Hydraulic Chuck Brazing

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1. Hydraulic Chuck Structure and Working Principle

The working principle of hydraulic transmission is to use oil as the working medium, relying on the change of the seal volume to transmit movement, and relying on the internal pressure of the oil to transmit power. In fact, the hydraulic transmission device is a kind of energy conversion device, which first converts the mechanical energy into hydraulic energy that is convenient for transportation, and then converts the hydraulic energy into mechanical energy to drive the working mechanism to complete various actions required.

The hydraulic chuck is mainly composed of oil cylinder, piston, clamp ring, support sleeve, slip seat, disc spring, slip, protective sleeve, protective cover, thrust ball bearing, sealing ring and other parts and standard parts, as shown in the figure below.

1. Slip seat, 2 disc springs, 3 oil cylinders, 4 pistons, 5 support sleeves, 6 clamp rings, 7 slips, 8 housings. 9 protective sleeves, 10 protective covers, 11 round nuts, 12 thrust ball bearings, 13 seals

Fig 1 Structure diagram of hydraulic chuck assembly

The working principle of the hydraulic chuck is that the hydraulic oil enters the oil cylinder from the oil inlet of the oil cylinder during work. The oil cylinder and the piston form a closed cavity. As the pressure increases, under the action of the pressure oil, the piston moves down and is pushed by the thrust ball bearing. The clamp ring and the support sleeve move down together, so that the disc spring is compressed. While the clamp ring moves down, it drives the three slips to move horizontally away from the center of the circle, so as to achieve
To loosen the drill pipe.

When the drill pipe needs to be clamped, operate the reversing valve to open the hydraulic control check valve. The oil in the closed cavity of the chuck passes through the tubing. The hydraulic control check valve and the reversing valve communicate with the mailbox. At this time, there is no pressure in the closed cavity. The spring automatically resets under the action of elastic force, and pushes the support sleeve, the clamp ring, the thrust ball bearing and the piston to move upwards, and drives the three slips to make centripetal horizontal movement, so as to achieve the purpose of clamping the drill rod.

 

2. Brazing of Hydraulic Chuck

(1) Preheating. Preheating helps reduce the maximum hardness of the heat-affected zone of medium carbon steel and prevents cold cracks.The main technological measures for welding medium carbon steel, preheating can also improve the plasticity of the joint and reduce the residual stress after welding. Normally, the preheating temperature of hydraulic chuck is 150~250C and the carbon content is higher or because of the large thickness and rigidity, when the crack tendency is large, the preheating temperature can be increased to 250~400C. If the weldment is too large, the overall preheating When heating is difficult, local preheating can be performed. The heating range of local preheating is 150~200mm on both sides of the weld.

(2) Alkaline electrodes are preferred when welding rod conditions permit.

(3) Groove form The weldment should be opened into a U-shaped groove as much as possible for welding. If it is a casting defect, the shape of the groove excavated by the shovel should be smooth. The purpose is to reduce the proportion of the base metal melted into the weld metal, so as to reduce the carbon content in the weld and prevent cracks.

(4) Welding process parameters. Since the base material is melted into the first layer of weld metal, the proportion of up to about 30%, so when the first layer of weld is welded, low current and slow welding speed should be used as much as possible to reduce the mother The penetration of the material.

(5) Post-weld heat treatment It is best to perform stress-relieving heat treatment on the weldments immediately after welding, especially for large-thickness weldments, high-rigidity structural parts, and weldments that work under severe conditions (dynamic load or impact load). The tempering temperature for stress relief is 600~650C.

3. Brazing Parameters of Hydraulic Chuck

Model	Temperature Uniform Size	MAX. Temperature	Ultimate Pressure	Pressure Rising Rate	Temperature Uniformity	Loading Capacity
RVB-559L	500*500*900mm	850℃	4~8*10-4Pa	0.5Pa/h	±3℃	150Kg
RVB-669L	600*600*900mm	850℃	4~8*10-4Pa	0.5Pa/h	±3℃	200Kg
RVB-6612L	600*600*1200mm	850℃	4~8*10-4Pa	0.5Pa/h	±3℃	300Kg
RVB-107012L	1000*700*1200mm	850℃	4~8*10-4Pa	0.5Pa/h	±3℃	500Kg
RVB-7816L	700*800*1600mm	850℃	4~8*10-4Pa	0.5Pa/h	±3℃	800Kg
RVB-100714L	1000*700*1400mm	850℃	4~8*10-4Pa	0.5Pa/h	±3℃	1000Kg
RVB-111325L	1100*1300*2500mm	850℃	4~8*10-4Pa	0.5Pa/h	±3℃	2000Kg

Shanghai Geheng Vacuum Technology Co., Ltd. is a vacuum heat treatment furnace manufacturer with many years of experience in design, manufacturing and production. Mainly produce vacuum heat treatment furnace, vacuum sintering furnace, vacuum brazing furnace, New Energy And Environmental Protection Equipment and other vacuum equipments.Provide customized services, equipment work area can be based on customer output.