鉆機履帶底盤底架設計,鉆機履帶底盤底架設計,鉆機,履帶,底盤,底架,設計 無錫太湖學院 信 機　系 　機械工程及自動化 　專業(yè) 畢 業(yè) 設 計論 文 任 務 書 一、題目及專題： 1、題目　 鉆機履帶底盤底架設計 　 2、專題　 　 二、課題來源及選題依據 錨固鉆機面世后，在建筑、地質、鐵路、公路和水利等各行業(yè)施工領域內廣泛應用。如長江三峽工程、北京十三陵水庫、龍灘電站、大朝山電站、小灣電站、成昆鐵路、南昆鐵路、達萬線、株六復線、京珠高速公路、元墨高速、大保高速、襄十高速等。這些新設備和新機型的不斷推出，為錨固工程施工提供了有力的設備保障。但以往的錨固鉆機都沒有行走功能，這對于在平地施工或有條件提供平地的施工場地而言是一大損失，增加了工人的勞動強度，移位對孔也及為不便，大大拖延了工期。而與此同時，過外的鉆探機械，包括國內的一些品種的鉆探機械都已經采用了輪式或履帶式底盤，增加了鉆機的移動功能，減輕了工人的勞動強度，提高了工作效率。而履帶底盤技術發(fā)展到現在已經比較成熟；另為了工作量適合畢業(yè)設計，故重點負責鉆機的履帶底盤設計和底架設計。 三、本設計（論文或其他）應達到的要求： 1. 履帶底盤設計要求 ① 應有較大的驅動力，使鉆機在濕軟或高低不平等不良地面上行走時具有良好的通過性能、爬坡性能和轉向性能； ② 在不增大行走裝置高度的前提下使鉆機具有較大的離地間隙，以提高其不平地面上的越野性能； ③ 行走裝置具有較大的支撐面積或較小的接地比壓，以提高鉆機穩(wěn)定性； ④ 在鉆機斜坡下行時不發(fā)生下滑和超速溜坡現象，以提高鉆機安全性； ⑤ 行走裝置的外形尺寸應符合道路運輸的要求； ⑥ 在鉆機作業(yè)時需要用專門支腿支撐，以確保鉆機穩(wěn)定性和安全性。2. 底架設計要求 ① 有足夠的強度，保證對桅桿組件的支撐； ② 有可以變角機構。角度范圍-10°～90°； ③ 有支撐機構； ④ 有滑移機構，滑移行程600mm，滑移油缸支撐力>6869N； ⑤ 有安裝桅桿組件的結構； ⑥ 有與底盤連接的結構； ⑦ 要充分考慮減小設計尺寸； ⑧ 要求結構簡單。 四、接受任務學生： 機械92 班 　　姓名 陳 嬋 五、開始及完成日期： 自2012年11月7日 至2013年5月25日 六、設計（論文）指導（或顧問）： 指導教師　　　　　　　簽名 簽名 　　　　　　　簽名 教研室主任 　　　　　　〔學科組組長研究所所長〕　　　　　　　簽名 　　 　　系主任 　　　　　　簽名 2012年11月7日 編號 無錫太湖學院 畢業(yè)設計（論文） 相關資料 題目： 鉆機履帶底盤底架設計 信機 系 機械工程及自動化專業(yè) 學 號： 　　　 0923053　　　　 學生姓名： 陳　 嬋 指導教師：屠德剛（職稱：高級工程師 ） （職稱： ） 2013年5月25日 目 錄 一、畢業(yè)設計（論文）開題報告 二、畢業(yè)設計（論文）外文資料翻譯及原文 三、學生“畢業(yè)論文（論文）計劃、進度、檢查及落實表” 四、實習鑒定表 無錫太湖學院 畢業(yè)設計（論文） 開題報告 題目： 鉆機履帶底盤底架設計 信機 系 機械工程及自動化 專業(yè) 學 號： 0923053 學生姓名： 陳 嬋 指導教師：屠德剛（職稱：高級工程師 ） （職稱： ） 2012年11月14日 課題來源 鉆機履帶底盤底架設計 科學依據（包括課題的科學意義；國內外研究概況、水平和發(fā)展趨勢；應用前景等） 錨固鉆機面世后，在建筑、地質、鐵路、公路和水利等各行業(yè)施工領域內廣泛應用。如長江三峽工程、北京十三陵水庫、龍灘電站、大朝山電站、小灣電站、成昆鐵路、南昆鐵路、達萬線、株六復線、京珠高速公路、元墨高速、大保高速、襄十高速等。這些新設備和新機型的不斷推出，為錨固工程施工提供了有力的設備保障。但以往的錨固鉆機都沒有行走功能，這對于在平地施工或有條件提供平地的施工場地而言是一大損失，增加了工人的勞動強度，移位對孔也及為不便，大大拖延了工期。而與此同時，過外的鉆探機械，包括國內的一些品種的鉆探機械都已經采用了輪式或履帶式底盤，增加了鉆機的移動功能，減輕了工人的勞動強度，提高了工作效率。而履帶底盤技術發(fā)展到現在已經比較成熟；另為了工作量適合畢業(yè)設計，故重點負責鉆機的履帶底盤設計和底架設計。 研究內容 （1） 履帶底盤設計要求 ① 應有較大的驅動力，使鉆機在濕軟或高低不平等不良地面上行走時具有良好的通過性能、爬坡性能和轉向性能； ② 在不增大行走裝置高度的前提下使鉆機具有較大的離地間隙，以提高其不平地面上的越野性能； ③ 行走裝置具有較大的支撐面積或較小的接地比壓，以提高鉆機穩(wěn)定性； ④ 在鉆機斜坡下行時不發(fā)生下滑和超速溜坡現象，以提高鉆機安全性； ⑤ 行走裝置的外形尺寸應符合道路運輸的要求； ⑥ 在鉆機作業(yè)時需要用專門支腿支撐，以確保鉆機穩(wěn)定性和安全性。 （2） 底架設計要求 ① 有足夠的強度，保證對桅桿組件的支撐。 ② 有可以變角機構。角度范圍-10°～90° ③ 有支撐機構。 ④ 有滑移機構，滑移行程600mm，滑移油缸支撐力>6869N ⑤ 有安裝桅桿組件的結構。 ⑥ 有與底盤連接的結構。 ⑦ 要充分考慮減小設計尺寸。 ⑧ 要求結構簡單。 擬采取的研究方法、技術路線、實驗方案及可行性分析 鉆機的設計要滿足潛孔錘常規(guī)鉆進、合金鉆進、螺旋鉆進三種鉆探工藝的要求，在鉆進方面要求有快速，慢速，可調速三種進給方式，在回轉方面要求有多檔變速功能，要求有行走移位功能，調節(jié)鉆孔的方位角的功能，具有自動上卸鉆桿的功能，不可拆部件不大于300Kg，可靠運行時間不低于3000h。此外還要考慮到拆卸方便結構簡單的因素，還要符合廠里的生產要求和已經成熟的成組技術要求。 研究計劃及預期成果 研究計劃： 2012年11月7日-2012年12月10日：按照任務書要求查閱論文相關參考資料，填寫畢業(yè)設計開題報告書。 2013年11月28日-2013年2月12日：填寫畢業(yè)實習報告。 2013年2月13日-2013年2月24日：翻譯英文資料。 2013年2月27日-2013年3月9日：履帶底盤及底架方案論證跟確定。 2013年3月12日-2013年3月30日：畫履帶底盤三維跟二維圖。 2013年4月2日-2013年4月13日：畫底架三維及二維圖。 2013年4月16日-2013年4月20日：拆總體畫零件圖。 2013年4月23日-2013年5月11日：設計說明書的編寫、整理及打印。 2013年4月1614日-2013年5月18日：最后檢查論文及圖紙準備答辯。 預期成果： 達到預期的實驗結論：鉆機通過履帶行走裝置行走穩(wěn)定，環(huán)境適應能力強。作業(yè)時使用支腿制成增強了穩(wěn)定性，底架用滑架、底座、變角油缸組件實現了變焦功能，也能實現推進架的滑移功能。 特色或創(chuàng)新之處 ① 采用了支腿和履帶共同作用的方式，目前在許多工程機械中，都是采用輪式底盤和支腿共同作用的方式，而在這里考慮到鉆機工作的特殊性，要鉆孔100m，不能讓孔有太大的彎曲，這就要求鉆機本身有一個很穩(wěn)定的工作平臺。這樣的設計滿足了實際需求。但在下一步的改良設計中建議重新準確的算一下鉆機各部件的重量，將履帶底盤的機架改為人字梁結構，優(yōu)化各部件布局，使得鉆機結構更合理，美觀，行動更靈巧。 ② 底架結構大體是用了滑架、底座、變角油缸組件組合而成，特點是不僅僅實現變角功能，還實現了推進架的滑移功能。 已具備的條件和尚需解決的問題 ① 已具備的條件：電腦；相關開發(fā)軟件；部分技術資料。 ② 尚需解決的問題：學習CAD確定產品的結構尺寸和技術要求。 指導教師意見 指導教師簽名： 年 月 日 教研室（學科組、研究所）意見 教研室主任簽名： 年 月 日 系意見 主管領導簽名： 年 月 日 MDL-50A型錨固鉆機使用說明書 MDL-50A Drilling Rig Operation China is the world's first national machinery development. Chinese mechanical engineering technology not only has a long history and splendid achievements in Chinese is not only the material culture and social economic development plays an important role in the world, and has made great contribution to promote the progress of technology civilization . Machine in the traditional，our country within a long period are leading in the word. In modern times, especially from the early 18th century, to the 19century40s, due to the economic and social and many other reasons, the machinery industry of Chinese was stagnation, but the 100 years is western bourgeois political revolution and industrial revolution time, mechanical science and technology is developing rapidly, and far more than the level of China. So, China mechanical development level and the western gap widens, to the 19th century middle， our country already behind western more than one hundred years. Over the past 40 years, roof bolter of China are developing from nothing, in some places roof bolter were also called anchor rig, the varieties from the original single to variety, from single power to multiple power. Our country successively has developed a mechanical support leg type electric roof bolter, drill roof bolter, supporting leg and the guide rail type hydraulic pressure roof bolter, supporting leg type pneumatic roof bolter, non-mechanical transmission support leg electric roof bolter, airborne roof bolter and double-stage Air-leg drill etc.. According to the main power source, roof bolter has two kinds - Pneumatic and hydraulic. But electro-hydraulic combination will be the trend of its development. Over the past 40 years, roof bolter of China are developing from nothing, in some places roof bolter were also called anchor rig, the varieties from the original single to variety, from single power to multiple power. Our country successively has developed a mechanical support leg type electric roof bolter, drill roof bolter, supporting leg and the guide rail type hydraulic pressure roof bolter, supporting leg type pneumatic roof bolter, non-mechanical transmission support leg electric roof bolter, airborne roof bolter and double-stage Air-leg drill etc.. According to the main power source, roof bolter has two kinds - Pneumatic and hydraulic. Hydraulic roof bolter is mainly component of the medium of hydraulic oil and the drive actuator witch is including cylinder and motor. Pointing from the walking in the domestic the hydraulic roof bolter mainly has two kinds –skid and crawler. Structure of skid hydraulic Roof bolter is simple, but the strength is higher, operation is simple, manufacturing cost is relatively low. Such as Wuxi dual-fan production of YG-80, Chengdu Hamma production of YXZ-70, Chongqing prospecting plant production of MGJ-50 etc… Holing main technology is double eccentric, commonly used in drill pipe isΦ73, Φ89, according to different design of jacket tube drill pipe commonly useΦ108, Φ127, Φ146 etc specifications. They need to be equipped with proper air compressor to driven impact power, because the bottom of impact always role in the hole, so often be called as "blow". Anti-floating anchor, excavation, soil nail wall support are widely used in workers of the construction process. But they are moving heavy, function single, and increased with the processing costs, much higher and higher buildings, this kind of type has been unable to meet the needs of the market. So anchor bolt drill and tracked automatically walking got quickly development. In the domestic there are many types of the crawler roof bolter, which features in the main power head adopts the high torque motor drive, speed range usually is variable speed. They are greatly improving the rig performance. The track is driven by a hydraulic motor, which made the drilling machine more flexibility and reduces the complex of the artificial joint. This type of drill also adopted the "attack" mode, such as the Oriental industrial production of DF-3000, Xuanhua Ingersoll-Rand production of CM-351. This type of drill same with the slide drill on the pulling sleeve also need be equipped with auxiliary equipment and other auxiliary equipment. In China there is a kind of double anchor rig power head roof bolter, characteristic of this kind of drill rig is drill pipe and casing are driven rotation by each power head, and do not influence each other, pull casing can be done automatically by the machine. Every rig all have they own operation manual. The follow is MDL-50A Drilling Rig operation manual. 1. Preface The company has adopted its latest assembling technology for all main parts and components of this product. And the rig is completed with chassis for pretrial and pipe wrench and other accessories, which the re-designed fully new hydraulic system incorporates into one entity. Key elements are all renowned brands either local or imported, and are fully hydraulically controlled and displayed through instruments. The drilling rig is easy and flexible of operation and has high working efficiency and so well meets the requirements by the customer. MDL-50A Drilling Rig is a new type fully hydraulic long-stroke anchored drilling-rig for engineering purposes developed and manufactured by Jiangsu Wuxi Mineral Exploration Machinery General Factory Co. LTD (formerly Jiangsu Wuxi Mineral Exploration Machinery General Factory). MDL-50A Drilling Rig is a hydraulically controlled, anchored power head engineering drill. Its overall weight is under 4000kg, is mainly for the anchoring engineering of coast and dangerous rock/cliff mass for geological disaster prevention activity, and the anchoring engineering of rock body etc to control displacement of buildings, and also for supporting of deep-foundation pit and groundwork reinforcing engineering in urban construction site, for blowing up engineering or blowing up hole etc. But the Drilling Rig isn’t suitable for anchoring engineering of high-edge slope or dangerous rock body. MDL-50A Drilling Rig possesses the characteristics of stable performance, high working efficiency, multiply usage, as well as the capability of drilling sophisticated stratum and handling accidents etc. This drilling rig, deployed by common alloy drill tools or other drill tools, can perform revolving-and-drilling. In the rigid rock stratum, the drilling rig deploys the spheroid drill bit to perform striking and revolving and drilling to have high-speed-bored hole; if deployed with air-compressor and pneumatic in-the-hole hammer, and accepted the cannula-followed drill tools, the drilling rig can drill the hole with cannula together in those unstable stratum such as conglomerate stratum. Following are the main features of the drilling rig: 1） Compact in structure, fully hydraulically controlled, easy and flexible of operation and easy to move, good mobility, time- saving and energy-saving. 2） Fitted with exclusive drilling follow-up devices (drill rod, thimble, and eccentric drill bit etc). When drilling in unstable stratum thimble can be used at collaring and the hole can be finished with conventional ball teeth bit to achieve good drilling efficiency and good quality holes. 3） Optimized heat diffusion system in the light of customer’s plant conditions to ensure that the max temperature in the hydraulic system does not exceed 70℃ when outdoors temperature reaches 50℃. 4） Power head of the drilling rig has big torque and long stroke with high drilling efficiency, which greatly enhances working efficiency. Fitted with devices for mechanically mounting/dismounting drilling rod to reduce the operators’ labor intensity. 2. Technical Specification Main drilling mode of this product is: conventional drilling, alloy bit drilling, and spiral drilling 1) Hole dia.（mm）：φ85-φ160 2) Hole depth（m）：40-60 4) Boring angle（°）： -15-90 5) Rated speed（r/min）：12、25、45、60、90、125 6) Rated lift capacity（kN）：42.5kN 7) Rated pull down capacity（kN）：25kN 8) Feed stroke（mm）：1800 9) Dynamic：Motor，18.5kw+11kw+1.5kw 10) Weight（kg）：4000 11) Shape (L×W×H，mm) ：4200×2000×7200 12) Plumb condition：3800×1800×3600 13) Transport state：3800×1800×2000 3. Structure of the Drilling Rig MDL-50A drilling rig comprises of the following main components: （1）The power assembly The power module is made up of three electric motors which respectively drive three sets of pumps. Among them, one group is a double gear pump. The big one is responsible for drilling quickly of the drill; and the small one is responsible for the movement and the support of one side of crutch as well as the medium-speed, low-speed drilling. One set of pump is responsible for the movement and the support of another side of crutch and the medium-speed drilling as well as the quickly lift of the power head. The last set of pump is responsible for the rise of the tower. When you start operating the drill, you should notice the rotated direction of three electric motors, its turning should be identical with the red arrow on the pump or the back shell of the motors, or the drill can't work normally. （2）The power head assembly Power head of MDL-50A type drilling rig is driven by Double hydraulic motor through gear box transmission and speed regulating, and it drives the main shaft and fore end drilling rod connection to turn in positive/reverse directions, thereby driving the drilling bits below. In the power head box is stored gear oil. When in operation be sure to check the oil level from time to time to see there is sufficient oil. On the side of the box is fitted an oil level threaded plug. Just by raising the mast to vertical position and loosening the oil level screw you can check the oil level. The up/down motion of the power head is effected by the roller assembly beneath it, which is driven by the chains. After the drilling rig has worked for a period of time there will be a certain amount of rocking motion because the roller assembly will have worn. Now is the time to loosen the locking nut and turn the fixing screw of the roller assembly to adjust the sliding clearance between the bottom and the side, then re-tighten the nut. Only be sure you do not tighten the wear- resistant plate excessively. （3）The propelling rack assembly This assembly is part of the orifice-supporting device, power head assembly and pressurizing elevation assembly. （4）The pretrial chassis With the pretrial fitted on it is possible to effect the drilling rig’s forward/ backward movement and turning and leveling through controlling the proportional pump. and that is why the drilling rig can move easily, has good mobility and is time- saving and energy- saving. （5）The hydraulic system Working oil pumps, valves, execution elements and pipe- fittings of the hydraulic system of MDL-50 drilling rig are mostly imported fine quality parts, ensuring a good working performance. （6）The electrical system As the drilling rig is not equipped with power generator an external three-phase AC power supply has to be connected to the control cabinet. The motor is started in the planetary triangle mode for the sake of reducing starting current. Total input power of the electrical cabinet is 45 kW. The cabinet is fitted with leakage protection switch as safety device, which also serves as excessive voltage protection for the hydraulic system and for various kinds of warning signals for user to be aware of the rig’s instant status. Before starting be sure to check the cabinet’s earth connection to see it is securely done. Unqualified personnel are not allowed to do any checkup or maintenance, failing that the person will have to bear the consequences. 4. Operation Points for attention in the preparation before starting the rig 1.1 The drill should be installed on the flat ground. 1.2 Be sure to tighten all the connections. In case of any loosening be sure to tighten up and make proper adjustments. 1.3 Checking each part if it get stuck or not, checking each shield and oil pipe whether it is installed correctly. 1.4 Checking whether the joy stick is on the close position, make sure it is not on working to prevent any accident. 1.5 Checking whether each connection of vitta is fast, if it is loose, adjusting it. 1.6 Checking the oil if it is enough to achieve the settled level, and making sure that inlet valve and outlet valve is on. 1.7 Clean up the surfaces of all parts and components of the rig. Apply lubricants (oil/grease) to all lubrication nozzles and sliding parts. 1.8 While using the electromotor, paying attention to its turning, its turning should be identical with the escutcheon, and reversion is forbidden. 1.9 Make sure that there is enough oil in the oil box. There is a liquid temperature meter and liquid position meter on the side of oil box. The choice of liquid presses oil: When environment temperature is-10 ~ 40 ℃, you can use L- HM 46(GB 11118.1- 1994) or YB-N 46(GB2512-81); When environment temperature is –40~ -10℃, you can change it to use L-HV 46( GB11118.1-1994) or the other low temperature liquid press the oil. If drill lasts working several days, oil box should be cleaned every month and remove from impurity. The filter in the absorb mouth of the oil pump should be replaced and cleaned each half month. 1.10 Checking whether the oil of the drill is leak or not. And before it is clear, don't drive drill. 1.11 In the cold condition, pump should be open and close by spells for some times. In the heat condition, there should be a shield on top of oil box. (You should settle it by yourself.) 1.12 If drill doesn't work for a long time, oil pump should work without loading for 10 minutes after driving drill. In the moment, the handle is on the middle position, then checking whether the handle is identical to the escutcheon. 1.13 It is forbidden that two joysticks are opposite when power head is rotating after the drill drove. 1.14 Erect the propelling rack assembly. Then fix the longer supporting rod of the supporting assembly together with the supporting base of the propelling rack. 1.15 Try start the drill and checking if the fast add press is in gear. Since the parameter in the escutcheon is confirmed by hydraulic press element in normal condition and also the efficiency of the system is unsure. So the error between the real and the grade parameter in 15% is in gear when the drill is in trial run. 1.16 The drilling Rig can on working after the above movement is in gear. Points for attention when operating the drilling rig 2.1 Before leaving factory the drilling rig has had its hydraulic system pressure adjusted. So do not change it without approval of the manufacturer. For the sake of safety and prevention of accidents be sure to use your greatest discretion when using excessive system pressure. 2.2 After the propelling rack is erected the ideal thing to do is to remove the rig erecting operation handle in order to prevent mistaken operation. 2.3 Before starting drilling, check the cylinders of the rig’s supporting legs to see they are properly supported. 2.4 While drilling is going on it is not allowed to pull the handle of the supporting leg’s oil cylinders in order to prevent any accidental change to the angle of drilling. 2.5 When power head is close to either extreme position near the end it is not allowed to have any quick motion. Any great impact is to be avoided. 2.6 The drilling rig is fitted with protection against overload pressure and with overload warning. When hydraulic system is overloaded the rig will automatically cut off power to motor and issue warning. Now you will have to find out the cause of overload and remove it before starting the drilling rig again. Warning： 1）The power head function of quick feed-in and elevation can only be used when operating and coordinating have become really skilled; otherwise accident may happen. 2）When operating simultaneously the power head feed-in and elevation handles, there must not be simultaneous working in opposite directions, which may cause damage to the system 5. Normal Failure & Its Shooting Method 1）Normal faults and remedies of the hydraulic pump Phenomenon Analysis Remedy No oil, The oil measure is Insufficient, the pressure is not enough 1. The electromotor turnaround worry 1. Check the electromotor turnaround 2. Suction pipe or filter blocked 2. Dredge pipe, clean filter, replace oil 3. Too large clearance between shafts or radials 3. Check and replace relevant parts 4.Leakage in joints, air interfused 4. Screw down bolts on joints，remove the leakage, prevent air into 5. High viscosity of the hydraulic oil or too high oil temperature of hydraulic oil 5. Select the correct hydraulic oil，and control oil temperature The noise is serious, the pressure wave is severe 1. Suction pipe or filter blocked, or too small with filter content Clean filter for the suction pipe smooth， select the correct filter 2. The seal of suction pipe blow by or there is air bubble in the oil Add oil in the conjunction part or seal place, if the noise let up, can screw down conjunction part or replace to seal ring; Return pipe nozzle should be below the oil, and have the certain distance with suction pipe. 3. Pump and the joint cardo is not concentric Adjust concentric 4. Insufficient oil Add oil 5. High viscosity of the hydraulic oil or low oil temperature of hydraulic oil Heat oil to the appropriate temperature 6. Pump bearings mangle Check the temperature of pump bearings(Use hands to feel that) 2）Normal faults and remedies of hydraulic cylinders Phenomenon Analysis Remedy Crawl Air incursion 1. Increase vent-pipes; If there is no exhaust, can run the hydraulic system with the longest journey to make the work parts fast run, force releasing air. The seal ring of hydraulic cylinders end cover press too tight or too loose. 2. Adjust the seal ring, make it not loose and not tight, and the piston pole can be ensured to placidly draw it by hand but no leakage( Mostly admit to leak tiny oil) The piston pole and the piston have not concentric 3. Correct concentricity between the piston pole and the piston The span or part of piston pole bend 4. Alignment the piston pole The installation position of hydraulic cylinders move 5. Check and correct the parallel between the hydraulic cylinder and the lead rail The linearity of the hydraulic cylinder inner hole is bad( The drum taper etc.) 6. Renovate the hydraulic cylinder with milling and boring, and match piston again. 7. Canker the cylinder ,or wear away the cylinder wall 7. It removes rust and burr that it is slight, it must bore and mill that it is serious. 8. Both sides screw caps of double piston poles are tweaked too tight, and make its concentricity be bad 8. The screw caps should not be tweaked too tight, can tweak them with hand generally, then keep the piston to be placed in nature. Impingement Too large clearance between pistons and hydraulic cylinders that used clearance seal, the throttle lose the effect of throttle. The clearance between pistons and hydraulic cylinders should be matched with the provision, and reduce the leakage phenomenon. The cushion check valve of the end is failure, and can not react the cushion. Revise and match the check valve with the valve holder he thrust lack or the work speed gradually descend even to stop Too large the coordination clearance between the hydraulic cylinder and the piston or O seal ring damage, and result the high and low-pressure cavity to connect with each other 1. Match the clearance between the piston and the hydraulic cylinder or replace the O seal ring Because a certain section of the work journey was used usually on the working hours, and result in the linearity of the hydraulic cylinder hole bad( Have the drum form p