Mechanical screw jack for a car
The jack is one of the first things that should be in the set of a motorist. It is with the help of this device that we can replace a broken wheel or lift the car for repair in the absence of a viewing pit. This is an indispensable thing on long journeys. When selecting this tool, many people prefer to buy a mechanical screw jack. It’s very difficult to do it yourself. And the cost of it allows you to purchase the tool even the most economical car enthusiast. Today we will look at what a screw mechanical jack (UAZ includes) is and how it works.
The described tool is an uncomplicated mechanism that allows lifting and fixing loads at height. In our case, the mechanical screw jack performs the function of lifting the car (it is a UAZ or a foreign car, it does not matter).
Its feature is the ability to install directly under the load.The lifting of the machine is carried out thanks to the screws. Hence the name - "mechanical screw jack".
The mechanism is no different complex design. So, the screw mechanical bottle jack consists of the following elements:
- lever arm;
- worm gear.
When the driver delivers torque (in our case, this is a hand), the force transforms, and as a result of translational movements, the mechanism lifts the car. Now mechanisms with the three "screw-roller-nut" are very popular. They are a more advanced design of the classic screw jack. But such mechanisms are also very reliable compared to electrical analogues.
By the way, on some screw jacks install additional electric motors. This allows you to increase the efficiency of the mechanism. But the cost of such parts at times more expensive. Therefore, most motorists prefer to buy a mechanical jack screw bottle 2t. Such a tool will cope with the task of lifting both passenger cars and SUVs.
Principle of operation
How does a mechanical screw jack 2t? Its principle of operation is extremely simple - thanks to the lever, rotational forces are produced.Further, through the worm gear, they are converted to translational. The jack rises.
If we consider the advanced three "screw-roller-nut", here the ball or roller participates in the work. Thanks to him, the driver will have to make less effort than with a regular pair. At the same time lifting speed increases.
Is there a mechanical screw jack 5t? There is necessarily an electric motor. Manually this mass simply does not raise. The use of an electric drive significantly increases the efficiency of the mechanism and the speed of its operation.
Mechanical screw jack vertical was invented about 30 years ago. Its main components are a screw, a lever and a metal case. The maximum capacity of such devices is no more than one ton. The main advantages of vertical devices:
- large working stroke mechanism;
- low weight, despite being completely metallic;
- low cost.
- ease of operation (for lifting does not need to put a lot of effort).
For insurance against the “undermining” of a vertical jack, experienced car enthusiasts recommend additionally placing logs, bricks or other suitable objects under the body of a raised car.
Among the disadvantages it is necessary to note the small area of contact. As a result, vertical mechanical jacks are among the most unstable. They can be used only on the most even surface. Also, these tools are very long - in the usual niche under the boot floor they are not put. And the main drawback is the ascent through special lugs.
In its construction, the described mechanical jack screw has one or two screws. This type is designed to lift goods weighing up to three tons. And if you consider that only one side rises, then such a jack can be used for large minibuses and some trucks. The body itself serves as a support nut for tools with two screws.
Their design is extremely simple - a second, smaller diameter is screwed into the first screw. The latter has a large thread. This design allows you to significantly increase the load capacity of the mechanism with minimal effort from the car owner.
The main advantage that, for example, the “Avtoprofi” mechanical screw jack of this type has, is stability.Rack mount mechanisms can even be used on curved surfaces with a slight incline. The main disadvantages are the small working stroke and the large weight. Therefore, such mechanisms are selected strictly for clearance.
Such mechanical jacks are often found on the VAZ “classics” and “Lada” of the tenth family. Lever-screw devices are used for cars. Their carrying capacity is up to one and a half tons.
In the construction of mechanical jacks of this type there is a screw, a handle and two levers (lower and upper). At the last there is a grab and a nut. The upper one serves as a supporting platform for a car.
The main advantage of such devices is their low weight and low cost. Also, the lever elements have a large working stroke. Among the minuses of these mechanical jacks it is necessary to note the low stability. If the ascent is carried out on the slope or slope, or the machine is skewed a few degrees, such a tool simply bends. This is not the most reliable solution. Even expensive models are not insured from such deformations. All because of the design feature of the levers.
They are less common than lever-screw and rack-type counterparts. In terms of load capacity such jacks are slightly inferior rack. The maximum mass for which they are designed, is two tons.
But this is enough for lifting frame SUVs and minivans. The design uses four hinged levers. They are located in a diamond - hence the characteristic name.
With a change in the angle of inclination of the levers, the car is raised and lowered. Such elements have a large footprint and can be used on virtually any curb. No matter what angle of inclination the car has - the rhombic jack is not deformed and will withstand all the load placed on it The only drawback of such devices is a small working stroke.
As in the case of rack, they are selected in accordance with the clearance of a particular car. Also very popular rhombic jacks with electric drive. But their price is 4-5 times higher than that of mechanical analogs.
When selecting the described tool, it is necessary to be guided by certain principles and requirements:
- Efficiency It must be at least 25 percent.Ideally, this figure should be close to 90 percent.
- High accuracy. The upper support mechanism, which is in contact with the body element (threshold) must exactly follow its contours. Usually on the threshold there is a special groove. The jack is inserted into it. If it does not repeat the shape of the groove, it can cause the car to overturn. As a result - damage to the body and the jack itself. By the way, in order not to scratch the metal part of the car, this support has a rubber or polyurethane pad. If it is, it is a big plus. After all, if the paint is damaged, this metal begins to rot quickly, especially if the roads are sprinkled with salt.
- Load capacity The higher the score, the more universal the mechanism will be. It can be used not only for cars, but also for trucks.
- Good lubrication. Places where the nut is in contact with the screw should be well lubricated. If not, such a mechanism will not last long. If water enters, rust forms on the threads. As a result, such a car cannot be lifted with ordinary hands. This lubricant must withstand temperatures from minus 45 to +95 degrees Celsius.
- Lifting heightThe higher it is, the better.
So, we figured out how the screw-type mechanical jack works and works. Having considered the advantages and features of each type, you will be able to choose the most suitable option for you. Good luck!