Compact crankshaft of diesel engine

Abstract

The utility model discloses a compact crankshaft of a diesel engine, which comprises a main shaft, a crank, counterbalances and a crank throw, the crank throw is correspondingly provided with two counterbalances, the compact crankshaft is characterized by further comprising balancing weights, the balancing weights are fixed on the counterbalances through bolts, and the density of the balancing weights is larger than the material density of the counterbalances; the balance block is of a fan-shaped structure, and the balancing weight is fixed to the vertical side face of the balance block or arranged along the arc face of the end of the balance block. The utility model has the advantages of compact structure, light weight, small volume and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of engine crankshafts, in particular to a compact crankshaft for a diesel engine. Background Art

[0002] Small diesel generator sets are widely used in industry, agriculture, commerce and daily life due to their advantages of easy operation, significant effect and low cost. They are the first choice for power generation equipment adopted by various departments and enterprises. With the arrival of aging population in China, the physical fitness of the labor force is declining, and the demand for small and lightweight equipment is becoming increasingly strong.

[0003] The engine converts the chemical energy of fuel into mechanical energy through combustion. The fuel burns in the engine combustion chamber, and the combustion gas force is converted into piston reciprocating kinetic energy. The crankshaft converts the piston reciprocating kinetic energy into rotational power and transmits it to the generator, which transmits electrical energy to the user. When the engine is running, the crankshaft is subjected to the combined action of periodic reciprocating gas force, inertia force and its torque, and bears alternating bending and torsion loads.

[0004] The reciprocating force transmitted by the piston and the high-speed rotation of the crankshaft will generate centrifugal force, which must be effectively balanced and controlled. If it is not well controlled, the engine will vibrate violently during operation, seriously affecting the safety and reliability of operation. The crankshaft mainly uses a counterweight to achieve balance and offset the rotational centrifugal force and reciprocating inertia force.

[0005] The crankshaft is a circular motion part. For every 1mm reduction in the balance block radius or crank radius profile, the engine profile can be reduced by 2mm. By optimizing the crankshaft size, the compactness of the engine can be achieved efficiently. Because the engine cylinder diameter and stroke dimensions must remain unchanged, the crankshaft's crank radius profile cannot be modified, and only the balance block radius profile can be optimized. Changes in the balance block size will seriously affect the dynamic balance of the crankshaft, and thus affect the smoothness of the engine operation. Therefore, the size adjustment of the crankshaft balance block must be subject to a systematic rebalancing analysis and calculation. Designing a highly compact engine meets the current needs for compact and lightweight engines.

[0006] Existing patent document CN102808898A discloses a gasoline engine crankshaft powder metallurgy balance block and a production method thereof, but the designed balance block is too large and difficult to meet the market demand for compactness.

[0007] The disclosure of the above background technology content is only used to assist in understanding the concept and technical solution of the utility model. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Utility Model Content

[0008] The utility model (mainly) aims to provide a compact crankshaft for a diesel engine which has a compact structure, is lightweight and has a small volume.

[0009] Therefore, the utility model provides a compact crankshaft for a diesel engine.

[0010] Preferably, the utility model may also have the following technical features:

[0011] A compact crankshaft for a diesel engine comprises a main shaft, a crank, a balancing block, and a crank throw, wherein the crank throw has two balancing blocks corresponding thereto, and further comprises a counterweight block, wherein the counterweight block is fixed to the balancing block by bolts, and the density of the counterweight block is greater than the material density of the balancing block; the balancing block is a fan-shaped structure, and the counterweight block is fixed to the vertical side surface of the balancing block or arranged along the arc surface of the end of the balancing block.

[0012] Furthermore, the counterweight block and the balancing block are connected and fixed by three bolts.

[0013] Furthermore, the counterweight block is a planar fan-shaped structure, and an assembly groove for assembling with the counterweight block is provided on the side of the balancing block, so that the outer side of the counterweight block is flush with the side of the balancing block.

[0014] Furthermore, the counterweight block is arranged along the arc surface of the end of the balancing block. Correspondingly, the counterweight block is an arc-shaped block, and its inner side is tightly attached to the arc surface of the balancing block.

[0015] Furthermore, the material of the counterweight block is lead-antimony alloy.

[0016] Furthermore, a packaging shell is provided on the outer side of the lead-antimony alloy.

[0017] Furthermore, the material of the counterweight block is tungsten-cobalt alloy.

[0018] Furthermore, a weight-reducing groove is provided at the rotation center of the crankshaft.

[0019] Compared with the prior art, the utility model has the following beneficial effects: the unit weight of the balancing block is increased by density difference, thereby reducing the volume of the balancing block, achieving the purpose of compact design. A high-density metal counterweight is installed at the crankshaft balancing block position to solve the problem that the weight cannot be increased within a limited space. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the front view of the utility model.

[0021] Figure 2 It is a side view of the utility model.

[0022] Figure 3 yes Figure 2AA section view.

[0023] Figure 4 It is a front view of the counterweight of the utility model.

[0024] Figure 5 It is a schematic diagram of the lead-antimony alloy packaging of the utility model.

[0025] Figure 6 yes Figure 5 CC section view.

[0026] Figure 7 It is a side view of another embodiment of the utility model.

[0027] Figure 8 yes Figure 7 BB section view.

[0028] Fig. 9 yes Figure 7 Front view of the counterweight of the illustrated embodiment. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with specific implementations and in conjunction with the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope and application of the present invention.

[0030] Non-limiting and non-exclusive embodiments will be described with reference to the following figures, wherein like reference numerals refer to like parts unless otherwise specifically stated.

[0031] like Figures 1 to 9 A compact crankshaft of a diesel engine shown in the figure includes a main shaft 2, a crank 1, a balance block 4, and a crank. There are two balance blocks 4 on the crank, and a counterweight 3. The counterweight 3 is fixed to the balance block 4 by bolts 5, and the density of the counterweight 3 is greater than the material density of the balance block 4, so that the weight of the counterweight 3 of equal volume is greater than the weight of the balance block 4. The unit weight of the balance block 4 is increased by the density difference, and the volume of the balance block 4 is reduced to achieve the purpose of compact design. Specifically, the balance block 4 is a fan-shaped structure, and the counterweight 3 is fixed to the vertical side of the balance block 4 or arranged along the arc surface of the end of the balance block 4. In this embodiment, in order to achieve the goal of reducing the size of the engine structure, the radius size of the engine balance block 4 is reduced. The reduction in size reduces the weight of the balance block 4, thereby destroying the original balance of the crankshaft, and it is necessary to increase the weight of the balance block 4 to achieve a new balance. However, the weight of the traditional carbon steel crankshaft balance block 4 cannot be increased within the limited structural size. This solution installs a high-density metal counterweight 3 at the position of the crankshaft balance block 4 to solve the problem that the weight cannot be increased within the limited space size.

[0032] Preferably, the counterweight 3 and the balancing block 4 are connected and fixed with three bolts. In particular, when the counterweight 3 is installed on the side of the balancing block 4, the bolt 5 is axially installed and tightened, which effectively increases the contact area between the counterweight 3 and the crankshaft, and then the centrifugal force generated by the high-speed rotation of the crankshaft acts on the shear force of the bolt, thereby improving the overall reliability of the crankshaft.

[0033] Furthermore, the counterweight 3 is a planar sector structure, and a mounting groove for mounting the counterweight 3 is provided on the side of the balancing block 4, so that the outer side of the counterweight 3 is flush with the side of the balancing block 4. The counterweight with a planar sector structure is easy to manufacture and has low cost.

[0034] In the above embodiment, the counterweight 3 can be made of two kinds of high-density metals, namely, lead-antimony alloy 10 and tungsten-cobalt alloy, which are high-density metals produced in large quantities on the market. Figure 5 and Figure 6 The lead-antimony alloy 10 is cheap and easy to manufacture, but due to its low hardness, it will deform and crack if it is directly fixed and pressed with bolts. It must be made of a shell made of a material with higher hardness to encapsulate the lead-antimony alloy before it can be installed and used. The encapsulation shell 9 increases the difficulty of manufacturing and doubles the cost, but the encapsulated lead-antimony alloy has the risk of environmental pollution caused by lead leakage. The price of tungsten-cobalt alloy is three times that of lead-antimony alloy. It has high hardness and good chip processing performance. After the counterweight block 3 is processed, it can be directly fixed and installed with bolts.

[0035] In another aspect, in combination with Figures 7 to 9 As an alternative solution, the counterweight 3 is arranged along the arc surface of the end of the balancing block 4. Correspondingly, the counterweight 3 is an arc block, and its inner side is closely attached to the arc surface of the balancing block 4. The processing difficulty of the counterweight 3 with a curved arc structure in this embodiment is greater than that of a flat sector structure, and the cost is high. In addition, it is difficult to balance the installation and positioning of the counterweight 3 and the crankshaft. At the same time, the centrifugal force of the high-speed rotation of the crankshaft will cause the arc surface counterweight 3 to deform, and then there is a risk of detachment and falling.

[0036] In order to reduce the centrifugal force generated by the rotation of the crankshaft, and further reduce the mass of the counterweight 3, and ensure that the structural strength of the crankshaft meets the requirements, a weight reduction process is performed at the rotation center of the crankshaft. That is, a weight reduction groove 6 is provided at the rotation center of the crankshaft.

[0037] Those skilled in the art will appreciate that numerous variations to the above description are possible, and that the examples and figures are intended only to describe one or more specific implementations.

[0038] Although exemplary embodiments of the present invention have been described and described, it will be understood by those skilled in the art that various changes and substitutions may be made thereto without departing from the spirit of the present invention. In addition, many modifications may be made to adapt specific situations to the teachings of the present invention without departing from the central concept of the present invention described herein. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but the present invention may also include all embodiments and their equivalents that fall within the scope of the present invention.

Claims

1. A compact crankshaft for a diesel engine, comprising a main shaft, a crank, a balancing block, and a crank, wherein the crank has two balancing blocks, and wherein: It also includes a counterweight block, which is fixed to the balancing block by bolts, and the density of the counterweight block is greater than the material density of the balancing block; the balancing block is a fan-shaped structure, and the counterweight block is fixed to the vertical side of the balancing block or arranged along the arc surface of the end of the balancing block.

2. A compact diesel engine crankshaft as claimed in claim 1, characterized in that: The counterweight block and the balancing block are connected and fixed by three bolts.

3. A compact diesel engine crankshaft as claimed in claim 1, characterized in that: The counterweight block is a planar fan-shaped structure, and a mounting groove for mounting with the counterweight block is provided on the side of the balancing block, so that the outer side of the counterweight block is flush with the side of the balancing block.

4. A compact diesel engine crankshaft as claimed in claim 1, characterized in that: The counterweight block is arranged along the arc surface of the end of the balancing block. Correspondingly, the counterweight block is an arc block, and the inner side of the counterweight block is tightly attached to the arc surface of the balancing block.

5. A compact diesel engine crankshaft as claimed in claim 1, characterized in that: The material of the counterweight block is lead-antimony alloy.

6. A compact diesel engine crankshaft as claimed in claim 5, characterized in that: A packaging shell is arranged on the outer side of the lead-antimony alloy.

7. A compact diesel engine crankshaft as claimed in claim 1, characterized in that: The material of the counterweight block is tungsten-cobalt alloy.

8. A compact diesel engine crankshaft as claimed in claim 1, characterized in that: A weight-reducing groove is provided at the rotation center of the crankshaft.

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