What Is a Self-Locking Screw Jack? How Self-Locking Jack Screws Work? What Is Self Locking of Thread Screw Jacks? to Ensure Self Locking in a Screw Jack.

• Application: Motor, Electric Cars, Motorcycle, Machinery, Marine, Toy, Agricultural Machinery, Car, Lifting and Positioning
• Hardness: Hardened Tooth Surface
• Installation: 90 Degree
• Layout: Coaxial
• Gear Shape: Worm Gear
• Step: Single-Step
• Model NO.: 1/4-tons to 100-tons
• Type: Worm Reducer
• Transport Package: Standard Exporting Plywood Cases
• Trademark: JACTON
• Origin: Made in China
• HS Code: 8428909090
• Production Capacity: 3400PCS Per Month

Product Description

What Is A Self-Locking Screw Jack? How Self-Locking Jack Screws Work? What Is Self Locking of Thread Screw Jacks? To Ensure Self Locking In A Screw Jack.

Compared with some other types of screw jack,the worm gear machine screw jack has an important advantage that is it is self-locking, which means when the rotational force on the screw is removed, it will remain motionless where it was left and will not rotate backwards, regardless of how much load it is supporting. This makes them safer than the hydraulic jack itself, for example, if the force on the hydraulic actuator is released accidentally, it will move backwards under load.

Then what is "self-locking"? Let us see the following information.  
Large frictional forces cause most screws in practical use to be "self-locking", also called "non-reciprocal" or "non-overhauling". This means that applying a torque to the shaft will cause it to turn, but no amount of axial load force against the shaft will cause it to turn back the other way, even if the applied torque is zero. This is in contrast to some other simple machines which are "reciprocal" or "non locking" which means if the load force is great enough they will move backwards or "overhaul". Thus, the machine can be used in either direction. For example, in a lever, if the force on the load end is too large it will move backwards, doing work on the applied force. Most screws are designed to be self-locking, and in the absence of torque on the shaft will stay at whatever position they are left. However, some screw mechanisms with a large enough pitch and good lubrication are not self-locking and will overhaul, and a very few, such as a push drill, use the screw in this "backwards" sense, applying axial force to the shaft to turn the screw. 
A push drill, one of the very few mechanisms that use a screw in the "backwards" sense, to convert linear motion to rotational motion. It has helical screw threads with a very large pitch along the central shaft. When the handle is pushed down, the shaft slides into pawls in the tubular stem, turning the bit. Most screws are "self locking" and axial force on the shaft will not turn the screw.

This self-locking property is one reason for the very large use of the screw in threaded fasteners such as wood screws, sheet metal screws, studs and bolts. Tightening the fastener by turning it puts compression force on the materials or parts being fastened together, but no amount of force from the parts will cause the screw to untighten. This property is also the basis for the use of screws in screw top container lids, vises, C-clamps, and screw jack lifts of jacton industry co.,ltd factory. A heavy object can be raised by turning the jack shaft, but when the shaft is released it will stay at whatever height it is raised to.  

Whether a screw is self-locking ultimately depends on the pitch angle and the coefficient of friction of the threads; very well-lubricated, low friction threads with a large enough pitch may "overhaul". 

Now come back to screw jacks. In the case of large shocks, the self-locking function of the lift may be invalidated. Jacton worm gear screw lift self-locking function depends on the following parameters: 
• The size of the lead
• Different gear ratios
• Lubrication
• Friction coefficient
• Environmental effects such as high or low temperature, vibration, etc.
• Installation location
 Ball screw type and large pitch of the trapezoidal screw series without self-locking function. Therefore, in these cases must use the appropriate brake or brake motor. For smaller guides
(Single line), providing a limited self-locking function. Self-locking function depends on the specific situation. 







Important Note: The original actual pictures, videos, designs and molds came from the audited manufacturer and supplier - JACTON Industry Co.,Ltd. Don't copy the pictures, videos, models, designs and drawing dimensions without JACTON permission.

Shipment and Packing Pictures 
Shipping:
1. Ocean freight: seaport to seaport, price terms CIF, FOB, EXW, CFR etc.
2. Air freight: airport to airport, price terms EXW, CRF etc.
3. Air courier: DHL, FEDEX, UPS, TNT door to door shipment, price terms DDU, CPT etc.
Packing: 
100% standard exporting plywood cases. 
Note: International Exporting Standard Wooden Material with Free Fumigation.


JACTON Advantages
1. International standard materials for All JACTON brand products. We insist on choosing brand suppliers to supply the high quality raw materials to control the producing process. Optimization constantly the production processes, inspecting in each link and managing production site.
2. 100% quality assured with double quality inspections. The quality inspection by quality inspectors from processing to finished products as the first time. Before packing, the corresponding sales engineers must inspect the orders following the paper drawings, order quantities and special markings in the invoice or sales contracts as the second time. After that, fill in the inspection report with signature and company stamp.
3. 100% safety transportation. Packing with strong standard export plywood cases materials (free fumigation), inner packing with epe foams to prevent products swaying and outer packing with iron sheets and fasteners to fasten the packages.
4. Internationl sales engineers have professional knowledge and skills on our standard products and service. They have enough ability to solve the basic technical problem immediately whatever by phone, online chat, face to face communications.
5. All the standard products with 2D CAD Drawings (PDF, DWG and DXF formats), and 3D CAD Models (STEP, STP, MODEL, IGS, PRT and CATParT formats).
6. Custom design available, OEM service available, Free engineering advice, Free quotes available and Customer label available.
7. Inspection equipments include motor with inverter drive system, height adjustmemt motorized lifting system, coordinate measuring machines, outside micrometers, inside micrometers, depth calipers, vernier calipers, digital calipers, hardness testers, digital noise meters, industrial infrared thermometers, digital speed measuring instruments, digital multimeters, and high precision clamp digital ammeter etc. 
8. Processing with modern advanced machines such as CNC gear hobbing machines, CNC flank grinding machines, CNC cylindrical grinding machines, multi-axis CNC milling machines, CNC lathes and others equipments.


Finished Projects
1. Theatrical solutions stage and orchestra platform lifts projects. Customers are from France, Australia, Netherlands, United Kingdom, Spain and Canada. 
2. Hydroelectric power station projects and water conservancy projects. Customers are from Vietnam, Australia, Malaysia, Russian Federation, Nepal, Pakistan, Belgium, United States and United Kingdom. 
3. Aircraft maintenance platforms and docking systems projects. Customers are from Pakistan, Singapore and United Arab Emirates.  
4. Solar panel tracking system projects. Customers are from Spain, India and Canada. 
5. Bolted steel storage tanks and silos lifting solutions. Customers are from South Africa, United States, Mexico, Russian Federation, Brazil and Vietnam. 
6. Dish antenna elevation and azimuth positioning projects. Customers are from Singapore, Malaysia and United States. 
7. Railway wagon projects. Customers are from South Africa. 
8. Beverage can production lines. Customers are from Netherlands, United States, Thailand and Indonesia. 
9. Steel factories production lines. Customers are from Iran, United States and Turkey. 
10. Continuous PU sandwich panel production lines. Customers are from Thailand and United Kingdom.  


JACTON Customers Areas(Countries)
1. American Countries: United States, Mexico, Canada, Chile, Bolivia, Brazil, Colombia, Dominican Republic, Honduras, Costa Rica, Panama, Puerto Rico, Jamaica, Trinidad and Tobago, Aruba, Argentina, Peru, Venezuela.
2. European Countries: Russia, Germany, Turkey, France, United Kingdom, Italy, Spain, Ukraine, Poland, Romania, Netherlands, Belgium, Greece, Czech Republic, Portugal, Sweden, Hungary, Belarus, Austria, Switzerland, Bulgaria, Denmark, Finland, Slovakia, Norway, Ireland, Croatia, Georgia, Armenia, Lithuania, Slovenia, Estonia, Cyprus, Luxembourg, Iceland.
3. Asian Countries: Malaysia, Indonesia, Singapore, Pakistan, Philippines, Vietnam, United Arab Emirates, Thailand, Saudi Arabia, Iran, Turkey, India, Nepal, Yemen, Taiwan, Sri Lanka, Israel, Jordan, Kuwait, Qatar.
4. Oceanian Countries: Australia, New Zealand, Fiji.
5. African Countries: South Africa, Egypt, Ethiopia, Nigeria, Kenya, Tanzania. 


JACTON Products List
1. Manual Screw Jacks, Electric Screw Jacks.
2. Screw Jacks Series: JT series acme screw jacks, JTC series cubic screw jacks, JTW series machine screw jacks, JTM series worm screw jacks, JTB series ball screw jacks, JTD series cubic ball screw jacks, JSS series stainless steel screw jacks, JTS series bevel gear screw jacks, Non-standard series screw jacks. 
3. Bevel Gearboxes Series: JT series bevel gearboxes, JTP series cubic bevel gearboxes, JTA series aluminum bevel gearboxes, JTH series hollow shaft bevel gearboxes, BSS series stainless steel bevel gearboxes.  
4. Lifting Systems and Systems Accessories: two-jacks systems, three-jacks systems, four-jacks systems, six-jacks systems, eight-jacks systems. Accessories cover couplings, universal joints, cardan shafts, connecting shafts, electric motors, geared motors and reducers, hand wheel with crank handles, pillow block bearings, flange block bearings, rod end bearings, stop nuts, limit switches, safety nut, travel nuts, linear shafts and bearings, linear guides and bearings, telescopic spring covers, bellows boot, protective tube, trunnion adapter plates, trunnion mounting brackets, motor flanges, rotary encoders, potentiometers, frequency inverters and position indicators etc.
5. Electric Linear Actuators Series: Parallel heavy duty linear actuators, In-line heavy duty linear actuators.
6. Geared Motors and Speed Reducers Series: helical gearmotors R series, helical bevel gearmotors K series, parallel shaft helical gearmotors F series, helical worm gearmotors S series, small AC gear motor series and worm gear motor reducer series.


Contact Information
JACTON Industry Co.,Ltd (VAT No.: 9144190007026567X3, registered Capital 500000CNY) is a leading manufacturer and supplier of Screw Jacks (Mechanical Actuators), Bevel Gearboxes, Lifting Systems, Electric Linear Actuators, Gearmotors and Speed Reducers, and Others Linear Motion and Power Transmission Products in China. We are Alibaba, Made-In-China and SGS (Serial NO.: QIP-ASI192186) audited manufacturer and supplier. We also have a strict quality system, with senior engineers, experienced skilled workers and practiced sales teams, we consistently provide the high quality equipments to meet the customers electro-mechanical actuation, lifting and positioning needs. JACTON Industry guarantees quality, reliability, performance and value for today's demanding industrial applications.
Website (English): screw-jacks.en.made-in-china.com
Website (English): screw-jacks.en.made-in-china.com
Website (Chinese): screw-jacks.en.made-in-china.com