Combined crankshaft

Abstract

The utility model relates to the technical field of crankshafts, in particular to a combined crankshaft. Comprising a left crank, a right crank and an auxiliary assembly, the auxiliary assembly comprises a connecting rod, a roller pin, an auxiliary key, a chain wheel, a chain wheel positioning pin and a matched bearing, a splayed part is arranged at the front end of the chain wheel, and a threaded hole is formed in the top of the chain wheel positioning pin. Shaking caused by deformation of a matched flat key of the chain wheel and the left crank can be avoided, stable transmission is facilitated, the splayed part on the front side of the chain wheel can directly abut against and be matched with the inner ring of the bearing, a spacer bush does not need to be additionally arranged, the structure is simplified and optimized, then a chain wheel positioning structure can be optimized, and more stable transmission of a crankshaft connecting rod is facilitated.

Description

Technical Field

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

[0002] The crankshaft-connecting rod mechanism is a common mechanical transmission mechanism with widespread application in various fields. The kinematic principle of the crankshaft and connecting rod can be simply described as converting rotational motion into linear motion, or vice versa. The crankshaft is a rotating component with an eccentric shaft. It converts rotational motion into linear motion by connecting to a connecting rod. As the crankshaft rotates, the rod seat (also called the connecting rod), whose central axis is connected to the connecting rod, reciprocates. The connecting rod is the connector between the crankshaft and other mechanical components, and its length and angle determine the kinematic characteristics of the crankshaft-connecting rod system. The connecting rod is typically made of rigid material and has a movable and fixed connection point. By adjusting the length and angle of the connecting rod, the kinematic behavior of the crankshaft and connecting rod can be controlled, such as simple harmonic or non-simple harmonic motion. The combined action of the crankshaft and connecting rod can be used to generate motions such as linear propulsion, reciprocating compression, or rotational conversion. Currently, they are widely used in internal combustion engines, oil production machines, steam engines, and robotics.

[0003] During transmission, a sprocket will be installed on the crankshaft to cooperate with the chain for transmission. Traditional sprockets are mostly installed directly on the crankshaft mounting part through a flat key. During long-term rotation transmission, a gap is likely to occur between the flat key and the keyway of the sprocket. As time goes by, the gap increases, which will cause the sprocket to shake, thereby seriously affecting the smoothness of the transmission. Utility Model Content

[0004] The purpose of the utility model is to provide a combined crankshaft, aiming to optimize the sprocket positioning structure, so as to achieve more stable transmission of the crankshaft and connecting rod.

[0005] To achieve the above object, the present invention provides a combined crankshaft, comprising a left crank and a right crank, wherein the right crank is connected to the left crank via a crank pin, and further comprising an auxiliary component;

[0006] The auxiliary component includes a connecting rod, a needle roller, an auxiliary key, a sprocket, a sprocket locating pin and a matching bearing. The connecting rod is arranged between the left crank and the right crank, and the needle roller is arranged between the crank pin and the connecting rod. The auxiliary key is detachably connected to the left crank and is located on the end side of the left crank away from the right crank. The sprocket is installed on the left crank and is close to the matching bearing. The front end of the sprocket has an eight-shaped portion. A threaded hole is provided on the top of the sprocket locating pin, and is detachably connected to the left crank and the sprocket respectively, and is located on the side of the sprocket close to the left crank. The matching bearing is sleeved on the left crank.

[0007] Wherein, a rectangular keyway is provided in the mounting inner hole of the sprocket, and is mounted in cooperation with the flat key provided on the left crank.

[0008] Wherein, the auxiliary key adopts a semicircular key and can be directly installed in the semicircular installation groove of the left crank.

[0009] Wherein, the mating bearing adopts a deep groove ball bearing.

[0010] Wherein, the surfaces of the multiple teeth of the sprocket are respectively provided with a wear-resistant coating.

[0011] The utility model provides a combined crankshaft, in which the right crank is connected to the left crank through a crank pin, the connecting rod is arranged between the left crank and the right crank, the needle is arranged between the crank pin and the connecting rod, the auxiliary key is installed on the left crank, the sprocket is installed on the left crank and is close to the matching bearing, the front end of the sprocket has an eight-shaped portion, and the top of the sprocket locating pin is provided with a threaded hole, and is respectively detachably connected to the left crank and the sprocket, and the matching bearing is set on the left crank. After the sprocket is installed, the present application provides a sprocket locating pin on the sprocket mounting portion and the left crank for limiting. When used for a long time, it can avoid the shaking caused by the deformation of the matching flat key between the sprocket and the left crank, which is conducive to stable transmission. The eight-shaped portion on the front side of the sprocket can directly abut the inner ring of the matching bearing without the need for an additional spacer, which simplifies and optimizes the structure, thereby optimizing the sprocket positioning structure, and is conducive to more stable transmission of the crankshaft connecting rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.

[0013] Figure 1 It is a schematic diagram of the overall structure of the combined crankshaft of the present utility model.

[0014] Figure 2 It is a structural schematic diagram of the sprocket locating pin of the utility model.

[0015] In the figure: 1- auxiliary key, 2- sprocket locating pin, 3- sprocket, 4- matching bearing, 5- left crank, 6- connecting rod, 7- needle roller, 8- right crank, 9- crank pin, 10- eight-shaped part, 11- threaded hole. DETAILED DESCRIPTION

[0016] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0017] like Figure 1 and Figure 2As shown, Figure 1 It is a schematic diagram of the overall structure of the combined crankshaft. Figure 2 The schematic diagram of the structure of the sprocket locating pin 2 shows the structure of the utility model. The utility model provides a combined crankshaft comprising a left crank 5, a right crank 8, and an auxiliary assembly. The auxiliary assembly comprises a connecting rod 6, a needle roller 7, an auxiliary key 1, a sprocket 3, a sprocket locating pin 2, and a mating bearing 4. The front end of the sprocket 3 has an oval portion 10, and the top of the sprocket locating pin 2 is provided with a threaded hole 11. The above-mentioned solution optimizes the positioning structure of the sprocket 3, facilitating more stable transmission of the crankshaft and connecting rod. It can be understood that the above-mentioned solution can improve the transmission stability of the crankshaft and connecting rod.

[0018] In this embodiment, the right crank 8 is connected to the left crank 5 via a crank pin 9 .

[0019] Among them, the connecting rod 6 is arranged between the left crank 5 and the right crank 8, the needle roller 7 is arranged between the crank pin 9 and the connecting rod 6, the auxiliary key 1 is detachably connected to the left crank 5, and is located on the end side of the left crank 5 away from the right crank 8, the sprocket 3 is installed on the left crank 5, and is close to the matching bearing 4, the front end of the sprocket 3 has an eight-shaped portion 10, and the top of the sprocket locating pin 2 is provided with a threaded hole 11, and is respectively detachably connected to the left crank 5 and the sprocket 3, and is located on the side of the sprocket 3 close to the left crank 5, and the matching bearing 4 is sleeved on the left crank 5. The needle roller 7 is provided in the through hole of the mounting end of the connecting rod 6. When the left crank 5 and the right crank 8 are connected through the crank pin 9, they are fitted together at the same time. The auxiliary key 1 is used to prevent rotation when external components are installed. It is directly installed on the mounting portion of the left crank 5. A keyway is provided on the left crank 5, and a flat key is installed in the keyway to facilitate the installation of the sprocket 3. The front side of the sprocket 3 has the eight-shaped portion 10, and the eight-shaped portion 10 will be able to abut against the inner ring of the matching bearing 4, so that there is no need to set up an additional spacer, which simplifies the structure. A threaded hole 11 is provided on the top of the sprocket locating pin 2. The function of this structure is that the sprocket locating pin 2 can be pulled out and removed by means of a pin puller and a pin puller. A matching hole is provided on the left crank 5 to facilitate the embedding of the bottom part of the sprocket locating pin 2, thereby forming a stable positioning structure, and the matching bearing 4 is used for rotational matching.

[0020] Secondly, a rectangular keyway is provided in the mounting inner hole of the sprocket 3, and is matched with the flat key provided on the left crank 5. Through this structure, the sprocket 3 and the left crank 5 can realize transmission.

[0021] Then, the auxiliary key 1 adopts a semicircular key, which can be directly installed in the semicircular mounting groove of the left crank 5. The main features of the semicircular key include that it does not weaken the shaft much, the stress concentration of the keyway is small, it can transmit a large torque, and it is suitable for the connection between the tapered shaft head and the wheel hub. The semicircular key is a special key with a flat upper surface, a semicircular arc surface on the lower surface, and two parallel side surfaces, commonly known as a crescent key. This design allows the semicircular key to swing around the geometric center in the shaft groove, thereby adapting to different inclinations. At the same time, this characteristic enables the semicircular key to have good centering performance, and can provide a good fixing effect between axial parts. Furthermore, its structure is simple and easy to assemble and disassemble. In addition, the semicircular key can transmit a large torque. Therefore, the auxiliary key 1 adopts a semicircular key to obtain better transmission stability.

[0022] Furthermore, the mating bearing 4 adopts a deep groove ball bearing. The structural design of the deep groove ball bearing is simple, and it is very convenient to use and maintain. This type of bearing usually adopts a steel plate stamping cage composed of two parts, but a solid cage is used in large-size or high-speed bearings. This structure means that the deep groove ball bearing does not require special maintenance during installation and use. It can withstand a variety of loads: deep groove ball bearings are mainly used to bear radial loads, but can also withstand certain axial loads. When the radial clearance of the bearing is increased, it also has the function of an angular contact ball bearing and can withstand larger axial loads. In addition, when the speed is high and thrust ball bearings are not suitable, deep groove ball bearings can be used to bear pure axial loads and are suitable for high-speed rotation: deep groove ball bearings have a low friction coefficient and a high maximum speed, making them suitable for high-speed rotation. Therefore, after the mating bearing 4 adopts a deep groove ball bearing, a certain transmission stability will also be achieved.

[0023] Finally, the surfaces of the multiple teeth of the sprocket 3 are provided with a wear-resistant coating. By providing the wear-resistant coating on the surfaces of the multiple teeth of the sprocket 3, the wear resistance of the teeth is enhanced through this structural design, which can increase the service life of the sprocket 3 and extend the replacement time during the transmission of the sprocket 3 and the chain.

[0024] The present invention is used to optimize the positioning structure of the sprocket 3, which is beneficial to achieving more stable transmission of the crankshaft connecting rod. After the sprocket 3 is installed, the present invention provides the sprocket positioning pin 2 on the mounting portion of the sprocket 3 and the left crank 5 for limiting. When used for a long time, the shaking caused by the deformation of the matching flat key of the sprocket 3 and the left crank 5 can be avoided, which is beneficial to stable transmission. Furthermore, the eight-shaped portion 10 on the front side of the sprocket 3 can directly abut the inner ring of the matching bearing 4. This structure does not require an additional spacer, and simplifies and optimizes the structure. Further, by respectively providing a wear-resistant coating on the surfaces of multiple teeth of the sprocket 3, the wear resistance of the teeth of the sprocket 3 is enhanced through this structural design. It can improve the service life of the sprocket 3 in the matching transmission between the sprocket 3 and the chain, extend the replacement time, and help reduce the cost of use, thereby achieving optimization of the positioning structure of the sprocket 3 and being more conducive to achieving more stable transmission of the crankshaft connecting rod.

[0025] The above disclosure is merely one or more preferred embodiments of the present application and is not intended to limit the scope of the present application. A person skilled in the art will understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present application are still within the scope of the present application.

Claims

1. A combined crankshaft comprising a left crank and a right crank, wherein the right crank is connected to the left crank via a crank pin, wherein: Also included are auxiliary components; The auxiliary component includes a connecting rod, a needle roller, an auxiliary key, a sprocket, a sprocket locating pin and a matching bearing. The connecting rod is arranged between the left crank and the right crank, and the needle roller is arranged between the crank pin and the connecting rod. The auxiliary key is detachably connected to the left crank and is located on the end side of the left crank away from the right crank. The sprocket is installed on the left crank and is close to the matching bearing. The front end of the sprocket has an eight-shaped portion. A threaded hole is provided on the top of the sprocket locating pin, and is detachably connected to the left crank and the sprocket respectively, and is located on the side of the sprocket close to the left crank. The matching bearing is sleeved on the left crank.

2. The combined crankshaft according to claim 1, wherein: A rectangular keyway is provided in the mounting inner hole of the sprocket and is mounted in cooperation with the flat key provided on the left crank.

3. The combined crankshaft according to claim 1, wherein: The auxiliary key is a semicircular key and can be directly installed in the semicircular installation groove of the left crank.

4. The combined crankshaft according to claim 1, wherein: The matching bearing is a deep groove ball bearing.

5. The combined crankshaft according to claim 1, wherein: The surfaces of the multiple teeth of the sprocket are respectively provided with wear-resistant coatings.

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