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Title: |
1890 Article-Chandler & Taylor Co., Steam Engine |
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Source: |
The Steam User, 1890 pg 52 |
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Insert Date: |
12/12/2011 1:17:49 PM |
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One of the distinguishing features of this engine is the bed, in which the metal is so distributed as to present the greatest resistance in the line of motion between the cylinder and crank shaft, and furnishing within itself both of the bearings for the crank shaft, which brings it absolutely and permanently square with the other working parts of the engine. This point cannot fail to be appreciated, especially by engine builders, who understand the difficulties and expense they have been subjected to, when starting engines, by the failure of unskilled or careless engineers to properly square the crank-shaft and get the outboard bearing in place, thereby cramping the journals and causing the crank-pin to knock and heat from lack of proper alignment. The guides, which are also a part of the bed, and of th:; same general form as are used on Corliss and other first-class engines, are of large area and of cylindrical form, and, being a part of the bed, are not adjustable; consequently they cannot be misadjusted, and their concave surfaces allow the cross-head to adjust itself to the crank-pin, thus rendering it impossible to throw the connecting-rod in twist, as would be done by raising one side of a cross-head that has adjustable guides each side of it. The cross-head is made of cast steel, and has gibs filled with Babbitt-metal. These gibs are, in length, about equal to the diameter of the cylinder, and their breadth is about one-half of their length. These present a very ample wearing surface, and as they are adjustable in the line of wear, they serve all the requirements of adjustable guides, without any of their disadvantages. The flanged end of the bed is faced and turned to fit the counterbore of the cylinder, and takes the place of a cover or head for its front end, and also forms a rigid support for the cylinder that is attached to it. This method is growing more and more into general favor, as it always maintains the cylinder true with the guides, regardless of measurement, presents the most favorable resistance to the thrust of the crank, and allows the cylinder to contract and expand, without disarranging any of the other parts. The crank-pin, piston-rod, valve-rod, and some of the other minor parts are made of steel. The glands and stuffing-boxes are made of brass, so that they will not rust, and cannot be screwed up so as to chafe the piston-rod or valve stem. The piston is of the simplest form, being simply a plain disc turned to fit the bore of the cylinder, and having two recesses in its surface, into which rings of eccentric shape are sprung to form a joint between the piston and cylinder surfaces. These require no adjustment, cause no undue friction or wear, and leave the piston free to move, although perfectly steam tight. The steam-ports are at the side, and are as low as the bore of the cylinder, which provides for perfect drainage. The eccentric, instead of being fastened with a set-screw, has two key-seats, one for the over stroke and the other for the under stroke, and has an interchangeable key, which secures it in either position, and completely frustrates any tampering with the valve adjustment, which is permanently fixed to cut off at five-eighths stroke. The crank-shaft, which is of hammered iron, is of large diameter, being about one-half the diameter of the cylinder, and runs in wide Babbitted bearings; the crank bearings being two and the outboard bearing two and one-half diameters of the crank-shaft, which give it support in a manner best calculated to resist the deflecting tendency caused by the overhang of the crank. This overhang is reduced to a minimum by extending the crank bearing into the crank-wheel, and by making the connecting-rod flat, so that it will run close to the face of the crank-wheel. This will be better understood by the description of the crank wheel and pin. The large steel crank-pin, whose diameter and breadth are about equal, is ground to size, by special machine, after being hardened. It is made without collars, and allows the brass boxes of the connecting-rod to face against the crank wheel. The crank wheel is cast with a counterbalancing weight within itself, and has a short hub on the back side, which meets the extended crank-bearing under the rim and counterweight; this short hub is reinforced on the front side, to maintain the necessary length for keying to the shaft on which it is pressed. The engine, while not specially placed in the market as a high-speed engine, is nevertheless designed for quick motion, and may be run at almost any desired speed, as it has all the elements of endurance. Its bed frame is rigid, its ports are ample, and it has large bearing and wearing surfaces, adapting it to long and continuous runs under heavy duty. (Manufactured by the Chandler & Taylor Co., Indianapolis, Ind). |
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