KR20000023792A - A torsional vibration damper - Google Patents

Abstract

PURPOSE: A torsion vibration damper is provided to reduce the vibration caused by torsion in a crankshaft for an engine and to remarkably simplify the preparing process. CONSTITUTION: A torsion vibration damper is operated by; slightly revolving a hub(2) with torsion vibration when working a damper; reducing the volume in a head chamber(16) and increasing the volume in a following chamber(16a) corresponding to the reduction in the head chamber if the hub(2) revolve clockwise on an external member; and pumping buffer oil to the following chamber(16a) through a non-return valve(27) by lifting up the oil along a radial inlet passage(8). The non-return valve prevents the pressurized oil in the head chamber from being exhausted through a radial inlet path(7). Therefore, the pressurized oil is so moved to the other chamber(16a) as to be filled with the increased volume across a blade(11) through a contraction flow passage(18).

Description

Torsion Vibration Damper {A TORSIONAL VIBRATION DAMPER}

Torsional vibration dampers for engine crankshafts are known in which an outer inertia member is connected to an inner hub member and capable of limited relative rotation thereto. In some of these dampers damping is achieved by the presence of a pump chamber constructed between the hub and the outer inertial member. The chambers are formed by cavities in the inertial member occupied by the small blade on the hub member such that in use there is a gap in each side of the blade occupied by the engine oil. The relative motion between the inner member and the outer member causes oil to be pumped between the cavities to create a cushioning effect. Such dampers are called "sadner" dampers in the name of the inventor. In some particular sadner configurations, the blade has a transverse passageway in communication with each side of the blade. These dampers are expensive because they require many complex precision machine parts and machining operations.

It is an object of the present invention to eliminate or mitigate this problem.

The present invention relates to a torsional vibration damper, for example a torsional vibration damper used to dampen the torsional vibration of an engine crankshaft.

1 is a side cross-sectional view taken along line AA of FIG. 2.

FIG. 2 is a front sectional view taken along the line BB of FIG. 1.

3 is a cross-sectional view through the blade and side plate of the embodiment shown in FIG.

4 is a cross-sectional view taken along line CC of FIG. 3.

FIG. 5 is a diagram corresponding to FIG. 3 for the first modification of the present invention. FIG.

FIG. 6 is a cross-sectional view taken along the line DD of FIG. 5.

FIG. 7 is a view of a cross section through the blade and side plate for a second variant of the invention. FIG.

FIG. 8 is a cross-sectional view taken along line EE of FIG. 7.

According to the present invention, there is provided an annular driven member and an annular inertial member coaxial with the driven member and capable of limited relative rotational movement, wherein the driven member and the inertial member are other members for receiving the protruding elements of one member. Having at least one set of variable dose chambers formed by cavities of said relative movement of said driven member and said inertial member in a first direction, reducing the volume of one of said chambers and increasing the other; The relative motion of the chambers is such that the chambers are installed such that the chamber volume is reversed, and the variable volume chambers are in use connected to a fluid source, wherein the surfaces of the cavity adjacent to the surface of the protruding element are each substantially planar. A torsional vibration damper is provided.

Providing a planar cavity significantly simplifies the manufacturing process and as a result allows relatively low angular displacements of the driven and inertial members.

In a preferred embodiment, the planar cavity surface is provided with a seal therein to provide a recess.

The protruding element may have a through conduit to allow fluid to flow between the variable volume chambers on each side of the protruding face and the conduit may be provided with a constriction. Alternatively, the projecting element may preferably have a convolute through conduit having a biased parallel bore hole interconnected with a nearly vertical bore hole. The vertical bore hole may have an extension that forms an outlet conduit to provide an outlet through which fluid can be discharged to the atmosphere.

In a preferred embodiment, two sets of variable volume chambers can be provided opposite the diameter.

Preferably, the driven member is provided with one or more radial conduits for delivering buffer fluid to each of the variable volume chambers. The radial conduit has a one-way valve. Radial conduits and one-way valves may be simple and compact in view of the features of the present invention that only a relatively small amount of buffer fluid flow is required into the variable volume chamber.

In a preferred embodiment there are two cooling conduits having bends that are bent almost vertically, one for each transverse conduit, but the protruding elements may have one or more cooling conduits passing by at least part of the transverse conduit. The first portion of the conduit passes the side of the transverse conduit and the second portion is away from the transverse conduit and towards the outlet.

Preferably, the outlet of the cooling conduit can be fitted to a non-return valve. In addition, the inlet of each cooling chamber is preferably coupled to the orifice.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings in an exemplary sense only.

Referring to FIGS. 1 and 2, the torsional vibration damper includes a flat cylindrical rotary body 1 having an inner hub member 2 and an outer inertia member 3. The members 2, 3 usually rotate together, for example with the engine crankshaft, but the torsional vibration in the shaft tends to produce a limited rotation of the hub member 2 relative to the outer inertia member 3. The buffer effect is achieved by buffering this relative motion. In the following description, it is assumed that vibration dampers are used to dampen torsional vibrations in the engine crankshaft using engine oil as the buffer fluid. However, it should also be taken into account that other buffer fluids may be used.

The hub member 2 has a central bore hole 4 for receiving one end of the crankshaft (not shown), in which the projecting flanges 5 of the hub member 2 projecting radially inward are equidistantly spaced. It is fixed by bolts (not shown) which are inserted into the arranged holes 6 (see FIG. 2).

Two opposite pairs of parallel radial inflow flow passages 7, 8 pass through the hub member 2, which interconnect the oil reservoir (not shown) and the damping structure described below. The engine oil is pressurized and passed through the center of the crankshaft to the reservoir in the central bore hole 4 of the hub member 2.

The radial inflow flow passages 7, 8 are connected to a cavity 9 formed on the outer circumference of the hub member 2. Each cavity 9 is substantially rectangular in cross section and has a planar base wall 10 with grooves for receiving the oil seal 10a.

The outer inertial member 3 is provided with a radially inwardly projecting blade 11 located opposite the radial direction. These protruding blades 11 are each received in a corresponding hub member cavity 9. Each blade 11 is fixed between an annular side plate 12 (not shown in FIG. 2 to simplify the drawing) and these side plates 12 are externally oriented by bolts 13 that are spaced equiangularly apart. It is fixed on the opposite side of the member 3. The blade 11 is fixed to the side plate 12 by means of four parallel bolts 14. Two are respectively provided on one side, and each is accommodated in a bore hole in which a screw in the blade 11 is formed. The side plate 12 overlaps the hub member 2 and an oil seal 15 is provided on the contact surface. The blades 11 are separated from the cavity wall by axial gaps consisting of variable volume chambers 16, 16a on the outer and right sides of each blade 11, as shown in FIG. 2. Each blade 11 has a planar radius inner surface 17 which is in almost contact with the planar base wall 10 of each cavity 9. There is a small gap here.

3 and 4, the blade 11 is secured by bolts (not shown for the sake of brevity) that fit into the bore holes 14a in which a screw is formed between the two annular side plates 12. It is shown. The transverse shrinkage flow passage 18 traverses the blade 11 in a direction substantially perpendicular to the axis of rotation of the damper to communicate between the variable volume chambers 16 on each side of the blade 11. Shrinkage 19 is provided in the central portion of flow passage 18 to limit the flow of oil there through. Cooling conduits 20, 20a are provided on each side of the blade 11, each of which has a first portion 21 and a constriction 19 extending close and adjacent to one half of the retracted flow passage 18, respectively. Next to each side) is provided with a second portion extending perpendicular to the first portion 21 up to each side plate 12. The first portion 21 of each cooling conduit 20, 20a extends laterally to the other half of the contraction flow passage 18 to provide a means for cooling over the entire length of the flow passage 18. The ends of the cooling conduits 20, 20a adjacent to the side plate 12 are provided with non-return valves 23, 23a, respectively, and are provided with an engine oil sump through the jets 25, 25a to control the outflow of oil. (Not shown) is in communication with the outlet bore holes 24, 24a in the side plate 12 to allow oil to exit.

The pair of chamber sets opposite the diameter and consisting of blade 11 and cavity 9 constitute the pump chamber. The pump chamber forms part of a pump mechanism that can be considered as a dual acting piston through the cylinder in which the blade 11 is constituted by a cavity. The variable volume chambers 16, 16a form part of the cylinder at the opposite end of the cylinder. The buffer oil has a radial inflow passage 7, each with a simple non-return valve 27, 28 with a ball 29 that lies on the valve seat 30 formed in the radial inflow passages 7, 8, respectively. 8) flows into the chambers 16, 16a.

In operation, the torsional vibration of the crankshaft causes the hub member 2 to rotate slightly relative to the outer inertia member 3. This movement is small enough that the planar surface 17 of the blade 11 can move without interfering with the base wall 10 of the cavity 9. If the hub member 2 rotates clockwise relative to the stationary outer member 3, the volume decreases in the leading chamber 16 of each variable volume pair and correspondingly increases in the subsequent chamber 16a. do. This is followed by a pump action in which the buffer oil is pulled along the radial inlet passage 8 and enters the subsequent chamber 16a via the non-return valve 28. The corresponding non-return valve 27 in the other radial inlet passage 7 prevents pressurized oil in the fore chamber 16 from exiting through the radial inlet passage 7, so that the pressurized oil passes through the transverse shrinkage flow passage 18. Through the blade 11 to move to another variable volume chamber 16a to fill the increased volume. The transverse constriction 19 in the flow passage 18 minimizes the flow through the blade 11 to create a cushioning effect. Turbulence in the buffer oil occurs across the blade 11.

In addition to the oil being forced between the variable volume chambers 16 and 16a, a small volume of oil is also forced into the cooling conduit 20 to relatively stable the temperature of the blade 11 near the shrinkage flow passage 18. Keep at the level. The oil is pumped through the non-return valve 23 to the outlet bore hole 24 in the side plate 12, where the oil exits through the jet 25 and returns to the engine sump. The non-return valve 23a provided in the other cooling conduit 20a prevents air from entering during inhalation that occurs when the volume of the variable volume chamber 16a increases.

If the hub member 2 rotates counterclockwise relative to the outer member 3, the volume of the chamber 16 will increase while the volume of the chamber 16a will decrease. Thus, the buffer oil is drawn from the radial inlet passage 7 into the chamber 16 and passes through the transverse shrinkage flow passage 18 in the blade 11 in the opposite direction described above. Moreover, oil is forced through the corresponding cooling conduit 20a and exits through the outlet bore hole 24a in the other side plate 12.

Most of the oil in the variable volume chambers 16, 16a passes through the blade 11 during operation, and only a small volume leaves the chambers 16, 16a through the cooling conduits 20, 20a. Thus, during each stroke only a small replacement volume needs to be pulled out of the radial inlet passages 7, 8 into the variable volume pump chambers 16, 16a. The small volume flow rate allows the radial inlet passages 7 and 8 and the non-return valves 27 and 28 to have a compact and simple structure, reducing manufacturing costs, future maintenance or repair costs, and other features on the damper. To be applied. In particular, low flow rates do not require return springs for non-return valves.

The degree of buffering of the oil passing through the cooling conduits 20, 20a and the generation of heat during the buffering process are the cooling conduits 20, 20a, the chambers 16, 16a, the transverse passages 18 and the radius. It should be understood that this is a circulating flow of oil around the inlet passages 7, 8.

Since the relative motion between the blades 11 and the cavities 9 is small, the planar surfaces on the inner surface 17 of each blade 11 and the bottom wall 10 of each cavity 9 are separated by very small gaps. do. This configuration allows the blade 11 and the cavity 9 to be manufactured simply and simply as compared to a conventional damper having a corresponding arc surface. The cavity is simply formed by polishing a slot with a flat bottom into the hub and then polishing the groove in which the oil seal 10a is mounted.

In the first variant shown in FIGS. 5 and 6, the inlet orifice 31 is fitted in the cooling conduits and the pressure-regulated non-return outlet valve 32 is such that the outlet valve does not adversely affect the maximum buffer pressure. To ensure.

A second variant of the invention is shown in FIGS. 7 and 8. The blade 11 'has a flow passage 18' having two biased parallel conduits 40 connected to each other by a vertical bore hole 41, forming a substantially z-shaped flow passage. Each biased conduit has an inlet / outlet buffer jet 42. One end of the vertical bore hole 41 is closed while the other extends through the blade 11 'and meets the outlet bore hole 42 in the side plate 12'. The discharge jet 44 is fitted in the outlet bore hole 43. The blade 11 ′ has two parallel spaced and through bore holes 45 extending below the flow passage 18 ′ and parallel to the vertical bore holes 41. A bolt (not shown) is received in the through bore hole 45 to secure the blade 11 'to the side plate 12'.

In use, the oil passes through the flow passage 18 'across the blade 11' and provides particularly improved cushioning for the path of the convolute. Excess oil passes through the vertical bore hole 41 and exits the discharge jet 44. A non-return discharge valve is not necessary for the discharge bore hole 43 because the pressure in the flow passage 18 'between the buffer jets 42 is always higher than the atmosphere.

It should be considered that various modifications from the above-described configuration are possible without departing from the scope of the following claims. For example, the seal 10a is optional in that a gap between the blade 11 and the base wall 10 of the cavity 9 can be employed for oil transfer between the chambers 16, 16a. The present invention can be used with the British spring GB 2261716, the regulated spring disclosed in the international application WO 95/23300 or the gas spring regulated damper described in GB 4014673.

Claims (16)

An annular driven member and an annular inertial member coaxially with the driven member and capable of limited relative rotational movement, wherein the driven member and the inertial member are arranged in a cavity of another member that receives the protruding element of one member. Having at least one set of variable dose chambers, wherein relative motion of the driven member and the inertial member in a first direction decreases the volume of one of the chambers and increases the other, relative motion in the opposite direction In the torsional vibration damper, the chambers are installed so that the chamber volume is reversed, and the variable volume chambers are connected to a fluid source in use, Torsional vibration damper, characterized in that the surfaces of the cavity adjacent to the surface of the projecting element are each substantially planar. The torsional vibration damper according to claim 1, wherein the planar surface of the cavity has a recess in which a seal is provided. The torsional vibration damper according to claim 1 or 2, wherein the cavity is provided in the driven member and the protruding element is provided on the inertial member. 4. The torsional vibration damper according to any one of claims 1 to 3, wherein the projecting element has a through conduit through which fluid can flow between the variable volume chambers on each side of the projecting element. 5. The torsional vibration damper according to claim 4, wherein the conduit is a straight through bore hole having a contraction portion. 5. The torsional vibration damper according to claim 4, wherein the conduit is a conduit passage. 7. The torsional vibration damper as recited in claim 6, wherein said conduits are interconnected by deviating parallel bore holes connected by substantially vertical bore holes. 8. A torsional vibration damper according to claim 6 or 7, wherein the discharge conduit is connected to the through conduit and serves to discharge excess fluid into the atmosphere. 9. The torsional vibration damper as claimed in claim 8, wherein when subjected to the seventh aspect, the vertical bore hole has a portion extending to form the discharge conduit. The torsional vibration damper of claim 1, wherein there are two sets of variable volume chambers in radially opposite positions. Torsional vibration according to any one of the preceding claims, wherein at least one radial conduit is provided in said driven member for supplying buffer fluid to each variable volume chamber, said radial conduit having a one-way valve. Damper. The torsional vibration damper of claim 1, wherein the protruding element has one or more cooling conduits through at least a portion of the transverse conduits. 13. The system of claim 12, wherein two cooling conduits, one on each side of the transverse conduit, each bent almost vertically, the first portion of each conduit passing through the side of the transverse conduit and directed towards the exit from the conduit A torsional vibration damper comprising a second portion. 14. The torsional vibration damper of claim 13, wherein a non-return valve is fitted at the outlet of the cooling conduit. 15. The torsional vibration damper according to claim 12, 13 or 14, wherein an orifice is fitted at an inlet of each cooling chamber. A torsional vibration damper described herein in connection with FIGS. 1 to 4, 5 and 6, 7 and 8.