Circular-arc and straight-line segmented continuous conjugate internal gear pump

Abstract

The application discloses a circular-arc and straight-line segmented continuous conjugate internal meshing gear pump and belongs to the technical field of hydraulic pumps. The core component of the pump is an internal meshing gear pair, which comprises an external gear and an internal gear ring. The tooth profile of the external gear is formed by several circular arcs and straight-line segments which are sequentially and smoothly connected with their end points coinciding, and they all satisfy geometric first-order continuity at the connection positions and have a common tangent at the connection positions. The tooth profile of the internal gear ring is a conjugate envelope curve formed by the meshing movement of the tooth profile of the external gear. The external gear is eccentrically located in the inner cavity of the internal gear ring, and the two are meshed and paired to form the internal meshing gear pair. The gear pair effectively reduces tooth surface friction and meshing impact, has strong bearing capacity, and has the advantages of super-silence, fluid dynamic oil film stability and the like. In addition, the liquid suction flow channels and the liquid discharge flow channels of the front body, the intermediate body and the rear body in the pump body assembly are smoothly and smoothly tangent and continuously designed without dead angles, and the smooth transition curved surfaces of the flow channels are all G 1 and above high-order geometric continuity (G n , n> or=1).

Description

Technical Field

[0001] This invention relates to the field of hydraulic pump technology, specifically disclosing a contamination-resistant, high-speed, low-loss, and high-load-bearing internal gear pump. In particular, it relates to the segmented continuous design of the tooth profile of the internal gear pair, a core component of the pump. Background Technology

[0002] Internal gear pumps that generate high pressure in liquids have long been patented. As positive displacement power components, they are widely used in CNC machine tools, injection molding machinery, and construction machinery. Existing internal gear pumps employ various tooth profiles, including involute profiles and those with single-straight-line profiles. A comprehensive analysis of these tooth profiles reveals that either the tooth profile curve is inherently flawed, or there are sharp points in certain areas of the profile curve, lacking a geometrically continuous first-order design. These geometric defects can lead to various problems under high-pressure and high-speed conditions: 1. For involute tooth profiles, a closed oil trapping volume will be formed in the meshing area. The compression and expansion of the trapped oil will bring vibration, noise, pressure shock, flow pulsation, etc., which is not conducive to the stable operation of high-precision hydraulic systems. This has long been a consensus. 2. If the tooth profile is a single straight line, the effective contact area of ​​the gear pair is short. The lack of geometric first-order continuous design at the tooth tip and root affects the overlap ratio, leading to insufficient bending strength under heavy loads. Under high pressure conditions, tooth root cracking is prone to occur, internal leakage is excessive, and volumetric efficiency decreases. It also increases the risk of tooth surface friction during meshing, resulting in higher tooth surface contact stress. After long-term operation, tooth surface pitting and scuffing wear are likely to occur, affecting the service life of the gears. It will also further amplify noise, pulsation, and vibration problems, thus affecting the quality of use. Therefore, the industry urgently needs an internal gear pump with less wear, lower noise, higher load capacity, and flexible adaptability to multiple equipment and scenarios. Summary of the Invention

[0003] The technical problem to be solved by this invention is to overcome the various shortcomings of the prior art, and discloses a novel tooth profile of the internal meshing gear pair, the core component of a circular arc and straight line segmented continuous conjugate internal meshing gear pump. This internal meshing gear pair achieves several key benefits: good tooth surface fit with low leakage and high volumetric efficiency; smooth meshing transition and low flow pulsation, resulting in lower operating noise; uniform tooth surface contact stress distribution and uniform relative sliding rate, without localized severe slippage, which is conducive to oil film formation; suitable for media with a wide viscosity range, capable of conveying both hydraulic oil and some clean water media; low tooth root bending stress and good load adaptability; and outstanding anti-fouling performance. The technical solution adopted by this invention to solve the above-mentioned technical problems is: proposing a segmented continuous design concept for the tooth profile of the external gear meshing working side of the internal meshing gear pair. It also includes designs for pump body components, support components, etc., all adapted to this internal meshing gear pair, to fully utilize the innovative effects of this internal meshing gear pair.

[0004] The aforementioned internal gear pair includes an external gear and an internal gear ring. Both the external gear and the internal gear ring have a number of teeth evenly arranged circumferentially, and all teeth have identical tooth profiles. Each tooth of the external gear and the internal gear ring has a symmetrical tooth profile on both sides, with one side being the meshing working side. The "meshing working side" refers to the side of the tooth profile where the teeth are in close contact during gear pair operation, transmitting rotational loads and compressing the medium. This side's geometric orientation can change as the gear rotates or changes direction, based on the actual meshing force transmission tooth surface. The other side of the gear is the non-working side tooth profile, which does not participate in meshing force transmission during unidirectional operation.

[0005] The tooth profile of the aforementioned external gear is divided into five segments: circular arc A1B1, circular arc B1C1, straight line segment C1D1, circular arc D1E1, and circular arc E1F1. These segments have their beginning and end points coincide and are smoothly connected. Their connection points satisfy geometric first-order continuity and share a common tangent. The tooth profiles involved in meshing are: circular arc B1C1, straight line segment C1D1, and circular arc D1E1. The end point of circular arc B1C1 coincides with the beginning point of straight line segment C1D1, i.e., they coincide at point C1. They satisfy geometric first-order continuity at point C1 and share a common tangent. The end point of straight line segment C1D1 coincides with the beginning point of circular arc D1E1, i.e., they coincide at point D1. They satisfy geometric first-order continuity at point D1 and share a common tangent. Circular arc A1B1 is the root arc, serving as a transitional connection between the root of one side of the tooth profile of two adjacent teeth. Arc E1F1 is the tooth tip arc, serving as a transitional connection between the top edges of the tooth profiles on both sides of the same gear tooth. The entire profile has no inflection points or sharp angles. This design offers several technical advantages: First, it effectively ensures the sealing of the gear meshing. Second, the meshing process helps form a fluid lubricating oil film, reducing the risk of tooth surface wear. Third, it eliminates stress concentration at the tooth root, greatly improving load adaptability. The tooth profile segments of the working tooth profile of the internal gear ring include: the conjugate envelope curve B2C2 formed by the meshing motion of arc B1C1, the conjugate envelope curve C2D2 formed by the meshing motion of straight line segment C1D1, and the conjugate envelope curve D2E2 formed by the meshing motion of arc D1E1. A2B2, B2C2, C2D2, D2E2, and E2F2 are connected sequentially with their beginning and end points overlapping, exhibiting geometric first-order continuity at the connection points. The external gear is located in the inner cavity of the internal gear ring. The two are eccentrically meshed and paired to form a continuous conjugate internal meshing gear pair consisting of circular arcs and straight lines.

[0006] The tooth profile segments of the aforementioned external gear involved in meshing can also include: circular arc B1C1, straight line segment C1D1, circular arc D1E1, and circular arc E1F1. The endpoint of circular arc B1C1 coincides with the starting point of straight line segment C1D1, i.e., they coincide at point C1. They satisfy geometric first-order continuity at point C1 and share a common tangent. The endpoint of straight line segment C1D1 coincides with the starting point of circular arc D1E1, i.e., they coincide at point D1. They satisfy geometric first-order continuity at point D1 and share a common tangent. The endpoint of circular arc D1E1 coincides with the starting point of circular arc E1F1, i.e., they coincide at point E1. They satisfy geometric first-order continuity at point E1 and share a common tangent. The tooth profile segments of the working tooth profile of the mating internal gear ring include: the conjugate envelope curve B2C2 formed by the meshing motion of circular arc B1C1, the conjugate envelope curve C2D2 formed by the meshing motion of straight line segment C1D1, the conjugate envelope curve D2E2 formed by the meshing motion of circular arc D1E1, and the conjugate envelope curve E2F2 formed by the meshing motion of circular arc E1F1. A2B2, B2C2, C2D2, D2E2, and E2F2 have their beginning and end points coincide and are smoothly connected, and are also geometrically continuous at the connecting end points.

[0007] The tooth profile segments of the aforementioned external gear involved in meshing may further include: circular arc A1B1, circular arc B1C1, straight line segment C1D1, circular arc D1E1, and circular arc E1F1. The endpoint of circular arc A1B1 coincides with the starting point of straight line segment B1C1, i.e., they coincide at point B1. They satisfy geometric first-order continuity at point B1 and share a common tangent. The endpoint of circular arc B1C1 coincides with the starting point of straight line segment C1D1, i.e., they coincide at point C1. They satisfy geometric first-order continuity at point C1 and share a common tangent. The endpoint of straight line segment C1D1 coincides with the starting point of circular arc D1E1, i.e., they coincide at point D1. They satisfy geometric first-order continuity at point D1 and share a common tangent. The endpoint of circular arc D1E1 coincides with the starting point of circular arc E1F1, that is, they coincide at point E1. They satisfy geometric first-order continuity at point E1 and have a common tangent at point E1. The tooth profile segments of the working tooth profile of the mating internal gear ring include: the conjugate envelope curve A2B2 formed by the meshing motion of circular arc A1B1, the conjugate envelope curve B2C2 formed by the meshing motion of circular arc B1C1, the conjugate envelope curve C2D2 formed by the meshing motion of straight line segment C1D1, the conjugate envelope curve D2E2 formed by the meshing motion of circular arc D1E1, and the conjugate envelope curve E2F2 formed by the meshing motion of circular arc E1F1. A2B2, B2C2, C2D2, D2E2, and E2F2 have their beginning and end points coincide and are smoothly connected, and are also geometrically first-order continuous at the connecting endpoints.

[0008] The pump body assembly includes a front body, an intermediate body, and a rear body. There may be no intermediate body, or several intermediate bodies. Bearing seat holes are provided in the front body, intermediate body, and rear body. In the absence of an intermediate body, the front body is directly assembled in series with the rear body. The pump body assembly is assembled together via a coaxial series-assembled structure with the drive shaft. The four corner fastening bolts of the pump body are hidden internally and not exposed. The assembled product has a simple and neat overall appearance, with a solid rectangular shape. This structure improves the rigidity of the pump body, suppressing elastic deformation under high pressure. It also helps resist pressure impact and alternating fatigue. These features stabilize the internal clearance, thereby reducing internal leakage. Vibration is also suppressed, enhancing the tolerance to operational faults. The overall thermal stability of this pump body structure is also better, with less thermal expansion deformation due to temperature rise, thus improving the performance and lifespan of the gear pump.

[0009] The aforementioned front body features a pump lug seat on its upper side and flange mating surfaces on both sides. Internally, it includes a liquid suction channel and bearing housing holes. The pump lug seat connects to the motor flange and can be disassembled independently or integrated into the front body as a single unit. The flange mating surfaces connect to external liquid pipeline flanges and have liquid suction ports, enabling seamless connection between the front body and external liquids. The liquid suction channel of the front body adopts a smooth, continuous, and tangential design with no dead angles; that is, the entire channel has a smooth transition surface with G-shaped curves. 1 and higher-order geometrical continuity (G) n (n> or=1), which makes the liquid flow more smoothly and stably, and the stress inside the forebody will be significantly reduced.

[0010] The aforementioned intermediate and rear bodies are provided with a pump chamber and a sealing groove. The pump chamber includes: a gear pair receiving cavity, a crescent-shaped isolation plate, a liquid suction area, a liquid discharge area, and a bearing seat hole. The internal meshing gear pair is installed in the gear pair receiving cavity, and the external gear is circumferentially fixed to the drive shaft via a square key or spline, or it can be designed as an integral gear and shaft structure. A crescent-shaped isolation plate is provided in the crescent-shaped area enclosed by the eccentricity of the external gear tip circle and the internal gear ring tip circle. The crescent-shaped isolation plate includes a concave arc surface, a convex arc surface, and a crescent-shaped end face. The crescent-shaped isolation plate and the internal meshing gear pair are at the same height. Its concave part mates with and is coaxial with the external gear tip circle, and its convex part mates with and is coaxial with the internal gear ring tip circle. The bottom end face of the gear pair fits against the bottom of the gear pair receiving cavity. The function of the crescent-shaped isolation plate is to seal the tooth grooves covered by it by forming a surface contact with the tooth tip in the tip circle area. The axial side of these tooth grooves is sealed by the axial end face of the front or intermediate body. In this way, the internal meshing gear pair and the crescent-shaped isolation plate divide and enclose within the gear pair's receiving cavity to form independent liquid intake and liquid discharge areas.

[0011] The liquid intake channel of the precursor is connected to the liquid intake channel and liquid intake region of the intermediate or subsequent body. The liquid discharge region and liquid discharge channel of the intermediate body are connected to the liquid intake channel and liquid intake region of the subsequent body, and the liquid discharge region of the subsequent body is connected to the liquid discharge channel of the subsequent body. Here, the intermediate body plays a role in the initial compression of the liquid, which is then further compressed by the subsequent body. The intake and discharge channels of the intermediate and subsequent bodies are designed to be smooth, continuous, and without dead angles, with the entire intake and discharge channels having a smooth transition surface of G. 1 and higher-order geometrical continuity (G) n (n> or=1).

[0012] The pump's function is achieved by external power driving the rotation of the drive shaft.

[0013] The aforementioned support components include a drive shaft and bearings. The drive shaft passes sequentially through the central through-hole of the external gear and the central hole of the bearing. The bearing is assembled and positioned in the bearing housing hole, and the bearing provides rotational support to the drive shaft through the bearing housing hole. The rotation of the drive shaft drives the gear pair to rotate in the same direction, causing the volume of the liquid suction area and the liquid discharge area to change periodically, thereby realizing the pump's function of suction and discharge of liquid.

[0014] The aforementioned sealing components include: a skeleton oil seal and an O-ring. The function of the skeleton oil seal is to prevent oil leakage from the shaft. The function of the O-ring is to provide a static seal at the mating parts of the front body and the intermediate body, the intermediate body and the rear body, the front cover and the front body, the rear body and the rear cover, or the front body and the rear body.

[0015] After conducting comparative experiments in multiple batches and scenarios, the following results were obtained: The above-mentioned circular arc and straight line segmented continuous conjugate internal meshing gear pairs have extremely small oil trapping capacity due to the meshing and closure of the tooth profile. They will not experience the sudden rise and fall of oil pressure, cavitation, vibration and other working conditions caused by oil trapping in involute gears, and will almost eliminate the oil trapping phenomenon. The aforementioned segmented continuous conjugate internal gear pumps with circular arcs and straight lines exhibit low meshing impact vibration and low vibration amplitude. The aforementioned segmented continuous conjugate internal gear pumps with circular arc and straight line configurations exhibit good low-speed stability and do not produce severe noise, cavitation, or whistling at high speeds. The above-mentioned segmented continuous conjugate internal gear pump with circular arc and straight line will have extremely stable liquid output, very low pulsation, and valves and oil pipes will not easily resonate and loosen. The above-mentioned segmented continuous conjugate internal gear pumps with circular arcs and straight lines exhibit a performance degradation rate far lower than that of conventional gear pumps during long-term durability testing. They are durable and do not easily wear out under high-temperature hydraulic oil conditions, resulting in minimal internal leakage. The aforementioned segmented continuous conjugate internal gear pumps with circular arc and straight lines have a higher tolerance for impurities in hydraulic oil, thus exhibiting better anti-fouling performance, making them more suitable for ordinary industrial hydraulic oil conditions, and lowering the maintenance threshold. The aforementioned segmented continuous conjugate internal gear pumps with circular arc and straight line configurations offer smooth pressure relief without drastic volume changes and stable pressure holding, making them suitable for injection molding machines and precision machine tools that require continuous pressure stabilization. The servo system also consumes less energy. The above-mentioned segmented continuous conjugate internal gear pumps with circular arc and straight line sections have a uniform inter-tooth volume change pattern and good flow consistency at high and low speeds. The aforementioned segmented continuous conjugate internal gear pumps with circular arcs and straight lines have superior load-bearing capacity. The above-mentioned segmented continuous conjugate internal gear pump with circular arc and straight line has better radial force balance of the gears, which will reduce the bearing load and make the bearing less prone to damage under high pressure; The above-mentioned circular arc and straight line segmented continuous conjugate internal meshing gear pumps have a compact structure and lighter weight, making them very suitable for installation in machine tools and equipment in confined spaces. The gear pairs of the above-mentioned arc and straight segmented continuous conjugate internal meshing gear pumps can form a stable dynamic pressure oil film, resulting in low friction loss, lower heat generation, and less oil temperature exceeding the standard during long-term continuous operation. This reduces problems such as oil aging and seal failure, and also extends the life of the gear pairs. The above-mentioned circular arc and straight line segmented continuous conjugate internal gear pumps are well-suited for lubricating oil, ordinary hydraulic oil and some low-temperature media, and are applicable to machine tools, rubber and plastic machinery, engineering machinery and automated production lines; In summary, this segmented continuous conjugate internal gear pump with circular arc and straight line configurations exhibits excellent performance in reducing operating noise, enhancing anti-pollution capabilities, and improving low-speed operation stability. Attached Figure Description

[0016] Figure 1 This is a front view of the external gear in an embodiment of the present invention; Figure 2 This is a partial enlarged view of the external gear tooth profile in an embodiment of the present invention; Figure 3 This is an enlarged view of the circular arcs A1B1 and B1C1 of the external gear in an embodiment of the present invention; Figure 4 This is an enlarged view of the circular arcs D1E1 and E1F1 of the external gear in an embodiment of the present invention; Figure 5 This is a front view of the internal gear ring according to an embodiment of the present invention; Figure 6 This is a partial enlarged view of the tooth profile of the internal gear ring in an embodiment of the present invention; Figure 7 This is an enlarged view of the partial tooth profile segments A2B2 and B2C2 of the internal gear ring in an embodiment of the present invention; Figure 8 This is an enlarged view of the partial tooth profile segments D2E2 and E2F2 of the internal gear ring in an embodiment of the present invention; Figure 9This is a perspective view of the internal gear pump according to an embodiment of the present invention; Figure 10 This is a structural diagram of the internal structure of the internal meshing gear pump cavity according to an embodiment of the present invention; Figure 11 This is a front view of the front pump lug of an embodiment of the present invention; Figure 12 This is a rear view of the front body of an embodiment of the present invention; Figure 13 This is an assembly drawing of the internal meshing gear pair according to an embodiment of the present invention; Figure 14 This is a front view of the intermediate pump chamber structure in an embodiment of the present invention; Figure 15 This is a front view of the rear pump chamber structure according to an embodiment of the present invention; Figure 16 This is a rear view of the rear body of an embodiment of the present invention; Figure 17 This is an integral drawing of the gear shaft according to an embodiment of the present invention. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments: like Figure 1 , Figure 5 , Figure 9 , Figure 10 , Figure 13 As shown, the circular arc and straight line segmented continuous conjugate internal meshing gear pump includes a circular arc and straight line segmented continuous conjugate internal meshing gear pair, a pump body assembly, a support assembly, and seals. The circular arc and straight line segmented continuous conjugate internal meshing gear pair consists of an external gear 1 and an internal gear ring 2. The external gear 1 has a number of teeth evenly arranged circumferentially, and all teeth have completely identical tooth profiles. The internal gear ring 2 has a number of internal teeth evenly arranged circumferentially, and all internal teeth have completely identical tooth profiles. Each tooth of the external gear 1 and the internal gear ring 2 has a single-sided tooth profile that is symmetrical on both sides, with one side being the meshing working side. The "meshing working side" refers to the side of the tooth profile where the teeth are in close contact during gear pair operation, transmitting rotational loads and compressing the fluid medium. This side can change its geometric orientation as the gear rotates or changes direction, based on the actual meshing force transmission tooth surface. The other side of the gear is the non-working side tooth profile, which does not participate in meshing force transmission during unidirectional operation.

[0018] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8As shown, the teeth of the external gear 1 consist of five segments: a root arc, a tip arc, and a single-sided profile. These five profile segments include arcs A1B1, B1C1, C1D1, D1E1, and E1F1. Their beginning and end points coincide and are smoothly connected, satisfying first-order geometric continuity at each connection point, and sharing a common tangent. Specifically, they smoothly connect at points B1, C1, D1, and E1, satisfying first-order geometric continuity at each connection point, and sharing a common tangent at each connection point. The profiles involved in meshing are: arc B1C1, straight segment C1D1, and arc D1E1. The end point of arc B1C1 coincides with the starting point of straight segment C1D1, meaning they coincide at point C1. They satisfy first-order geometric continuity at point C1 and share a common tangent at point C1. The endpoint of straight line segment C1D1 coincides with the starting point of circular arc D1E1, that is, they coincide at point D1. They satisfy geometric first-order continuity at point D1 and have a common tangent at point D1. Circular arc A1B1 is the root arc, which is the transition connecting the root of the two single-sided tooth profiles of two adjacent teeth. Circular arc E1F1 is the tip arc, which is the transition connecting the tops of the two single-sided tooth profiles of the same tooth. The entire contour line has no inflection points and no sharp angles. This design has many technical advantages: First, it effectively ensures the sealing of gear meshing. Second, it helps to form a fluid lubricating oil film during meshing, reducing the risk of surface wear. Third, it eliminates the stress concentration problem at the tooth root, greatly improving the load adaptability. The working tooth profile of the internal gear ring includes: a conjugate envelope curve B2C2 formed by the meshing motion of circular arc B1C1, a conjugate envelope curve C2D2 formed by the meshing motion of straight line segment C1D1, and a conjugate envelope curve D2E2 formed by the meshing motion of circular arc D1E1. A2B2, B2C2, C2D2, D2E2, and E2F2 are connected with their end points overlapping sequentially. The external gear is eccentrically located within the internal gear ring cavity, and the two mesh together to form a continuous conjugate internal meshing gear pair consisting of circular arcs and straight lines. For example... Figure 1 , Figure 2 As shown, the circular arc B1C1, straight line segment C1D1, and circular arc D1E1 of the tooth profile of external gear 1 are symmetrical on both sides. Circular arc A1B1 is the root circular arc, and circular arc E1F1 is the tip circular arc.

[0019] like Figure 9 , Figure 10As shown, the pump body assembly includes a front body 14, an intermediate body 15, and a rear body 16. There may be no intermediate body 15, or there may be several. Without an intermediate body 15, the front body 14 and the rear body 16 are directly assembled in series. The pump body assembly is assembled together via a coaxial series-assembled structure using a drive shaft 5. The four corner fastening bolts 28 are hidden internally and not exposed. Bearing seat holes are provided in the front body 14, intermediate body 15, and rear body 16. The front body 14 has a pump ear seat 11 and a flange mating surface 9 on its exterior, and a liquid suction channel 27 and bearing seat holes 24 internally. The pump ear seat 11 is used to connect to the motor flange; it can be disassembled independently or integrated into the front body as a single structure. The flange mating surface 9 is used to connect to an external liquid pipeline flange, and a liquid suction port 10 is provided at its center to connect the front body suction channel to the external liquid pipeline. The liquid intake channel 27 of the precursor 14 adopts a smooth, continuous, and tangential design without dead angles, meaning that the entire channel has a smooth transition surface of G. 1 and higher-order geometrical continuity (G) n (n> or=1), this design makes the liquid flow smoother and more stable, and the stress inside the forebody is also significantly reduced.

[0020] like Figure 10 , Figure 12 , Figure 14 , Figure 15 As shown, the intermediate body 15 has a pump chamber and a sealing groove 4, which includes: a gear pair receiving cavity 21, a crescent-shaped isolation plate 3, a liquid suction area 25, a liquid discharge area 26, a sealing groove 4, and a bearing seat hole 24, etc. The rear body 16 has a pump chamber, which includes: a gear pair receiving cavity 21, a crescent-shaped isolation plate 3, a liquid suction area 22, a liquid discharge area 23, a sealing groove 4, and a bearing seat hole 24, etc. The internal meshing gear pair is installed in the gear pair receiving cavity, and the external gear 1 is circumferentially fixed to the drive shaft 5 by a square key 27 or a spline. It can also be designed as an integral gear and shaft structure, such as... Figure 17As shown, a crescent-shaped isolation plate 3 is provided in the crescent-shaped area enclosed by the eccentricity of the addendum circles of the external gear and the internal gear ring. The crescent-shaped isolation plate 3 includes a concave arc surface, a convex arc surface, and a crescent-shaped end face. The height of the crescent-shaped isolation plate 3 is the same as that of the internal meshing gear pair. Its concave part mates with and is coaxial with the addendum circle of the external gear, and its convex part mates with and is coaxial with the addendum circle of the internal gear ring. The bottom end face of the gear pair is in contact with the bottom of the gear pair receiving cavity. The function of the crescent-shaped isolation plate 3 is to seal the tooth grooves covered by it by forming a surface contact with the tooth tip in the addendum circle area. The axial side of these tooth grooves is sealed by the axial end face of the front body 14 or the intermediate body 15. In this way, the internal meshing gear pair and the crescent-shaped isolation plate 3 divide and enclose the gear pair receiving cavity to form an independent liquid suction area 22 and a liquid discharge area 26. The liquid suction channel of the front body 14 is connected to the liquid suction channel and liquid suction area of ​​the intermediate body or the rear body. The liquid extrusion region 26 and liquid extrusion channel of intermediate body 15 are connected to the liquid intake channel and liquid intake region 22 of rear body 16. The liquid extrusion region 23 of rear body 16 is connected to the liquid extrusion channel 18 of rear body 16. Here, the internal meshing gear pair in the gear pair receiving cavity of intermediate body 15 plays the role of initial compression of liquid, and then further compression is achieved through the internal meshing gear pair in the gear pair receiving cavity of rear body 16. The intake channel and extrusion channel of intermediate body 15 and rear body 16 adopt a smooth, continuous, and tangential design without dead angles. The smooth transition surface of the entire intake and extrusion channel is G. 1 and higher-order geometrical continuity (G) n (n> or=1).

[0021] like Figure 10 , Figure 13 As shown, the aforementioned support assembly includes a drive shaft 5 and bearings 6. The bearings are placed in bearing housing holes 24 in the front, intermediate, and rear bodies, and the bearings 6 provide rotational support to the drive shaft 5 through the bearing housing holes 24. A through hole is opened in the center of the external gear 1. The drive shaft 5 sequentially passes through the bearing hole in the front body 14, the center hole of the external gear 1, the bearing hole in the intermediate body 15, the center hole of the external gear 1, and the center hole of the bearing in the rear body 16. When the pump is working, external power drives the drive shaft 5 to rotate. The drive shaft 5 drives the external gear 1 to rotate synchronously via a flat key 27 or a spline. The external gear 1 relies on the tooth profile formed by arcs A1B1, B1C1, straight segment C1D1, arc D1E1, and arc E1F1 to interact with the tooth profile segments A2B2, B2C2, C2D2, and D2E on the internal gear ring. 2、 The tooth profiles formed by E2F2 mesh and rotate in the same direction. Here, the external gear 1 and the drive shaft 5 can be a separate, detachable structure, facilitating individual gear removal and replacement without replacing the entire drive shaft. Alternatively, it can be designed as a gear-shaft structure where the gear and shaft are integrated, such as... Figure 17As shown, both types can engage normally. When the drive shaft rotates, the volumes of the liquid suction area and the liquid discharge area change periodically, thereby realizing the pump's function of suction and discharge of liquid.

[0022] like Figure 10 As shown, the sealing assembly includes a skeleton oil seal and an O-ring. The skeleton oil seal is placed at position 7 of the front cover, and its function is to prevent oil leakage from the shaft and to prevent external dust, water, mud, and other impurities from intruding and causing wear and damage to the shaft surface and bearings. The O-ring is placed in the groove at the joint between the front and middle bodies, the joint between the middle and rear bodies, the joint between the front cover and the front body, the joint between the rear body and the rear cover, or the joint between the front and rear bodies, and its function is to provide a static seal for pressurized liquids.

[0023] like Figure 9 As shown, the concave portion 13 of the curved surface of the front body 14 is shaped like a shell cut. This treatment facilitates the installation and removal of the bolts in the lug holes 12 of the pump ear seat 11, while maximizing the thickness and rigidity of the front body. The lug holes 12 of the pump ear seat 11 of the front body 14 are elliptical, racetrack-shaped, capsule-shaped, or mathematically termed rounded rectangles or ovals, etc., shapes that differ from perfect circles. This design facilitates the insertion and positioning of the screws, ensures the mechanical strength of this area, and the ample space in the screw holes makes it easier to screw the oil pump fastening screws onto the flange.

[0024] The illustrations in this embodiment only provide a set of tooth profiles and tooth ratios for adapting to arc and straight segmented continuous internal meshing gear pumps as a reference. Specific gear parameters, tooth ratios, eccentricity, etc., should be adjusted according to the application scenario and working conditions. As long as the tooth profile combination described in the independent claims is used, the effects of anti-fouling, high speed, low loss, high load capacity, and ultra-quiet operation can be achieved.

Claims

1. A segmented continuous conjugate internal gear pump with circular arc and straight line configurations, comprising: The core components include a circular arc and a straight-line segmented continuous internal meshing gear pair, a pump body assembly, and a support assembly. The pump body assembly includes a front body, a middle body, a rear body, and seals. The support assembly includes a drive shaft and bearings. The circular arc and straight-line segmented continuous conjugate internal meshing gear pair includes an external gear and an internal gear ring. Both the external gear and the internal gear ring have a number of teeth evenly arranged circumferentially, and all teeth have completely identical tooth profiles. Each tooth of the external gear and the internal gear ring has a single tooth profile on both the left and right sides. The external gear tooth tip arc is the transition connecting arc E1F1 between the tops of the single tooth profiles on the left and right sides of the same tooth. The external gear tooth root arc is the transition connecting arc A1B1 between the roots of the single tooth profiles on the left and right sides of two adjacent teeth. The meshing working side tooth profile of the external gear is formed by the smooth connection of the first and last endpoints of circular arc B1C1, straight line segment C1D1, and circular arc D1E1. Adjacent tooth profile segments on the working side tooth profile satisfy geometric first-order continuity at the connection position and have a common tangent at the connection position. The tooth profile of the internal gear ring is the conjugate envelope curve formed by the meshing motion of the tooth profile segments of the external gear. The external gear is located inside the internal gear ring, and the two are eccentrically meshed to form a continuous conjugate internal meshing gear pair consisting of circular arcs and straight lines. The external gear is circumferentially fixed to the drive shaft and drives the internal gear ring to rotate in the same direction through tooth profile meshing. The pump body assembly includes a front body, an intermediate body, and a rear body. There may be several intermediate bodies, or none. In the case of no intermediate bodies, the front body and the rear body are directly assembled in series. The pump lug hole of the front body is elliptical, racetrack-shaped, capsule-shaped, or mathematically termed rounded rectangle or oval, etc., which are different from a perfect circle. The pump body components are assembled together via a coaxial series stacked structure using the drive shaft. The four corner fastening bolts of the pump body are hidden internally and not exposed. After assembly, the overall structure is solid and rectangular. The liquid suction and liquid discharge channels of the pump body adopt a smooth, continuous, and tangential design without dead angles. The entire channel has a smooth transition surface with G-shaped curves. 1 and higher-order geometrical continuity (G) n (n> or=1). The intermediate and rear bodies are provided with a pump chamber and a sealing groove. The pump chamber includes: a gear pair receiving cavity, a crescent-shaped isolation plate, a liquid suction area, a liquid discharge area, and a bearing seat hole, etc. The internal meshing gear pair is installed in the gear pair receiving cavity. The crescent-shaped area enclosed by the addendum circles of the external gear and the internal gear ring due to eccentricity is provided with a crescent-shaped isolation plate. The function of the crescent-shaped isolation plate is to seal the tooth grooves covered by it by forming a surface contact with the tooth tip in the addendum circle area. The axial side of these tooth grooves is sealed by the axial end face of the front or intermediate body. The pump function is realized by external power driving the rotation of the drive shaft.

2. The external gear as described in claim 1, wherein the left and right endpoints of its root arc coincide with the starting points of the arc tooth profile segments on its left and right sides. For example, one endpoint B1 of the root arc A1B1 coincides with the starting point of the arc tooth profile segment B1C1 on its left and right sides, that is, they coincide at point B1. They satisfy geometric first-order continuity at point B1 and have a common tangent at point B1. The other endpoint A1 is similar.

3. The external gear as described in claim 1, wherein the tooth profile section participating in the meshing operation comprises: The external gear consists of circular arc B1C1, straight line segment C1D1, and circular arc D1E1. The endpoint of circular arc B1C1 coincides with the starting point of straight line segment C1D1, i.e., they coincide at point C1. They satisfy geometric first-order continuity at point C1 and have a common tangent at point C1. Similarly, the endpoint of straight line segment C1D1 coincides with the starting point of circular arc D1E1, i.e., they coincide at point D1. They satisfy geometric first-order continuity at point D1 and have a common tangent at point D1. The circular arc B1C1, straight line segment C1D1, and circular arc D1E1 in the tooth profile segments of a single tooth of the external gear are symmetrical on both sides. The working tooth profile segments of the internal gear ring include: the conjugate envelope curve B2C2 formed by the meshing motion of circular arc B1C1, the conjugate envelope curve C2D2 formed by the meshing motion of straight line segment C1D1, and the conjugate envelope curve D2E2 formed by the meshing motion of circular arc D1E1. A2B2, B2C2, C2D2, D2E2, and E2F2 are connected with their first and last endpoints overlapping, and are also geometrically first-order continuous at the connecting endpoints.

4. The external gear as described in claim 1, wherein the tooth profile section participating in the meshing operation may also include: The external gear consists of circular arc B1C1, straight line segment C1D1, circular arc D1E1, and circular arc E1F1. The endpoint of circular arc B1C1 coincides with the starting point of straight line segment C1D1 (i.e., they coincide at point C1), satisfying first-order geometric continuity at point C1 and sharing a common tangent. The endpoint of straight line segment C1D1 coincides with the starting point of the third circular arc D1E1 (i.e., they coincide at point D1), satisfying first-order geometric continuity at point D1 and sharing a common tangent. The endpoint of circular arc D1E1 coincides with the starting point of circular arc E1F1 (i.e., they coincide at point E1), satisfying first-order geometric continuity at point E1 and sharing a common tangent. The circular arcs B1C1, C1D1, and D1E1 in the tooth profile segments of a single tooth of the external gear are symmetrical on both sides. The working tooth profile of the internal gear ring includes: the conjugate envelope curve B2C2 formed by the meshing motion of circular arc B1C1, the conjugate envelope curve C2D2 formed by the meshing motion of straight line segment C1D1, the conjugate envelope curve D2E2 formed by the meshing motion of circular arc D1E1, and the conjugate envelope curve E2F2 formed by the meshing motion of circular arc E1F1. A2B2, B2C2, C2D2, D2E2, and E2F2 have their beginning and end points coincide and are smoothly connected, and are also geometrically first-order continuous at the connecting endpoints.

5. The external gear as described in claim 1, wherein the tooth profile section participating in the meshing operation may further include: Consider circular arcs A1B1, B1C1, line segment C1D1, D1E1, and E1F1. The endpoint of arc A1B1 coincides with the starting point of line segment B1C1 (i.e., they coincide at point B1). They are geometrically continuous at point B1 and share a common tangent. Similarly, the endpoint of arc B1C1 coincides with the starting point of line segment C1D1 (i.e., they coincide at point C1). They are geometrically continuous at point C1 and share a common tangent. Likewise, the endpoint of line segment C1D1 coincides with the starting point of arc D1E1 (i.e., they coincide at point D1). They are geometrically continuous at point D1 and share a common tangent. Finally, the endpoint of arc D1E1 coincides with the starting point of arc E1F1 (i.e., they coincide at point E1). They are geometrically continuous at point E1 and share a common tangent. The circular arc B1C1, straight line segment C1D1, and circular arc D1E1 in the tooth profile segments of a single tooth of the external gear are symmetrical on both sides. The tooth profile segments of the working tooth profile of the internal gear ring include: the conjugate envelope curve A2B2 formed by the meshing motion of circular arc A1B1, the conjugate envelope curve B2C2 formed by the meshing motion of circular arc B1C1, the conjugate envelope curve C2D2 formed by the meshing motion of straight line segment C1D1, the conjugate envelope curve D2E2 formed by the meshing motion of circular arc D1E1, and the conjugate envelope curve E2F2 formed by the meshing motion of circular arc E1F1. A2B2, B2C2, C2D2, D2E2, and E2F2 have their beginning and end points coincide and are smoothly connected, and are also geometrically continuous at the connecting end points.

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