Balancing piston, balancing piston assembly and engine assembly

Abstract

The application provides a balance piston, a balance piston assembly and an engine assembly, and relates to the technical field of engines. The air permeation channel arranged on the balance piston can effectively balance the air pressure difference on the top end surface side and the bottom end surface side of the balance piston during the working process, improve the wind resistance and movement resistance phenomenon of the balance piston during the working process, and make the balance piston movement more stable and smooth. On the other hand, the lubricating oil mist can freely diffuse through the air permeation channel, reliably and efficiently lubricate the outer wall of the balance piston, ensure the excellent durability and reliability of the balance piston and the low running friction loss. The balance piston is also provided with a lubricating oil channel, which can actively lubricate the balance piston through pressure oil supply, and the splash oil mist in the engine cylinder can also directly lubricate the skirt. The above lubricating mode realizes efficient lubrication of the balance piston.

Description

Technical Field

[0001] This application relates to the field of engine technology, and more specifically, to a balance piston, a balance piston assembly, and an engine assembly. Background Technology

[0002] Currently, the market demands higher performance from vehicles, which in turn places higher requirements on engine quality. During the movement of the piston assembly, the reciprocating inertial force generated causes severe engine vibration, exacerbating wear and fatigue load on the crankshaft connecting rod mechanism, limiting the engine's ability to reach higher speeds, and reducing overall vehicle ride comfort.

[0003] Related technologies typically employ a balance weight positioned on the crankshaft away from the piston to counteract the reciprocating inertial force of the working piston. However, using this balance weight structure to balance the crankshaft connecting rod mechanism requires extremely high precision in the assembly position of the guide holes and guide rods of the balancing mass, often resulting in significant frictional noise and frictional power loss. Furthermore, this balance weight structure has numerous parts and insufficient lubrication. Summary of the Invention

[0004] The purpose of this application is to provide a balance piston, a balance piston assembly, and an engine assembly to solve the aforementioned technical problems.

[0005] The embodiments of this application can be implemented as follows: In a first aspect, this application provides a balancing piston having a top end face and a bottom end face disposed opposite to each other along its axial direction; the balancing piston is provided with a venting channel, the two ends of which respectively penetrate the top end face and the bottom end face.

[0006] In an optional embodiment, the balance piston includes a head and a skirt connected together, the top end face is disposed on the head, the bottom end face is disposed on the skirt, the head is provided with a vent hole, and the skirt is provided with a cavity; The ventilation channel includes a ventilation hole and a cavity that are connected. One end of the ventilation hole passes through the top surface and the other end is connected to one end of the cavity. The other end of the cavity passes through the bottom surface.

[0007] In an optional embodiment, the number of vent holes is at least one, and at least one of the vent holes is located at the center of the balance piston.

[0008] In an optional embodiment, the number of vent holes is at least two, and the at least two vent holes are spaced apart.

[0009] In an optional embodiment, the vent hole includes an upper section, a middle section, and a lower section, which are connected sequentially. At least one of the upper section and the lower section of the hole is in the shape of an outwardly flared opening.

[0010] In an optional embodiment, a gas channel is provided on the outer peripheral wall of the head, and the gas channel extends through the head at least axially.

[0011] In an optional embodiment, the skirt is provided with a pin hole, and the cavity is connected to the pin hole; the balance piston is provided with a lubricating oil passage, the lubricating oil passage includes an oil outlet provided on the outer wall of the skirt, and a branch provided inside the balance piston; the branch includes an oil inlet end and an oil outlet end, the oil inlet end is connected to the pin hole, and the oil outlet end is connected to the oil outlet.

[0012] In an optional embodiment, the branch includes a first branch and a second branch arranged at intervals, and the oil outlet includes a first oil outlet and a second oil outlet disposed on the outer wall surface of the skirt; the oil outlet end of the first branch is connected to the first oil outlet, and the oil outlet end of the second branch is connected to the second oil outlet; the oil inlet ends of the first branch and the second branch are both connected to the pin hole; the first branch, the second branch, the first oil outlet, and the second oil outlet together constitute the lubricating oil circuit.

[0013] In an optional embodiment, an oil outlet groove is provided on the outer wall of the balance piston, and the oil outlet is located in the oil outlet groove.

[0014] In an optional embodiment, the oil outlet groove has two oppositely arranged inclined sides, which are arranged at an included angle; the cross-section of the inclined sides is arc-shaped or straight.

[0015] In an optional embodiment, the outer wall of the balance piston is provided with a coating area, and a friction-reducing coating is provided in the coating area; the oil outlet and the oil outlet groove are located in the coating area.

[0016] In an optional embodiment, the balance piston includes a head and a skirt connected together, with the top end face disposed on the head and the bottom end face disposed on the skirt; the skirt is formed by a first skirt, a first pin seat, a second skirt and a second pin seat connected in sequence, the first skirt and the second skirt being symmetrical, and the first pin seat and the second pin seat being symmetrical. Both the first pin seat and the second pin seat are provided with a first side window near the first skirt, and both the first pin seat and the second pin seat are provided with a second side window near the second skirt.

[0017] Secondly, this application provides a balance piston assembly, including a balance piston, a balance pin, and a balance connecting rod as described in any of the foregoing embodiments, wherein the balance piston, the balance pin, and the balance connecting rod are connected in sequence.

[0018] Thirdly, this application provides an engine assembly including the balance piston assembly described in the foregoing embodiments.

[0019] The beneficial effects of the balance piston, balance piston assembly, and engine assembly provided in this application embodiment include: The balance piston provided in this application embodiment, through the venting channel provided on the balance piston, on the one hand, effectively balances the air pressure difference between the top and bottom surfaces of the balance piston during operation, and also reduces the wind resistance of the balance piston's movement. This effectively improves the wind resistance and movement obstruction phenomena that occur during the operation of the balance piston, making the movement of the balance piston more stable and smooth. On the other hand, the lubricating oil mist can freely diffuse through the venting channel, reliably and efficiently lubricating the outer wall of the balance piston, ensuring the excellent durability and reliability of the balance piston and low operating friction loss. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure in which the balance piston is disposed inside the balance cylinder according to this embodiment. Figure 2 The top view of the balance piston provided in this embodiment being disposed in the balance cylinder; Figure 3 for Figure 2 Sectional view of AA; Figure 4 for Figure 3 Sectional view of BB; Figure 5 for Figure 4 Sectional view of CC; Figure 6 A bottom view of the balance piston provided in this embodiment; Figure 7 This is a schematic diagram of the balance piston provided in this embodiment on one side of the first skirt. Figure 8 This is a partial schematic diagram of the oil outlet groove provided in the first skirt according to this embodiment.

[0022] Icons: 01-Balance piston assembly; 10-Balance piston; 101-Head; 102-Skirt; 11-Top surface; 12-Bottom surface; 13-Ventilation hole; 131-Upper section of hole; 132-Middle section of hole; 133-Lower section of hole; 14-Cavity; 15-Gas passage; 16-First skirt; 17-Second skirt; 18-Coating area; 181-Anti-friction coating; 19-First pin seat; 191-First pin hole; 192-First branch; 193-First oil outlet; 20-Second pin seat; 201-Second pin hole; 202-Second branch; 203-Second oil outlet; 21-Oil groove; 211-Bevel; 22-Annular oil groove; 23-First side window; 24-Second side window; 30 - Balance cylinder; 31 - Balance chamber. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] In the description of this application, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0027] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0028] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0029] Currently, the market demands higher performance from vehicles, which in turn places higher requirements on engine quality. During the movement of the piston assembly, the reciprocating inertial force generated causes severe engine vibration, exacerbating wear and fatigue load on the crankshaft connecting rod mechanism, limiting the engine's ability to reach higher speeds, and reducing overall vehicle ride comfort.

[0030] Related technologies typically employ a balance weight positioned on the crankshaft away from the piston to counteract the reciprocating inertial force of the working piston. However, using this balance weight structure to balance the crankshaft connecting rod mechanism requires extremely high precision in the assembly position of the guide holes and guide rods of the balancing mass, often resulting in significant frictional noise and frictional power loss. Furthermore, this balance weight structure has numerous parts and insufficient lubrication.

[0031] Therefore, please refer to Figures 1-8 This application provides a balance piston 10, a balance piston assembly 01, and an engine assembly. The balance piston 10 is used in a balance piston assembly 01, which is used in an engine assembly and can balance the reciprocating inertial force generated by the working piston.

[0032] In a first aspect, this application provides an engine assembly including an engine block, a crankshaft, a working piston assembly, and a balance piston assembly. The engine block is provided with a balance cylinder 30 and a working cylinder. The crankshaft is rotatably disposed in the engine block. The working piston assembly is hinged to the crankshaft and slidably disposed in the working cylinder. The balance piston assembly 01 is hinged to the crankshaft and slidably disposed in the balance cylinder 30. The balance cylinder 30 and the working cylinder are located on opposite sides of the crankshaft.

[0033] Understandably, during the operation of the balancing mechanism, as the working piston reciprocates linearly and generates reciprocating inertial force, this inertial force is transmitted to the crankshaft via the connecting rod. For example, when the crankshaft rotates and the working piston reaches its highest point, it generates a downward inertial force. At this time, the balancing piston 10, driven by the crankshaft and the connecting rod, reaches its lowest point and generates an upward inertial force. The two generate two inertial forces in opposite directions, which ultimately cancel each other out on the crankshaft, thus preventing the crankshaft from transmitting vibrations outward.

[0034] Therefore, the engine assembly provided in this application, by setting a balance piston assembly, with the balance piston assembly 01 arranged opposite to the working piston assembly, can balance the reciprocating inertial force generated by the working piston, thus avoiding the situation where the crankshaft transmits vibration outward and causes the engine to vibrate violently, and has a high degree of operational stability.

[0035] Optionally, the crankshaft is provided with multiple working piston assemblies and multiple balance piston assemblies, with the multiple working piston assemblies and multiple balance piston assemblies 01 spaced apart.

[0036] Secondly, this application also proposes a balance piston assembly, including a balance piston 10, a balance pin, and a balance connecting rod, wherein the balance piston 10, the balance pin, and the balance connecting rod are connected in sequence.

[0037] One end of the balance link is connected to the balance pin, and the other end is connected to the crankshaft.

[0038] In this embodiment, the engine block is provided with a balance cylinder 30 and a working cylinder; wherein, the working cylinder has a working chamber, and the working piston is slidably disposed in the working chamber; wherein, the balance cylinder 30 is provided with a balance chamber 31, please refer to Figure 1 The balance piston 10 is slidably disposed within the balance chamber 31.

[0039] It is worth mentioning that during the operation of the aforementioned balance piston assembly 01, the balance piston 10 usually exhibits aerodynamic resistance, accompanied by significant frictional noise, frictional work loss, and insufficient oil supply.

[0040] Therefore, in a third aspect, this application also proposes a balance piston 10 having a top surface 11 and a bottom surface 12 disposed opposite to each other along its axial direction; the balance piston 10 is provided with a venting channel, the two ends of which pass through the top surface 11 and the bottom surface 12 respectively.

[0041] Understandably, on the one hand, the venting channels on the balance piston 10 effectively balance the air pressure difference between the top surface 11 and the bottom surface 12 of the balance piston 10 during operation, and also reduce the wind resistance of the balance piston 10. This effectively improves the wind resistance and movement obstruction phenomena that occur during the operation of the balance piston 10, making the movement of the balance piston 10 more stable and smooth. On the other hand, the lubricating oil mist can freely diffuse through the venting channels, reliably and efficiently lubricating the outer wall of the balance piston 10, ensuring the excellent durability and reliability of the balance piston 10 and low operating friction loss.

[0042] The following is a detailed description of the design of the ventilation channels: In this embodiment, the venting channel is located at the center of the balance piston 10.

[0043] It is understandable that setting a venting channel at the center of the balance piston 10 allows the balance piston 10 to move more smoothly, avoiding the deflection torque caused by eccentric airflow, thereby significantly improving the coaxiality and linear stability of the balance piston 10.

[0044] In this embodiment, the balance piston 10 includes a head 101 and a skirt 102 connected to each other. The top surface 11 is disposed on the head 101, and the bottom surface 12 is disposed on the skirt 102. The head 101 is provided with a vent hole 13, and the skirt 102 is provided with a cavity 14. The venting channel includes the vent hole 13 and the cavity 14 connected together. One end of the vent hole 13 passes through the top surface 11, and the other end is connected to one end of the cavity 14. The other end of the cavity 14 passes through the bottom surface 12.

[0045] The skirt 102 is used to connect the balance pin, and the cavity 14 is used to provide the movement space for the balance pin.

[0046] In one embodiment, the number of vent holes 13 is at least one, and at least one vent hole 13 is located at the center of the balance piston 10.

[0047] In one embodiment, the number of vent holes 13 is at least two, with one vent hole 13 located at the center of the balance piston 10, and the other vent holes 13 spaced apart from it.

[0048] In one embodiment, the number of vent holes 13 is at least two, and the at least two vent holes 13 are arranged at intervals.

[0049] In one embodiment, there are multiple vent holes 13, which are arranged in a circular array around the central axis of the balance piston 10.

[0050] In one embodiment, there are multiple vent holes 13, one of which is located at the center of the balance piston 10, and the remaining vent holes 13 are arranged in a circular array around the central axis of the balance piston 10.

[0051] In one embodiment, there are multiple vent holes 13, which are arranged in a matrix.

[0052] It should be noted that the above embodiments only provide several specific arrangements of the vent holes 13 as examples; in practical applications, the arrangement of the vent holes 13 can be adjusted according to specific needs and is not limited to the above embodiments.

[0053] In this embodiment, the vent 13 includes an upper section 131, a middle section 132, and a lower section 133, which are connected in sequence; at least one of the upper section 131 and the lower section 133 is an outwardly flared shape.

[0054] The upper section 131 of the hole is shaped like an outward-facing flared mouth. This can be understood as the size of the lower section 133 of the hole gradually increasing from the top surface 11 to the bottom surface 12.

[0055] The lower section 133 of the hole is shaped like an outward-facing flared mouth. This can be understood as the size of the upper section 131 of the hole gradually increasing from the bottom end face 12 to the top end face 11.

[0056] It is understandable that if the vent 13 is a straight hole, the balance piston 10 will reciprocate in a straight line in the balance chamber 31. When the airflow flows through the vent 13 at high speed, the opening edge of the vent 13 is often a sharp right angle. These sharp edges will periodically cut the airflow and generate high-frequency vibration, thus producing a sharp whistling sound.

[0057] Therefore, this application configures the vent 13 as an upper section 131, a middle section 132, and a lower section 133, with at least one of the upper section 131 and the lower section 133 being an outward-facing flared shape, resulting in a gradually expanding design at at least one end of the vent 13. This prevents severe vortex stripping of gas at the upper and lower edges of the vent 13 during the movement of the balance piston 10, resulting in a gentler pressure gradient and more uniform flow velocity distribution. This eliminates the conditions for high-frequency resonance at its source, avoids sharp whistling sounds, and improves the overall NVH characteristics. Simultaneously, it reduces the wind resistance of the balance piston 10 and facilitates the free diffusion of lubricating oil mist, reducing frictional losses and increasing the lubricating oil supply to the skirt 102.

[0058] Optionally, the upper section 131 of the hole is connected to the top surface 11, and the upper section 131 is a tapered hole; wherein, the taper of the upper section 131 is 30°-50°, for example, 30°, 31°…40°, 41°…, 49°, 50°. This can significantly reduce airflow resistance and improve the flow efficiency of airflow or lubricating oil mist.

[0059] Optionally, the lower section 133 of the hole is connected to the inner wall of the cavity 14 by a circular arc surface; wherein the radius of the circular arc surface is 3mm-7mm, for example, the radius of the circular arc surface can be 3mm, 4mm, 5mm, 6mm, or 7mm. This can improve the problem of stress concentration and facilitate the free diffusion of lubricating oil mist. Optionally, the diameter of the middle section 132 is greater than or equal to 15mm; wherein the height of the middle section 132 is 3mm-7mm, for example, the height of the middle section 132 is 3mm, 4mm, 5mm, 6mm, or 7mm.

[0060] In one embodiment, the vent 13 may be any one of the upper section 131, the middle section 132, or the lower section 133. Alternatively, the vent 13 may include an upper section 131 and a middle section 132, with the upper section 131 connected to the top surface 11 and the middle section 132 connected to the cavity 14. Alternatively, the vent 13 may include a middle section 132 and a lower section 133, with the middle section 132 connected to the top surface 11 and the lower section 133 connected to the cavity 14.

[0061] The following is a detailed description of the structure of the balance piston 10: In this embodiment, the balance piston 10 includes a head 101 and a skirt 102 connected to each other. The top surface 11 is disposed on the head 101, and the bottom surface 12 is disposed on the skirt 102. The head 101 is provided with a vent hole 13, and the skirt 102 is provided with a cavity 14. The venting channel includes the vent hole 13 and the cavity 14 connected together. One end of the vent hole 13 passes through the top surface 11, and the other end is connected to one end of the cavity 14. The other end of the cavity 14 passes through the bottom surface 12.

[0062] Specifically, the diameter of the cross-section of the skirt 102 is larger than the diameter of the cross-section of the head 101; the outer peripheral surface of the skirt 102 is used for sliding engagement with the inner wall forming the balance cavity 31.

[0063] Specifically, the balance piston 10 includes a head 101 and a skirt 102 connected together. The top surface 11 is disposed on the head 101, and the bottom surface 12 is disposed on the skirt 102. The skirt 102 is formed by a first skirt 16, a first pin seat 19, a second skirt 17, and a second pin seat 20 connected in sequence. The first skirt 16 and the second skirt 17 are symmetrical, and the first pin seat 19 and the second pin seat 20 are symmetrical. The first pin seat 19 and the second pin seat 20 are each provided with a first side window 23 near the first skirt 16, and the first pin seat 19 and the second pin seat 20 are each provided with a second side window 24 near the second skirt 17.

[0064] The first side window 23 and the second side window 24 on both sides are connected. By setting the first side window 23 and the second side window 24, it is beneficial to reduce the overall weight of the balance piston 10 and also to accommodate the swing of the balance link.

[0065] Optionally, the first skirt 16 and the second skirt 17 are symmetrical, with the first skirt 16 located on the main thrust side and the second skirt 17 located on the secondary thrust side. The piston connecting rod pushes the balance piston 10 to move within the balance chamber 31, with the balance piston 10 pressed tightly against one side of the inner wall of the balance chamber 31, i.e., the main thrust side. Alternatively, the piston connecting rod pulls the balance piston 10 to move within the balance chamber 31, with the balance piston 10 pressed tightly against one side of the inner wall of the balance chamber 31, i.e., the secondary thrust side.

[0066] Optionally, the connection between the first side window 23 and the second side window 24 and the first skirt 16 and the second skirt 17 is made by using a large arc connecting surface for smooth transition, and the cross section of the cavity 14 is approximately elliptical.

[0067] Understandably, the use of a large arc connecting surface for a smooth transition at the aforementioned connection points, combined with a near-elliptical piston cavity design, effectively eliminates sharp structural corners within the balance piston 10's inner cavity. This not only optimizes stress distribution and ensures structural strength but also significantly reduces the machining difficulty and thermal stress concentration of the forging die, thereby extending the die's service life. Through the above design, this balance piston 10 can reduce overall weight while increasing structural rigidity, facilitating the distribution and heat dissipation of the lubricating oil film, and reducing machining difficulty.

[0068] In this embodiment, a gas channel 15 is provided on the outer peripheral wall of the head 101, and the gas channel 15 extends through the head 101 at least axially.

[0069] Understandably, a groove is formed on the outer peripheral wall of the head 101, extending axially from the top surface 11 to the bottom surface 12 or the skirt 102, so that the inner wall of the groove in the head 101 forms a gas passage 15 with the inner wall of the balance cylinder 30. By providing the gas passage 15, the wind resistance of the balance piston 10 can be reduced, and the free diffusion of lubricating oil mist in the crankcase can be facilitated, thereby reducing the frictional loss of the balance piston 10.

[0070] Optionally, if the gas channel 15 is axially offset from the first skirt 16 or the second skirt 17, the gas channel 15 only penetrates the outer peripheral wall of the head 101. If the gas channel 15 is axially corresponding to the first skirt 16 or the second skirt 17, the gas channel 15 must penetrate the outer peripheral walls of both the head 101 and the skirt 102.

[0071] Optionally, the number of gas channels 15 can be one, two, three, etc.

[0072] In one embodiment, the skirt 102 includes a first skirt 16 and a second skirt 17 arranged circumferentially, the first skirt 16 and the second skirt 17 being symmetrically arranged; there are two gas channels 15, the two gas channels 15 being respectively arranged at opposite ends of the head 101; the first skirt 16, the second skirt 17 and the two gas channels 15 are staggered along the circumferential direction of the balance piston 10.

[0073] Understandably, the two gas channels 15 are separated by the first skirt 16 and the second skirt 17, which can greatly reduce the machining area of ​​the balance piston 10 on the outer circular surface; at the same time, it is beneficial to improve the guiding stability of the balance piston 10 and also beneficial to the diffusion of lubricating oil mist.

[0074] It is worth mentioning that the inner wall of the two gas channels 15 is composed of two equal arcs with the center located on the axis of the balance piston 10. The diameter of the arc is 3mm-6mm smaller than the diameter of the head 101 of the balance piston 10. It can also be understood that the width of the gas channel 15 is 3mm-6mm. This design can provide an effective gas channel 15.

[0075] It is worth mentioning that while oil mist splashed into the engine cylinder can usually directly lubricate the skirt 102, under some high-load conditions, this method of lubrication is insufficient and can easily lead to cylinder scoring. Therefore, this application also provides a lubrication oil passage and an oil outlet on the skirt 102, and provides active lubrication to the skirt 102 through pressure oil supply, achieving efficient lubrication and alleviating insufficient lubrication.

[0076] Therefore, in this embodiment, the skirt 102 is provided with a pin hole, and the cavity 14 is connected to the pin hole; the balance piston 10 is provided with a lubricating oil passage, which includes an oil outlet provided on the outer wall of the skirt 102, and a branch provided inside the balance piston 10; the branch includes an oil inlet end and an oil outlet end, the oil inlet end of the branch is connected to the pin hole, and the oil outlet end of the branch is connected to the oil outlet.

[0077] The skirt 102 has a pin hole for inserting a balance pin, which is used to connect the balance rod and the balance piston 10. Both the balance pin and the balance rod have oil passages for lubrication, and the oil passages of the two are connected. The axis of the pin hole is coaxial with the axis of the balance pin.

[0078] It is understood that the oil passage within the balance pin is connected to the lubrication passage of the balance piston 10, enabling the balance pin to actively supply oil to the outer wall surface of the skirt 102 of the balance piston 10 through the connected branch and oil outlet. Therefore, by providing a lubrication passage—namely, the connected branch and oil outlet—the balance piston 10 achieves active oil supply to the outer wall surface of the skirt 102, thereby realizing active lubrication of the skirt 102 through pressure oil supply, forming a stable lubricating oil film, reducing friction, and improving the lubrication reliability of the balance piston 10.

[0079] Therefore, the skirt 102 of the balance piston 10 in this application employs two lubrication methods: 1. Splashed oil mist from the engine cylinder can directly lubricate the skirt 102. 2. A lubrication oil passage, i.e., a connected branch and an oil outlet, is provided on the skirt 102 of the balance piston 10, which can actively lubricate the skirt 102 through pressure oil supply. These two lubrication methods provide sufficient and efficient lubrication to the skirt 102, improving the lubrication reliability of the balance piston 10.

[0080] In one embodiment, please refer to Figure 5 , Figure 5The hollow arrows in the diagram indicate the oil supply direction for each branch to actively lubricate the skirt 102. Specifically, the branches include a first branch 192 and a second branch 202 spaced apart, and the oil outlets include a first oil outlet 193 and a second oil outlet 203 located on the outer wall of the skirt 102. The oil outlet of the first branch 192 is connected to the first oil outlet 193, and the oil outlet of the second branch 202 is connected to the second oil outlet 203. The oil inlet of both the first branch 192 and the second branch 202 is connected to the pin hole. The first branch 192, the second branch 202, the first oil outlet 193, and the second oil outlet 203 together constitute the lubrication oil circuit.

[0081] The first oil outlet 193 and the second oil outlet 203 can be a single oil hole or two separate oil holes.

[0082] Specifically, the first branch 192 and the second branch 202 are arranged in a mirror-symmetric manner with respect to the radial direction of the pin hole; there are two lubrication oil passages, which are arranged in a mirror-symmetric manner with respect to the axial direction of the pin hole.

[0083] Understandably, the above design ensures consistent oil supply in each oil hole, improves the uniformity of oil supply to the first skirt 16 and the second skirt 17, further reduces friction, and improves the lubrication reliability of the balance piston 10 in the first skirt 16 and the second skirt 17.

[0084] It is worth mentioning that during the processing of the first branch 192 and the second branch 202, four countersunk holes can be machined at the corresponding positions of the balance piston 10 to form a hole bottom platform, which is beneficial to the drilling of the first branch 192 and the second branch 202, reduces the drilling difficulty and the drilling scrap rate, and reduces costs.

[0085] Specifically, please refer to Figure 4 The first pin seat 19 has a first pin hole 191, and the second pin seat 20 has a second pin hole 201. The first pin hole 191 and the second pin hole 201 are coaxially arranged and are used to install a balance pin. A first branch 192 penetrates the skirt 102 and is correspondingly arranged and connected to the first pin hole 191; a second branch 202 also penetrates the skirt 102 and is correspondingly arranged and connected to the second pin hole 201.

[0086] Furthermore, both the first pin hole 191 and the second pin hole 201 are provided with annular oil grooves 22; please refer to Figure 5The oil inlet of the first branch 192 is connected to the first pin hole 191 through the annular oil groove 22 therein, and the oil outlet of the first branch 192 is connected to the first oil outlet 193; the oil inlet of the second branch 202 is connected to the second pin hole 201 through the annular oil groove 22 therein, and the oil outlet of the second branch 202 is connected to the second oil outlet 203.

[0087] Through the above design, the annular oil groove 22 can store lubricating oil, ensuring that the balance pin can be fully lubricated and not seize up during high-speed oscillation.

[0088] In this embodiment, an oil outlet groove 21 is provided on the outer wall of the balance piston 10, and the oil outlet is located in the oil outlet groove 21.

[0089] Alternatively, please refer to Figures 7-8 Oil outlet grooves 21 are provided on the outer walls of both the first skirt 16 and the second skirt 17. The first oil outlet 193 and the second oil outlet 203 are both connected to the oil outlet grooves 21. Alternatively, oil outlet grooves 21 may be provided on the outer walls of either the first skirt 16 or the second skirt 17.

[0090] By setting up an annular oil groove 22, a first branch 192, a second branch 202, and an oil outlet groove 21, a reliable and efficient lubrication oil circuit arrangement is formed, so as to supply the lubricating oil at the first pin hole 191 and the second pin hole 201 to the first skirt 16 and the second skirt 17 respectively, so as to achieve overall lubrication of the balance piston 10, and further facilitate the uniform distribution of oil film, preventing cylinder scoring during operation.

[0091] Optionally, if the oil outlet groove 21 is a trapezoidal oil outlet groove structure, then the oil outlet groove 21 has two oppositely arranged inclined sides 211, and the two inclined sides 211 are arranged at an included angle; the cross section of the inclined side 211 is straight.

[0092] Optionally, if the oil outlet groove 21 is an arc-shaped oil outlet groove structure, then the oil outlet groove 21 has two oppositely arranged inclined sides 211, and the two inclined sides 211 are arranged at an included angle; the cross section of the inclined side 211 is arc-shaped.

[0093] Alternatively, please refer to Figure 8 The oil outlet groove 21 has two oppositely arranged inclined sides 211, which are set at an included angle J, and the included angle J ranges from 100° to 140°.

[0094] Understandably, on the one hand, the groove structure of the oil outlet groove 21 can store oil, which can improve the lubrication performance of the balance piston 10 or the skirt 102. On the other hand, the two inclined sides 211 of the oil outlet groove 21 are set at an included angle. During the reciprocating motion of the balance piston 10, the two inclined sides 211 can guide the flow of oil, increase the lubrication area, and ensure that the first skirt 16 and the second skirt 17 are fully lubricated. At the same time, it is easier to remove burrs from the edge of the oil outlet groove 21 during machining, which is conducive to the uniform distribution of oil film, reduces lubrication friction loss, and reduces the risk of cylinder scoring.

[0095] In this embodiment, the outer wall of the balance piston 10 is provided with a coating area 18, and a friction-reducing coating 181 is provided in the coating area 18; the oil outlet and the oil groove 21 are located in the coating area 18.

[0096] Specifically, please refer to Figure 7 The outer walls of the first skirt 16 and the second skirt 17 are both provided with a coating area 18, and a friction-reducing coating 181 is provided in the coating area 18. Preferably, the two coating areas 18 are arranged symmetrically.

[0097] The coating area 18 can be rectangular, circular, or other shapes, and the friction-reducing coating 181 can be a resin friction-reducing coating 181, which is applied to the coating by printing or other methods.

[0098] It is understandable that by setting the oil outlet and oil groove 21 within the coating area 18, friction can be reduced, frictional work loss can be reduced, frictional noise can be suppressed, and processing can be facilitated, thus improving the processability of the coating process.

[0099] In this embodiment, the balance piston 10 is made of forged steel, aluminum alloy, gray cast iron, or ductile iron. These materials are readily available, inexpensive, and ensure overall structural strength.

[0100] Furthermore, this application also provides a vehicle including the engine assembly described in the above embodiments.

[0101] In summary, the balance piston 10, balance piston assembly 01, and engine assembly provided in this application embodiment, through the venting channel provided on the balance piston 10, on the one hand, enable the balance piston 10 to effectively balance the air pressure difference on the top surface 11 side and the bottom surface 12 side during operation, and also reduce the wind resistance of the balance piston 10. This effectively improves the wind resistance and movement obstruction phenomenon that occurs during the operation of the balance piston 10, making the movement of the balance piston 10 more stable and smooth. On the other hand, the lubricating oil mist can diffuse freely through the venting channel, reliably and efficiently lubricating the outer wall of the balance piston 10, ensuring the excellent durability and reliability of the balance piston 10 and low operating friction loss.

[0102] Furthermore, by configuring the vent 13 into an upper section 131, a middle section 132, and a lower section 133, with at least one of the upper section 131 and the lower section 133 being an outward-facing flared shape, the size of at least one end of the vent 13 is designed to gradually expand. This prevents the gas from generating severe vortex stripping at the upper and lower edges of the vent 13 when the balance piston 10 is in motion, resulting in a gentler pressure gradient and more uniform flow velocity distribution at the vent 13. This eliminates the conditions for high-frequency resonance at its source, avoids sharp whistling sounds, and improves the overall NVH characteristics of the machine. Simultaneously, it reduces the wind resistance of the balance piston 10 and facilitates the free diffusion of lubricating oil mist, reducing frictional losses of the balance piston 10 and increasing the lubricating oil supply to the skirt 102.

[0103] Furthermore, this application describes two lubrication methods for the skirt 102 of the balance piston 10: 1. Splashed oil mist from the engine cylinder can directly lubricate the skirt 102. 2. A lubrication oil passage, i.e., a connected branch and an oil outlet, is provided on the skirt 102 of the balance piston 10, which can actively lubricate the skirt 102 through pressure oil supply. These two lubrication methods provide sufficient and efficient lubrication to the skirt 102, improving the lubrication reliability of the balance piston 10.

[0104] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A balanced piston, characterized in that, The balance piston (10) has a top surface (11) and a bottom surface (12) arranged opposite to each other along its axial direction; the balance piston (10) is provided with a venting channel, the two ends of which pass through the top surface (11) and the bottom surface (12) respectively.

2. The balance piston according to claim 1, characterized in that, The balance piston (10) includes a head (101) and a skirt (102) connected to each other. The top surface (11) is disposed on the head (101), and the bottom surface (12) is disposed on the skirt (102). The head (101) is provided with a vent hole (13), and the skirt (102) is provided with a cavity (14). The ventilation channel includes the ventilation hole (13) and the cavity (14) that are connected. One end of the ventilation hole (13) passes through the top surface (11), and the other end is connected to one end of the cavity (14). The other end of the cavity (14) passes through the bottom surface (12).

3. The balance piston according to claim 2, characterized in that, The number of the vent holes (13) is at least one, and at least one of the vent holes (13) is located at the center of the balance piston (10); Alternatively, the number of the vent holes (13) is at least two, and the at least two vent holes (13) are spaced apart.

4. The balance piston according to claim 2, characterized in that, The ventilation hole (13) includes an upper section (131), a middle section (132), and a lower section (133), which are connected in sequence. At least one of the upper section (131) and the lower section (133) of the hole is an outwardly flared shape.

5. The balance piston according to claim 2, characterized in that, A gas channel (15) is provided on the outer peripheral wall of the head (101), and the gas channel (15) penetrates the head (101) at least axially.

6. The balance piston according to claim 2, characterized in that, The skirt (102) is provided with a pin hole, and the cavity (14) is connected to the pin hole; The balance piston (10) is provided with a lubricating oil passage, which includes an oil outlet disposed on the outer wall of the skirt (102) and a branch disposed inside the balance piston (10). The branch includes an oil inlet and an oil outlet. The oil inlet is connected to the pin hole, and the oil outlet is connected to the oil outlet.

7. The balance piston according to claim 6, characterized in that, The branch includes a first branch (192) and a second branch (202) arranged at intervals, and the oil outlet includes a first oil outlet (193) and a second oil outlet (203) disposed on the outer wall of the skirt (102). The oil outlet of the first branch (192) is connected to the first oil outlet (193), and the oil outlet of the second branch (202) is connected to the second oil outlet (203); the oil inlet of both the first branch (192) and the second branch (202) is connected to the pin hole. The first branch (192), the second branch (202), the first oil outlet (193), and the second oil outlet (203) together constitute the lubricating oil circuit.

8. The balance piston according to claim 6, characterized in that, The outer wall of the balance piston (10) is provided with an oil outlet groove (21), and the oil outlet is located in the oil outlet groove (21).

9. The balance piston according to claim 8, characterized in that, The oil outlet groove (21) has two oppositely arranged inclined sides (211), which are arranged at an angle; the cross section of the inclined side (211) is arc-shaped or straight.

10. The balance piston according to claim 8, characterized in that, The outer wall of the balance piston (10) is provided with a coating area (18), and a friction-reducing coating (181) is provided in the coating area (18); the oil outlet and the oil outlet groove (21) are located in the coating area (18).

11. The balance piston according to claim 1, characterized in that, The balance piston (10) includes a head (101) and a skirt (102) connected together. The top surface (11) is disposed on the head (101), and the bottom surface (12) is disposed on the skirt (102). The skirt (102) is formed by a first skirt (16), a first pin seat (19), a second skirt (17), and a second pin seat (20) connected in sequence. The first skirt (16) and the second skirt (17) are symmetrical, and the first pin seat (19) and the second pin seat (20) are symmetrical. The first pin seat (19) and the second pin seat (20) are provided with a first side window (23) near the first skirt (16), and the first pin seat (19) and the second pin seat (20) are provided with a second side window (24) near the second skirt (17).

12. A balanced piston assembly, characterized in that, It includes the balance piston (10), balance pin and balance connecting rod as described in any one of claims 1-11, wherein the balance piston (10), the balance pin and the balance connecting rod are connected in sequence.

13. An engine assembly, characterized in that, Includes the balance piston assembly (01) as described in claim 12.

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