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Showing papers on "Reducer published in 2014"


Proceedings ArticleDOI
03 Nov 2014
TL;DR: This work is the first to give guarantees on the maximum load of each reducer for an arbitrary input graph, and is competitive with existing methods improving the performance by a factor up to 2X, and can significantly increase the size of datasets that can be processed.
Abstract: We describe an optimal randomized MapReduce algorithm for the problem of triangle enumeration that requires O(E3/2/(M√m) rounds, where m denotes the expected memory size of a reducer and M the total available space. This generalizes the well-known vertex partitioning approach proposed in (Suri and Vassilvitskii, 2011) to multiple rounds, significantly increasing the size of the graphs that can be handled on a given system. We also give new theoretical (high probability) bounds on the work needed in each reducer, addressing the "curse of the last reducer". Indeed, our work is the first to give guarantees on the maximum load of each reducer for an arbitrary input graph. Our experimental evaluation shows the scalability of our approach, that it is competitive with existing methods improving the performance by a factor up to 2X, and that it can significantly increase the size of datasets that can be processed.

74 citations


Journal ArticleDOI
TL;DR: In this paper, a two-stage cycloidal speed reducer with tooth modifications is proposed, and the topological structure of cycloidal drives is discussed and analyzed with the aid of graphs.

70 citations


Journal ArticleDOI
TL;DR: In this article, a system dynamics analysis model of a cycloidal speed reducer is constructed, together with dynamics analysis models for two design types: a traditional pinwheel design and a nonpinwheel design (i.e., a design in which a cycloid internal gear replaces the pinwheel).
Abstract: Cycloidal speed reducers are composed primarily of an eccentric shaft, output parts, and a set comprising a cycloidal gear and pinwheel with pins or a cycloidal gear and cycloid internal gear. This paper investigates the contact and collision conditions of these components, as well as their stress variations during the transmission process. To do so, a system dynamics analysis model of a cycloidal speed reducer is constructed, together with dynamics analysis models for two design types: A traditional pinwheel design and a nonpinwheel design (i.e., a design in which a cycloid internal gear replaces the pinwheel). Based on the theory of gearing, a mathematical model of the pinwheel with pins, cycloidal gear, and cycloid internal gear is then built from which the component geometry can be derived. These dynamics analysis models, constructed concurrently, are used to investigate the components' movements and stress variations, and determine the differences between the transmission mechanisms. The results indicate that the nonpinwheel design effectively reduces vibration, stress value, and stress fluctuation, thereby enhancing performance. An additional torsion test further suggests that the nonpinwheel design's output rate is superior to that of the traditional pinwheel design.

61 citations


Journal ArticleDOI
Shuting Li1
TL;DR: In this paper, a new mechanics model and finite element method (FEM) are presented to conduct loaded gear contact analysis of the trochoidal gear reducers in order to solve strength calculation and evaluation problems of the reducers.

47 citations


Journal ArticleDOI
01 Jan 2014
TL;DR: In this paper, experimental and theoretical analyses of the power losses in an industrial planetary speed reducer were performed in order to define the weight of the different types of power losses, and the power loss weights were defined.
Abstract: In this work, experimental and theoretical analyses of the power losses in an industrial planetary speed reducer were performed in order to define the weight of the different types of power losses ...

31 citations


Journal ArticleDOI
TL;DR: In this article, a new transmission design for eccentric speed reducers was proposed, which differs from that used with a traditional cycloid speed reducer, other than the input and output shafts, is that it uses the internal gear as its fixed part and transmission between the external gear and the output shaft occurs via pins connected to a drive plate.

29 citations


Journal ArticleDOI
01 Sep 2014-Fuel
TL;DR: In this paper, a micro-sized fluidic chip was used to represent the micro-fracture and friction reducer solution is used to block the pore entrance on fracture face to prevent the fluid from leak off and help pressure build up during slickwater fracturing.

29 citations


Patent
12 Mar 2014
TL;DR: In this article, a water-soluble drag reducer is used in quick water fracturing fluid to reduce the friction drag of pipelines, which is suitable for oil and gas exploitation of unconventional low permeability reservoirs, has good dissolving property and obvious drag reduction effect which can reach 50-70% compared with that of the clear water, and is convenient to use.
Abstract: The invention relates to a water-soluble drag reducer as well as a preparation method and application thereof. The preparation method is characterized by adding an emulsifier and solvent oil to a reactor to form an oil phase, adding a lipophilic propenyl monomer to the oil phase, dissolving a hydrophilic propenyl monomer in water, regulating the pH value to 8-9 to form an aqueous phase, slowly dropping the aqueous phase into the oil phase, carrying out emulsification while stirring, adding an initiator by times under the condition of introducing nitrogen, reacting at 30 DEG C for 48 hours, cooling, adding a polymerization inhibitor so as to obtain an inverse microemulsion system, and mixing the prepared inverse microemulsion system with a surfactant so as to obtain the water-soluble drag reducer. The water-soluble drag reducer is used in quick water fracturing fluid to reduce the friction drag of pipelines, reduces the pump power, improves the sand-carrying capacity of the construction fluid, is suitable for oil and gas exploitation of unconventional low permeability reservoirs, has good dissolving property and obvious drag reduction effect which can reach 50-70% compared with that of the clear water, and is convenient to use.

28 citations


Proceedings ArticleDOI
25 Feb 2014
TL;DR: In this article, a salt-tolerant, water-based friction reducer was developed to address the challenges of high total dissolved solids (TDS) produced water, especially from shale plays such as Marcellus and Bakken.
Abstract: Currently inverse-emulsion polymers are the most popular friction reducers used in fresh water slickwater fracturing in shale reservoirs. The fluid volumes in fracturing treatments have increased substantially, while water supply has become more of a public concern. Rather than paying to treat and dispose of produced and flowback water, operators would like to reuse it in subsequent stimulation treatments. Produced water, especially from shale plays such as Marcellus and Bakken, is known for its high total dissolved solids (TDS) and high divalent cation content. This poses extreme challenges for current friction reducers because cations hinder the inversion of friction reducers and cause loss of efficiency of friction reduction to below 30%. Treating produced water to the quality suitable for conventional fracturing fluids is time-consuming and often costprohibitive. A salt-tolerant, water-based friction reducer was developed to address the challenges of high-TDS produced water. It was tested in a friction loop in a wide variety of produced water types from Bakken, Marcellus, Permian basin and other shale plays at different temperatures and was found to be highly effective. In a produced water sample with TDS over 300,000 ppm and total hardness as CaCO3 (TH) over 90,000 ppm as representative water, the new polymer hydrates within 10 seconds and gives a friction reduction profile similar to that of current inverse-emulsion friction reducers in fresh water. The fluid is compatible with other common stimulation additives such as scale inhibitors, biocides, clay stabilizers, surfactants, and breakers. The new friction reducer was also field tested in New Mexico using produced water with higher than 250,000 ppm TDS and 50,000 ppm total hardness as CaCO3, and head-to-head comparison with a conventional friction reducer under field conditions showed significant performance improvement in terms of pumping at much higher rates while maintaining much lower surface treating pressure. This paper will discuss the evolution of the technology and show friction reduction performance in various high-TDS water samples under lab conditions. Successful field test and comparison against conventional friction reducers are presented. The new friction reducer provides the oilfield industry a cost-effective solution of reducing produced water disposal and fresh water demands, thereby ultimately improving environmental impact of well operations.

25 citations


Patent
02 Apr 2014
TL;DR: In this article, a reparation method of the shale gas acid fracturing drag reducer is presented, which consists of mixing monomer acrylic acid and 2-acrylamide-2 methyl propane sulfonic acid, dissolving in water, subsequently adding acrylamides, and finally adding ethylenediamine tetraacetic acid disodium to prepare into a water phase.
Abstract: The invention discloses a shale gas acid fracturing drag reducer and a reparation method of the shale gas acid fracturing drag reducer. The preparation method comprises the following steps: mixing monomer acrylic acid and 2-acrylamide-2 methyl propane sulfonic acid, dissolving in water, subsequently adding acrylamide, and finally adding ethylenediamine tetraacetic acid disodium to prepare into a water phase; mixing and dissolving a compounded surfactant with base oil to form an oil phase; performing inverse emulsion polymerization on the oil phase and the water phase to prepare the shale gas acid fracturing drag reducer. As a great amount of acid resistance monomers are introduced into the drag reducer, the acid resistance of the dreg reducer is greatly improved; the dreg reducer is milk white emulsion in appearance, is high in stability, non-ignitable, non-explosive, safe to transport and store, rapid to dissolve in water and free of fisheye; the requirements of continuous blending in shale gas acid fracturing can be met; the resistance reduction rate of a dreg reducer solution with the mass percentage of 0.2% can be greater than 70%.

24 citations


Patent
01 Oct 2014
TL;DR: In this article, a comprehensive servo motor and harmonic speed reducer testing platform is presented, which consists of a machine frame, a vibration isolation platform, a linear guide rail and a magnetic powder brake.
Abstract: The invention discloses a comprehensive servo motor and harmonic speed reducer testing platform. The comprehensive servo motor and harmonic speed reducer testing platform comprises a machine frame, a vibration isolation platform, a linear guide rail and a magnetic powder brake, wherein the vibration isolation platform is arranged on the machine frame, and the linear guide rail and the magnetic powder brake are installed on the vibration isolation platform in a matched mode. The linear guide rail is provided with a wide-range torque revolving speed sensor, a first angle encoder, a harmonic speed reducer, a second angle encoder, a narrow-range torque revolving speed sensor and a servo motor. The comprehensive servo motor and harmonic speed reducer testing platform is simple and reasonable in structure, the load torque is not prone to fluctuation, data detecting accuracy is high, the system error is small, and assembling and adjusting are convenient.

Journal ArticleDOI
TL;DR: In this paper, a helical gear pair of a heavy duty gear reducer is considered for the objective of minimum volume, since the most power transmission systems require low weight energy efficient and cost effective system elements.

Patent
10 Dec 2014
TL;DR: In this paper, a rope drive device with a reciprocating wire arrangement function is described, which consists of a backup motor gearbox, a rope roller reducer, a winding roller, a reciprocation screw mechanism and an arrangement guide wheel set.
Abstract: The invention discloses a rope drive device with a reciprocating wire arrangement function. The rope drive device comprises a backup motor gearbox, a rope roller reducer, a winding roller, a reciprocating screw mechanism and an arrangement guide wheel set. A driving motor is connected with an output shaft of a backup motor and an input shaft of a planetary reducer through the backup motor gearbox, so that both the driving motor and the backup motor can drive the motor gearbox to move. The rope roller reducer transmits rotation of an output shaft of the planetary reducer to the winding roller according to a specified speed ratio, and a large torque is obtained. The winding roller is mounted at an output shaft of the rope roller reducer; a drive rope is wound on and unwound from the winding roller. A reciprocating screw of the reciprocating screw mechanism is connected with the winding roller through a gear and drives a nut slider mounted on the reciprocating screw, to reciprocate. The arrangement guide wheel set is fixedly connected with the screw slider and reciprocates with the screw slider to guide the drive rope being tightly wound on the winding roller in a reciprocating manner. The rope drive device allows winding and unwinding of the rope and allows the rope to be regularly and tightly wound.

Journal ArticleDOI
TL;DR: It can be observed that the proposed Genetic Algorithm offers better design solutions as compared with the results obtained by using the traditional design method (i.e. a commonly trial and cut error).

Journal ArticleDOI
Y. G. Sun, X. F. Zhao, F. Jiang, L. Zhao, D. Liu, G. B. Yu 
TL;DR: In this paper, an improved backlash estimation model is proposed for RV reducer, which is conductive to taking fix action in the design stage, reducing backlash, improving the transmission accuracy.
Abstract: Error factors of RV reducer are not completely considered, leads to backlash precision is limited, so an improved backlash estimation model is proposed. RV reducer structure and working principle is deeply analyzed, a variety of error factors are considered, and the backlash estimation model is improved according to error propagation. Furthermore, sensitivity of all the error factors are analyzed, RV reducer backlash is obtained through Monte-Carlo simulation, and the simulation results are compared with the traditional computation results. It is conductive to taking fix action in the design stage, reducing backlash, improving the transmission accuracy.

Patent
20 Aug 2014
TL;DR: In this article, a closed cycloid precision gear reducer is proposed, where the inner ring of the pin wheel housing is provided with containing grooves which correspond to the wheel pins in a one-to-one mode.
Abstract: The invention discloses a closed cycloid precision gear reducer. The closed cycloid precision gear reducer comprises an input part, a pin wheel housing, an output part and a small-tooth-difference inside-gear reducing mechanism. Wheel pins used for being meshed with a cycloidal gear of the small-tooth-difference inside-gear reducing mechanism are arranged on the inner ring of the pin wheel housing in the circumferential direction. The inner ring of the pin wheel housing is provided with containing grooves which correspond to the wheel pins in a one-to-one mode and are used for containing the wheel pins. The wheel pins make double-line contact with the inner walls of the corresponding containing grooves. According to the closed cycloid precision gear reducer, the double-line contact characteristic exists between the wheel pins and the containing grooves in the pin wheel housing; as the wheel pins make double-line contact with the corresponding containing grooves in the tooth width direction, the bending strength is enhanced, and carrying capacity is improved; meanwhile, due to the increase of the number of contact lines, the achievement of the error leveling effect is facilitated, transmission accuracy can be improved, and then the requirements for machining errors and assembly errors can be lowered. Compared with an existing RV gear reducer, the return difference of the closed cycloid precision gear reducer is smaller; besides, the closed cycloid precision gear reducer is compact in structure, long in service life, simple in machining process and low in manufacturing cost.

Patent
01 Jan 2014
TL;DR: In this article, an electric cylinder consisting of a servo motor, a worm wheel worm reducer, a lead screw assembly, and an anti-rotating mechanism was designed for rectilinear motion.
Abstract: The utility model discloses an electric cylinder possessing a self-locking characteristic. The electric cylinder comprises a servo motor, a worm wheel worm reducer, a lead screw assembly and an anti-rotating mechanism. The lead screw assembly comprises a lead screw and a lead screw nut which are cooperated with each other. An end surface of the lead screw nut is fixedly provided with a push rod. The anti-rotating mechanism is acted with two parallel planes of an outer surface of the push rod so as to complete rotation prevention. The servo motor is connected with one end of the lead screw through the worm wheel worm reducer and carries out unidirectional transmission. According to the electric cylinder of the utility model, through transmission connection of the worm wheel worm reducer, a unidirectional self-locking characteristic of worm wheel worm transmission is used to realize mechanical self-locking of the electric cylinder; a dependence to an electrical element is eliminated; operation reliability is guaranteed and increased. The push rod is used to realize output of rectilinear motion. Through rotation prevention of the anti-rotating mechanism to the push rod, conversion of rotational motion and the rectilinear motion by the lead screw nut is realized. The design is reasonable and the structure is ingenious. Working is stable and connection is compact.

Patent
02 Apr 2014
TL;DR: In this paper, a speed reducer was used for testing the return difference and the elastic constant of a speed reduction system. But the authors did not specify the angle measurement precision.
Abstract: The invention discloses a speed reducer testing equipment which is used for testing the return difference and the elastic constant of a speed reducer to be tested The speed reducer testing equipment comprises a support platform, and a servo motor, an input rotating wheel, an output rotating wheel, load equipment and an angle sensor which are arranged on the support platform, wherein an output shaft of the servo motor is connected with one of a first side shaft and a second side shaft, which are opposite, of the input rotating wheel so as to drive the input rotating wheel to rotate around a first rotating shaft defined by the first side shaft or the second side shaft; the speed reducer to be tested and the angle sensor are respectively connected with a third side shaft and a fourth side shaft, which are opposite, of the output rotating wheel; the output rotating wheel is meshed with the input rotating wheel to further synchronously rotate around a second rotating shaft which is defined by the third side shaft or the fourth side shaft and parallel to the first rotating shaft; the angle sensor is used for obtaining a torque angle of the speed reducer to be tested Due to the adoption of the mode, according to the speed reducer testing equipment disclosed by the invention, the angle measurement precision of the speed reducer to be tested is improved

Patent
06 Jun 2014
TL;DR: An electric brake actuator includes first and second electric motors and an actuator output, a first cycloidal speed reducer having a first reducer input rotatable about a first-reducer axis and operatively connected to the first motor output gear to receive a first driving force, and a second reducer output rotating about the first reducers axis to transfer the driving force to the actuator.
Abstract: An electric brake actuator includes first and second electric motors and an actuator output, a first cycloidal speed reducer having a first reducer input rotatable about a first reducer axis and operatively connected to the first motor output gear to receive a first driving force, and a first reducer output rotatable about the first reducer axis and operatively connected to the actuator output to transfer the first driving force to the actuator output, and a second cycloidal speed reducer having a second reducer input rotatable about a second reducer axis and operatively connected to the second motor output gear to receive a second driving force and a second reducer output rotatable about the second reducer axis and operatively connected to the actuator output to transfer the second driving force to the actuator output.

Patent
09 Jul 2014
TL;DR: In this article, the utility model provides a reeling type irrigating machine, where a rotary disc is arranged on a chassis, which is attached to the front portion of a main vehicle wheel.
Abstract: The utility model provides a reeling type irrigating machine A rotary disc is arranged on a chassis which is arranged on the front portion of a main vehicle wheel; a cross beam is arranged on the rotary disc; a support is arranged on across beam; one side of the support is provided with a speed reducer; a water turbine is arranged on the upper portion of the speed reducer; a quick joint is connected to the water turbine; a water circulating shaft is communicated with the water turbine; a water turbine large plate is arranged on the water turbine; a manipulating rod is connected to the speed reducer; a pipe pressing device is arranged on the support; the upper portion at the front end of the chassis is provided with a spraying head support According to the reeling type irrigating machine, water power is converted to mechanical power due to a water turbine type power system; water-saving irrigation relevant policies are confirmed due to the facts that high pressure water flows flow a PE (Poly Ethylene) pipe to uniformly spray above the crops and then small water drops uniformly fall off; automatic recycling of the PE pipe and a water spraying vehicle is achieved due to the fact that the irrigating machine is driven by a water turbine and transmitted through chain; the four-level speed changing function is achieved due to the fact that the irrigating machine adopts a multifunctional speed changing device; the spraying direction can be locked within 270-degree range due to adjustment of the rotary disc when the water spraying vehicle is align to the direction of irrigation belts

Patent
02 Apr 2014
TL;DR: In this paper, a speed reducer testing equipment consisting of a support platform and a servo spindle motor, a first rotation speed and torque sensor, a second rotation speed sensor, and a transmission and a brake is presented.
Abstract: The invention discloses speed reducer testing equipment. The speed reducer testing equipment comprises a support platform, and a servo spindle motor, a first rotation speed and torque sensor, a second rotation speed and torque sensor, a transmission and a brake which are arranged on the support platform, wherein an output shaft of the servo spindle motor is connected with an input shaft of a speed reducer to be tested through the first rotation speed and torque sensor; an output shaft of the speed reducer to be tested is connected with an input shaft of the transmission through the second rotation speed and torque sensor; an output shaft of the transmission is connected with the brake; the first rotation speed and torque sensor is used for detecting input rotation speed and/or input torque; the second rotation speed and torque sensor is used for detecting output rotation speed and/or output torque of the speed reducer to be tested; the transmission and the brake are matched to provide a load for the speed reducer to be tested. Due to the adoption of the mode, according to the speed reducer testing equipment, the transmission and the brake are matched to provide the load, the load provided by the brake is exponentially amplified by the transmission, so that a large-size brake is not needed even through a large load is needed during testing, and thus the cost is reduced.

Patent
14 Mar 2014
TL;DR: Surgical instruments and devices including drivers, inserters, and reducers as mentioned in this paper include a ratcheting mechanism configured to provide uni-directional motion when engaged, and a reducer includes a geared system for persuading together surgical components and aligning misaligned vertebrae.
Abstract: Surgical instruments and devices including drivers, inserters, and reducers. The driver includes a ratcheting mechanism configured to provide uni-directional motion when engaged. The inserter includes a rack, pinion, and cam system designed to secure an implant and release an implant in-situ. The reducer includes a geared system for persuading together surgical components and aligning misaligned vertebrae.

Patent
12 Mar 2014
TL;DR: In this paper, a hollow intelligent modularization joint consisting of a motor, a brake, an incremental encoder, a harmonic reducer, an absolute encoder and a torque transducer, a hollow wire pipe and an end output shaft is presented.
Abstract: The utility model belongs to the technical field of robots, and particularly relates to a hollow intelligent modularization joint The hollow intelligent modularization joint comprises a motor, a brake, an incremental encoder, a harmonic reducer, an absolute encoder, a torque transducer, a hollow wire pipe and an end output shaft The brake and the incremental encoder are arranged on a rear end cover of the motor and are in transmission connection respectively through a transmission device and a rear end of a motor output shaft, the front end of the motor output shaft is connected with the harmonic reducer, the harmonic reducer is connected with one end of the end output shaft, the other end of the end output shaft is connected with the torque transducer, and the absolute encoder is mounted on the end output shaft The motor output shaft and the end output shaft are both in a hollow structure, the hollow wire pipe sequentially penetrates through the end output shaft, the harmonic reducer and the motor output shaft, one end of the hollow wire pipe is connected with the rear end cover of the motor, and the other end of the hollow wire pipe is rotatably connected with the end output shaft The hollow intelligent modularization joint is in modular design, is applied to robot joints, and various components are all replaceable, and accordingly the hollow intelligent modularization joint is convenient to transform

Patent
24 Dec 2014
TL;DR: In this article, a compound oil-soluble viscosity reducer was proposed for reducing viscosities of thickened oil and a preparation method of the compound oil solubility reducer.
Abstract: The invention relates to a compound oil-soluble viscosity reducer for reducing viscosity of thickened oil and a preparation method of the compound oil-soluble viscosity reducer. The compound oil-soluble viscosity reducer is compounded of a ternary oil-soluble copolymer and an oil-soluble fatty alcohol polyoxyethylene ether nonionic surfactant. The compound oil-soluble viscosity reducer is characterized by comprising the following contents: 1) preparing octadecyl methacrylate; 2) preparing SMA which is a maleic anhydride-styrene-octadecyl methacrylate copolymer; 3) preparing SMZA which is an ester copolymer of maleic anhydride-styrene-acrylamide and higher alcohols; and 4) compounding the SMA or SMZA copolymer with a surfactant, wherein the mass ratio of the surfactant to the terpolymer is (0.5-1) to (1-3), and adding a solvent and stirring for an hour at 60 DEG C. The compound oil-soluble viscosity reducer is wide in raw material source, low in price, free of pollution, and simple in synthetic process, and has a wide market prospect.

Patent
12 Jun 2014
TL;DR: In this paper, a multi-joint robot consisting of a motor, a speed reducer, and an output angle detecting unit is configured to detect an output rotational angle of the rotational axis of a rotating shaft of the motor.
Abstract: A robot apparatus includes a multi-joint robot including, in at least one portion, a joint including a motor, a speed reducer connected to the motor, an input angle detecting unit configured to detect a rotational, angle of a rotating shaft of the motor, and an output angle detecting unit configured to detect an output rotational angle of the speed reducer, and a controller configured to diagnose a state of the speed reducer from an angle difference between the input rotational angle detected by the input angle detecting unit and the output rotational angle detected by the output angle detecting unit.

Patent
11 Jun 2014
TL;DR: An electric wheel hub motor testing stand belongs to the technical field of electric vehicle devices as discussed by the authors, which comprises a magnetic powder brake, a TK2-105 plum coupling, a speed reducer, etc.
Abstract: An electric wheel hub motor testing stand belongs to the technical field of electric vehicle devices. The stand comprises a magnetic powder brake, a TK2-105 plum coupling, a speed reducer, etc. The magnetic powder brake (1) is located on one end of a pedestal (12) and is fastened via parallel grooves in the cast iron pedestal (12). A support is under the speed reducer, so that the left side of the speed reducer (3) is positioned with the same axial direction as the magnetic powder brake (1). An electric wheel vertical loading system (7) is installed on an electric wheel loading system support (9). The stand is connected to a host computer during testing, can achieve testing of mechanical properties, efficiency properties and adjustment properties of an electric wheel hub motor, and provides testing means for ASR system simulation and control strategy studies. The stand can test basic properties of an electric wheel motor and provides bases for design of a vehicle controller. The stand can also be used for studies of control algorithms of ASR and the like, so that research is accelerated, the efficiency of R&D is improved, and the costs are lowered.

Patent
03 Dec 2014
TL;DR: In this article, a low-temperature preparation method of a high-adaptability ether polycarboxylic acid water reducer is described, which comprises the following steps: preparing unsaturated carboxyric acid, unsaturated sulfonate, uns saturated phosphonic acid, a chain-transfer agent and water into a mixed solution A; preparing a reducer a and water, and adding unsaturated polyethenoxy ether a buffering agent, and dropping them into a reaction kettle; regulating the reaction temperature to 10-40 DEG C, adding an oxid
Abstract: The invention discloses a low-temperature preparation method of a high-adaptability ether polycarboxylic acid water reducer, which comprises the following steps: preparing unsaturated carboxylic acid, unsaturated sulfonate, unsaturated phosphonic acid, a chain-transfer agent and water into a mixed solution A; preparing a reducer a and water into a mixed solution B; adding unsaturated polyethenoxy ether a buffering agent and water into a reaction kettle; regulating the reaction temperature to 10-40 DEG C, adding an oxidizer at one time, and dissolving by stirring; dropwisely adding the mixed solution A and mixed solution B simultaneously; after finishing drowse addition, adding 0-0.5 part of reducer b at one time, and continuing reaction for 1-2 hours; and finally, adding 10-20 parts of 30 wt% sodium hydroxide solution for neutralization, thereby obtaining the polycarboxylic acid water reducer. The method is simple, and the prepared water reducer can have high dispersibility by low doping amount. The low-temperature high-efficiency reducer is introduced to implement low-temperature polymerization of the polycarboxylic acid, thereby enhancing the conversion rate of the product.

Patent
30 Jul 2014
TL;DR: In this article, a hydraulic fluid drag reducer was proposed for field application, using 5-15wt% acrylic monomer, 1-3wt% of 2-methyl-2-allyl ammonium chloride and 1-2wt% 2-acrylamido-2methylpropanesulfonic acid.
Abstract: The invention provides a fracturing fluid drag reducer, and a preparation method and an application thereof. The fracturing fluid drag reducer is prepared by using 5-15wt% of an acrylic monomer, 1-3wt% of 2-methyl-2-allyl ammonium chloride, 1-2wt% of 2-acrylamido-2-methylpropanesulfonic acid, 2-6wt% of an alkali, 10-20wt% of an acrylamide monomer, 0.02-0.07wt%of an initiator, 2-4wt% of an emulsifier, 1-2wt% of a co-emulsifier, 15-30wt% of oil, and the balance water. The drag reducer has the advantages of fast dissolving speed, realization of the fast dissolving time of less than 30s, good tackifying effect, and excellent drag reduction performance, and can realize a maximum drag reduction rate of 87% in field application.

Patent
05 Feb 2014
TL;DR: In this paper, a valve timing control system of an internal combustion engine employing both an electric-motor-driven intake valve timing controller and an EH-driven exhaust valve control device for changing exhaust valve timing is described.
Abstract: In a valve timing control system of an internal combustion engine employing both an electric-motor-driven intake valve timing control device for changing intake valve timing and an electric-motor-driven exhaust valve timing control device for changing exhaust valve timing, the intake valve timing control device includes a less-friction roller speed reducer having a toothed gear and configured to transmit torque by repeated relocations of each of rollers rolling and relocating from one of two adjacent teeth of the toothed gear to the other. In contrast, the exhaust valve timing control device includes a planetary-gear speed reducer having a friction greater than a friction of the roller speed reducer and configured to transmit torque by meshed-engagement of toothed gears in mesh with each other.

Patent
15 Oct 2014
TL;DR: In this article, an electric push rod with a drive motor, a reducer, a bearing base, a push rod outer cylinder, a screw-nut pair, an inner cylinder which is installed together with a nut and a joint of the inner cylinder, and a zero-point sensor is installed between the two limit position sensors.
Abstract: The utility model discloses an electric push rod which includes a drive motor, a reducer, a bearing base which is installed together with the reducer, a push rod outer cylinder, a screw-nut pair, an inner cylinder which is installed together with a nut and a joint of the inner cylinder A mounting hole is respectively formed in each of the left side and the right side of the bearing base and a shaft hole, which is matched with a boss of the reducer, is also respectively formed in each of the left side and the right side of the bearing base A limit position sensor is installed at each of the two ends of the outer cylinder A zero-point sensor is installed between the two limit position sensors, wherein the limit position sensors and the zero-point sensor are used for ensuring accurate control of an initial working position and a limit working position of the push rod when the push rod works The push rod has a mall occupied area, is simple in structure and is good in sealing performance By means of the three position sensor, accurate control of the screw nut in a limit travel position can be achieved In addition, with the motor, the reducer and a proper screw spiral angle, a self-locking control protection of the push rod is achieved Safety and reliability of the electric push rod is improved