CN1625652A

CN1625652A - Crankshaft special for compressor

Info

Publication number: CN1625652A
Application number: CN02828975.7A
Authority: CN
Inventors: V·比安基
Original assignee: Embraco Europe SRL
Current assignee: Embraco Europe SRL
Priority date: 2002-05-17
Filing date: 2002-05-17
Publication date: 2005-06-08
Also published as: WO2003098044A1; BR0215715A; AU2002304251A1; DE10297740T5

Abstract

The crankshaft, in particular for a compressor, comprises at least one substantially cylindrical main journal, one crack arm, and one substantially cylindrical crank pin. It also has, on its outer surface, at least one recess located on the main journal in a first position axial in the vicinity of the crank arm and conforming circumferentially to the position of the crank pin, or on the crank pin in a second position, circumferentially opposite the first position.

Description

Be used in particular for the bent axle of compressor

The present invention relates to a kind of bent axle that is used in particular for compressor.

Specifically, this bent axle comprises at least one the roughly main journal, crankweb of cylindricality and one crank pin of cylindricality roughly.Usually, under serviceability, main journal is rotatably mounted by main bearing, and crank pin is connected on the big end of connecting rod, and lubricating fluid places between the mechanical part of contact, so that reduce the friction that is produced by their relative rotation.

The object of the present invention is to provide a kind of like this bent axle, the geometrical construction of this bent axle can further reduce the friction that causes owing to rotation.

According to the present invention, this purpose can realize by a kind of bent axle with the feature in this specification start-up portion and the characteristic, this bent axle is characterised in that this bent axle has at least one recess on its outer surface, described recess is positioned on this main journal and is in primary importance, perhaps be positioned on this crank pin and be in the second place, near crankweb and along circumferentially and the position consistency of crank pin, this second place is circumferentially relative with this primary importance vertically for this primary importance.

The recess of bent axle of the present invention or a plurality of recess are formed in the circumferential curved portion, the most critical of rotation in the stage this circumferential curved portion bear mechanical stress, this mechanical stress is the minimal mechanical stress in the mechanical stress that acts on the different curved portions of corresponding circular section in principle.Therefore, recess reduces for the pressure that is present in the lubricating fluid layer in the key area that bears maximum machine stress does not have adverse influence.And this recess has reduced the slide relative surface between bent axle and corresponding bearing simultaneously, and has therefore reduced friction, and friction is roughly proportional with this surperficial scope.

With reference to accompanying drawing and in conjunction with specific embodiment of the present invention, can understand these and other purpose, advantage and feature of the present invention better, in the accompanying drawings:

Fig. 1 is the stereogram of bent axle of the present invention, and this bent axle is connected on the connecting rod;

Fig. 2 is the stereogram of parts under decomposing state shown in Figure 1;

Fig. 3 is the sectional view along the parts of the line III-III intercepting of Fig. 1;

Fig. 4 is the enlarged view of the details of Fig. 3; With

Fig. 5 is the sectional view along the intercepting of the line V-V among Fig. 3.

The bent axle that is used in particular for compressor comprises at least one the roughly main journal 10, crankweb 12 of cylindricality and one crank pin 14 of cylindricality roughly.

The first recess 16a is formed on the outer surface of main journal 10, be positioned at vertically near crankweb 12 and along circumferentially and the primary importance place of the position consistency of crank pin 14, i.e. on same side the plane of the drawing of Fig. 5 (and be transverse to thus) and extend through the longitudinal axis 18 of main journal 10 perpendicular to the plane of the midplane of crank pin 14.

The second recess 16b is formed in the outer surface of crank pin 14, is positioned at and the circumferential relative second place place of this primary importance.

The 3rd recess 16c is formed in the outer surface of main journal 10, be positioned at vertically with respect to crankweb 12 biasings and with circumferential the 3rd relative position of this primary importance, i.e. on opposite flank the plane of the drawing of Fig. 5 (and be transverse to thus) and extend through the longitudinal axis 18 of main journal 10 perpendicular to the plane of the midplane of crank pin 14.

Recess 16a, 16b, 16c have the shape of the essentially rectangular that has fillet, and along the angular range that circumferentially has about 120 degree.

In (unshowned) of the present invention modification, recess 16a, 16b, 16c for example in the scope of 60-180 degree, are preferably in the scope of 90-150 degree along circumferentially having different angular range independent of each other.

Recess 16a, 16b, 16c are preferably the degree of depth that has between the 40-300 micron, and this degree of depth can change arbitrarily.

Crankweb 12 can be configured as plate in the usual way, and it has counterweight so that the centrifugal force of balance inertia.Common in addition is, the outer surface of main journal 10 and crank pin 14 is provided with groove, wherein has the helical groove 20 that is used for by the distribution of the lubricating fluid of pumping installations supply, and this pumping installations is arranged on the inboard and not shown in the accompanying drawings of bent axle.

Main journal 10 is rotatably installed in (Fig. 5) in the supporting member 22, and this supporting member has main bearing 24 and supplementary bearing 26, and they are in the face of the axial component that has the first recess 16a and the 3rd recess 16c in its surface respectively of main journal 10.

Crank pin 14 is rotatably installed in the big end 28 of annular of connecting rod 30, and this big end 28 is as bearing.In known manner, axle 32 is hinged on the piston 34 from big end 28 extensions of annular of connecting rod 30 and in its opposite end, and this piston is mounted to slide (Fig. 1) in cylinder of compressor 36.

In operation, bent axle bears mechanical stress, and this stress changes according to the angle of swing that centers on longitudinal axis 18.Particularly, when piston 34 this stress maximum when upper dead center position (Fig. 1), upper dead center position is corresponding to the maximum compression of the gas in cylinder 36 and therefore form most critical stage for the generation of the frictional force on bent axle.In this stage, crank pin 14 has maximum offset with respect to the hole 38 in the big end 28 of connecting rod 30, (see Fig. 4, wherein be shown clearly in respect to actual conditions and strengthened this phenomenon), and the curved portion displacement of the big end 28 that is fixed to the upper towards axle 32 of crank pin 14.Therefore, place the lubricating fluid layer 40 between this curved portion and the crank pin 14 to bear maximum pressure, and its supporting role is applied on the bent axle.On the contrary, the relative part of the diametric(al) of crank pin 14 and bear less pressure near the lubricating fluid layer 42 of this part.This relative part of the diametric(al) of crank pin 14 is the part that wherein is formed with the second recess 16b.This second recess 16b has reduced the slide relative surface between the big end 28 of crank pin 14 and connecting rod 30 thus, therefore reduced relative friction, and it reduces for pressure of lubricating fluid layer 40 and does not have adverse influence, this lubricating fluid layer 40 to be present in to bear in the zone of big pressure.

Roughly similar phenomena appears in the part with the first recess 16a and the 3rd recess 16c of main journal 10, and the first recess 16a and the 3rd recess 16c are respectively in the face of main bearing 24 and supplementary bearing 26.Yet, should be noted that the first recess 16a turns to 180 degree with respect to the 3rd recess 16c, the 3rd recess 16c is formed on similar angular orientation with respect to second recess.Under any circumstance, the also close part of the stressed minimum of the lubricating fluid of circular section accordingly of the first recess 16a and the 3rd recess 16c.Therefore, they have such effect, have promptly reduced friction and do not influenced unfriendly to be present in the lubricating fluid that bears in the bigger zone of pressure.

Naturally, under the identical situation of principle maintenance of the present invention, the details of structure and form of implementation can change and modification with respect to described example, and do not depart from the scope of the present invention.Particularly, the recess that differs from one another can have Any shape, comprises asymmetric shape.And the edge of recess can have lead angle and fillet.

Claims

1. bent axle that is used in particular for compressor, it comprises at least one the roughly main journal of cylindricality (10), a crankweb (12) and one crank pin of cylindricality (14) roughly, this bent axle is characterised in that, this bent axle has at least one recess (16a, 16b) on its outer surface, described recess is positioned on this main journal (10) and is in primary importance, perhaps be positioned on this crank pin (14) and be in the second place, near crankweb (12) and along circumferentially and the position consistency of crank pin (14), this second place is circumferentially relative with this primary importance vertically for this primary importance.

2. bent axle as claimed in claim 1, it is characterized in that, this bent axle has first recess (16a), this first recess be positioned at be on the outer surface of main journal (10) vertically near crankweb (12) and along circumferentially with the primary importance of the position consistency of crank pin (14), second recess (16b) is formed on and is on the crank pin (14) and the circumferential relative second place of this primary importance.

3. as each described bent axle in the above-mentioned claim, it is characterized in that at least one recess (16a, 16b) has the shape of the essentially rectangular that has fillet.

4. as each described bent axle in the above-mentioned claim, it is characterized in that at least one recess (16a, 16b) edge circumferentially has the angular range between the 60-180 degree, and is preferably between the 90-150 degree.

5. as each described bent axle in the above-mentioned claim, it is characterized in that at least one recess (16a, 16b) has the degree of depth between the 40-300 micron.

6. as each described bent axle in the above-mentioned claim, it is characterized in that, this bent axle also has the 3rd recess (16c), the 3rd recess on main journal (10), be positioned at vertically with respect to crankweb (12) biasing and with circumferential the 3rd relative position of this primary importance.

7. bent axle as claimed in claim 6 is characterized in that, the 3rd recess (16c) has the degree of depth between the 40-300 micron.