2014年10月7日星期二

乾燥機-幹燥機工作原理


如木材在制作木模、木器前的幹燥可乾燥機以防止制品變形,陶瓷坯料在煅燒前的幹燥可以防止成品龜裂。另外幹燥後的物料也便于運輸和貯存,如將收獲的糧食幹燥到一定濕含量以下,以防黴變。由于自然幹燥遠不能滿足生産發展的需要,各種機械化幹燥機越來越廣泛地得到應用。

壓縮空氣中水蒸氣的量是由壓縮空氣的溫度決定的:在保持壓縮空氣壓力基本不變的情況下,降低壓縮空氣的溫度可減少壓縮空氣中的水蒸氣含量,而多余的水蒸氣會凝結成液體。冷凍幹燥機就是利用這一原理采用制冷技術幹燥壓縮空氣的。因此冷幹熱風循環烘箱機具有制冷系統。冷凍幹燥機的制冷系統屬于壓縮式制冷,由制冷壓縮機、冷凝器、蒸發器、膨脹閥等四個基本部件組成。它們之間用管道依次連接,形成一個密閉的系統,制冷劑在系統中不斷地循環流動,發生狀態變化並與壓縮空氣和冷卻介質進行熱量交換。壓縮空氣幹燥機還有吸附式幹燥機和溶解式幹燥機。

制冷壓縮機將蒸發器內的低壓(低溫)制冷劑吸入壓縮機汽缸內,制冷劑蒸汽經烘箱過壓縮,壓力、溫度同時升高;高壓高溫的制冷劑蒸汽被壓至冷凝器,在冷凝器內,溫度較高的制冷劑蒸汽與溫度比較低的冷卻水或空氣進行熱交換,制冷劑的熱量被水或空氣帶走而冷凝下來,制冷劑蒸汽變成了液體。這部分液體再被輸送至膨脹閥,經過膨脹閥節流成了低溫低壓的液體並進入蒸發器;在蒸發器內低溫、低壓的制冷劑液體吸收壓縮熱風乾燥機空氣的熱量而汽化(俗稱“蒸發”),而壓縮空氣得到冷卻後凝結出大量的液體水;蒸發器中的制冷劑蒸汽又被壓縮機吸走,這樣制冷劑便在系統中經過壓縮、冷凝、節流、蒸發這樣四個過程,從而完成了一個循環。

在冷凍幹燥機的制冷系統中,蒸發器是輸送冷量的設備,制冷劑在其中吸收壓縮空氣的熱量,實現脫水幹燥的目的。壓縮機是心髒,起著吸入、壓縮、輸送制冷劑蒸汽的作用。冷凝器是放出熱量的設備,將蒸發器中吸收的熱量連同壓縮機輸入功率轉化的熱量一起傳遞給冷卻介質(如水或空氣)帶走。膨脹閥/節流閥對制冷劑起節流降壓作用、同時控制和調節流入蒸發器中制冷劑液體的數量,並將系統分爲高壓側和低壓側兩大部分。

2014年9月2日星期二

Plastic bearing-How to Maintain the Sliding Bearing Accurately


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As is known to us, the accurate maintenance of the sliding bearing is of great importance for the normal operation of the highway machinery。 If the maintenance of the sliding bearing is satisfactory, its service life can be prolonged。 In contrast, if the maintenance is not good, the service life will be seriously shortened and even the severe incident will happen。 In the normal situation, the working temperature of the lubricating oil can not surpass 50 Celsius degrees。 In addition, in order to ensure the abundant lubricating oil, the oil face should be inspected immediately and regularly。 In order to ensure the cleanliness of the oil, it is advised to change the oil timely。 What´s more, according to specific situations the problems of the sliding bearing should be analyzed in detail and solved immediately。 The common problems and its corresponding solutions are analyzed as follow:

(1) The sliding bearing is too hot。 If the lubricating oil is not enough, people should remember to add the oil and meanwhile remember to check whether the oil channel is unobstructed。 Besides, the bearing should be cleaned immediately and the oil must be replaced by the clean oil。 If the equipment is not in a good condition, the axle neck may be not straight。 For this problem, it is suggested that people should put a gasket under the bearing base。

(2) The axis is too hot。 If the rubber seal ring is too tight, the cover should be closed after the filling material is adjusted。 If there is friction between axis and bearing cover, the clearance between them should be adjusted as soon as quickly。 Generally speaking, the width of the clearance ranges from 0。25 to 0。3mm。

(3) There is oil on the surface。 If the oil pipe is blocked or the oil groove is too shallow, the pipe should be cleaned and the oil groove should be deepened。 What´s more, if the oil temperature is too low and the liquidity is too weak, it is advised to change the lubricating oil。 If the adjustable gasket blocks the lubricating oil, people must remember to inspectPlastic bearing the position of the adjustable gasket。

sintered metal-Let´s Talk Economics: Powder Metals - Solid Relations



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Expert Author Quintin I Goynes

powder metallurgy is a precision metal forming technology that is a part of the economic breakthrough for today´s manufacturers。 The concept implies the manufacturing of parts--net to near-net shape--and is preferred to by manufactured gear makers。

powder metals and Manufacturers

Powder metal (P/M) and gear makers have established a solid relationship。 This particular type of technology continues to advance as an enhancement to density and strength。 According to sources, major automakers are increasing their usage of this product, which is used in transmissions and engines (as gears)。 And with the use of new high speed steel alloy cutting tools, gears are being produced。

Frankly, gear performance characteristics are based on the required surface hardness; core hardiness; hardness profile; grade of steel/micro-structure of steel; and residual stress distribution。 Today, metal industry enthusiasts claim that most of today´s P/M gear capabilities are adequatesintered metal, in relation to shape complexities and tolerance; however, they tend to ´fall short´ on hardiness。

Heavy Density

Heavy density is what gear makers are after。 ´Near-fully´ dense P/M products: the part as less than 1% residual porosity or emptiness within its structure。 The four most effective methods of compacting are powder forging, isostatic pressing, metal injection, and spray forming。 And with powder forging, a work-piece is pressed into shape (preform)。 Then, the same piece is sintered, placed into a forge, and re-struck until fully compacted into the designed shape。 More steps may be added to suit。

Chiefly, this particular method has become popular for producing a lot of powder metal steel products that possess ´wrought´ steel properties-gears。 Ideally, a ´solid´ metal part structure provides a smooth surface that is free of voids, cracks, notches, and porous activity; while improving heat treating conditions-exhibiting enhancing gear characteristics: bending fatigue strength, impact strength, durability and endurance levels-powder metal production。

2014年8月27日星期三

竹北室內設計-家具選擇要做到與裝飾設計風格搭配

  在家裝設計中,完美的設計和過竹北裝潢設計硬的施工質量是非常重要的前提,不過業主對于家具顔色與樣式的選擇,家具是否與裝修風格搭配也是特別重要的一點新竹室內設計。好的家具不僅自身要美觀、大方,更新竹系統家具要能與周圍環境相得益彰。下面跟設計師來一起看下吧。

  一、居室缤紛多彩但是並不輕佻,需要用好深色家具:一些人希望讓自己的居室顯得色彩缤紛,比如將牆壁塗刷成鮮豔的色彩,但是又擔心過分豔麗的顔新竹裝潢設計色會令房間變得輕佻、庸俗。其實,只要在家具和飾品搭配上用點心思,你所擔心的情況完全可以避免。

  對于色彩鮮豔的牆面來說,一套深色家具是最合適的了。值得注意的是,如果牆面顔色是暖色調,那麽家具的色調竹北室內設計最好也是暖色調的。如果牆面顔色偏冷色調,那麽家具就要避免選擇上述材質。深色家具往往顯得沈穩、大氣,讓家居環境在缤紛美麗的同時,不會失去優雅格調。

  二、恬淡、純淨、自然的家庭港灣:都市生活過于紛繁和喧鬧,因此許多人都希望自己的家能展現出甯靜、自然的一面,讓疲憊的心靈有個休憩的港灣。減少色彩的選擇,淺淡的色調更容易帶給人們這樣的家居空間。

  淡淡的藍灰色能夠幫助人們放松緊張的神經,將這種顔色使用在牆面、窗簾等處,會令房間顯得恬淡而柔和,並有一種隱約閃現的懷舊情懷。在這樣的空間裏,搭配灰白色的木質家具或是冷色系的布藝家具都是不錯的選擇。

鋼片聯軸器-減速機維護、保養及操作注意事項是什麽

  ①所有減速機嚴禁帶負荷啓動。減速機更換配件後必須經過磨合和負荷試車後,才能正常使用。

  免鍵式軸環②在使用過程中,應密切注意各傳動部分的轉動靈活性,對使用過程中發現的異常聲音及高溫現象應四段變速機及時通知維修人員。

  ③經常檢查螺栓緊固程度和油量,油位低于油標尺的下刻度線時應及時通知維修人員進行補油。

  ④爲使減速機易于散熱,應保持表面清潔,通氣孔不得堵塞。

  ⑤應對運行中的減速機每小時巡檢一次,注意觀察油泵供(立式擺線減速機)油情況。對油溫過高造成油管斷裂的減速機應進行重點巡查。

鋼片聯軸器  ⑥對減速機的液體攪拌機運行中發現的問題應詳實、認真記錄。

噴洗機-高壓清洗機選購學問大


高壓清洗機是普通自來水加噴洗機壓後變成具有一定壓力的高壓清洗設備水射流,來進行對清洗的一種清潔機器。因其具有環保高效、對物體沒有損害備受用戶親睐。如何選購高洗淨機清洗機呢?因爲市場魚目混珠,一些商家盲目追求低價位和市場銷量,質量區別很大。更由于人們購物時貪圖便宜,在選購高壓清洗機時如果對市場和技術不熟悉,就會吃虧上當甚至危及使用者的人生安全。

購買高壓清洗機時一定要認准質量好的品牌,搞清設備配置。不要盲目看外表包裝精美就認爲高壓清洗機質量也很好。對高壓清洗機選用的材料進行對比,選擇國內發展比較久正規高壓清洗機廠家對高壓清洗機本身安全有一定的保障作用。對于些小廠生産、組裝的設備一定要小心,對于沒有銷售、超音波清洗機售後維修資質的商家一定小心,不真空超音波清洗機要爲了少花幾十元而選擇假冒高壓清洗機而帶來不必要的損失。

當然,高壓清洗機所能應用的範圍很廣,由于設備的不同參真空回收機數,所超音波洗淨設備側重的領域也不同,有家用便攜式的、商用真空清洗機的及工業級清洗機,而目前高壓清洗機的生産廠家主要有上海科球、潔普斯、凱馳、熊貓等自動清洗機等。用戶在選購之時,應充分考慮自身的需求和品牌效應,合理采購。

拉伸彈簧-壓縮對比法--用于粗略測定彈簧彈力大小


對于氣門彈簧和離合器壓拉伸彈簧簧來說,在維修工作中除了外觀上檢查其完好程度外,重要的是檢查彈簧的彈力情況。

這兩種彈簧如果彈力嚴重衰退的話,前者可使氣缸高速工作不良,後者會引起離合器傳遞扭矩時打滑,使行車無力、無高速。如果手邊有一個台鉗,即可對其作壓縮對比,檢驗其彈力如何。其方法是:挑一根手感彈力較好的彈簧作爲標准簧(也可用新簧壓縮彈簧作標准簧),然後將懷疑彈力減弱的簧與之首尾對正,在兩簧之間用一塊4Omm×40mm大小的平鐵皮(也可用厚些的平板紙)隔開,作爲下一步測量兩簧各自長度的分界點。再把它們放在台鉗鉗口之內擺正(縱向擺正)。

轉動台鉗手柄,使彈簧長度從自由狀態下壓縮至原長度的3/4左右停止。此時可用遊標卡尺或鋼板尺,分別測量兩簧在壓縮狀態下的各自長度,如被測彈簧此時的長度明顯小于標准彈簧的長度,或是長度差在2mm以上時,即可確定該彈簧之彈力衰退嚴重,不可再用。