CN217029617U - Bent axle and air compressor machine - Google Patents

Abstract

The utility model discloses a crankshaft, which comprises a main shaft, a first eccentric shaft and a second eccentric shaft, wherein the axes of the main shaft, the first eccentric shaft and the second eccentric shaft are parallel to each other, a first shaft hole is at least arranged in the first eccentric shaft, and a second shaft hole is at least arranged in the second eccentric shaft; the first shaft hole is not coaxial with the second shaft hole. In the scheme, the radial distance between the first eccentric shaft and the second eccentric shaft is not limited by the radial distance between the first shaft hole and the second shaft hole, and in other words, compared with the prior art, the distance between the axis of the first eccentric shaft and the axis of the second eccentric shaft in the scheme is wider in a settable range; therefore, compared with the prior art, the stroke of the vertical movement of the connecting rod assembly can be increased, and the technical problem that the stroke of the vertical movement of the connecting rod assembly in the prior art is smaller is solved.

Description

Bent axle and air compressor machine

Technical Field

The utility model relates to the technical field of air compressor accessories, in particular to a crankshaft and an air compressor.

Background

The crank shaft is one of the most important parts in the air compressor, external power of the motor and the like is transmitted to the air compressor through the crank shaft, so that the crank shaft drives the connecting rod arranged on the crank shaft to convert the rotary motion into reciprocating motion, and the work of the piston type air compressor is realized.

Patent document CN201520334625.1 discloses a double crank of a component of an oil-free air compressor, wherein mention is made of: two end faces of the adjusting circular plate are respectively provided with an eccentric bearing seat, and the two eccentric bearing seats are arranged in a staggered manner; the adjusting circular plate is provided with shaft holes which respectively penetrate through the two eccentric bearing seats, and the axes of the shaft holes and the axes of the two eccentric bearing seats are parallel to each other and do not coincide with each other.

The prior art has the following defects: in order to enable the shaft holes to be simultaneously arranged in the two eccentric bearing blocks, the distance between the axes of the two eccentric bearing blocks needs to be close enough, and the two eccentric bearing blocks are distributed on two sides of the axis of the adjusting circular plate, so that the axes of the eccentric bearing blocks are too close to the axis of the adjusting circular plate; and the circumferential outer surface of the eccentric bearing seat is used for sleeving the connecting rod assembly, so that the stroke of the connecting rod assembly in vertical motion is smaller in the process that the adjusting circular plate and the output shaft of the motor rotate coaxially.

SUMMERY OF THE UTILITY MODEL

The utility model provides a novel crankshaft and an air compressor, aiming at the technical problem that in the crankshaft structure in the prior art, the stroke of a connecting rod assembly which does vertical movement is small.

The utility model is realized by the following technical scheme:

a crankshaft comprises a main shaft, a first eccentric shaft and a second eccentric shaft, wherein the axes of the main shaft, the first eccentric shaft and the second eccentric shaft are parallel to each other, the first eccentric shaft and the second eccentric shaft are respectively arranged on the end surfaces of two sides of the main shaft, and the axis of the first eccentric shaft and the axis of the second eccentric shaft are positioned on two sides of the axis of the main shaft;

the flywheel is sleeved on the outer surface of the circumference of the main shaft;

the first shaft hole is at least arranged in the first eccentric shaft, and the second shaft hole is at least arranged in the second eccentric shaft;

the first shaft hole and the second shaft hole are not coaxial.

Furthermore, the flywheel is provided with a plurality of first weight removing holes, and any one of the first weight removing holes is not crossed with the first eccentric shaft and the second eccentric shaft.

Furthermore, the hole center line of the first shaft hole and the axis of the first eccentric shaft are on the same straight line, and the first shaft hole is a through hole penetrating through the first eccentric shaft and the main shaft.

Further, the first shaft hole comprises a first taper hole and a first straight hole which are communicated with each other and coaxially arranged;

one end of the first taper hole forms a first opening at the end part of the first eccentric shaft, and one end of the first straight hole forms a second opening at the end part of the main shaft;

the radial section of the first taper hole is gradually reduced in the direction from the first opening to the second opening.

Furthermore, the hole wall of the first taper hole is provided with a positioning groove, the positioning groove is far away from one end of the first straight hole, and an opening is formed at the end part of the first eccentric shaft.

Furthermore, one end of the first taper hole, which is connected with the first straight hole, is a small end, the radial section of the small end is smaller than that of the first straight hole, and a step is formed between the small end and the first straight hole along the radial direction.

Furthermore, the hole center line of the second shaft hole and the axis of the second eccentric shaft are on the same straight line, and the second shaft hole is a linear through hole penetrating through the second eccentric shaft and the main shaft.

Furthermore, a plurality of second weight-removing holes are formed in the main shaft; any one second weight-removing hole is not crossed with the first eccentric shaft and the second eccentric shaft.

The utility model further provides an air compressor which comprises the crankshaft.

The device also comprises a motor and a coupler, wherein an output shaft of the motor is coaxially arranged with the main shaft, and the output shaft of the motor is connected with the first eccentric shaft through the coupler.

Compared with the prior art, the utility model has the advantages that:

1. in the scheme, the first eccentric shaft and the second eccentric shaft are equivalent to two eccentric bearing blocks in the prior art, the first shaft hole or the second shaft hole is equivalent to a shaft hole in the prior art, and the first shaft hole is at least arranged in the first eccentric shaft, the second shaft hole is at least arranged in the second eccentric shaft, and the first shaft hole and the second shaft hole are not coaxial; that is, the distance between the axis of the first eccentric shaft and the axis of the main shaft, or the distance between the axis of the second eccentric shaft and the axis of the main shaft, is not limited by the radial distance between the first shaft hole and the second shaft hole; in other words, compared with the prior art, the distance between the axis of the first eccentric shaft and the axis of the second eccentric shaft is larger in the scheme; and first eccentric shaft and second eccentric shaft are used for the cover respectively and establish link assembly, consequently, compare in prior art, and this scheme can increase link assembly vertical motion's stroke, has solved the less technical problem of the stroke that link assembly is vertical motion among the prior art promptly.

Drawings

Fig. 1 is a schematic structural view of a crankshaft of embodiment 1;

FIG. 2 is a sectional view of the crankshaft structure of embodiment 1;

FIG. 3 is a schematic view of another perspective of the crankshaft structure of embodiment 1;

FIG. 4 is a schematic view showing the installation of the crankshaft in embodiments 1 and 3;

fig. 5 is a schematic structural view of a crankshaft of embodiment 2;

fig. 6 is a schematic structural view of a first split in embodiment 3;

fig. 7 is a schematic view of a second segment structure in embodiment 3.

The mark in the figure is: the main shaft 1, the first eccentric shaft 2, the second eccentric shaft 3, the flywheel 4, the first shaft hole 5, the first taper hole 501, the first straight hole 502, the positioning groove 503, the step 504, the first opening 505, the second opening 506, the second shaft hole 6, the second weight-removing hole 7, the first weight-removing hole 8, the first link assembly 9, the second link assembly 10, the first sub-body 11, the second sub-body 12 and the screw 13.

Detailed Description

The following non-limiting detailed description of the present invention is provided in connection with the preferred embodiments and accompanying drawings. In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain the present invention and should not be construed as limiting the present invention.

Example 1

As shown in fig. 1 to fig. 2, a crankshaft according to a preferred embodiment of the present invention includes a main shaft 1, a first eccentric shaft 2, and a second eccentric shaft 3, wherein axes of the main shaft 1, the first eccentric shaft 2, and the second eccentric shaft 3 are parallel to each other, wherein the first eccentric shaft 2 and the second eccentric shaft 3 are respectively disposed at two side end surfaces of the main shaft 1, and the axis of the first eccentric shaft 2 and the axis of the second eccentric shaft 3 are located at two sides of the axis of the main shaft 1; the flywheel 4 is sleeved on the outer circumferential surface of the main shaft 1; the first shaft hole 5 is at least arranged in the first eccentric shaft 2, and the second shaft hole 6 is at least arranged in the second eccentric shaft 3; the first shaft hole 5 is not coaxial with the second shaft hole 6.

With further reference to fig. 1, 2, and 4, the first eccentric shaft 2 is disposed on an end surface of one side of the main shaft 1, an axis of the first eccentric shaft 2 is parallel to an axis of the main shaft 1, and a circumferential outer surface of the first eccentric shaft 2 is used for sleeving and mounting the first link assembly 9.

The second eccentric shaft 3 is arranged on the end face of the other side of the main shaft 1, the axis of the second eccentric shaft 3 is parallel to the axis of the main shaft 1, the axis of the second eccentric shaft 3 and the axis of the first eccentric shaft 2 can be overlapped or not overlapped, and the outer circumferential surface of the second eccentric shaft 3 is used for being sleeved with and provided with a second connecting rod assembly 10.

Preferably, the axis of the first eccentric shaft 2 and the second eccentric shaft 3 are parallel to each other.

The flywheel 4 is sleeved on the circumferential outer surface of the main shaft 1, the flywheel 4 and the main shaft 1 are coaxially arranged, the flywheel 4 can be disc-shaped or in other geometrical shapes, and the flywheel 4 and the circumferential outer surface of the main shaft 1 can be detachably connected or integrally formed; preferably, the flywheel 4 may be a disk shape, the flywheel 4 is integrally formed with the circumferential outer surface of the main shaft 1, and the flywheel 4 is disposed near the second eccentric shaft 3.

As described in the background art, in the prior art, in order to simultaneously dispose the shaft holes in the two eccentric bearing seats, the axial distances of the two eccentric bearing seats need to be close enough, and the two eccentric bearing seats are distributed on the two side end surfaces of the axial line of the adjusting circular plate, which causes the axial line of the eccentric bearing seat to be too close to the axial line of the adjusting circular plate; and the circumferential outer surface of the eccentric bearing seat is used for sleeving the connecting rod assembly, so that the stroke of the connecting rod assembly in vertical movement is smaller in the process that the adjusting circular plate and the output shaft of the motor rotate coaxially, and the crankshaft is only suitable for being used in a V-shaped air compressor. If the stroke of the connecting rod assembly for vertical movement needs to be increased, the diameter of the eccentric bearing seat needs to be increased, so that the diameter of the adjusting circular plate is increased, correspondingly, the weight of the crankshaft is increased, and further the motor load of the air compressor is increased.

In the scheme, the first eccentric shaft 2 and the second eccentric shaft 3 are equivalent to two eccentric bearing blocks in the prior art, the first shaft hole 5 or the second shaft hole 6 is equivalent to a shaft hole in the prior art, the first shaft hole 5 is at least arranged in the first eccentric shaft 2, the second shaft hole 6 is at least arranged in the second eccentric shaft 3, and the first shaft hole 5 and the second shaft hole 6 are not coaxial; that is, the distance between the axis of the first eccentric shaft 2 and the axis of the main shaft 1, or the distance between the axis of the second eccentric shaft 3 and the axis of the main shaft 1, is not limited by the radial distance between the first shaft hole 5 and the second shaft hole 6; in other words, compared with the prior art, the distance between the axis of the first eccentric shaft 2 and the axis of the second eccentric shaft 3 is larger in the scheme; and first eccentric shaft 2 and second eccentric shaft 3 are used for the cover respectively and establish link assembly, consequently, compare in prior art, and this scheme can increase the stroke of the vertical motion of link assembly, has solved promptly that link assembly is the less technical problem of stroke of vertical motion among the prior art, and the bent axle of this application is applicable in multiple air compressor machine, does not confine to V type air compressor machine. Furthermore, because in this scheme, only rely on the distance between increase first eccentric shaft 2 and the second eccentric shaft 3, can reach the purpose of increase link assembly vertical movement stroke to avoided in the prior art, through the diameter that increases eccentric bearing, and the method of the stroke of increase link assembly vertical movement, consequently, this scheme has also avoided the increase of bent axle weight among the prior art, and then made the technical problem of the motor load increase of air compressor machine.

How to balance the rotational inertia force and the moment of the first connecting rod assembly 9 and the second connecting rod assembly 10 is realized by the following technical scheme:

with further reference to fig. 3, the flywheel 4 is provided with a plurality of first weight-removing holes 8, and any one of the first weight-removing holes 8 is not crossed with the first eccentric shaft 2 and the second eccentric shaft 3.

The first weight-removing hole 8 is formed by removing partial materials of the flywheel 4, the first weight-removing hole 8 can be a through hole or a blind hole, the cross section of the first weight-removing hole 8 can be a circle or any other geometric shape, and the first weight-removing hole 8 can be a linear hole or a curved hole; preferably, the first deduplication holes 8 are straight through holes with circular cross sections. The number of the first weight-removing holes 8 is determined according to parameters such as the mass of the connecting rod assembly, the rotating radius and the like, and is not limited in the prior art. Any first deadweight removing hole 8 is not crossed with the first eccentric shaft 2 and the second eccentric shaft 3, namely, any first deadweight removing hole 8 is not arranged in the first eccentric shaft 2 and the second eccentric shaft 3.

On one hand, the flywheel 4 is provided with a plurality of first weight-removing holes 8, and on the other hand, the first weight-removing holes 8 are formed by removing partial materials of the flywheel 4, so that the weight of the flywheel 4 is effectively reduced, and the whole weight of the crankshaft is further reduced; on the other hand, the flywheel 4 can be regarded as a counterweight structure except the remaining parts of the first counterweight holes 8, and the counterweight structure is used for balancing the rotating inertia force and the moment of the connecting rod assembly, so that the crankshaft operates stably, specifically, the rotating inertia force is a centrifugal inertia force which is along the radial direction of the eccentric shafts (the first eccentric shaft 2 and the second eccentric shaft 3) and points to the outside from the axis line. The market has additionally to install the measure that the balancing weight piece is used for balanced rotatory inertia in bent axle drive mechanism additional, nevertheless has spare part quantity to increase, the problem of air compressor machine structure complicacy, weight increase, and adopts the weight removal mode to form built-in balance weight quality to the bent axle herein, has the advantage that simple structure is reliable.

With further reference to fig. 2 and 4, both the first shaft hole 5 and the second shaft hole 6 may be used for mounting a coupler, in this embodiment, the first shaft hole 5 is used for mounting a coupler, the second shaft hole 6 is used as a spare hole for the first shaft hole 5, and no coupler is mounted; the so-called backup holes are explained below; how the shaft coupling is installed in first shaft hole 5 solves through following technical scheme:

the hole center line of the first shaft hole 5 is on the same straight line with the axis of the first eccentric shaft 2, and the first shaft hole 5 is a through hole penetrating through the first eccentric shaft 2 and the main shaft 1.

First shaft hole 5 runs through first eccentric shaft 2 and main shaft 1, and first shaft hole 5 is the linear type through-hole, and when first shaft hole 5 installation shaft coupling, the one end of shaft coupling inserts to first shaft hole 5 in to with the pore wall fixed mounting in first shaft hole, and then make the output shaft of motor pass through the shaft coupling and drive first eccentric shaft 2 motion. In this embodiment, in order to prevent the coupling from sliding in the first tapered hole 501 along the axial direction of the first tapered hole 501, one end of the coupling is inserted into the first tapered hole 501, and the screw 13 extends into the first straight hole 502 from the second opening 506 and is screwed with the threaded hole of the coupling.

In this embodiment, because the first shaft hole 5 is the through-hole that runs through first eccentric shaft 2 and main shaft 1, when the one end of shaft coupling inserted the one end of first shaft hole 5, the inserted position of shaft coupling was observed to the other end of user's accessible first shaft hole 5, effectively avoided the shaft coupling to insert the not in place technical problem in first shaft hole 5.

How the first shaft hole 5 plays a guiding role in the outer surface of the coupler is realized by the following technical scheme:

the first shaft hole 5 comprises a first taper hole 501 and a first straight hole 502 which are communicated with each other and coaxially arranged; one end of the first taper hole 501 forms a first opening 505 at the end of the first eccentric shaft 2, and one end of the first straight hole 502 forms a second opening 506 at the end of the main shaft 1; the radial cross section of the first conical hole 501 decreases gradually in the direction from the first opening 505 to the second opening 506.

Specifically, any radial cross section of the first taper hole 501 is the same geometric shape, the first opening 505 points in the direction of the second opening 506, and the radial cross section of the first taper hole 501 gradually decreases. In the process that the coupler extends into the first taper hole 501 from the first opening 505, the hole wall of the first taper hole 501 plays a role in radially limiting and guiding the outer surface of the coupler, so that when a user cannot completely observe the coupler, the user can still insert the coupler into the first taper hole 501 in a blind manner; meanwhile, the user can observe the insertion position and installation condition of the coupler through the second opening 506.

With further reference to fig. 2 and 4, the technical solutions mentioned above are: one end of the coupler is inserted into the first shaft hole 5 and fixedly mounted with the wall of the first shaft hole, and the screw 13 is in threaded connection with the threaded hole of the coupler, so that the coupler can rotate in the circumferential direction with the first shaft hole; therefore, how to fix the coupling and the first shaft hole in the circumferential direction is a technical problem to be solved, and the technical problem is achieved by the following technical scheme.

The hole wall of the first taper hole 501 is provided with a positioning groove 503, and the positioning groove 503 is far away from one end of the first straight hole 502, and an opening is formed at the end of the first eccentric shaft 2.

Specifically, the positioning slot 503 is a linear slot, and a space enclosed by the slot wall of the positioning slot 503 is communicated with the first taper hole 501.

Further refer to fig. 2 and 4, the coupler is provided with a mounting groove, a wedge is arranged in the mounting groove, the wedge is arranged between the bottom wall of the coupler and the bottom wall of the positioning groove, and the coupler and the bottom wall of the positioning groove are installed in a key groove formed by the wedge, namely, the upper end and the lower end of the wedge are respectively in close contact with the positioning groove 503 and the mounting groove, so that the coupler and the first shaft hole are fixed in the circumferential direction, the coupler and the first shaft hole are prevented from rotating in the circumferential direction, and the coupler and the first shaft hole are fixed in the circumferential direction.

In the foregoing, it can be seen that, the screw 13 is in threaded connection with the threaded hole of the coupler, and if the head of the screw 13 protrudes out of the crankshaft, the screw 13 may interfere with the connecting rod assembly, so how to avoid the interference of the screw 13 with the connecting rod assembly is a technical problem to be solved, and the technical problem is solved by the following technical solutions:

the end of the first taper hole 501, which is connected with the first straight hole 502, is a small end, the radial cross section of the small end is smaller than that of the first straight hole 502, and a step 504 is formed between the small end and the first straight hole 502 along the radial direction.

The step 504 is disposed at a joint of the small end and the first straight hole 502, the step 504 is formed by integrally extending from a hole wall of the first straight hole 502 to an axial direction of the first straight hole 502, and the step 504 is annular.

When one end of the coupler is inserted into the first taper hole 501, the screw 13 extends into the first straight hole 502 from the second opening 506; the rod part of the screw 13 is inserted into the threaded hole of the coupler and is in threaded connection with the threaded hole, and the head part of the screw 13 abuts against the step 504; the pole portion and the head of screw 13 all are held inside the bent axle promptly, and screw 13 does not leak outward to avoided screw 13 to cause the technical problem of interference to link assembly, simultaneously, because screw 13 is held inside the bent axle, also further practiced thrift bent axle and screw 13's axial installation space, improved space utilization.

With further reference to fig. 2 and 4, the second shaft hole 6 may be configured in the same configuration as the first shaft hole 5 or in a different configuration from the first shaft hole 5; in this embodiment, the second shaft hole 6 is different from the first shaft hole 5 in structure, and the second shaft hole 6 is a spare hole for the first shaft hole 5, that is, when the first shaft hole 5 fails, the second shaft hole 6 is activated, so that the coupler is connected with the second shaft hole 6.

Specifically, the hole center line of the second shaft hole 6 is on the same straight line with the axis of the second eccentric shaft 3, and the second shaft hole 6 is a linear through hole penetrating through the second eccentric shaft 3 and the main shaft 1; the second shaft hole 6 is a spare hole, and when the second shaft hole 6 is used and a coupler is required to be connected, the second shaft hole 6 can be properly reamed, trimmed and adjusted according to a connecting shaft required to be connected, which is a common manufacturing process and is not described herein. Meanwhile, since the second shaft hole 6 is formed by removing a portion of material for the crankshaft, it is advantageous to reduce the overall weight of the crankshaft.

Example 2

In the embodiment, on the basis of the embodiment 1, the following technical scheme is added:

referring to fig. 5, a plurality of second weight-removing holes 7 are formed in the main shaft 1; any one of the second weight-removing holes 7 is not crossed with the first eccentric shaft 2 and the second eccentric shaft 3.

The second weight-removing hole 7 is formed by removing partial materials of the flywheel 4, the second weight-removing hole 7 can be a through hole or a blind hole, the cross section of the second weight-removing hole 7 can be circular or any other geometrical shape, and the second weight-removing hole 7 can be a linear hole or a curve hole; the second weight-removing hole 7 has the same action principle and effect as the first weight-removing hole 8, and the part of the main shaft 1 where the second weight-removing hole 7 is removed can be regarded as a counterweight part which is used for balancing the rotational inertia force and the moment of the first connecting rod assembly 9 and the second connecting rod assembly 10. Any second weight-removing hole 7 is not crossed with the first eccentric shaft 2 and the second eccentric shaft 3, namely, any second weight-removing hole 7 is not arranged in the first eccentric shaft 2 and the second eccentric shaft 3.

Example 3

The present embodiment proposes an air compressor, which includes the crankshaft in the above embodiments.

Further, referring to fig. 4, the air compressor further comprises a motor and a coupler, wherein an output shaft of the motor is coaxially arranged with the main shaft 1, and the output shaft of the motor is connected with the first eccentric shaft 2 through the coupler; this part is the prior art and will not be described herein.

Further, referring to fig. 6 to 7, the coupling is split, and includes a first split 11 and a second split 12, wherein the first split 11 is connected to an output shaft of the motor, the first split 11 and the second split 12 form a tooth-shaped engagement, and the second split 12 is connected to the first eccentric shaft 2; in the above embodiment, it is mentioned that one end of the coupling is inserted into the first shaft hole 5, i.e. the second section 12 is inserted into the first shaft hole 5, and correspondingly, the coupling is provided with the mounting groove, i.e. the second section 1 is provided with the mounting groove.

Preferably, the one end that first minute body 11 and motor output shaft link to each other inserts in the preformed hole on the motor output shaft, first minute body 11 and preformed hole are the cooperation of conical surface, second minute body 12 also is the conical surface cooperation with first shaft hole 5, namely, in this application, between first minute body 11 and the preformed hole, all adopt the mode of conical surface laminating between second minute body 12 and the first shaft hole 5, rely on the frictional force transmission, under the special operating mode that vehicle air compressor machine frequently starts to have impact load, according to the transmission mode that adopts key and keyway in the past, can have the wearing and tearing of key and the problem that the keyway receives the impact deformation, lead to structural reliability to reduce, and the structure that adopts the conical surface to combine to tighten to drive in dependence frictional force has the even characteristics of atress, the reliability is higher relatively, life is longer.

The above examples only show several embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the utility model, and these changes and modifications are all within the scope of the utility model. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. The crankshaft is characterized by comprising a main shaft (1), a first eccentric shaft (2) and a second eccentric shaft (3) which are parallel to each other in axis, wherein the first eccentric shaft (2) and the second eccentric shaft (3) are respectively arranged at the end surfaces of two sides of the main shaft (1), and the axis of the first eccentric shaft (2) and the axis of the second eccentric shaft (3) are positioned at two sides of the axis of the main shaft (1);

the flywheel (4) is sleeved on the outer surface of the circumference of the main shaft (1);

the first shaft hole (5) is at least arranged in the first eccentric shaft (2), and the second shaft hole (6) is at least arranged in the second eccentric shaft (3);

the first shaft hole (5) and the second shaft hole (6) are not coaxial.

2. A crankshaft according to claim 1, characterized in that the flywheel (4) is provided with a number of first de-weighting holes (8), any one of the first de-weighting holes (8) being non-intersecting with the first eccentric shaft (2) and the second eccentric shaft (3).

3. A crankshaft according to claim 1 or 2, characterized in that the centre line of the first shaft hole (5) is in line with the axis of the first eccentric shaft (2), and the first shaft hole (5) is a through hole through the first eccentric shaft (2) and the main shaft (1).

4. A crankshaft according to claim 3, characterized in that the first shaft hole (5) comprises a first conical hole (501) and a first straight hole (502) which are communicated with each other and coaxially arranged;

one end of the first taper hole (501) forms a first opening (505) at the end of the first eccentric shaft (2), and one end of the first straight hole (502) forms a second opening (506) at the end of the main shaft (1);

the radial section of the first taper hole (501) is gradually reduced in the direction from the first opening (505) to the second opening (506).

5. A crankshaft according to claim 4, characterized in that the wall of the first conical hole (501) is provided with a positioning groove (503), and the positioning groove (503) is far away from one end of the first straight hole (502), and an opening is formed at the end of the first eccentric shaft (2).

6. A crankshaft according to claim 5, characterized in that the end of the first conical bore (501) that is in contact with the first straight bore (502) is a small end, the radial cross section of the small end is smaller than the radial cross section of the first straight bore (502), and a step (504) is formed radially between the small end and the first straight bore (502).

7. A crankshaft according to claim 6, characterized in that the hole centre line of the second shaft hole (6) is collinear with the axis of the second eccentric shaft (3), and the second shaft hole (6) is a straight through hole passing through the second eccentric shaft (3) and the main shaft (1).

8. A crankshaft according to claim 7, characterized in that the main shaft (1) is provided with a plurality of second weight-reducing holes (7); any one of the second weight-removing holes (7) is not crossed with the first eccentric shaft (2) and the second eccentric shaft (3).

9. An air compressor characterized by comprising the crankshaft of any one of claims 1 to 8.

10. The air compressor of claim 9, further comprising a motor and a coupling, wherein an output shaft of the motor is coaxially arranged with the main shaft (1), and the output shaft of the motor is connected with the first eccentric shaft (2) through the coupling.

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