1、CEMA Standard 501.1 Specifications for Welded Steel Wing Pulleys Conveyor Equipment Manufacturers Association BSR/CEMA 501.1-2003 (R2009) Reaffirmation of ANSI/CEMA 501.1-2003 ( Approved: March 26, 2009 ) ISBN 978-1-891171-37-6For Information on Company Membership visit the CEMA Web Site at http:/ww
2、w.cemanet.org CEMA ORGANIZATIONAL CHART SAFETY NOTICE The Conveyor Equipment Manufacturers Association has developed Industry Standard Safety Labels for use on the conveying equipment of its member companies. The purpose of the labels is to identify common and uncommon hazards, conditions, and unsaf
3、e practices which can injure, or cause the death of, the unwary or inattentive person who is working at or around conveying equipment. The labels are available for sale to member companies and non-member companies. A full description of the labels, their purpose, and guidelines on where to place the
4、 labels on typical equipment, has been published in CEMAs Safety Label Brochure No. 201. The Brochure is available for purchase by members and non-members of the Association. Safety Labels and Safety Label Placement Guidelines, originally published in the Brochure, are also available free on the CEM
5、A Web Site at http:/www.cemanet.org/CEMA_Safety_Pg.htm PLEASE NOTE: Should any of the safety labels supplied by the equipment manufacturer become unreadable for any reason, the equipment USER is then responsible for replacement and location of these safety labels. Replacement labels and placement gu
6、idelines can be obtained by contacting your equipment supplier or CEMA. Conveyor Chain Controls Palletizers Meet in March and/or September Conference Strategic Planning Insurance Meetings Marketing/Membership Statistics Finance and Budget Past Presidents Bulk Handling Section Committees Unit Handlin
7、g Section Engineering Conference Conveyor Chain Performance T erminology Unit Handling Standards Idlers Pulleys Belt Systems Screw Conveyors Belt Manual Accessories Safety Controls T erms and Definitions International Standards Meets Each June Screw Conveyors Bulk Handling Components and Systems Gen
8、eral Bulk Handling Section Bulk Accessories Unit Handling Conveying Section COMMITTEES BOARD OF DIRECTORS OFFICERS DISCLAIMER The information provided in this document is advisory only. These recommendations are provided by CEMA in the interest of promoting safety in the work place. These recommenda
9、tions are general in nature and are not intended as a substitute for a thorough safety program. Users should seek the advise, supervision or consultation of qualified engineers or other safety professionals. Any use of this document, the information contained herein, or any other CEMA publication ma
10、y only be made with the agreement and understanding that the user and the users company assume full responsibility for the design, safety, specifications, suitability and adequacy of the system component, or mechanical or electrical device designed or manufactured using this information. The user an
11、d the users company understand and agree that CEMA, its member companies, its officers, agents and employees shall not be liable in any manner under any theory of liability for the user or users reliance on these recommendations. The users and the users company agree to release, hold harmless and in
12、demnify CEMA, its member companies, successors, assigns, officers, agents and employees from any and all claims of liability, costs, fees (including attorneys fees), or damages arising in any way out of the use of this information. CEMA and its member companies, successors, assigns, officers, agents
13、 and employees make no representations or warranties whatsoever, either express or implied, about the information contained in this document, including, but not limited to, representations or warranties that the information and recommendations contained herein conform to any federal, state or local
14、laws, regulations, guidelines or ordinances. FOREWORD and SUMMARY OF CHANGES These recommended load ratings should be of benefit to the entire industry and, in particular, establish a basis for economical pulley selection. This standard is not intended in any way to limit the design of any manufactu
15、rer. In 1966, the Wing Pulley Subcommittee of the Mechanical Power Transmission Association (MPTA) was formed to study a recommended standard for pulley load ratings and dimensions. This committee, composed of pulley and conveyor engineers, studied the available information on pulley design and theo
16、retical stress analysis and data from actual tests. All parts of the pulley and shaft assembly were included in this study. This standard was later approved as ANSI/MPTA 501-1977 and was subsequently revised MPTA 501.1-1984. In November, 1985 the standard was transferred to the Conveyor Equipment Ma
17、nufacturers Association (CEMA). The Conveyor Pulley Subsection of the Conveyor Equipment Manufacturers Association was assigned the responsibility for maintenance of the standard. On January 27, 1988 the standard was approved as ANSI/CEMA 501.1-1988. In 1995 CEMA reviewed the document and determined
18、 that no changes were required. It was reaffirmed as an ANSI/CEMA Standard in 1996. In 2003, the Conveyor Pulley Subsection reviewed the standard and and made four changes. The document was subsequently approved as ANSI/CEMA 501.1-2003. See next page for a summary of the changes. The Conveyor Pulley
19、 Subsection of the Conveyor Equipment Manufacturers Association has the responsibility for maintenance of this standard. Copyright 2009 Conveyor Equipment Manufacturers Association 6724 Lone Oak Blvd Naples, FL 34109 (239) 514-3441 FAX (239) 514-3470 http:/www.cemanet.org i Note - CEMA Has Reaffirme
20、d the 2003 Edition. This 2009 Edition is Identical to the 2003 EditionSpecifications for Welded Steel Wing Pulleys 1 1. SCOPE 1.1 This Standard applies to a series of straight face and crown face welded steel wing pulleys which have a number of steel wing plates that extend radially from the longitu
21、dinal axis of two compression type hub assemblies and are equally spaced about the pulley circumference. The purpose of the compression type hubs is to provide a clamp fit on the shaft. The wings are supported or joined by welded steel plates so arranged as to form the shape of two frustums of cones
22、 or regular pyramids being joined at their bases. A bar of sufficient radius is attached to the outer longitudinal edge of each wing to provide more contact area with the belt. This standard is restricted to pulleys which do not transmit torque. This standard is not applicable to pulleys with contin
23、uous (uninterrupted) rims, or cast pulleys. This standard applies to pulleys using compression type hubs. It does not cover pulleys welded to the shaft or high pressure keyless locking assemblies. This standard establishes load ratings, allowable variation from nominal dimensions, permissible crown
24、dimensions and such overall dimensions as are normally necessary to establish clearances for location of adjacent parts. The pulley diameters, face widths and shaft sizes shown are those that are nominally used in current belt conveyor and elevator practice. These only are covered by this standard;
25、all other sizes and capacities are not covered by this standard. 1.2 Welded steel wing pulleys covered by this standard should not be used with steel cable and other high modulus belts because such belts create stress concentrations and demand manufacturing tolerances beyond the capacities of these
26、pulleys. 2. DIMENSIONS AND TOLERANCES 2.1 DIAMETERS: Standard welded steel wing pulley diameters are 8, 10, 12, 14, 16, 18, 20, 24, 30 and 36 inches. All other sizes are considered special. These nominal diameters apply to straight and crown-face pulleys and are for bare pulleys only. They do not in
27、clude any increase brought about by lagging. 2.2 DIAMETER VARIATIONS: Permissible variations from nominal diameter are based on face width as follows:FACE OVER NOMINAL UNDER NOMINALWIDTH DIAMETER DIAMETER(inches) (inches) (inches)8 thru 26 1/8 3/8 over 26 thru 66 1/8 3/4 These limitations apply equa
28、lly to straight face and crown face pulleys. The nominal diameter is measured at the midpoint of the face width. The diameter is defined as the bare diameter exclusive of any lagging. The permissible diameter variations listed are not to be construed as runout tolerance on diameter. The listed varia
29、tion in nominal diameter may occur from one pulley to another. Runout tolerance on diameter shall not exceed 3/16“ total indicator reading for all pulley diameters. 2.3 FACE WIDTHS: Standard welded steel wing pulley face widths are 12, 14, 16, 18, 20, 22, 26, 32, 38, 44, 51, 57, 63, and 66 inches. A
30、ll other sizes are considered special. 2.4 FACE WIDTH VARIATIONS: Permissible face width variation from nominal face width is 1/4“ for all sizes. Face width is defined as the length of the wing or contact bar along the shaft axis. The permissible face width variation is not to be construed as an edg
31、e runout tolerance. The listed variation in face width may occur from one pulley to another. Edge runout tolerance shall not exceed 1/4“ total indicator reading for all pulley face widths. 2.5 CROWN: Crown is defined as the amount (expressed in inches) per foot of total face width by which the diame
32、ter at the center of the face exceeds the diameter at the edge. The amount of crown may be from 1/16 to 1/8 inch per foot of total face width. 2.6 SHAFT RUNOUT: The shaft extension runout is measured from the bearing journals after the shaft is installed in the pulley. Radial shaft extension total i
33、ndicator reading (TIR) shall not exceed 0.002 inches per inch of shaft extension beyond the bearing center. Typically bearings will introduce an additional runout, which is not included in this limit. 3. PULLEY SELECTION GENERAL INSTRUCTIONS 3.1 PULLEY DIAMETER AND FACE WIDTH: The following selectio
34、n procedures assume the pulley diameter and face width have been established consistent with belting and conveyor design requirements. 3.2 RATINGS: The tabulated ratings for pulley and shaft combinations are based on using non-journalled shafting thru the pulley hubs, with pulleys centrally located
35、between two bearings. Ratings are based on SAE 1018 shaft material using either a maximum shaft bending stress of 6000 psi or a maximum free shaft deflection slope at the hub of 0.0023 inches per inch (tan of 8 min.), whichever governs. (See Appendix II for shaft deflection formula.)2. Pulleys used
36、on shafting selected with a bending stress greater that 6000 psi, or a slope exceeding 0.0023 inches per inch, are special and are not covered by this standard. High strength shafting is of value in some cases where it may permit turning down the shaft ends to allow the use of smaller-diameter, high
37、- capacity anti-friction bearings. The allowable shaft load in the rating tables must not be exceeded. 3.3 OVERLOADS: Normal running loads should not exceed ratings in the load tables. Starting and occasional peak loads should not exceed ratings by more than 50 percent. Overloads may result from suc
38、h causes as starting, jam-ups, screw take- ups, backstops, misalignment and excess amounts of material on the belt. 3.4 BELT SPEED: The maximum belt speed for welded steel pulleys shall not exceed 450 feet per minute. (For conveyor speeds in excess of the maximum, the manufacturer should be consulte
39、d.) 4. SELECTION OF PULLEY SIZE 4.1 DETERMINATION OF ACTUAL RESULTANT RADIAL LOAD: The resultant radial load is the vector sum of the belt tensions, pulley weight and the weight of the shaft. The forces from the weights always act downward and the forces from the belt act in the path of the belt and
40、 away from the pulley. In most cases, a graphical solution, as illustrated in Fig. 1 is a simple means of obtaining the resultant load. WHERE: T 3 = Tension (non-driving pulleys), pounds. W = Weight, pounds. R = Resultant radial load, pounds. Fig 1. GRAPHICAL SOLUTION OBTAINING RESULTANT RADIAL LOAD
41、3. 4.2 SELECTION PROCEDURE (See Fig. 2) The following selection procedure is used: Fig. 2. PULLEY DIMENSIONS AND NOMENCLATURE A = Moment Arm for Pulley (inches). See Table 1 B = Bearing Centers (Inches). R = Resultant Pulley Load (Pounds). L = B - Face Width (Inches). Step 1. Determine the pounds pe
42、r inch width (PIW) by dividing belt tension (T 3 ) by belt width. Compare this PIW to the values listed in Table 2 using applicable pulley diameter. If calculated PIW is higher than the pulley rating, select a pulley diameter having the required rating. Step 2. After referring to the general instruc
43、tions in Section 3, determine R, the resultant pulley load from section 4.1, using the pulley diameter determined in step 1. Step 3. Select a shaft diameter from Table 3 under Ratings for Pulley and Shaft Combinations using R, the appropriate pulley face width, and dimension L. The pulley and shaft
44、rating should be equal to or greater than R. Step 4. Refer to Table 4 to make sure the pulley diameter, face width, and shaft diameter selected are available. If the combination is not available, it will be necessary to go to a larger pulley or shaft. Step 5. Now that the shaft size and pulley diame
45、ters are determined, the resultant load may be re-evaluated. The added weight of the shaft and the larger pulley diameter may or may not change the resultant appreciably depending upon other factors involved. Example: Given: 36 Belt 4,000 pounds belt tension 38 Pulley Width 108 Arc of Contact (Take-
46、up Bend) Bearing Centers minus face is 52 38 = 14 Step 1. Tension divided by belt width is 4,000 36 = 111 pounds. Table 2 (Maximum Belt Tension) indicates that a pulley with a diameter of at least 12 must be used. Step 2. Pulley weight W is estimated from the manufacturers catalog to be 200 pounds.
47、The resultant R is 6,635 pounds. (See Figure 1, Graphical Solution Obtaining Resultant Radial Load, third diagram.) Step 3. In Table 3 (Load Ratings) note that a 3-15/16 shaft with a rating of 7,380 pounds is required for an R value of 6,635 pounds. Step 4. Referring to T able 4 (Available Shaft Dia
48、meters) and using a face width of 38, read down until the shaft diameter of 3-15/16 is found. Step 5. Using the shaft diameter of 3-15/16 and the length between bearings of 52, the shaft weight is 180 pounds. A 14 diameter by 38 face pulley is 270 pounds. The re- evaluated resultant R is 6,840 pound
49、s, which remains smaller than the 7,380 pound rating of the 3-15/16 shaft. TABLE 2 NOTE: These load ratings are computed using a maximum allowable face pressure of 200 psi and a typical contact bar radius. *N = 1/2 of the difference (L) between bearing centers and pulley face width. TABLE 1 A VALUES Shaft Diameter (inches) 1-3/16 to 2-7/16 2-11/16 to 2-15/16 3-7/16 3-15/16 4-7/16 4-15/16 5-7/16 to 6 6-1/2 to 7 7-1/2 to 8 A (Inches) *N + 1-5/8 N + 1-3/4 N + 2-1/2 N + 2-3/4 N + 3 N + 3-1/4 N + 4-1/2 N + 5 N + 5-1/4 MAXIMUM BELT TENSION ( po
