioning collimation system is required.

2 and FIG. 3, the large-scale, precise, embracing rotating frame and its transmission mechanism provided by the embodiment are applied to the proton and heavy ion therapeutic apparatus, and are mainly composed of a proton emitter and a rotating body. The proton emitter is composed of a steering magnet 10, a beam line and a valve 11, a correction (focusing) magnet 12, and a beam emitting head 13, and the components are integrated into a whole through a beam line and integrated with the rotating body. Fixed together. The rotary body is integrated by the installation and maintenance passage 14, the front rotary power base 6 (the absolute position of the drive wheel is mounted on the multi-turn encoder), the rear rotary bracket base 7, the pin gear transmission system, the tail center bracket 9, the rotating body 1, and the The weight bracket 17, the floating beam treatment room 15, the six-axis treatment bed 16, and the like are composed. Among them, the tail of the rotating body 1 is supported by the tail center bracket 9. Both ends of the rotating body 1 are supported by a front rotating power base 6 and a rear rotating bracket base 7 respectively. The pin gear transmission system is fixed to one end as a power driving member of the rotating body 1. The weight bracket 17 is fixed at an intermediate position of the rotating body 1 and rotates therewith. The inside of the front end of the rotating body 1 is designed with a floating beam treatment chamber 15, and the floating beam treatment chamber 15 does not rotate with the rotating body 1. The six-axis treatment couch 16 is placed in the floating beam treatment room 15.

As shown in FIG. 2, the rear rotating bracket base 7 and the front rotating power base 6 constitute a front and rear double-wound slewing support structure. The rotating body 1 has a section of shoulders at both ends thereof, and cooperates with the inner holes of the rear rotating bracket base 7 and the front rotating power base 6 to form an inner arms structure to support and fix. The support mechanism can easily install a variety of angle swinging magnets for beam transport, send protons or heavy ions to the beam head of the tumor lesion, and can also install CT components for finding tumors and achieving positioning.

The pin gear transmission system used in this example adopts the "roller type slewing support + pin gear (rigid) transmission mode. As shown in Fig. 4 and Fig. 5, the roller type slewing bearing is integrated with the rotating body 1, the rotating body 1 The outer circle is designed with the raceway structure as the inner ring of the slewing bearing, and the cylindrical roller is formed between the outer ring of the raceway and the inner ring. The entire slewing bearing. The pin wheel 3 is fastened to the outer ring of the roller slewing ring by means of screws. The gears 4-1, 4-2 are driven by the motor to mesh with the pin teeth on the pin wheel 3 (the number 5 in Fig. 5 points to the meshing line), thereby driving the rotation of the entire rotating body 1. This structure replaces the foreign "double roller support + friction (soft, also known as "elastic") transmission" structure, its smaller size, higher strength, anti-overturning force and bearing strength is unmatched by the roller.

The transmission system with low noise and high precision pin wheel or gear meshing can provide non-slip transmission, does not produce slip error like friction wheel transmission system, improves positioning accuracy, and makes positioning accuracy from 0.1°. Increase to 0.001°.

This example uses a gapless drive, which is a new high-precision drive system without gaps, consisting of two AC servo motors + zero backlash reducer. The two AC servo motor output shafts are directly connected to the zero backlash reducer, and then connected to the gears 4-1 and 4-2. The gears 4-1, 4-2 and the pin wheel 3 form a pin gear transmission, thereby driving the entire rotation. Body 1 rotates. In this embodiment, a numerical control system with "double servo motor drive anti-backlash technology" is used, which effectively overcomes the transmission gap error caused by the mechanical transmission chain by the tension torque; and simultaneously uses two sets of servo motor systems with wide response bands to form a linkage system. The system realizes the high-speed response follow-up control while dynamically eliminating the transmission gap, thereby improving the static and dynamic transmission precision of the machine tool and smoothly transitioning various load areas.

As shown in Figs. 6A and 6B, the present invention uses the film ring 8 as a brake to achieve rapid braking. The film ring 8 is located between the rear rotating carriage base 7 and the rotating body 1. Before the inflation, the rear rotating bracket base 7 and the rotating body 1 do not come into contact and can rotate with each other. The film ring 8 is quickly inflated by the inflating hole on the rotating body 1 by using special equipment. After the inflation, the film ring 8 is expanded and deformed, so that the rear rotating bracket base 7 and the rotating body 1 come into contact, resulting in a uniform and huge whole. The circumferential frictional friction force drags the rotating body 1 as a whole, and can generate an emergency braking torque within 10ms to achieve ms-level braking.

The rear center bracket 9 has a cylindrical mechanism for cable retraction, which can be rotated with the cable to ensure that the frame can rotate more than ±360°.

The whole machine electrical control of the invention adopts a PLC automatic control unit, and the self-control unit outputs a 0~10V level signal to the frequency conversion speed regulating unit, and the synchronous servo motor drives the actuator, the rotation speed is stable and the manual continuous adjustment and the program automatic control, the actual The speed is displayed in digital real time.

The invention can be applied to the welding of structures such as aerospace tanks, in addition to the proton and heavy ion therapeutic apparatus.

Aerospace tanks and other structures belong to aluminum alloy thin-walled grid welded structures. Structural welds exist in various shapes and sizes, such as straight longitudinal joints, curved longitudinal joints, spatial secondary curved welds, butt joints and flanges. Through-line welds, etc. The structural parts are mostly processed by friction stir welding, and the above-mentioned rotating frame and its transmission mechanism can also be used for the clamping and precise positioning of the structure of the multi-tubular storage tank during the welding process.

The specific embodiments of the present invention have been described above. It is to be understood that the invention is not limited to the specific embodiments described above, and various modifications and changes may be made by those skilled in the art without departing from the scope of the invention.

Claims

A transmission mechanism comprising a slewing sleeve sleeved on a rotating body (1), a pin wheel (3) fastened to an outer ring of the slewing ring, and at least two gears and a pin wheel (3) The pin teeth mesh to form a pin gear transmission, and the gear is coupled with a zero backlash reducer. The zero backlash reducer is directly connected to the output shafts of two AC servo motors controlled by a numerical control system with a dual servo motor drive backlash prevention technology.
A transmission mechanism according to claim 1, wherein said rotating body (1) is integral with said slewing ring.
A transmission mechanism according to claim 2, wherein a raceway structure is designed as an inner ring of the slewing bearing in the outer circle of the main rotating body (1), and a cylindrical roller is mounted between the inner ring and the outer ring. The sub-form forms a complete slewing bearing.
A rotating frame for an aerospace tank and a particle therapy apparatus, comprising a rotating body (1), characterized in that the rotating body (1) is driven by the transmission mechanism according to claim 1, in the rotating body (1) The front and rear ends are respectively provided with a front rotating power base (6) and a rear rotating bracket base (7), and the front rotating power base (6) and the rear rotating bracket base (7) form a front and rear pair of the rotating body (1) In the slewing type of slewing support structure, the rear end of the rotating body (1) is supported by the tail center bracket (9).
A rotating gantry for aerospace tank and particle therapeutic apparatus according to claim 4, wherein a section of the shoulder is formed at each of the front and rear ends of the rotating body (1), An inner hole is formed on the inner circumferential surfaces of the rotary power base (6) and the rear rotary bracket base (7), and the inner hole cooperates with the shoulder of the corresponding position to form an inner arms structure.
A rotating gantry for aerospace tank and particle therapy apparatus according to claim 4, wherein a film is disposed between said rear rotating carriage base (7) and said rotating body (1) a ring (8) having an inflatable hole communicating with the film ring (8) on the rotating body (1), and the rotating body (1) and the rear rotating bracket base (7) during normal operation Not touching, can rotate with each other, when braking, the external device inflates the film ring (8) via the inflation hole on the rotating body (1), and the inflated film ring (8) expands and deforms, so that The rear rotating bracket base (7) or the front rotating power base (6) is in contact with the rotating body (1) such that the rotating body (1) stops rotating.
A rotating gantry for aerospace tank and particle therapy apparatus according to claim 4, wherein said tail center bracket (9) has a cylindrical mechanism for cable retraction inside.