CN1580590A

CN1580590A - Crankshaft

Info

Publication number: CN1580590A
Application number: CNA2004100574801A
Authority: CN
Inventors: 瑟伦·H·延森
Original assignee: MAN B&W Diesel AS
Current assignee: MAN Energy Solutions Filial af MAN Energy Solutions SE
Priority date: 2003-08-13
Filing date: 2004-08-13
Publication date: 2005-02-16
Anticipated expiration: 2024-08-13
Also published as: CN100381715C; CN101126410A; DE10337246B4; JP4445344B2; KR20050016230A; DE10337246A1; CN101126410B; KR101188289B1; JP2005061628A

Abstract

Provided is a crankshaft capable of transmitting relatively large torque in a simple structure at reasonable costs. The crankshaft comprises at least one bearing pin 2, and at least one crankshaft pin 3 offset from the bearing pin to a radial direction. The bearing pin 2 and/or the crankshaft pin 3 are connected with a hole 4 with a step arranged on a crank web 1 in the crankshaft. The bearing pin 2 has a connecting strut 5 to be fixed in the hole by means of compressed combination, and the connecting strut is arranged along an inserting direction of the bearing pin. An over-size and/or the structure of the connecting strut 5 at a radial direction of the ranges 7 and 8 of the connecting strut are adjusted with each other so as to be approximately compressed at the same degree along the full length of the connecting strut 5 against ranges 9 and 10 related to the hole 4 with a step respectively in the crankshaft. Thus, large transmittable torque can be realized in the crankshaft.

Description

Bent axle

Technical field

The present invention relates to a kind of bent axle, be used for particularly constituting the oversquare engine of large-scale diesel engine, comprise at least one main journal and at least one radially with the rod journal of its relativity shift; Wherein main journal and rod journal oppositely protrude from a radius bar that is connected them, and main journal and/or rod journal have in the shoulder hole that matches that is embedded into radius bar, be fixed in wherein scarf joint by a kind of shrink fit, this scarf joint has along pushing direction series connection each several part that be provided with, that be in ladder, and their corresponding parts that matches with respect to shoulder hole under cold unassembled state have the radial interference amount.

Background technique

This bent axle is known by DK-PS122 682.In big-block engine, constitute by less parts in order to reduce the assembling weight bent axle that always requires to run through whole cylinders.Difference in this respect is, the bent axle that some are such, wherein a mode is identical, general main journal is connected and another axle journal with the radius bar that matches by shrink fit, general rod journal is molded on the radius bar that matches, and some such bent axles, wherein main journal and rod journal soaking press fit in the hole that matches of radius bar.

In oversquare engine, seek to make spacing between main journal and the rod journal to be in the scope of summation of two axle journal radiuses now or smaller.For because the hole that matches for scarf joint does not still too weaken radius bar, in the device that can learn by above-mentioned DK-PS122 682, the back of scarf joint form ladder mutually with the part front, the diameter of part that makes the front is less than the diameter of the part of back.With respect to the magnitude of interference in the corresponding aperture that matches a constant percentage in aperture in order to set up the needed axle journal of shrink fit so far wherein.Therefore there is such danger, the having than the part of major diameter and therefore also bigger magnitude of interference of back that is scarf joint is expanded into generation one gap between the part that makes in front comprises the part of front of less magnitude of interference and radius bar at the less diameter of having of scarf joint the part in the hole that matches for this part with the part that matches of radius bar after shrink fit is set up, as shown in Figure 5, therefore whole power stream must transmit via the part of the back of scarf joint under the situation of stand under load, and this is unfavorable for obtaining transferable peak torque.

Summary of the invention

Therefore set out thus, the objective of the invention is, improve the shortcoming that the bent axle that starts described pattern is avoided known devices simultaneously, make it can transmit bigger torque with the device that simply hangs down expense.

First solution of the present invention of this purpose is that whole part of scarf joint numerically equates with respect to the radial interference amount of the part that matches accordingly of shoulder hole.

Because the radial interference amount in the scope of all parts of scarf joint numerically equates, guarantee that radius bar rabbets whole parts of scarf joint reliably with the wall of whole parts of its shoulder hole and prevent that in an advantageous manner the gap from forming.Reach total length by means of measure of the present invention along scarf joint, that is the pressure of the mutual equilibrium in the scope of whole parts of scarf joint, thereby bigger torque can be transmitted generally.

The radial interference amount of whole parts of scarf joint can be equivalent to have minimum diameter part see the magnitude of interference of permission by material technology.Thereby get rid of the overload of machinery whereby reliably and get rid of plastic deformation.

But also possible, all the radial interference amounts of part be equivalent to scarf joint different parts see the mean value of the magnitude of interference of permission by material technology.Preferred this scheme when requiring very big transferable torque.

Second solution arranged side by side of above-mentioned purpose is, radial interference amount on each front end of the each several part of the series connection setting of scarf joint meet the percentage that equates of diameter of the corresponding part that matches of shoulder hole and part that each is positioned at another part front additional have one from front end begin in contrast to the conical overstriking that pushes direction, the difference between the diameter wherein front and the back is equivalent to the difference between the magnitude of interference that is provided with on each front end of the each several part in succession of scarf joint.

What keep magnitude of interference in this case in an advantageous manner determines that by percentage this is convenient to the manufacturing of each parts and particularly assembles so far.The tepee structure of the part of the front of scarf joint is chosen to make it just in time to offset because thereby the gap that the big magnitude of interference of the part of the back of scarf joint causes prevents that also the gap that will worry so far from forming.But cone angle is less, thereby can ignore the axial force that is caused by it.

Description of drawings

Below by means of accompanying drawing two embodiments are described in more detail.Wherein:

Fig. 1 bent axle of the present invention is equivalent to the part that part section is arranged of first solution;

Fig. 2 is in the device of unassembled cold state according to Fig. 1;

Fig. 3 bent axle of the present invention is equivalent to the part that second solution is in unassembled cold state.

Fig. 4 is in the device of assembled state according to Fig. 3; And

The partial view of Fig. 5 prior art;

Embodiment

Main application fields of the present invention is a big-block engine, particularly as the two-stroke large diesel engine with vat bore dia and little stroke of application such as marine propulsion.Can mention the twelve-cylinder large-scale diesel engine with cylinder bore dia 980mm as the example of large-scale plant, wherein stroke drops to 1200mm so that reach high rotational speed from 2400mm so far.Such illustrative explanation nature does not constitute any restriction.

Crank according to Fig. 1 comprises a radius bar 1, by its protrude on the one hand a main journal 2 with protrude on the other hand one with its reverse rod journal 3 of inverse migration mutually radially.Radial spacing between main journal 2 and the rod journal 3 is less than half of the summation of two axle journal diameters.A main journal 2 shown in Fig. 1 and a rod journal 3.In a bent axle of a big-block engine, be provided with the main journal of a plurality of coaxial line series connection settings and the rod journal of the parallel axes of a plurality of relative dislocations of ignition order as requested certainly.

Shown main journal 2 is connected with radius bar 1 by a kind of shrink fit.Shown rod journal 3 is molded on the radius bar 1.Naturally also can imagine such form of implementation, promptly wherein a rod journal 3 or main journal 2 all are connected with radius bar 1 by shrink fit with rod journal 3.To the preferred last described mode of execution of the super-huge motor with very heavy parts.

Be connected in each axle journal of the radius bar of adjacency by shrink fit, here be main journal 2 comprise one embed in the hole that matches 4 of radius bar 1, be fixed in wherein scarf joint 5 by shrink fit.Heating radius bar 1 during assembling.Then with scarf joint 5 edge pushing in the direction patchhole 4 by the direction shown in the arrow 6.In the cooling subsequently of radius bar 1, form the shrink fit that requires.In the part of scarf joint 5, be provided with one with respect to the corresponding magnitude of interference of the hole 4 that matches under cold conditions for this reason.

Scarf joint 5 has two edges and pushes the part that is in ladder 7,8 that the direction series connection is provided with, and both have the cylindrical circumference profile in by the form of implementation of Fig. 1 and 2 for it.Have bigger diameter D along the cylindrical part 7 that pushes the direction back, it is equivalent to the diameter of main journal 2 approximately.The diameter d of the part 8 of front is relative with it reduces to about 1/3, thereby produces the ladder that requires.Hole 4 constitutes shoulder hole, its have part for scarf joint 57,8 that match, be in the part 9,10 of ladder in the corresponding way, with D ' or its diameter of d ' mark.

As shown in Figure 2, the diameter d of the part 8 of the diameter D of the part 7 of the back of scarf joint 5 and front is respectively and realizes the d ' of set magnitude of interference 2 ü of shrink fit greater than the part 10 of the diameter D ' of the part 9 of the back in the hole that constitute shoulder hole 4 of cold radius bar 1 under unassembled state and front.Magnitude of interference 2 ü of the part 7 of the back of scarf joint 5 and the part 8 of front numerically equate, that is miss same distance.Guarantee in the foundation of shrink fit not only to produce the pressure that equates approximately in the part 7 of the back of scarf joint 5 but also in the part 8 in front whereby and prevent since the hole 4 that the part 7 of the back in the part 9 of the back of the embedded hole 4 of scarf joint 5 causes have a less diameter d ' the expansion of part 10 of front, prevented that therefore the gap that occurs in the prior art from forming.

Magnitude of interference 2 ü that are provided with in the part 7 of the back of scarf joint 5 and the part of front 8 can meet the front with less diameter d part 8 see the magnitude of interference of permission by material technology, thereby can prevent also that whereby unallowed pressure also prevents unallowed distortion this part 8 in.According to another in the suitable especially scheme of reality, this magnitude of interference be scarf joint 5 whole parts 7,8 see the mean value of the magnitude of interference of permission by material technology.

Have diameter d one ' be that 980mm and diameter D ' obtain good result for adopting magnitude of interference 2 ü of 2.6mm in the big-block engine of 1090mm.The magnitude of interference that is provided with conforms with the destination should be no less than maximum franchise, and would rather surpass.This tolerance is 2.48 or is 2.58mm in the part of back in the part of front in above-mentioned example.

The basic structure of the device by Fig. 3 and 4 described below is equivalent to the device by Fig. 1 and 2.Therefore adopt same tag for the sake of simplicity for identical parts.Consult above description about essential structure.Below be primarily aimed at its difference.

In the form of implementation of pressing Fig. 3 and 4, be respectively magnitude of interference 2 ü that the part 8 of the part 7 of back of scarf joint 5 and front matches ₁Or 2 ü ₂Be equivalent to the corresponding part that matches 9 that constitutes shoulder hole 4 of radius bar 1 or a percentage that equates of 10 diameter respectively.This percentage is relevant with material and is positioned at 0.1 to 0.13% in the big-block engine of current pattern.Because the diameter D ' of part 9 or 10 and the numerical difference between of d ' are therefore at the part 7 of scarf joint 5 or 8 magnitude of interference 2 ü ₁With magnitude of interference 2 ü ₂Between produce numerical difference between, as shown in Figure 4.

In order still to prevent since the expansion of the part 10 of the front in the hole 4 that the part 7 of the back in the part 9 of the back of the embedded hole 4 of scarf joint 5 causes and the gap therefore avoiding producing in the prior art form, the part of the front of scarf joint 58 is additional have one from front end begin in contrast to pushing the conical overstriking that direction increases gradually.Therefore the part 8 of front has the circumference profile of cutting the circle dimension bodily form.Front end in the part 8 of scarf joint 5 is provided with diameter d.It is by the diameter d of the part that matches 10 of shoulder hole ' add magnitude of interference ü in addition ₂Draw.The diameter d of the back that on the part 7 of back, is provided with in the zone of the extension of part 8 in front _rBecause the overstriking of circular cone type is greater than the diameter d of front.d _rAnd the difference between the d is equivalent to the magnitude of interference ü of part 7 of the back of scarf joint 5 ₁With the magnitude of interference ü that on the front end of the part 8 of the front of scarf joint 5, is provided with ₂Between difference.Consequent cone angle alpha is less, as seen from Figure 3, thereby is very little and is prevented moving axially of scarf joint 5 without any need for measure by the axial force that tapering produces.

As learning by Fig. 4, in order to ensure set up the enough surface of contact of wall on the excircle of the part 8 of the front that matches of scarf joint 5 of the part 10 of the front that constitutes shoulder hole 4 of radius bar 1 later in shrink fit, the tapering of the part 8 of this front of scarf joint 5 remains enough, and the power stream that therefore transmits torque is distributed on the total length of scarf joint 5 in an advantageous manner.

In pressing the example shown in Fig. 3 and 4,5 of scarf joints have two-part, i.e. the part 8 of the truncated cone bodily form of the cylindrical part 7 of back and front.If scarf joint has more than two parts, what then conform with purpose is, each part that is positioned at another part front constitutes truncated cone body formula.What only rearmost part conformed with purpose is columniform, as in the example illustrated name.It is same that what be suitable for is that magnitude of interference and diameter that the diameter that the diameter of each front of the part of each truncated cone bodily form is equivalent to the corresponding part that matches of shoulder hole adds calculating begin to increase a little in contrast to pushing direction thus.The rearmost diameter of scarf joint 5 is identical on the total length of the part that matches.

Claims

1. bent axle, be used for particularly constituting the oversquare engine of large-scale diesel engine, comprise at least one main journal (2) and at least one radially with the rod journal (3) of its relativity shift, wherein, main journal (2) is gone up oppositely protrusion with rod journal (3) from a radius bar (1) that is connected them, and main journal (2) and/or rod journal (3) have in the shoulder hole that matches (4) that is embedded into radius bar (1), be fixed in wherein scarf joint (5) by a kind of shrink fit, this scarf joint (5) has that direction series connection is provided with along pushing, be in the each several part (7 of ladder, 8), their parts that respectively matches (9 or 10) with respect to shoulder hole (4) under cold unassembled state have the radial interference amount; It is characterized in that all parts of scarf joint (5) (7,8) numerically are (Fig. 1,2) that equates with respect to the radial interference amount of the part that respectively matches (9,10) of shoulder hole (4).

2. according to the described bent axle of claim 1, it is characterized in that the radial interference amount of all parts of scarf joint (5) (7,8) is equivalent to the magnitude of interference of permission of part (8) of the front with minimum diameter of scarf joint (5).

3. according to the described bent axle of claim 1, it is characterized in that the magnitude of interference of all parts of scarf joint (5) (7,8) is equivalent to the mean value of magnitude of interference of each permission of all parts (7,8) of scarf joint (5).

4. one of require a described bent axle according to aforesaid right, it is characterized in that, magnitude of interference is equivalent to the diameter tolerance that the maximum in the part of scarf joint (5) allows at least.

5. according to the described bent axle of claim 4, it is characterized in that the diameter tolerance that magnitude of interference allows above the maximum in the part of scarf joint (5).

6. according to one of an aforesaid right requirement described bent axle, it is characterized in that, in a big-block engine, the diameter of the part (9) of the back of the shoulder hole (4) of radius bar (1) (D ') be 1080mm, described radial interference amount is 2.6mm.

7. bent axle, be used for particularly constituting the oversquare engine of large-scale diesel engine, comprise at least one main journal (2) and at least one radially with the rod journal (3) of its relativity shift, wherein, main journal (2) is gone up oppositely protrusion with rod journal (3) from a radius bar (1) that is connected them, and main journal (2) and/or rod journal (3) have in the shoulder hole that matches (4) that is embedded into radius bar (1), be fixed in wherein scarf joint (5) by a kind of shrink fit, this scarf joint (5) has along pushing the each several part that is in ladder (7 that the direction series connection is provided with, 8), their parts that respectively matches (9 or 10) with respect to shoulder hole (4) under cold unassembled state have the radial interference amount; It is characterized in that, the each several part (7 that the series connection of scarf joint (5) is provided with, 8) the radial interference amount on each front end is equivalent to the part that respectively matches (9 of shoulder hole (4), an equal percentage of diameter 10), and each of scarf joint (5) is positioned at, and the part (7) of another part (8) front is additional to be had one and begins from front end, in contrast to the overstriking that pushes the cone shape that direction increases gradually, wherein, the difference between the diameter of the diameter of the front of each frustoconical part (8) and back is equivalent in succession the each several part (7 successively at scarf joint (5), 8) difference (Fig. 3 between the magnitude of interference that is provided with on each front end, 4).

8. according to the described bent axle of claim 7, it is characterized in that the rearmost part (7) of scarf joint (5) is columniform.