Glossary of Terms. AAbrasion. A general wearing away of a surface by constant scratching, usually due to the presence of foreign matter such as dirt, grit, or metallic particles in the lubricant. It may also cause a break down of the material such as the tooth surfaces of gears. Lack of proper lubrication may result in abrasion. Abrasive WearOr cutting wear Comes about when hard surface asperities or hard particles that have embedded themselves into a soft surface and plough grooves into the opposing harder surface, e. Absolute Filtration Rating. The diameter of the largest hard spherical particle that will pass through a filter under specified test conditions. This is an indication of the largest opening in the filter elements. Absolute Pressure The sum of atmospheric and gage pressure. Absolute Viscosity. A term used interchangeably with viscosity to distinguish it from either kinematic viscosity or commercial viscosity. Absolute viscosity is the ratio of shear stress to shear rate. It is a fluids internal resistance to flow. The common unit of absolute viscosity is the poise. Absolute viscosity divided by fluid density equals kinematic viscosity. JPG' alt='How To Calculate Valve Spring Installed Height Measuring' title='How To Calculate Valve Spring Installed Height Measuring' />It is occasionally referred to as dynamic viscosity. Absolute viscosity and kinematic viscosity are expressed in fundamental units. Commercial viscosity such as Saybolt viscosity is expressed in arbitrary units of time, usually seconds. Absorbent Filter. A filter medium that holds contaminant by mechanical means. Absorption. The assimilation of one material into another in petroleum refining, the use of an absorptive liquid to selectively remove components from a process stream. Abrasion A general wearing away of a surface by constant scratching, usually due to the presence of foreign matter such as dirt, grit, or metallic particles in the. How To Calculate Valve Spring Installed Height Measuring' title='How To Calculate Valve Spring Installed Height Measuring' />AC Fine Test Dust ACFTDA test contaminant used to assess both filters and the contaminant sensitivity of all types of tribological mechanisms. Accumulator. A container in which fluid is stored under pressure as a source of fluid power. Acid. In a restricted sense, any substance containing hydrogen in combination with a nonmetal or nonmetallic radical and capable of producing hydrogen ions in solution. Acid Number. The quantity of base, expressed in milligrams of potassium hydroxide, that is required to neutralize the acidic constituents in 1 g of sample. Model Rating Range Option Resolution Measuring Range Tolerance Lower Limit of measured Rated Current Central Scale Value MY4001 125V200M 0. Acid Sludge. The residue left after treating petroleum oil with sulfuric acid for the removal of impurities. It is a black, viscous substance containing the spent acid and impurities. Acid Treating. A refining process in which unfinished petroleum products, such as gasoline, kerosene, and lubricating oil stocks, are contacted with sulfuric acid to improve their color, odor, and other properties. Acidity. In lubricants, acidity denotes the presence of acid type constituents whose concentration is usually defined in terms of total acid number. The constituents vary in nature and may or may not markedly influence the behavior of the lubricant. Activated Alumina. A highly porous material produced from dehydroxylated aluminium hydroxide. Professional Engine Rebuilding, Buildups and Modifications. Decoding Kohler Engine Model, Specification and Serial Identification Numbers. Tekniikan Englannin sanastoa ja Englannilla tehostettua hydrauliikkaa Sislt Content. Eero Aula Tekniikan Englantia EnglantiSuomi sanasto Technical English. The Complete Cylinder Head Guide for Chevy Small Block Engines How to Build Max Performance Chevy Small Blocks on a Budget. Is used as a desiccant and as a filtering medium. Actuator. A device used to convert fluid energy into mechanical motion. Additive A chemical substance added to a petroleum product to impart or improve certain properties. Common petroleum product additives are antifoam agent, anti wear additive, corrosion inhibitor, demulsifier, detergent, dispersant, emulsifier, EP additive, oiliness agent, oxidation inhibitor, pour point depressant, rust inhibitor, tackiness agent, viscosity index VI. Additive Level. The total percentage of all additives in an oil. Expressed in of mass weight or of volume. Additive stability. The ability of additives in the fluid to resist changes in their performance during storage or use. Adhesion. The property of a lubricant that causes it to cling or adhere to a solid surface. Adhesive Wear. Is often referred to as galling, scuffing, scoring, or seizing. It happens when sliding surfaces contact one another, causing fragments to be pulled from one surface and to adhere to the other. Adsorbent Filter. A filter medium primarily intended to hold soluble and insoluble contaminants on its surface by molecular adhesion. Adsorption. Adhesion of the molecules of gases, liquids, or dissolved substances to a solid surface, resulting in relatively high concentration of the molecules at the place of contact e. Adsorptive Filtration. The attraction to, and retention of particles in, a filter medium by electrostatic forces, or by molecular attraction between the particles and the medium. Aeration. The state of air being suspended in a liquid such as a lubricant or hydraulic fluid. Agglomeration. The potential of the system for particle attraction and adhesion. AGMAAn acronym for American Gear Manufacturers Associations, an organization serving the gear industry. AGMA Lubricant Numbers. AGMA specification covering gear lubricants. The viscosity ranges of the AGMA numbers or grades conform to the International Standards Organization ISO viscosity classification system see ISO viscosity classification system. Air Bleeder A device for removal of air from a hydraulic fluid line. Air Breather. A device permitting air movement between atmosphere and the component inon which it is installed. Air Entrainment. The incorporation of air in the form of bubbles as a dispersed phase in the bulk liquid. Air may be entrained in a liquid through mechanical means andor by release of dissolved air due to a sudden change in environment. The presence of entrained air is usually readily apparent from the appearance of the liquid i. Air Motor. A device which converts compressed gas into mechanical force and motion. It usually provides rotary mechanical motion. AirOil Systems. A lubrication system in which small measured quantities of oil are introduced into an airoil mixing device which is connected to a lube line that terminates at a bearing, or other lubrication point. The air velocity transports the oil along the interior walls of the lube line to the point of application. These systems provide positive air pressure within the bearing housing to prevent the ingress of contaminants, provide cooling air flow to the bearing, and perform the lubrication function with a continuous flow of minute amounts of oil. Air Gap Solenoid. A solenoid that is sealed to prevent leakage of the liquid indo the plunger cavity. Alkali. Any substance having basic as opposed to acidic properties. In a restricted sense it is applied to the hydroxides of ammonium, lithium, potassium and sodium. Alkaline materials in lubricating oils neutralize acids to prevent acidic and corrosive wear in internal combustion engines. Almen EP Lubricant Tester. A journal bearing machine used for determining the load carrying capacity or Extreme Pressure properties EP of gear lubricants. Aluminum Alloy. White particles which indicate wear of aluminum component such as a casing wall. Ambient Temperature. Temperature of the area or atmosphere around a process, not the operating temperature of the process itself. Amp. Ampere. Analytical Ferrography. The magnetic precipitation and subsequent analysis of wear debris from a fluid sample This approach involves passing a volume of fluid over a chemically treated microscope slide which is supported over a magnetic field. Permanent magnets are arranged in such a way as to create a varying field strength over the length of the substrate. This varying strength causes wear debris to precipitate in a distribution with respect to size and mass over the Ferrogram. Hydraulic Power Pack This Ebook Answer You All Questions About Hydraulic Power Unit. The number of components in any hydraulic power unit may vary depending on the complexity of the system. Normally, all these depend on the specific applications of the power unit. You can assess these two images to have an idea of what I intend to discuss in this section. A hydraulic power pack after assembling all the components. Various components of a hydraulic power pack before the assembly process. I will make the entire discussion simple and easy to understand. This is because you need to evaluate every component before buying the hydraulic power unit. AC DC Electric Motors. An electric motor is an electro mechanical device that converts and electric energy to mechanical energy. That is, it converts electrical energy to magnetic energy then to rotational force. Broadly, motors are classified in three main categories 1. DC motors. Electric motors into this category include shunt motors, separately excited motors, series motors, permanent magnet DC motors and compound motors. AC motors. These electric motors include induction and synchronous motors. The induction motors are classified further as either single phase induction motors or three phase induction motors. Others. Examples of motors in this category include stepper motors, brushless DC motors, hysteresis motors, reluctance motors and universal motors. For the scope of this hydraulic power pack e. Book, I will focus on AC and DC motors. In a hydraulic circuit, electric motors convert the electrical energy into a rotational force that drives the pump gear. Youll learn more about pump gears in section 3. For now, lets focus on the different types of motors in hydraulic power pack circuits. DC Motors. The electrical DC motors convert direct current into a rotational mechanical energy. These motors use a direct power supply whose voltage may vary from DC1. Best Software For Primer Designing Software. V, DC2. 4V, DC4. 8V or DC9. V depending on the design specification of the hydraulic power pack system. A fully assembled DC motor. These motors are common in most micro or mini hydraulic power packs. This is because the DC power supply is portable thus, a perfect choice for mobile of portable hydraulic equipment. Youll find that most people opt for the DC hydraulic power packs. How DC Motors Work. These motors have the following key parts A stator that provides the magnetic field. For most portable equipment, the stator is a permanent magnet. An armature also referred to as the rotor in this case that connects to a DC power supply via commutator rings. Its a coil that conducts electrical energy. As the current flows through the coil, an electromagnetic force is induced. This causes the coil to rotate. Of course, this is according to the Lorentz law. When the coil is perpendicular to magnetic flux, the torque action will be zero. Therefore, to ensure smooth operation, there should be more conductor coils. In practical applications, a DC motor has more rotor loops with different pairs of commutators. The armature loops are always in a slot of highly permeable steel layers. For large DC motors that are commonly found in large hydraulic systems, the electric motor manufacturers use electromagnet instead of permanent magnets. That is, the field coil of the electromagnet is powered from the DC source that powers the armature. Depending on the type of connection, youll have either a shunt or series DC motor. The complexity of the design will depend on the type load the motor should drive. In the case of the hydraulic power packs, we have a hydraulic pump as the load. Why Use DC Motors in Hydraulic Pump Applications. Here are some of the reasons why DC motors are common in pump applications DC motors have variable speed control. They have a high starting torque. DC motors have good transient response. High efficiency and power density. Less maintenance. Simple and compact design. Better thermal properties and constant magnetic field. In the recent past, a number of hydraulic power pack manufacturers have adopted the permanent magnet and brushless DC motors for most pump applications. The brushed wound field DC motors are still common in some hydraulic applications. Common Specifications of DC Motors for Hydraulic Power Packs. For a DC motor specification purposes, you need to consider the following key aspects Voltage DC 1. V2. 4VPower 5. Duty S3Motor Rotation CW, CCW, or Bi Rotation. Speed 3. 00. 0RPMIngress protection IP5. Fan up 3kw will have a fanYou can follow this link to read more about DC motors. AC Motors. Alternatively, you may also opt for AC hydraulic power packs. Unlike the DC hydraulic power packs, this equipment uses an alternating current AC. The AC motors are such that they convert an alternating electrical energy into a rotating mechanical energy. Normally, when youre designing AC electric motors, you need to consider the AC voltage and frequency of the AC power grid. An AC motor. These two parameters may vary from one region to another. For instance, in Canada, the residential voltage is 1. V, 6. 0Hz while in the United Kingdom it is 2. V, 5. 0Hz. Can you see the difference In short, before you purchase an AC hydraulic power pack, you need to consider your grid supply. Now that youve learnt all vital aspects about the DC motors, it will be appropriate to know the difference between these two motors. Differences between AC and DC Motors. Here are the main differences between AC and DC motors The AC motors are powered with an alternating current AC while the DC motors are powered with a direct current DC. Construction of the electric motors. DC wound field motors have carbon brushes and commutators while the AC motors do not have the carbon brushes. Varying speed of the motor. By varying the current in the armature windings, you can easily control the speed of a DC motor. On the other hand, you can only control the speed of an AC motor by varying its frequency. Most AC motors in industrial setups use variable frequency drives VFDs. How an AC Motor Works. Quite a number of AC hydraulic power packs use induction motors. The most common types of induction motors are Three phase induction AC motors requires three power phases. Single phase induction AC motors requires one power phase. The induction motors are also called the asynchronous motors. Synchronous AC Motors. Alternatively, you may also opt a synchronous AC motor. In a synchronous motor, the rotation of the shaft is synchronized with the frequency of the supply current. In the synchronous motors, the magnetic field is generated by the current passing through the sip rings. Normally, the synchronous motors run faster. Asynchronous AC Motors. The stator has coils. When you supply with an alternating current produces a rotating magnetic field. The varying magnetic field will induce electricity in the rotor bars due to electromagnetic induction. Since current carrying bars are immersed in a magnetic field, this produces a force that rotates the rotor. It is this rotating shaft that youll connect to the hydraulic pump. Advantages of AC Motors. The main advantages of AC motors include High power output suitable for industrial applications. They are cheap to construct and maintain. Rugged and easy to maintain. Common Specifications of the AC Motor. Before you buy an AC motor, you need to check the following specifications. Voltage 1. 10v, 2. Power 3. 70w 7. Frequency 5. HZ, 6. HZDuty S1, S6Pole 2. Pole 3. 00. 0RPM, 4.