First of all, these two kinds of jacks are our very common jacks, and their applications are very extensive. What is the difference? Let’s briefly explain:
Let’s talk about the screw bottle jack first, which uses the relative motion of the screw and the nut to lift or lower the heavy object. It consists of main frame, base, screw rod, lifting sleeve, ratchet group and other main components. When working, it is only necessary to repeatedly turn the handle with the ratchet wrench, and the small bevel gear will drive the large bevel gear to rotate, making the screw rotate. The action of raising or lowering the product of the lifting sleeve. At present, this kind of jack has a lifting height of 130mm-400mm. Comparing with the hydraulic jack, it has a Higher lifting height, but the efficiency is lower, at 30%-40%.
Next is the hydraulic bottle jack, which transmits power through the pressure oil (or working oil), so that the piston completes the lifting or lowering action.
1. pump suction process
When the lever handle 1 is lifted by hand, the small piston is driven upward, and the sealing working volume in the pump body 2 increases. At this time, since the oil discharge check valve and the oil discharge valve respectively close the oil paths where they are located, the working volume in the pump body 2 increases to form a partial vacuum. Under the action of atmospheric pressure, the oil in the oil tank opens the oil suction check valve through the oil pipe and flows into the pump body 2 to complete an oil suction action.
2. Pumping oil and heavy lifting process
When the lever handle l is pressed down, the small piston is driven down, the working volume of the small oil chamber in the pump body 2 is reduced, the oil in it is squeezed out, and the oil discharge check valve is pushed open (at this time, the oil suction one-way Valve automatically closes the oil circuit to the oil tank), and the oil enters the hydraulic cylinder (oil chamber) through the oil pipe. Since the hydraulic cylinder (oil chamber) is also a sealed working volume, the entering oil is squeezed due to The force generated by the pressure will push the big piston up and push the weight up to do work. Repeatedly lifting and pressing the lever handle can make the heavy object rise continuously and achieve the purpose of lifting.
3. heavy object falling process
When the large piston needs to return downward, open the oil drain valve 8 (rotate 90°), then under the action of the weight of the heavy object, the oil in the hydraulic cylinder (oil chamber) flows back to the oil tank , and the large piston descends to in situ.
Through the working process of the bottle jack, we can conclude that the working principle of the hydraulic transmission is: using oil as the working medium, the movement is transmitted through the change of the sealing volume, and the power is transmitted through the internal pressure of the oil. A hydraulic transmission is essentially an energy conversion device.
Post time: Apr-01-2022