Hydraulic axial thrust bearing

Abstract

This utility model relates to a hydraulic shaft thrust bearing, which includes: a thrust cylinder sleeve, a thrust cylinder core, a hydraulic chamber, an annular groove reservoir, a hydraulic pump, a liquid medium, etc. This utility model patent applies liquid pressure technology to the axial bearing, avoiding the hard contact between the thrust plate and the balls or rollers in ordinary thrust bearings, greatly reducing the motion resistance around the shaft and improving the mechanical efficiency of the rotational motion around the shaft.

Description

Technical Field

[0001] This utility model relates to the field of thrust bearing technology and to liquid pressure technology. Background Technology

[0002] In the field of thrust bearing technology, common thrust bearings consist of two or more thrust washers and several rolling elements. Traditional thrust bearings are mainly divided into thrust ball bearings and thrust roller bearings. Thrust ball bearings are further divided into thrust ball bearings and thrust angular contact ball bearings. These bearings are mainly used in automotive steering mechanisms and machine tool spindles. Thrust roller bearings can be divided into thrust cylindrical roller bearings, thrust self-aligning roller bearings, thrust tapered roller bearings, and thrust needle roller bearings. Thrust cylindrical roller bearings are mainly used in oil drilling rigs and iron and steel manufacturing machinery; thrust self-aligning roller bearings are mainly used in hydroelectric generators, vertical motors, marine propeller shafts, tower cranes, extrusion presses, etc.; thrust tapered roller bearings are mainly used in crane hooks, oil drilling rig swivels, and rolling mill roll necks.

[0003] Magnetic levitation bearings are also a type of thrust bearing. Compared with traditional thrust bearings, magnetic levitation bearings are characterized by the absence of hard contact between the rotating body and the supporting body (equivalent to two thrust plates), resulting in high efficiency. However, their disadvantage is that the axial thrust is relatively small.

[0004] This invention provides a non-contact bearing technology similar to a magnetic levitation bearing, in which there is no hard contact between the rotating body and the supporting body (equivalent to two thrust plates), and gravity stress is transmitted through a liquid medium. Compared with traditional thrust bearings, it has higher mechanical efficiency; compared with magnetic levitation bearings, it has a simpler structure and lower cost. Summary of the Invention

[0005] The purpose of this utility model embodiment is to provide a hydraulic shaft thrust bearing, which aims to solve the problems of low efficiency of ordinary thrust bearings and small axial thrust of magnetic levitation thrust bearings.

[0006] This utility model embodiment is implemented as follows: A hydraulic shaft thrust bearing, characterized by comprising: a thrust cylinder sleeve, a thrust cylinder core, a hydraulic chamber, an annular groove reservoir, a hydraulic pump, and a liquid medium; the thrust cylinder sleeve is an inverted cylindrical body, with its upper sealed end connected to an axially rotating object, and its lower open end nested and installed outside the thrust cylinder core without connection; the thrust cylinder core is a cylindrical body with an open upper end, its upper open end inserted into the lower open end of the thrust cylinder sleeve, and its lower sealed end installed on a fixed base; the nesting installation of the thrust cylinder sleeve and the thrust cylinder core within it forms a relatively closed space, namely the hydraulic chamber, which is filled with a liquid medium during operation, and the liquid generates an upward thrust due to its pressure; because the thrust cylinder sleeve and the thrust cylinder core are nested and installed inside it, a relatively closed space, namely the hydraulic chamber, is formed. During operation, the hydraulic chamber is filled with a liquid medium, and the liquid generates an upward thrust due to its pressure; due to the nesting installation of the thrust cylinder sleeve and the thrust cylinder core, a hydraulic pump is formed within it, a hydraulic pump is formed, a hydraulic chamber is formed, and the hydraulic chamber is filled with a liquid medium, which generates an upward thrust due to its pressure; because the thrust cylinder sleeve and the thrust cylinder core are nested and installed inside it, a hydraulic pump is formed ... The cylindrical cylinder core is nested and installed without connection, forming an annular gap at the contact surface between the thrust cylinder sleeve and the thrust cylinder core. High-pressure liquid in the hydraulic chamber can be ejected through this annular gap. High-pressure liquid must be continuously replenished into the hydraulic chamber to maintain its working pressure. The annular reservoir is a hollow annular groove nested on the outer side of the lower end of the thrust cylinder core. It is used to collect the liquid ejected from the hydraulic chamber and recycle it. The hydraulic pump is installed at the bottom of the annular reservoir, and its outlet conduit is inserted into the hydraulic chamber to inject high-pressure liquid into it. The thrust cylinder sleeve, thrust cylinder core, hydraulic pump, annular reservoir, and pressure-conducting liquid medium together form a hydraulic shaft thrust bearing system.

[0007] In summary, this invention offers the following advantages: It utilizes high-pressure fluid within the hydraulic chamber to provide an upward thrust, counteracting the weight of the thrust cylinder liner and its connected components, thus avoiding hard-contact friction similar to that between the thrust plate and balls or rollers. When the thrust cylinder liner and its connected components rotate around the axis, their motion resistance primarily originates from the viscous resistance between the thrust cylinder liner and the fluid medium, which is calculated using the fluid viscous resistance formula. In contrast, the friction between the thrust plate and the balls or rollers is rolling or sliding friction, which is calculated using the ordinary sliding or rolling friction resistance formula. Therefore, compared to the former, the hydraulic shaft thrust bearing provided by this invention exhibits lower rotational motion resistance and higher mechanical efficiency. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of a hydraulic shaft thrust bearing.

[0009] In the diagram: 1-thrust cylinder liner, 2-thrust cylinder core, 3-hydraulic chamber, 4-annular groove reservoir, 5-hydraulic pump, 6-liquid medium. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. The specific implementation of the present utility model will be described in detail below with reference to specific embodiments. Example

[0011] like Figure 1 The following describes a hydraulic shaft thrust bearing, characterized by comprising: a thrust cylinder sleeve 1, a thrust cylinder core 2, a hydraulic chamber 3, an annular groove reservoir 4, a hydraulic pump 5, and a liquid medium 6; the thrust cylinder sleeve 1 is an inverted cylindrical body, with its upper sealed end connected to an axially rotating object, and its lower open end nested and installed outside the thrust cylinder core 2 without connection; the thrust cylinder core 2 is a cylindrical body with an open upper end, its upper open end inserted into the lower open end of the thrust cylinder sleeve 1, and its lower sealed end installed on a fixed base; the nesting of the thrust cylinder sleeve 1 and the thrust cylinder core 2 forms a relatively sealed space, namely the hydraulic chamber 3, which is filled with the liquid medium 6 during operation, and the liquid exerts an upward thrust due to its pressure; due to the nesting of the thrust cylinder sleeve 1 and the thrust cylinder core 2... The system is installed without connection. A ring-shaped gap is formed at the contact surface between the thrust cylinder sleeve 1 and the thrust cylinder core 2. The high-pressure liquid in the hydraulic chamber 3 can be ejected through the ring-shaped gap. High-pressure liquid must be continuously replenished into the hydraulic chamber 3 to maintain the working pressure of the liquid in the hydraulic chamber 3. The annular groove reservoir 4 is a hollow annular groove, which is nested on the outer side of the lower end of the thrust cylinder core 2 to collect the liquid ejected from the hydraulic chamber 3 and recycle it. The hydraulic pump 5 is installed at the bottom of the annular groove reservoir 4, and its outlet pipe is inserted into the hydraulic chamber 3 to inject high-pressure liquid into the hydraulic chamber 3. The thrust cylinder sleeve 1, thrust cylinder core 2, hydraulic pump 5, annular groove reservoir 4, and pressure-conducting liquid medium 6 together form a hydraulic shaft thrust bearing system.

[0012] Its main working principle is as follows: The hydraulic pump 5 is started to inject high-pressure liquid into the hydraulic chamber 3. The hydraulic chamber 3 is relatively sealed, and the pressure gradually rises, forming an upward thrust. When the upward thrust is equal to the weight of the thrust cylinder liner 1 and the object connected to it, the axial position of the thrust cylinder liner 1 relative to the thrust cylinder core 2 is relatively balanced. At this time, the hydraulic shaft thrust bearing enters the working state, and the thrust cylinder liner 1 and the object connected to it are suspended on the liquid medium 6 in the hydraulic chamber 3. The resistance encountered by the thrust cylinder liner 1 and the object connected to it when making axial rotational motion is small.

[0013] Below, we compare the operating efficiency of hydraulic shaft thrust bearings with that of ordinary thrust bearings through two examples:

[0014] Example 1: Assume the total weight of the thrust cylinder sleeve and its connected components is 4,000,000 kg; assume the inner diameter of the thrust cylinder sleeve is 1 m. Calculations show that when the hydraulic pressure is 50 MPa, the upward thrust slightly exceeds 4,000,000 kgf; assume the liquid medium in the hydraulic chamber is water; assume the viscosity coefficient of water at standard atmospheric pressure is 1.03 × 10⁻³, and the viscosity coefficient at 50 MPa is 1.39 × 10⁻³; assume the contact surface width between the thrust cylinder sleeve and the thrust cylinder core is 0.05 m, and the average gap between the contact surfaces is 0.00001 m. Calculate the bearing power consumption when the thrust cylinder sleeve and its connected components rotate around the axis at 10 r / s:

[0015] Calculate the viscous resistance power consumption between the thrust cylinder liner and the fluid in the hydraulic chamber during rotation:

[0016] Given the formula for viscous resistance of a liquid, Fviscous = μAv / h,

[0017] The viscosity coefficient of water at 50 MPa pressure is μ = 1.39 × 10^-3.

[0018] The linear velocity of the inner diameter of the thrust cylinder liner during rotation = 1m × 3.14 × 10 r / s = 31.4m / s.

[0019] When the linear velocity is 31.4 m / s, the thickness of the turbulent boundary layer of a cylinder rotating about its own axis is calculated using the commonly used empirical formula: δ ≈ \frac{0.37 r}{Re_ω^{0.2}} . Substituting this into the numerical calculation, the thickness of the water boundary layer is found to be 0.016 m. Therefore, the value of h is taken as 0.016 m.

[0020] Assuming the distance from the top of the hydraulic chamber to the contact point between the push cylinder sleeve and the thrust cylinder core is 0.1m, the contact area between the inside of the push cylinder sleeve and the liquid is A = (1m / 2)^2 × 3.14 + 1m × 3.14 × 0.1m ≈ 1.1㎡.

[0021] Substitute the relevant values ​​into the calculation:

[0022] Fviscous = 1.39 × 10^-3 × 1.1 m² × 31.4 m / s / 0.016 m ≈ 3 N, Viscous force power consumption = 3 N × 31.4 m / s = 94.2 W ≈ 0.09 KW.

[0023] Calculate the power consumption of the hydraulic pump to deliver high-pressure fluid to the hydraulic chamber while maintaining a pressure of 50 MPa:

[0024] First, calculate the energy required to replenish 1 cubic meter of liquid at a pressure of 50 MPa: W = P × V = 50 MPa × 1 m³ = 5 × 10^7 J ≈ 13.89 kW·h. Therefore, the energy consumed per cubic meter of high-pressure liquid is 13.89 kW·h / m³.

[0025] The width of the slit between the thrust cylinder liner and the thrust cylinder core is 1m × 3.14 = 3.14m. The height of the slit (i.e., the average gap between the contact surfaces of the thrust cylinder liner and the thrust cylinder core) is 0.00001m. The length of the slit (i.e., the width of the contact surface between the thrust cylinder liner and the thrust cylinder core) is 0.05m. Using the parallel plate flow formula under laminar flow conditions, the average flow velocity of the liquid flowing out of the pressurization chamber through the slit is calculated to be 8.32m / s.

[0026] The flow rate of water ejected through the gap between the lower inner wall of the suspended pressure-bearing cylindrical bowl and the upper outer wall of the booster cylinder is approximately 0.94 m³ / h.

[0027] The power consumption required to maintain the high pressure in the pressurization chamber and replenish the high-pressure liquid is approximately 13.06 kW (13.89 kWh / m³ × 0.94 m³ / h).

[0028] Calculate the power consumption generated by the viscous resistance of the fluid at the contact surface between the thrust cylinder liner and the thrust cylinder core:

[0029] The contact area between the thrust cylinder liner and the thrust cylinder core is A = 1m × 3.14 × 0.05m = 0.16㎡.

[0030] The clearance between the contact surfaces of the thrust cylinder liner and the thrust cylinder core is 0.00001m. When calculating the velocity gradient, h = 0.00001m is taken.

[0031] Viscous resistance Fviscous = 1.03 × 10^-3 × 0.16 m² × 31.4 m / s / 0.00001 m ≈ 517.5 N.

[0032] Viscous power consumption W = 517.5 N × 31.4 m / s ≈ 16250 W = 16.25 kW

[0033] Total power consumption: 0.07kw + 13.06kw + 16.25kw = 29.38kw.

[0034] Comparison: We use a thrust bearing with a contact surface diameter of about 1m between the thrust plate and the ball for comparison (we do not consider factors such as the possibility of the ball being crushed by gravity). Other relevant parameters are the same as the former. We assume that the rolling friction coefficient between the thrust plate and the ball is 0.001.

[0035] Calculation: The linear velocity of rotation at the contact point between the thrust plate and the ball bearing = 1m × 3.14 × 10 r / s = 31.4m / s.

[0036] The frictional resistance between the thrust plate and the ball bearings = 4,000,000 kg × 9.8 N / kg × 0.001 = 39,200 N.

[0037] The frictional resistance power consumption between the thrust plate and the ball is 39200N × 31.4m / s = 1230880w = 1230.88kw.

[0038] The power consumption of the hydraulic shaft thrust bearing provided by this utility model is approximately 2.39% compared to that of a conventional ball thrust bearing.

[0039] Example 2: Assume the total weight of the thrust cylinder sleeve and its connected components is 40,000 kg; assume the inner diameter of the thrust cylinder sleeve is 0.1 m. Calculations show that when the pressure inside the hydraulic chamber is 50 MPa, the upward thrust slightly exceeds 40,000 kgf; assume the liquid medium inside the hydraulic chamber is water, with a viscosity coefficient of 1.03 × 10⁻³ at standard atmospheric pressure and 1.39 × 10⁻³ at 50 MPa; assume the contact surface width between the thrust cylinder sleeve and the thrust cylinder core is 0.4 m, and the average gap between the contact surfaces is 0.00001 m. Calculate the bearing power consumption when the thrust cylinder sleeve and its connected components rotate around the shaft at 10 r / s.

[0040] Calculate the viscous resistance power consumption between the thrust cylinder liner and the fluid in the hydraulic chamber during rotation:

[0041] Given the formula for viscous resistance of a liquid, Fviscous = μAv / h,

[0042] The viscosity coefficient of water at 50 MPa pressure is μ = 1.39 × 10^-3.

[0043] The linear velocity of the inner diameter of the thrust cylinder liner during rotation = 0.1m × 3.14 × 10 r / s = 3.14 m / s.

[0044] When the linear velocity is 3.14 m / s, the commonly used empirical formula for calculating the turbulent boundary layer thickness of a cylinder rotating about its own axis is: δ ≈ \frac{0.37 r}{Re_ω^{0.2}} . Substituting this into the numerical calculation, the water boundary layer thickness is found to be 0.003 m. Therefore, the value of h = 0.003 m is taken.

[0045] Assume the distance from the top of hydraulic chamber 3 to the contact point between the push cylinder sleeve and the thrust cylinder core is 0.02m, and the internal area of ​​the push cylinder sleeve is A = (0.1m / 2)^2 × 3.14 + 0.1m × 3.14 × 0.02m ≈ 0.014㎡.

[0046] Substitute the relevant values ​​into the calculation:

[0047] Fviscous = 1.39 × 10^-3 × 0.014 m² × 3.14 m / s / 0.003 m ≈ 0.02 N, Viscous force power consumption = 0.02 N × 3.14 m / s ≈ 0.06 W = 0.00006 kW.

[0048] Calculate the power consumption of the hydraulic pump to deliver high-pressure fluid to the hydraulic chamber while maintaining a pressure of 50 MPa:

[0049] The width of the slit between the thrust cylinder liner and the thrust cylinder core is approximately 0.31m (0.1m × 3.14). The height of the slit (the average gap between the surfaces of the thrust cylinder liner and the thrust cylinder core) is 0.00001m. The length of the slit (the width of the contact surface between the thrust cylinder liner and the thrust cylinder core) is 0.4m. Using the parallel plate flow formula under laminar flow conditions, the average flow velocity of the liquid exiting the pressurization chamber through the slit is calculated to be 1.04m / s.

[0050] The flow rate of water ejected through the gap between the lower inner wall of the suspended pressure-bearing cylindrical bowl and the upper outer wall of the booster cylinder is approximately 0.1 m × 3.14 × 0.00001 m × 1.04 m / s × 3600 s / h ≈ 0.01 m³ / h.

[0051] The power consumption required to maintain the high pressure in the pressurization chamber and replenish the high-pressure liquid is approximately 13.89 kWh / m³ × 0.01 m³ / h ≈ 0.14 kWh.

[0052] Calculate the power consumption generated by the viscous resistance of the fluid at the contact surface between the thrust cylinder liner and the thrust cylinder core:

[0053] The clearance between the contact surfaces of the thrust cylinder liner and the thrust cylinder core is 0.00001m. When calculating the velocity gradient, h=0.00001.

[0054] The contact area between the thrust cylinder liner and the thrust cylinder core is A = 0.1m × 3.14 × 0.4m ≈ 0.13㎡.

[0055] Viscous resistance Fviscous = 1.03 × 10^-3 × 0.13 m² × 3.14 m / s / 0.00001 m ≈ 42 N.

[0056] Viscous power consumption W = 42N × 3.14m / s ≈ 131.9W ≈ 0.13kW

[0057] Total power consumption: 0.00006kw + 0.14kw + 0.13kw ≈ 0.27kw.

[0058] Comparison: We use a thrust bearing with a thrust plate and ball contact surface diameter of about 0.1m for comparison. Other relevant parameters are the same as in this example. The friction coefficient between the thrust plate and the ball is set to 0.001.

[0059] Calculation: The linear velocity of rotation at the contact point between the thrust plate and the ball bearing = 0.1m × 3.14 × 10 r / s = 3.14 m / s.

[0060] The frictional resistance between the thrust plate and the ball bearings = 40000kg × 9.8N / kg × 0.001 = 392N.

[0061] The frictional resistance power consumption between the thrust plate and the ball is 392N × 3.14m / s = 1230.88w ≈ 1.23kw.

[0062] The power consumption of the hydraulic shaft thrust bearing provided by this utility model is 0.27 / 1.23 = 22% compared to that of a conventional ball thrust bearing.

[0063] By comparing the experimental data from the two examples above, we draw the following conclusions: the hydraulic shaft thrust bearing provided by this invention consumes significantly less power than traditional thrust bearings, and the larger the sample size, the more significant the gain of comparison. The hydraulic shaft thrust bearing provided by this invention is mainly suitable for various large-scale equipment with high axial load capacity and high rotational speed, such as flywheel energy storage.

[0064] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hydraulic shaft thrust bearing, characterized in that... include: The thrust cylinder sleeve (1), thrust cylinder core (2), hydraulic chamber (3), annular groove reservoir (4), hydraulic pump (5), and liquid medium (6) are included. The thrust cylinder sleeve (1) is an inverted cylindrical body with its upper end sealed and connected to an axially rotating object. The lower end of the opening is nested and installed outside the thrust cylinder core (2) without connection. The thrust cylinder core (2) is a cylindrical body with an upper opening. Its upper opening is inserted into the lower end of the opening of the thrust cylinder sleeve (1), and its lower end is installed on a fixed base. The nested installation of the thrust cylinder sleeve (1) and the thrust cylinder core (2) inside them forms a relatively closed space, namely the hydraulic chamber (3). When working, the hydraulic chamber (3) is filled with liquid medium (6), and the liquid forms an upward thrust due to its pressure. Because the thrust cylinder sleeve (1) and the thrust cylinder core (2) are nested and installed without connection, the thrust cylinder core (1) is nested and installed inside the thrust cylinder core (2) without connection. The contact surfaces of the cylinder liner (1) and the thrust cylinder core (2) form an annular gap. The high-pressure liquid in the hydraulic chamber (3) can be ejected through the annular gap. High-pressure liquid must be continuously replenished into the hydraulic chamber (3) and the working pressure of the liquid in the hydraulic chamber (3) must be maintained. The annular groove reservoir (4) is a hollow annular groove. It is nested on the outer side of the lower end of the thrust cylinder core (2) and is used to collect the liquid ejected from the hydraulic chamber (3) and circulate it. The hydraulic pump (5) is installed at the bottom of the annular groove reservoir (4) and its outlet conduit is inserted into the hydraulic chamber (3) to inject high-pressure liquid into the hydraulic chamber (3). The thrust cylinder liner (1), the thrust cylinder core (2), the hydraulic pump (5), the annular groove reservoir (4) and the liquid medium (6) for transmitting pressure together form a hydraulic shaft thrust bearing system.

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