Background technique
In large cross-head formula two stroke IC engine field, this bent axle is widely known by the people.Because its weight is big, and relative rotational is low, so its static load as the weight of internal combustion engine component, is exactly a main design standard, and in the internal-combustion engine of small-sized fast turn-around, the power that is produced by moving-mass is only main design standard.For example, the large cross-head formula two stroke IC engine in patent DK1053/96 is known.This internal-combustion engine has many cylinders, is necessary so that bent axle is divided into two or more parts, and this is because otherwise the weight of whole bent axle will exceed weight limits.That is to say that the lifting capacity that for example is applied in the hoist in Production of Crankshaft equipment and the internal-combustion engine mounting equipment is limited in about about 220 tons.This internal-combustion engine with 8 to 14 cylinders, the weight of whole bent axle in its maximum model approximately is about 500 tons, and hoist can not be raised this whole bent axle, so it is necessary that bent axle longitudinally is divided at least two parts.The assembling bent axle is the top of partly hanging base by with each bent axle, subsequently they is transferred on the main bearing.Then, by being connected with each other with bolt, the flange on the bent axle part free end carries out bent axle assembling again.In a single day the bent axle part is placed on the main bearing, they just can only move in limited scope vertically.Therefore, other shrinkage assembling that is used to connect main journal and crank throw can not be used, this is that part has a sizable displacement vertically because such connection needs bent axle, but when bent axle partly was placed on the main bearing, sizable axial displacement was impossible realize.Therefore, up to now,,, flange is considered to easily so connecting because assembling can only be carried out in very limited shaft orientation moving range.In flange connected, the bent axle part was transferred on the main bearing one by one by complete vertical support, only reserves a spot of space between flange.Flange/bent axle part is by alignment, and bolt inserts in the hole on two flanges.Bolt is tightened then, and assembling is finished.Flange connects and to be considered to more advantageously because it can transmit very big moment of torsion, can transmit peak value up to about 12 in moment, the moment of torsion of 000KNm.
For example according to patent DK1053/96, be in the large combustion machine of 2000KW at the minimum output power of each cylinder, its crank throw be in order to carry the load that is applied thereto, and has to make an integral body by casting or forging and follow-up machining.
But, be positioned at the entire length that flange between bent axle part free end has increased bent axle, therefore, increased total length and the weight of internal-combustion engine.As noted earlier, weight is the design link of a key, and therefore, it is very important reducing weight.For example, when internal-combustion engine is used for freighter, and each inch of the loading cargo hold in the freighter is all very important, so the total length of internal-combustion engine is just very crucial.
Summary of the invention
Under this background, the purpose of this invention is to provide a kind of bent axle that reduces length overall above-mentioned.Described bent axle comprises the bent axle of many crank throws (2), wherein crank throw (2) is made up of two crankwebs (3) that linked together by crank pin (4), this crank throw (2) is intactly interconnected by many main journals (5), this bent axle (1) longitudinally is divided at least two bent axle part (1a, 1b), it is characterized in that: at least two above-mentioned bent axle part (1a, 1b) mode that couples together of a free end of free end by will separating main journal (5 ') and crankweb (3 ') interconnects, its Placement is that described bent axle part engages another bent axle macropore (13) partly by an axial projections (12) that is positioned on the described free end, and the described free end bolt of described separation main journal (5 ') is connected to the described free end of described crankweb (3 ') by a plurality of tensioning double-screw bolts (8) or tensioning bolt (8 ').Also different with initial stage hypothesis is between the free end of the free end of main journal and crankweb, and a kind of connection of structure is proved to be feasible, so just can transmit the huge moment of torsion by such internal-combustion engine generation.Therefore, it is feasible needn't utilizing the flange that takies length just can partly couple together bent axle.By using this bent axle, this internal-combustion engine is compared with feasible program up to now, and shorter length and lighter weight can be arranged.The minimizing of length is very favourable in the situation of part, because just connecting, the flange in patent DK1053/96 just is added on simply between crank throw and the main journal, therefore, this has increased by what flange connected that length connects and connects nearest axle journal and connect distance between the axle journal of the other end at flange from flange.The distance that increases between these main journals or the crank throw of a reinforcing need be arranged between main journal perhaps need have higher stress level in the crank throw that must accept.
The free end of crankweb preferably is fixed by bolts on the free end of main journal.In order to increase the torque-transfer capability of connection, be preferably between the free end of the free end of main journal and crankweb and use the material that can increase frictional force.The preferred application mode that can increase the material of frictional force is the both sides that cover a disc-shaped part, and this disc-shaped part is inserted between the free end of the free end of main journal and crankweb.When bent axle was partly had to experience assembling several times and assembled, using disc-shaped part was very convenient as the carrier that can increase the material of frictional force.And the material that can increase frictional force also can be applied on the free end of the free end of main journal and/or crankweb as coating.The material that can increase frictional force preferably comprises in fact than the free end of crankweb and the hard particle of free-ended material of main journal, and the size of described particle should partly be pressed in the free end of the free end of above-mentioned crankweb and main journal.
Bolt between the free end of main journal and the free end of crankweb connects and comprises that many free ends by crankweb vertically stretch into the bolt in the main journal.Bolt preferably extend in the tapped blind hole in the main journal, perhaps bolt is the expansion bolt in the blind hole that can extend in the main journal, thus, stretch in the main journal split sleeve or split casing the pick of and partly stretch in the crankweb so that it becomes a fitted bolt.
The main journal of joint can have two free ends.In this case, bolt is double-screw bolt preferably, and it can stretch in the hole in the main journal vertically and stretch in the hole in two crankwebs being close to the main journal side.
At least one this bent axle part (1a, have in main journal 1b) (5) double-screw bolt (8) is sent to bent axle part (1a from the end of bent axle, joint 1b) and the hole (16) that is sent to described tail end from described joint, and, be positioned at preceding two the nearest crank throws (2 of this connection, 2 ') have the passage (17) that allows double-screw bolt (8) radially outward to move to certain position and easily radially move inward, in the hole (7) that this double-screw bolt of described position (8) can be inserted into the hole (9) of the main journal (5 ') that is positioned at described separation and be positioned at described crankweb from this position.This layout can be changed the double-screw bolt that damages in the assembling internal-combustion engine.
According to the present invention, the more purpose of bent axle, characteristics, advantage and characteristic will be explained in detailed description.
Embodiment
Figure 1 shows that the bent axle of existing large-sized low-speed running cross hair style internal-combustion engine, this bent axle comprises the crank throw 2 that is intactly interconnected by main journal 5, and main journal 5 is being supported by main bearing 6.Bent axle is by two bent axle part 1a, and 1b constitutes, and they longitudinally connect c by flange, and d assembles.When the bent axle part was tightened with bolt mutually by the flange connection, crankcase body can be placed on the base.
According to the present invention, bent axle is described by the diagram among reference Fig. 2-Fig. 9.At Fig. 1, among Fig. 2 and Fig. 7, for simple and clear, all crank throws all are drawn into upwards and arrange on the bent axle.But yes can not exist for this situation in the bent axle of reality.
Figure 2 shows that first better embodiment of the bent axle 1 that comprises many crank throws 2, this crank throw comprises two crankwebs 3 that linked together by crank pin 4, and in the mode of execution shown in this, crankweb 3 is one, and forms an integral body with crank pin 4.In order to make bent axle keep balance, crank pin 4 is hollow.The manufacturing of integral part can or be forged and realize by metal casting.On each crank throw 2 macropore is arranged all, so that main journal 5 separately is fastened in this hole by contraction, main journal 5 can fully stretch in separately the crankweb 3 to obtain the contact surface of maximum possible between two parts thus.Bent axle can be made one by metal casting or forging, or by crank throw 2 being welded on the main journal 5 to form an integral body.
Bent axle longitudinally is divided into 1a and two parts of 1b, and crank throw 2 is intactly interconnected by main journal 5 in these two parts, and this main journal 5 is being supported by main bearing 6.Certainly, bent axle is divided into three or more parts, and the various piece of bent axle also needs not to be isometric, this also is feasible.
Shown in legend preferable among Fig. 3 and Fig. 4, two free ends of bent axle part 1a in first better embodiment and 1b have a free crankweb 3 ', are drilled with many axially extended through holes 7 on it, and this hole can hold the double-screw bolt 8 of respective number.Double-screw bolt 8 passes hole 9 in the main journal 5 ' and the hole 7 in the free crankweb 3 ' on another bent axle part 1b always.Tighten by nut 10 at the two ends of double-screw bolt 8.Nut 10 is installed in 11 li of the recess of crankweb 3 ', and tightens to obtain the required prestretching force of double-screw bolt 8 by hydraulic pressure.
According to this better embodiment, double-screw bolt 8, crankweb 3 ' go up that corresponding hole 7 is become by layout with hole 9 on the main journal 5 ' and the corresponding to general layout of circle of two concentric arrangement, so a lot of double-screw bolts can be installed in the limited available space.
Have axial protrusion 12 on two end faces of main journal 5 ', this protrusion is meshed with macropore 13 on the crankweb 3 ', with alignment main journal 5 ' and crankweb 3 '.
Shown in legend preferable among Fig. 4, another crankweb 3 of crank throw 2 ' has an enough dark recess 14, so that double-screw bolt 8 can fully be pushed in the crank throw 2 ',, promptly install by vertical fully support so the assembling between bent axle part 1a and 1b can reach minimum horizontal clearance.
During assembling, born very big pressure on the main journal 5 ', this can make main journal 5 ' produce distortion.But the bearing surface of main journal has an accurate shape accurately to cooperate mutually with the surface with the bearing that is used for main bearing, and this is a precondition.In order to overcome this problem, when main journal 5 ' is subjected to resembling the identical pressure that is subjected in the assembling, need carry out machining to it.So far, main journal 5 ' is mounted between free crankweb 3 ' and the imaginary bent axle (not shown), and double-screw bolt 8 be with and bent axle part 1a, identical prestretching force is tightened in the assembling of 1b.Bearing surface to main journal carries out machining with conventional mode then.When main journal 5 ' is assembled into a time-out with bent axle part 1a and 1b, main journal will adopt correct shape.
Shown in legend preferable among Fig. 6, the double-screw bolt 8 of damage is changed can the assembling bent axle from base, or even in being positioned at a complete assembling internal-combustion engine time.So far, main journal 5 has a center hole 16, and the double-screw bolt 8 that changes by this Kong Yaoxin can be sent to from the crankshaft end of internal-combustion engine tail end and be positioned at bent axle part 1a, the joint between 1b.The crank throw 2 ' and its crank throw 2 of next-door neighbour that have free crankweb 3 ' have passage 17, so that double-screw bolt 8 can radially outwards be sent in the scope at 7 places, hole in the free crankweb 3 ' that this double-screw bolt can be inserted into.In order to change impaired double-screw bolt 8, all double-screw bolts 8 all are fully retracted in the recess 14, so that bent axle part 1a, 1b separates and rotation relatively freely each other.So bent axle part 1a, 1b freely rotate each other relatively up to the hole 9 that comprises impaired double-screw bolt 8 and passage 17 point-blank.Impaired then double-screw bolt is pushed into passage 17 and further passes hole 16 and shift crankshaft end onto, leaves bent axle at last.The double-screw bolt 8 that will newly change then is inserted in the bent axle and by hole 16 and is sent to passage 17, enters hole 7 and hole 9 at last.All double-screw bolts 8 all are moved back on the original position as described above and are tightened.
It shown in Fig. 5 another better embodiment that bent axle connects.Between bent axle and bent axle part 1a and 1b be connected in fact with top shown in mode of execution consistent, still, the nearest crank throw 2 ' of main journal 5 ' and bent axle part 1a is integrated as a whole.Therefore, main journal 5 ' has only a free end.This free end is connected with the free crankweb 3 ' of the crank throw 2 ' on similar mode recited above and the bent axle part 1b.So being stretched into tapped blind hole 9 ' the interior bolt 8 ' of main journal 5 ', double-screw bolt 8 replaced.In this better embodiment,, do not need recess 14 so have in another crankweb 3 of crank throw 2 ' of free crankweb 3 ' because bolt 8 ' is shorter than double-screw bolt 8 in fact.
In the deformable body of the better embodiment shown in Fig. 5 a, used and had split casing or split sleeve 8 " expansion bolt 8 ', and do not have screw thread in the blind hole 9 '.Split casing as shown in FIG. or split sleeve 8 " can partly stretch in the blind hole 9 ' and partly stretch in the hole 7 in the crankweb 3 ', so that they become a fitted bolt.
There are several diverse ways can guarantee being connected between main journal 5 ' and crankweb 3 ' to transmit huge peak value up to 12, the moment of torsion of 000KNm.These methods are alternative method or additional method.Double-screw bolt 8 in the connection of a better embodiment or bolt 8 ' have formed required size and have been applied in prestressing force, so that the frictional force between the surface of contact of main journal 5 ' and crankweb 3 ' last adjacency surpasses shearing force.
Another method that increases the torque-transfer capability that connects is to use the material that can increase frictional force between the free end of the free end of main journal 5 ' and crankweb 3 '.But can increase the material nickel coating of frictional force, a but coating that contains the relative soft metal masterplate of hard particles preferably, its thickness is greater than the thickness of metal stencil plate, so that particle partly is being pressed in the free-ended surface of contact of the free end of main journal 5 ' separately and crankweb 3 ' in the assembling, and form miniature sawtooth effectively surface of contact is locked together mutually.Metal stencil plate contains nickel, the alloy of ferro-alloy or other metal.Hard particles comprises carbide, as silicon carbide, and Tungsten carbite, chromium carbide and/or oxide, as chromium oxide, silica or other hardening oxidation thing.This particle in fact must be harder than main journal 5 ' and crankweb 3 '.The material that can increase frictional force can be used thermal blanket, as plasma coating.Material directly is applied on main journal 5 ' and the crankweb 3 ' is fine, still, be preferably on the both sides of disk 15 and use the material that can increase frictional force.Shown in legend preferable among Fig. 4, this disk 15 is inserted between the free end of the free end of main journal 5 ' and crankweb 3 '.When connection must be experienced assembling several times and assemble, utilizing disk 15 was very useful as the carrier that can increase the material of frictional force.By new disk of each usefulness, the functional of material that can increase frictional force just is guaranteed.
Another guarantees to connect the method that can transmit huge moment of torsion is to utilize the cooperation double-screw bolt 8 or the fitted bolt 8 ' that do not have backlash that is assemblied in hole 7 and the hole 9.Cooperating double-screw bolt/fitted bolt to help to increase connection in fact bears the ability of shearing force and a good alignment is provided between main journal 5 ' and crankweb 3 '.It also is feasible using nutted rod/turnbuckle and cooperating the assemblying body of double-screw bolt/fitted bolt.
Shown in Figure 7 is second better embodiment of the present invention.The formation of bent axle part 1a and 1b is with identical method recited above, promptly crank throw 2 by main journal 5 by complete interconnecting.But bent axle partly is to interconnect by the separated type crank throw 2 ' shown in detail in Fig. 8 and Fig. 9.Crankweb 3 be divided into interactional radially exterior section 3a and interior section 3b radially.
Interior section 3b radially is an one, and can form by metal casting or forging and follow-up machining manufacturing.They connect by shrinking separately, or weldering combination and main journal
Interior section 3b radially is an one, and can form by metal casting or forging and follow-up machining manufacturing.They connect by shrinking separately, or weldering is in conjunction with linking together with main journal 5.
Two exterior section 3a radially of crank throw 2 ' interconnect by crank pin 4a.Exterior section 3a radially and crank pin 4a be an integral body, and perhaps they link together by shrinking to connect with crank pin 4a.Each exterior section 3a radially has two tapped holes that are used for holding stud 18.Stud 18 extends by the hole in the corresponding interior section 3b radially tangentially.Also available stud more than two in each crank arm.Stud 18 stretches out from the hole of radially interior section 3b.Be used to tighten stud 18 so that interior section 3b radially and exterior section 3a radially firmly are clamped together with the nut 19 of stud 18 thread engagement.
The surface of contact 21 of the surface of contact 20 of exterior section 3a radially and interior section 3b radially adjoins each other and is in the same place.As shown in the figure, surface of contact preferably be positioned at stud 18 around, but they also can be positioned at other position, as symmetry axis around crankweb 3.
Also have several diverse ways to be used for guaranteeing when internal combustion engine operation, under the influence of suffered shearing force, exterior section radially can not move with respect to interior section radially.These methods are alternative method or additional method.Stud 18 in a better embodiment has formed required size and has been applied in prestressing force, surpasses shearing force so that interior section 3b radially and exterior section 3a radially go up the frictional force of 20,21 of the surface of contact of adjacency.So far, make that the surface area of 20,21 of surface of contact is favourable for a short time, like this height that contact pressure will be relative.According to the deformable body of this mode of execution, the material of increased frictional force as described above is used in 20,21 of surface of contact.This material that increases frictional force as on the surface of contact 20,21 or a thin insert (not shown) on coating be employed, be coated with the friction reducing agent on the both sides of this thin insert.This insert is placed between the surface of contact 20,21.Guaranteeing to connect another method that can bear shearing force is to use cooperation stud 18 that does not have backlash that is assemblied in the hole or the assemblying body of using nutted rod 18 and fitted bolt, or the assemblying body of other type depending post.
Exterior section 3a radially has an arc protrusion 22 that radially extends in inside, and it is that hollow chamfer 24 forms a space, and this hollow chamfer 24 is the effects of blurting out that are used for avoiding transition position between crank pin 4a and the exterior section 3a radially.Interior section 3b radially has one accordingly for holding the recess 23 of protrusion 22.
Interior section 3b radially has an arc protrusion 25, and it forms a space for seamlessly transitting between radially interior section 3b and the main journal 5.Protrusion 25 is accommodated in 26 li of the recess of the respective shapes in radially the exterior section.
Although the present invention illustrates this purpose with description, these details only are only at this purpose certainly, and those variations that do not depart from the scope of the invention in the prior art field all exist.
Therefore, although according to their development environment the preferred forms of apparatus and method is described, they are explanation of the principles of the present invention.Other mode of execution and structure also can be designed in the scope that does not depart from purport of the present invention and claim.