truninger hydraulic pump manufacturer

Amin corporation is established in 1992 and are engaged in supply of all kinds of NEW and USED marine machinery, equipments and spares removed from largest ship recycling yard of the WORLD ALANG.We supply engine spares, hydraulic motors & pumps, auxiliary machinery & equipments, deck machinery and equipment, deck crane and winches, refrigeration machineries and equipments, steering gear equipments and all miscellaneous items available from the ALANG ship recycling yard.

Since 1935, Muncie® Power Products has been a leading source of mobile power components to the truck equipment industry. In addition to Power Take-Offs and hydraulic motors, Muncie offers directional, pressure and flow control valves as well as system design capabilities. Call us today or visit our website for more information.

FluiDyne is an ISO certified manufacturer of hydraulic pumps, motors & valves. Our promise is to serve and respect the rebuilders and resellers of North America and the global market with high quality new and remanufactured pumps, motors, valves, filters and filter elements.

Having innovative solutions for mission-critical applications makes Hydraulics Technology the preferred. For over 25 years, our impressive list of hydraulic pumps has met the needs of various applications. In assuring the highest quality products to our customers and meeting their expectations, Hydraulics Technology maintains ISO Certification. HTI is ISO 9001:2008 Certified.

Industrial Flow Solutions is a trusted manufacturer of hydraulic pumps and centrifugal pumps. We pride ourselves on our high-quality products and personalized customer service. Various industries we serve include industrial, food & beverage, and medical. All of our products are tested to ensure quality and durability.

AeroControlex began manufacturing pumps in Cleveland, Ohio in 1945. Over the years, AeroControlex has established itself as an industry leader in the production of hydraulic, fuel, lube and scavenge, centrifugal and coolant pumps. Our worldwide customer base demands the highest quality, cost effective products for the most demanding commercial and military applications.

All World Machinery Supply offers high-quality, affordable pumps, motors, and power units from reputable brands like Daikin, Nachi, Eaton, Tokimec, NOP, Grundfos, Yuken, and Fuji . Our team of representatives and engineers can find or cross any pump/mortor to what you are looking for. We can even help you design a custom application suited to your fit your needs.

American Eagle Accessories Group is a manufacturer of truck equipment accessories. These products include: hydraulic-driven air compressors, drawer systems (tool storage), bolt bins (fastener and fitting storage), lube skids, lube trailers, fuel trailers, and utility construction trailers. All of our products are designed and manufactured in the U.S.A.

Founded in 1991, AZ Hydraulic Engineering manufactures high quality air-operated hydraulic pumps serving a broad clientele. We offer hydraulic piston pumps, power units, tank pumps and more with 25 different pressure ranges up to 50,000PSI and a proven track record for reliability and easy, low cost maintenance. AZ Hydraulics is the source for quality hydraulic pumps and friendly customer service.

Barbee Engineered Testing Systems is a manufacturer of hydraulic power units, hydraulic valve testers, air-driven hydraulic piston pumps, high pressure pumps, hydraulic power systems, high pressure systems and more. Our hydraulic pumps are available with up to 30,000 PSI. Check out our website.

Berendsen Fluid Power is one of the largest distributors of pneumatic and hydraulic products in North America. We distribute from quality manufacturers products such as hydraulic pumps, hydraulic motors, hydraulic gear pumps, mixer pumps and more. Visit our website for more information.

Bosch Rexroth is a global leader in manufacturing industrial hydraulics, including proportional and servo valves. Directional control, high response, flow control, pressure relief, pressure reducing, and servo valves name some of our products. Our rugged valves are a perfect fit your electrohydraulic control applications. A variety of models are available for your viewing on our website.

Brand Hydraulics is a leading designer and manufacturer of high-quality hydraulic valves including hydraulic directional control valves, hydraulic flow control valves, hydraulic relief valves, hydraulic selector valves, shuttle valves, pilot check valves, flow dividers and more. Brand also has a line of quality hand-operated hydraulic pumps. Premium hydraulics since 1956.

For 40 years, Bucher Hydraulics, Inc. has specialized in hydraulic systems, including products such as hydraulic motors and hydraulic power units. Applications include concrete pumps, forage wagons, harvesters, lifting devices, recycling machines, door openers, log splitters and many others.

A Cascon hydraulic pump is used in a wide range of OEM equipment market applications. Whether you"re in the aircraft & aerospace, chemical, gas turbine or industrial or mobile markets, our hydraulic pumps and specialty pumps will meet your requirements and provide solutions that an off-the-shelf pump cannot. Contact Cascon, Inc. today for more information!

CAT PUMPS specializes in high pressure pumps, reciprocating pumps, positive displacement pumps, plunger-piston pumps and we also manufacture hydraulic pumps and hydraulic power units. We are an industry-leader in customer service and quality triplex pump design and products.

CLYDEUNION Pumps is one of the world"s leading pump companies - a centre of excellence in Pump Technology, Hydraulic Design and Engineering. We are structured to provide a specific focus on each of our customer"s key markets as well as providing full global aftermarket support. CLYDEUNION Pumps incorporates an accumulation of over 300 years of engineering expertise.

We have over 55 years of experience in manufacturing hydraulic components. CROSS Manufacturing, Inc. distributes hydraulic filters, hydraulic cylinders, hydraulic gear pumps and hydraulic systems worldwide. Our hydraulic systems are used for automotive, agricultural, mining and construction purposes.

D&D Machine & Hydraulics Inc, located in Fort Myers, Florida, is a manufacturer of hydraulically driven, submersible pumping systems that serves the Agricultural, Construction, Industrial, Mining, Petroleum and Municipal markets worldwide. More than 45 years ago, D&D realized the unlimited potential of hydraulics. Since then, D&D has revolutionized the dewatering industry with a series of hydraulically driven pumps that provide the most technologically advanced and precisely engineered features available today. Specifically, D&D builds electric or diesel-driven Power Units and Axial Flow, Trash, Sludge, Slurry/Digester and Mixed Flow pump heads. The flow capacity of these pump heads range from 450gpm to 55,000gpm and heads of 250 feet are attainable. If a standard pump will not meet the performance needed for a special application, D&D’s wide range of specialty pumps can meet your individual requirement.

When the owners acquired D&D, it was a four-employee, custom machine shop that repaired pumps used by local farmers. Shortly thereafter, D&D began to manufacture hydraulic pumps for a local sales and rental company. In the 1980s, as the business grew, D&D began to sell to other customers throughout the country, eventually achieving global recognition.

Danfoss will drive your vehicle transmission to a new level of performance with our Danfoss piston pumps and motors. Designed for intelligent vehicle management systems, our range brings you closer to your goals for reduced fuel consumption and high operator comfort. We deliver components and systems for machine from 15 to 2500 horsepower.

We create hydraulic pumps that can be utilized for standard and specialized purposes. Our high pressure pumps can handle pressures from 3,000 to 15,000 psi with flows of 200 gpm. Our systems can also perform with various fluids including mineral-oils, low-lubricity fire-resistant fluids. We are dedicated to developing the most reliable hydraulic pumps!

Eaton Hydraulics designs, manufactures and markets a comprehensive line of reliable, efficient hydraulic systems and components including hydraulic motors, hydraulic power units and other hydraulic systems. We serve various markets and applications with our quality systems and accessories.

We offer and repair hydraulic pumps and hydraulic motors. As one of the biggest suppliers of hydraulic power units (original or replacement) and a worldwide distributor, we can ship anywhere in the world immediately. Our inventory of motors is immense and our sales staff has years of experience.

Welcome to the Florida Hydraulic Industrial web site. Browse our categories for hydraulic pumps, hydraulic cylinders, hydraulic and industrial hose, including a wide variety of pressure washer hose, all common hydraulic hose fittings.

Flowserve® is the world leading manufacturer of quality hydraulic pumps — air piston pumps, hydraulic water pumps, vane pumps, entire hydraulic systems, plus valve repair. Our products are used by many industries — chemical; hydrocarbon processing; oil and gas; power; water resources.

Fluid Power International provides expertise in hydraulic pump repair & replacement. We specialize in repairing & replacing metric pumps & motors for Japanese and German heavy machinery as well as hydraulic components for excavators. We will tear down and inspect your part with no obligation.

Established in 1978, Gator Pump manufactures high volume pumps for irrigation, flood control, liquid waste pumping and many other applications. Steel fabricated hydraulic pumps are offered in several different sizes and configurations including vertical pumps, floating pumps and trailer pumps as well as custom pumps operated on electric, diesel or hydraulics to suit clients" needs. Call us today!

We provide a number of different styles of air driven high pressure hydraulic pumps ranging from 100 PSI to 60,000 PSI. Here at High Pressure Technologies, LLC we take customer satisfaction very seriously which is why we can customize our products to match your requirements. It is our goal to exceed your expectations. Please visit our website or give us a call today to learn more information!

We started developing hydraulic drive submersible pumps in 1977. We can provide you with a hydraulic pump, hydraulic gear pump and hydraulic power unit to match. If a standard system doesn"t meet your needs, we can custom design one for you. We make our models in a variety of materials.

Since our beginning in 1947, Hydraulic Supply Company (HSC) has been dedicated to fulfilling customers’ needs. We are a full service distributor of fluid power products and services. We carry a selection of over 20,000 hydraulic, pneumatic and industrial products in stock from the most recognized brands in the industry. Our goal is to provide customers with a large selection of hydraulic, pneumatic and industrial products with the best professional services, right when you need them.

Made-to-order & made-to-last custom hydraulic pumps faster than you can expect from other companies. The widest selection of hydraulic gear pumps & piston pumps, plus stock replacement pumps ready for immediate shipment. Brands: Webster, Danfoss, Barnes, Haldex, Cessna, Eaton, Vickers, etc. Hydraulic.Net’s specialization is in short run special application gear pumps with little tooling expense.

Hydraulics International, Inc. (HII), headquartered in Chatsworth, California, U.S.A., is a leading manufacturer and supplier of integrated products, services and support to military forces, aviation and commercial industries, government agencies and prime contractors worldwide. Focused on defense and commercial technology, HII develops manufactures and supports a broad range of products and systems for over a hundred industries as well as mission critical and military sustainment requirements worldwide. HII is also recognized as a leading manufacturer and supplier of air, electric, hydraulic, & manual driven high-pressure products to Automotive, Airline & Aerospace, Cannabis, CNG, Defense, Fire-Health & Safety, Fluid Power, Fuel Cell Hydrogen, General Manufacturing, Laboratory, University & Research, Mining, Oil & Gas, Paintball, Plastics, Power & Energy, Recreational Sports Diving, Electronics and other industries. We produce 85% of our products internally, thus eliminating our dependency upon outside sources for quality, reliability, and expediency. Because of our self-sufficiency, we are able to maintain key competitive advantages that include faster response to engineering and design problems, and reliability of components critical to functionality.

Here at Hydreco we manufacture hydraulic solutions for a number of markets including: agricultural, municipal, construction, mining and transportation. Our company has an extensive history of engineering success. If you are unsure what hydraulic products are best for your task then just let one of our representatives know your application and we can handle the rest!

Over 50 years, Hydro Leduc has developed more than 100 patents because of our passion for innovation in the hydraulics field. We find solutions to our customers’ most complex and demanding applications for piston pumps, hydraulic motors, hydro-pneumatic accumulators and custom hydraulic components.

HYTORC developed the jet series pumps which are portable, heavy duty, light weight, high flow to withstand harsh environments. These air or electric driven Hydraulic Pumps are engineered for continuous, non-stop use in harsh environments. If used on Torque Tools, Jacks, Cutters, Presses or Bending equipment, their reliability is unmatched by any other Hydraulic Power Pack.

We are a distributor of hydraulic and pneumatic products such as hydraulic pumps, filters, motors, valves and more. Our manufacturers make hydraulic gear pumps, piston pumps and hydraulic pumps with aluminum or cast iron casings. We have been in business for 30 years and service all of our products.

Founded in 1971, Interface Devices is a world-class designer and manufacturer of air driven fluid pumps, hydraulic valves and custom engineered fluid power products. IDI proudly designs and manufactures all our products at our Milford, CT facility. As we continue to grow and develop it is our principle aim to provide quality in our designs and manufacturing while responding to customer needs.

Jones Hydraulic Service is a company dedicated to solving the needs of our customers. Jones Hydraulic Service is a leading supplier / vendor too many large and small corporations, and many independent contractors. Our customer service is a top priority. Whether customers are looking to Purchase, Rent or Repair hydraulic tooling or keep their workers safe with High Visibility Apparel or Mosquito Repellent we get the job done. Jones Hydraulic Service is proud to be serving the energy, marine, petrochemical, railroad, construction, foundation repair, pipeline and shipyard industries since 1977. Jones Hydraulic represents some of the world’s leading Hydraulic Tool & Equipment manufacturers that include SPX Power Team, SafeWay Hydraulics, Pell Hydrashear, TORC LLC, Eagle Pro, and more. Offering Hydraulic Tool & Equipment Sales, Service and Repair for 40 years.

Jones Hydraulic listened to its customers needs for industrial supplies and now stocks LED Work Lights, Safety Mats, Hand Held Power Tools, LED Flood Head Lamp, Spill Clean Up Supplies, Water Dams and more. Jones Hydraulic represents the leading industrial supply companies including PowerSmith, Genesis, Spill Tackle, Quick Dams Nite Ize and more.

Jones Hydraulic helps their customer create a safe and healthy work environment by providing safety products that include Personal Protective Equipment, Hi-Vis Clothing, First Aid Supplies, Mosquito and Insect Repellents, Eye Protection and Outdoor Protective Equipment. Jones Hydraulic represents some of the leading safety product manufacturers such as SAS Safety, GSS Safety, Sawyer, Southern Glove and more.

We recently opened a Safety Equipment & Hydraulic Tool Showroom. We welcome you to stop by and see some of the latest product offerings. Our Showroom is located at 5955 Armour Drive, Houston, TX 77020. We are proud of our 40 year history and look forward to serving our customers for many more years to come.

At Linde Hydraulics, we pride ourselves on our designing/manufacturing of high pressure pumps and the Linde Hydraulic Valve. Our hydraulic pumps have been a mainstay since 1970. Our pumps are used in agriculture and defense. A complete hydraulic system can be offered, along with motors that deliver reliable performance.

Our Maximator® air-driven hydraulic pumps deliver from 60 to 60,000 PSI and cycle automatically. The Maximator® pumps are used in our hydraulic power units. We can provide you with standard or customized high pressure pump power systems. Repair and refurnishing services also available.

Since 1941, Metro Hydraulic Jack Co. has been your single source for all your hydraulic needs. We represent a wide variety of material lift and equipment manufacturers and we sell only the best. Our products are designed to help improve the safety of your work environment and increase your productivity. We are proud to provide a wide selection of high-quality hydraulic lifting products to our customers. As a third-generation family-owned business, all of us at Metro Hydraulic Jack Co. pride ourselves on delivering the same high-quality hydraulic products and top-notch customer service as we have always been. Our knowledgeable sales staff are experts at specifying the right equipment to meet our customers’ requirements and needs. Our extensive list of hydraulic lifting products includes aerial lifts , dock lifts , pallet lifts, platform lifts , rotary lifts, scissor lifts, small hydraulic lifts, and hydraulic lift systems. Additionally, we supply cylinders, pumps, valves, hydraulic and air jacks, pullers, punches, lubrication equipment, and more. The manufacturers we represent, including Autoquip, ECOA, Lift Products, Inc., and Lift-rite, are the best in the industry and we are proud to offer their products.

Our engineering services include custom hydraulic and lube system design to meet our customers’ specifications, as well as other specialized services. We are a supplier to numerous industries, including automotive, construction, industrial, material handling, mobile, and railroad. You can find an impressive list of our customers on our website. Call or email us today to learn how we can service your hydraulic needs.

Our Hydraulics Division, headquartered in Greenwood Indiana, is a world-class manufacturer of pumps, valves, flow controls, hydraulic power units and other products. We are known not only for our product excellence but for our competitive pricing and the ready availability of our products when customers need them.

Sales, service and rental for all major brands of hydraulic pumps and other air, electric and hydraulic equipment. Hydraulic pump offerings include hand pumps, air pumps, electric pumps, gas pumps and intensifiers. Highly skilled at matching tool to application for hydraulic pumps and more.

Oilgear heavy-duty axial piston hydraulic pumps are built. Engineered with Oilgear’s advanced “hard-on-hard” rotating group and hydrodynamic bearing support on the cylinder barrel, our pumps provide longer operational life and optimal resistance to contamination. Available in a variety of frame sizes and control options, Oilgear offers just the right pump to fit your demanding needs.

Founded nearly 25 years ago, Panagon Systems has remained a trusted company producing hydraulic parts on demand for a number of shops, manufacturers and industries. The company, located in Macomb, Michigan, is the largest aftermarket hydraulic piston pump and parts manufacturer in North America, providing a vast variety of current and obsolete components. Panagon has the ability to produce a product from raw materials to a finished pump, assembled, tested, painted and shipped from our facility. Due to the phasing out of old products, customers usually find that the parts they need are no longer available, or that the delivery time is too long or the cost is too high. Panagon Systems attempts to fill the void OEM’s create by manufacturing the phased out, expensive, unavailable pumps, motors and transmissions, from companies like Vickers, Denison and Rexroth.

We manufacture hydraulic pumps, motors and parts for a variety of industrial and mobile applications. Our replacements are equivalent to the Eaton/Vickers line of PVH, PVQ, PVB, PVM, PVE, PFB, MFB, MFE, TA19, TA1919, TDV10 and TDV20 series units and Rexroth A10V series units.

In addition to supplying complete replacement piston pumps, Panagon also offers all replacement parts for all series units such as Rotating Groups, Shafts, Compensators, Yokes, Valve Blocks, Housings, Bearings, Seal Kits, Cylinder Blocks, Shoe Plates, Swash Plates, Piston Kits, Wafer Plates, Control Pistons, Control Rods, Bias Pistons, Bias Rods, Spacer Kits, Saddle Bearings, and more.

Parker"s Hydraulic Pump and Power Systems Division provides a broad selection of piston pumps, hydraulic motors and power units that help our customers meet their industrial and mobile application needs.

The Parker Pump & Motor Division specializes in gear pumps and motors used in a myriad of industries. With decades of experience, PMD provides the best products in the market, supplemented by best-in-class customer service, and the deepest knowledge in the industry.

Perfection Hydraulics manufactures, distributes, and services hydraulic cylinders, hydraulic pumps, hydraulic valves, hydraulic gear pumps, and other hydraulic components for heavy equipment. Our products provide you with the best value available for today’s dynamic industry. With our reputation for quality and reliability, you can rely on us for your heavy duty hydraulics needs.

Pierce Sales is a manufacturer and distributor of 12-volt hydraulic pumps, hydraulic hoses, hydraulic fittings, tie-rod cylinders and many more products. We offer professional installation services. We also have spare parts and provide repair services to get your equipment running as soon as possible.

Precision Fluid Power is a distributor of hydraulic pumps, including hydraulic vane pumps, hydraulic piston pumps and hydraulic gear pumps. We provide new hydraulic motors or we rebuild them, as well as hydraulic valves and hydraulic cylinders. We also offer hydraulic pump repair. Call us today.

Robeck Fluid Power is a leading manufacturer of hydraulic pumps and an assortment of lubrication equipment. Our products include aluminum structural framing, automation equipment, electronics, fluid conveyance equipment, hydraulic pumps, lubrication systems, and pneumatic products. We are a fully authorized distributor of Eaton, Charlynn, Hydro-line, Aeroquip, and Vickers products. Visit our website to learn more about our manufacturers or to speak with a sales representative.

Since 1978, we have been offering hydraulic pumps, motors, valves and cylinders with 100 years combined experience. We distribute hydraulic systems, and also do on-site machine shop repair services and rebuilding. Our quality hydraulic power units can be ordered around the clock for your convenience.

SC Hydraulic Engineering has been a leader in the design & manufacture of various air-powered hydraulic pumps, hydraulic piston pumps, hydraulic power units and systems plus hydraulic valves—relief, inline check, high pressure. We also have the ability to customize our products to fit your needs. In business since 1953, we work worldwide through distributors and manufacturers.

Since 1899, SIMPLEX products have been used by industries that need hydraulic and mechanical equipment and solutions. Our continuous duty hydraulic pumps are equipped for up to 5HP, as are our gas, air & electric hydraulic pumps for heavy-duty tooling applications. Our positioning and lifting products turn challenges into progress.

Established in 1979, Southwest Seal and Supply has grown to become one of the most predominant distributors of sealing, hydraulic hoses, fittings, couplings/connectors, gasketing and fluid control products in the Southwest. We offer a wide range of products including the best in selection, quality, and value-added services.

POWER TEAM is a world leader in hydraulic special service tools and equipment for motor vehicle and industrial markets, manufacturingprecision quality high-pressure hydraulic products, which include pumps,cylinders, valves, clamping components, related hydraulic accessoriesand special tools and equipment.

Stone Hydraulic Systems manufactures AC and DC hydraulic power units for a broad range of OEM applications such as auto hoists, dock levelers, hose crimpers, lift tables and compactors to name a few. Stone"s products provide a wide power range up to 5.5 horsepower.

SRS Crisafulli hydraulic-powered pumps handle industrial-strength pumping jobs: trash, mud, waste, raw sewage, sludge. Discharge sizes 2" to 24" and flows to 18,000 GPM. Standard Power Unit models in electric, diesel or gas, 32 to 180 horsepower, outputs from 18 to 119 GPM or custom built to your spec.

Sunfab was founded by Eric Sundin in the year of 1925. Sunfab develops, produces and sells components to operate hydraulic equipment within the area of mobile vehicles. After more than 90 years, the third generation of the Sundins are still running the company in the spirit of Eric Sundin, with a family atmosphere, flexibility and innovative solutions.

TK Trailer Parts is a dedicated manufacturer of high quality products. We are a turnkey supplier of hydraulic cylinders, hydraulic pumps, hydraulic valves, and much more. If you need assistance with find the right solution for you then feel free to reach out to one of our representatives.

Serving customers worldwide since 1911 with our innovative positive displacement pumping solutions, including custom designs. For even the toughest industrial, OEM & sanitary applications, we manufacture Vane Pumps, Internal & External Gear Pumps & more.

Willman Industries is a large, independent, jobbing foundry, located in Cedar Grove, Wisconsin. We produce all types of gray iron and ductile iron components, ranging from ounces to 40,000 lbs. Thin-walled exhaust manifolds, heavy-section hydraulic pumps, valves, housings, flywheels, clutch plates, machine tools, power generating equipment are typical of our product mix.

Zinko Hydraulic Jack is a leading manufacturer of high-quality hydraulic products. In addition to our namesake hydraulic jacks, we provide scissor jacks and aluminum jacks as well as hydraulic cylinders, lifts and other material handling equipment. At Zinko, your needs are met with a diverse inventory of quality hydraulic pumps including air pumps, hand pumps, electric hydraulic pumps and more.

The model of the Truninger pump is shown in Fig. 1. Simerics-MP + directly modeled the internal fluid domain of the pump extracted from the CAD software. As shown in Fig. 9, the fluid domain was mainly composed of five parts: a suction passageway, delivery passageway, oil distribution area on the suction side, oil distribution area on the delivery side, and rotor area, which were meshed and interacted in the software. In the working process of a gear pump, the surfaces of each component are separated by a gap containing an oil film with a certain thickness, forming a friction pair to achieve lubrication and prevent the scratching of the surfaces of the components. Thus, the friction pair surface of the model included a corresponding oil film grid to simulate the realistic conditions of a pump. Based on engineering experience10.

The initial and boundary conditions of the model were consistent with that of the subsequent experiments in the following paper, which allows the results to be compared to verify the effectiveness of the simulation. The specific values are shown in Table 3. The fluid medium was No. 46 hydraulic oil. As the bulk modulus of oil is greatly affected by the actual working conditions, the value in the simulation was the corrected value of the bulk modulus of oil from experiments. To accurately represent the oil in the simulations, the Roelands equation was used to determine the dynamic viscosity \(\mu\) of No. 46 hydraulic oil at the simulation pressure and temperature

Grid independence verification was carried out after the pre-processing. Three groups of gradually refined grid were divided into coarse, normal and fine, the inlet and outlet pressure were set to 1 atm, the speed was set to 1200 r/min, and the average flow rate of the gear pump was monitored in the calculation software. The specific results are shown in Table 4.

According to the analysis in “Theoretical flow ripple characteristics” Section of this paper, the periodic change of gear meshing leads to the change of the internal flow channel structure of the gear pair, and the flow ripple will also undergo periodic changes, which makes the flow field of the oil in the pump also undergo periodic changes. The pump studied in this paper has 10 teeth, therefore, when the gear pump rotates a circle, the flow field of oil will occur 10 times of periodic change, in each cycle, the flow state of different positions will be very different, in order to fully understand the whole cycle flow change process of the pump, it is necessary to analyze the flow field in different positions of the pump. The simulation calculation results at speed of 1200 r/min and outlet pressure of 12 MPa were selected for analysis because it was the rated pump condition in which the system could run stably and maintain high volume efficiency under this condition. The setting of boundary conditions and oil properties were referred to “Initial and boundary conditions” Section. In the calculation process, in order to ensure the accuracy of the results and facilitate the effective analysis of the flow field at different moments, the external gear was set to simulate 5 turns, and 720 calculations were made for each turn, that is, one calculation was made for every 0.5° of gear rotation and the results were saved.

The pressure distribution of the internal flow field of the gear pump after calculation convergence is shown in Fig. 11, the pressure contours could not represent the change quantitatively due to the pressure gradient of tooth cavity is large, so the monitoring points were inserted into the tooth cavity of the central section of the external gear and the internal gear ring respectively during the simulation for the convenience of analysis, Point 1 in the tooth cavity of the external gear and Point 2 in the tooth cavity of the internal gear ring. The two monitoring cavities are apical cavity and root cavity corresponding to a pair of meshing target teeth, its initial positions are shown in Fig. 12, The external gear is the main driving gear and drives the internal gear ring to move clockwise. The oil suction cavity is on the left and the oil discharge cavity is on the right. When the gear rotates, the monitoring point rotates at the same angular velocity with the corresponding tooth cavity.

When the rotation angle is between 162° and 295°, the monitoring cavity is in the oil discharge cavity; When the rotation angle is between 295° and 302°, the monitoring cavity is in the trapped oil cavity formed by the engagement of the front and back teeth. The difference of tooth shape results in the change of trapped oil pressure of the pump is different from that of the involute gear pump. Therefore, the change of trapped oil pressure of the meshing tooth was discussed and analyzed in detail at point (4) of the conclusion. After the rotation Angle exceeds 302°, the monitoring tooth cavity is connected with the oil suction cavity and enters the oil suction cavity again. After that, the monitoring tooth cavity continues to rotate and return to the starting position for the next cycle. The pressure of the monitoring tooth cavity in the pump suction and oil discharge cavity fluctuates little, and is basically consistent with the pressure of the inlet and outlet. The pressure of the oil suction cavity is about 0.1 MPa, and the pressure of the oil discharge cavity is about 12.1 MPa.

When the rotation angle changes between 295° and 300°, the front and back teeth engage at the same time to form oil trapped phenomenon, which results in a wide range of pressure changes in the tooth cavity. The pressure changes in the tooth cavity during this period are plotted separately, as shown in Fig. 14. The tooth cavity pressure field along with the change of rotation angle when oil trapped phenomenon occurs is shown in Fig. 15, the selected section is the section of the central position of the internal flow field. When the rotation angle is about 295°, the gear pair is about to enter the two-tooth meshing state, and the high-pressure oil enters the meshing line of the front and back teeth and the end cover of the pump to form a closed space, resulting in oil trapped.

It can be seen from Figs. 14 and 15 that the pressure of trapped oil cavity drops sharply and reaches the lowest when the rotation angle is about 300°. Different from involute gear pumps, the pressure of trapped oil cavity pressure does not have a sharp rise stage, because the pump"s special tooth shape determines that its trapped oil volume has been increasing in the trapped oil process, only the expansion without compression process, so as to avoid gear, shaft and bearing by a large radial force, improve the stability of the pump operation

The velocity streamline diagram of the pump is shown in Fig. 16, which shows an overview of the velocity distribution and the flow state of the pump. The oil velocity in the rotor area and delivery passageway was significantly higher than that in the oil distribution area and the suction due to the continuous engagement of the gear pair to draw in and discharge oil. As can be seen from the previous analysis, the pressure difference of gear tooth meshing region is large and the meshing gap is very small. The constant change of meshing position will make the speed field in this region constantly change. Therefore, the speed field of the gear tooth meshing region is analyzed emphatically. According to the working principle, the number of external gears of the pump is 10, and 10 periodic changes will occur when the external gears rotate once a week. The corresponding rotation angle range of one meshing cycle is 36°, for the convenience of analysis, the monitoring tooth is the same as that in the pressure field analysis, and the velocity field in one meshing cycle is drawn, as shown in Fig. 17.

When the liquid is dissolved into the gas, the pressure in the liquid is reduced to the gas separation pressure under the local thermodynamic state, the gas dissolved in the liquid will be precipitated; when the pressure inside the liquid down to the saturated vapor pressure under the local thermodynamic state, the fluid medium will change from liquid phase to gas phase, both of which are called cavitation. In practical engineering, the oil will inevitably dissolve into a certain amount of gas, and the internal pressure of the gear pump changes violently during operation, and its cavitation state is often the coexistence of gas cavitation and vapor cavitation

As can be seen from Fig. 19, the gas volume fraction released by gas cavitation is almost the same as that of the total gas in the process of cavitation, while the vapor volume fraction is almost 0, indicating that gas cavitation plays a dominant role in the pump when cavitation occurs, and the gas generated by vapor cavitation is very little, almost none. Also, it indicates that there is no pressure drop below 400 Pa in the rotor region under this working condition.

Combined with Figs. 18 and 20, it can be seen that cavitation gas is generated at almost all angles in the rotation process, but there are certain differences in the amount of gas generated at different angles, the location and range of the region where the gas is generated. The location of cavitation is concentrated in the region close to the meshing point of the oil suction cavity, and the emergence of cavitation phenomenon at each position will undergo an evolution process of initiation, development and intensification, and gradual dissipation. During this evolution process, the cavitation intensity (the amount of cavitation gas generated) will undergo a weak-strong–weak process. The cavitation range (the area where cavitation gas is produced) will undergo a process from small to large to small, and the corresponding degree of cavitation will also undergo a process from mild cavitation to severe cavitation to mild cavitation. Combined with the working principle, pressure and velocity analysis results of the pump, a pair of gear teeth in front of the meshing point are detached, the volume expansion of the oil suction cavity at the place causes the oil suction empty, which reduces the pressure of the oil suction cavity, on the other hand, after the oil passes through the narrow gap between the teeth, the oil velocity is too large, which leads to the further reduction of local pressure. When the pressure is lower than the gas separation pressure, gas cavitation will occur.

According to the previous analysis, when the gas in the oil is separated out, the fixed volume in the oil suction chamber is occupied by bubbles, resulting in a decrease in the effective volume in the chamber, and the amount of bubbles produced is different with the degree of cavitation of the pump, which will certainly affect the pump outlet oil flow ripple characteristics. In order to control the cavitation degree and ensure that the regulating parameters will not affect the other performance of the pump, it can only be achieved by controlling the gas mass fraction in the oil. Multiple groups of different gas mass fraction were set and numerically calculated. The corresponding cavitation degree was from weak to strong, and the settings of other boundary conditions remained unchanged and consistent. The flow ripple results and the flow ripple characteristics at the pump outlet under different gas mass fraction were shown in Figs. 21 and 22.

With the increase of gas mass fraction, the flow ripple amplitude at the pump outlet increases, the average flow rate of output decreases, and the flow ripple rate increases. As the degree of cavitation intensifies, more bubbles are precipitated in the oil, when these bubbles are transported to the high-pressure part of the rotor region, the bubbles will compress and break under the action of high pressure, which reduces the stability of the oil flow and increases the flow ripple amplitude. At the same time, the bubbles generated by cavitation will occupy the volume of the suction and discharge chamber, so that the effective working volume of the pump decreases, when the cavitation intensifies, the gas generated will increase, and the volume of the cavity occupied will increase, leading to the decrease of the average flow rate of output and the increase of the flow ripple rate.

Therefore, suppressing cavitation can reduce flow ripple at the pump outlet and improve volumetric efficiency. In general, cavitation is alleviated by setting unloading groove at locations where cavitation is severe, as shown in Fig. 23, on the one hand, when vacuum-suction occurs, the unloading groove can timely supplement the oil from the oil suction cavity through the end face of the gear to the tooth cavity, on the other hand, the existence of the groove can alleviate the oil speed and improve the stability of oil suction and discharge. The effect of the unloading groove on the cavitation of the pump is explained by comparing the cavitation of the pump under the two conditions with or without the unloading groove, Fig. 23 shows the cavitation field without and with the unloading groove. By comparison, it can be seen that the cavitation position of the pump is basically the same under the two conditions, but the cavitation degree of the area near the unloading groove is obviously weakened with the unloading groove. Figure 24 shows the variation of gas volume fraction in the rotor region without and with unloading groove. The gas volume fraction fluctuates between 0 and 0.19% in gear pump without unloading groove, but fluctuates between 0 and 0.13% in gear pump with unloading groove. The gas volume fraction in the rotor region with unloading groove is significantly lower than that without unloading groove at the same rotation angle. It can be seen that reasonable setting of unloading groove can effectively reduce the cavitation degree of the pump.

Bucher Hydraulics located in Klettgau-Griessen, Germany is the internationally active hydraulic division of the Swiss conglomerate Bucher Industries, Niederweningen (ZH), a corporation listed on the SWX Swiss Stock Exchange.

Bucher Hydraulics develops and produces drive and control technology for the mobile and industrial hydraulics sector. Their range includes products for mobile and industrial hydraulics, elevator hydraulics, hydraulic drives for high-voltage switches and height-adjustable workbenches. Some of the many components produced include hydraulic pumps, hydraulic motors, valves, cylinders, power units, electronic devices and associated systems.

Their acquisitions include the Italian company "Hidroirma" (1994), "Beringer Hydraulik" in Neuheim, Switzerland (1996), "Hydrotechnik" in Frutigen, Switzerland and "Dingkind" in Taiwan (1997), "Truninger AG" in Solothurn, Switzerland (2000), "Monarch Hydraulics" (2007) and "Command Controls" (2008) in the United States, and "Eco Sistemas" (2013) in Brazil.

The Bucher Hydraulik corporate group was formed in 1996 with its business management in Klettgau-Grießen. Bucher Hydraulics became the company"s umbrella brand name in 2001.