They use hollowshaft speed reducers and do not require transmission components such as couplings, chains, or sprockets, so virtually nothing rotating is exposed to the outside, and high safety is assured without use of a safety cover. What are the advantages of a hollow shaft compared to a solid shaft. Figures 46 show typical hollowshaft high thrust motors and figures 7. Otherwise, it can be referred as a force needed to twist the hollow shaft. The standard is a solid shaft which is comparable to most other motor shafts and couple to the pumps shaft with a keyed coupling. Dec 17, 2011 to prove this we have to compare the shaft bending stress developed for the same applied bending moment to the hollow shaft and solid shaft. We will use the beam bending equation here for the calculation of bending moment stress. Thruhub diameter 30 mm mounting pcd 164 200 512 600 1024 ppr. Different measures are available for the joint hole and for the shaft diameter. Mar 02, 2016 example problem video for the mechanics of materials course offered by the faculty of aerospace engineering at delft university of technology. If the hollow shaft is to store 25 % more energy than the solid shaft when transmitting torque, what must be its internal and external diameters. Eltra has developed a broad catalog of incremental encoders here classified according to the type of mechanical mounting solid vs blindthough hollow shaft and the type of sensing technology optical vs magnetic, with a wide range of resolution, flange and electronic outputs available to meet the specific applications needs. Our product range includes besides bevel, hypoid, planetary and cycloidal gear boxes also special customized gear boxes and high precision gear technology. Figures 46 show typical hollow shaft high thrust motors and figures 79 show typical solid shaft high.
The kdu has a large hollow shaft design which allows cables, shafts or lasers to pass through the axis of rotation. Solid shaft for shorter applications will give better damping characteristics than a hollow shaft. Assume the same maximum shear stress applies to both shafts. Installation instructions for hollow shaft style encoders using a tether arm the solution, of course, is to ensure that some part of the assembly is flexible to minimize the stress on the encoder bearings. A hollow shaft encoder mount is one of the lowestoverhead, loweststress options. One way to check for strength or stiffness is to load the shafts by weights and see which one would be more likely to bear greater compressive and tensile stresses.
Hollow shaft construction is available in frame sizes 2 and larger whereas solid shaft construction is available in 182 and larger. A little bit of the tip was trimmed off, and a plastic pin was inserted into the shaft. The range of incremental encoders fit to be coupled to motor shafts includes different mechanical types. Design of hollow shaft when the shaft is subjected to axial tensile force, bending moment and torsional moment. Also evaluate the torque considering the hollow shaft of 100 mm inner.
I worked out the second moment of area for the solid shaft 9. Figure 1 shows a typical 2286 frame hollowshaft motor and figure 2 shows the 324405 frame construction. Torque transmitted by shaftsolid total turning moment due to turning force total. Direct drive and hollow shaft motors harmonic drive. Hollow shafts are having a more polar moment of inertia, thus they can transmit more torque compared to solid shafts. Difference between hollow shaft and solid shaft mechopedia. Easily accessible top coupling permits vertical adjustment of pump impellers. Consider a solid shaft of diameter dsh delivering power p at variable speed n. Hollow shaft the range of incremental encoders fit to be coupled to motor shafts includes different mechanical types. A hollow shaft has greater strength and stiffness than a. Sep 08, 2011 lecture torsion in solid and hollow shafts 1 1. I can find the separate shear stresses easily enough, but i havent found a single resource online that covers the situation of having a shaft be both solid and hollow at the same time.
A hollow shaft vertical motor works a bit differently. An overall shaft design procedure is presented including consideration. Vhs motors from 40hp up to 250hp motors, major turbine stocks a large number of vertical hollow shaft motors in both the dublin and camilla facilities. The machine shaft is inserted directly into the gearboxs hollow shaft and connected with a mounting set. The natural frequency of hollow shaft is higher than the solid shaft with the same weight. Gear motor hollow shaft 3d cad model library grabcad. I vaguely understood the ideas expressed in the answers there still trying to wrap my head around the second moment of. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. Therefore, hollow shafts are stronger than solid shaft having the same weight. Jun 25, 2011 nearly all drivers, especially in the older days, used to insert the shaft all the way through the head thrubore. One is solid and 100 mm diameter, the other is hollow. We provide the customer high quality,suitable products and professional,prompt service to ensure your machines keep running. Maximum shear stress in a hollow shaft subjected to a torsional moment is at the a.
An extensive range of customized shaft and cable versions as well as custommade products can be. The shear stress in a solid circular shaft in a given position can be expressed as. The solidshaft construction is similar except that the top halfcoupling is omitted, and the motor shaft extends out the bottom of the motor. Advantage of hollow shaft over the solid shaft answer parth. Vertical hollow shaft motors download pdf of this page. Aerospace mechanics of materials by tu delft opencourseware is licensed under a creative commons attributionnoncommercialsharealike 4.
Besides standard versions, eltra offers to its customers the. Mechanics of solids mcq question on simple stress and strain 1. Let, d s diameter of solid shaft d h external diameter of hollow shaft. The kdu series are direct drive motors which achieve 10 arcsec positioning accuracy as well as 0. Torque is a force required to rotate the hollow shaft at a fixed axis. Shafts hollow shafts misumi misumi south east asia. Compare solid shaft with the hollow, mechanical engineering. The diameter of the hollow shaft is more than the solid shaft and require more space. There are two kinds of shafts that a vertical pump motor typically has. Due to their long history of reliable service, major turbine has the us motor and ge motor branded product on the floor at all times. From what i can gather, the pin is basically just aesthetic, but it did keep dirtgrassjunk out of the shaft.
Hollow shaft is a rotating shaft, which uses lighter metal but hold strength similar to solid shaft of the same diameter. A hollow rod that weighs the same as a solid rod will be much wider so the force will be spread over a much larger area. Hollow shaft hole sizes from 6 to 30 mm, metal housing and resolution wetpit pump product lubrication the vtp is a single casing, diffuser type, single or multiple stage vertical turbine pump designed for continuous duty in a variety of wetpit and deep well applications. A solid shaft and a hollow shaft are to be of equal strength in torsion.
This design offers simplicity because a hollow shaft encoder is compact, adjustable, and versatile. To prove this we have to compare the shaft bending stress developed for the same applied bending moment to the hollow shaft and solid shaft. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray. If the area of cross section of both the hollow and the solid shaft is same along with power transmission in solid and hollow shaftread more. In drive technology, especially in the field of tool machinery, automation and robotics, these compact designed, high transmission precision gear boxes. Hollowshaft construction is available in frame sizes 2 and larger whereas solidshaft construction is available in 182 and larger. Deflection due to shear force as compared to bending moment will be. The manufacturer used solid shafts to make up for the fact that they did not use a strong enough alloy to make the more expensive laborwise hollow shaft. Kdu the kdu series are direct drive motors which achieve 10 arcsec positioning accuracy as well as 0.
Mainly, amount of torque you can transfer given that the amount of. This series accepts a dshaft and features resolution wetpit pump unequaled hydraulic coverage and design flexibility the flowserve vtp is a single casing, diffusertype, applications. Incremental encoders, solid and hollow shaft, with hall effect. Nearly all drivers, especially in the older days, used to insert the shaft all the way through the head thrubore. When a shaft or a bar is loaded from above using heavy weights, the bar or the sha. The impeller is fixed at the bearing of the inner wall of the tube shaft by welding and other methods. Our hollow shaft gearbox allows you to directly power a machine shaft via a clamping set. Typical sizes of solid shaft that are available in the market are. The oem hollow shaft will be tortionally stiffer and with less vibration in the drivetrain, will.
We use triedandtested highprecision spiral gearing, which facilitates the rightangled transmission of torque and speed. Two shafts are of the same material, length and weight. Lecture torsion in solid and hollow shafts 1 slideshare. Example problem video for the mechanics of materials course offered by the faculty of aerospace engineering at delft university of technology. The shaft has an outer diameter of 79 mm, and the thickness of the wall of the hollow segment is 10 mm. Vertical hollowsolid shaft motors universal fiberglass. But if we have radial space constraint then solid shaft is preferred since, in this case solid shaft has more power transfer capacity than hollow shaft. When there is no space constraint, then for same mass, hollow shaft is better than solid shaft. Both hollow shaft and solid shaft motors are described in this instruction book. Apr 26, 2017 design of hollow shaft when the shaft is subjected to axial tensile force, bending moment and torsional moment. Both hollowshaft and solidshaft motors are described in this instruction book. They use hollow shaft speed reducers and do not require transmission components such as couplings, chains, or sprockets, so virtually nothing rotating is exposed to the outside, and high safety is assured without use of a safety cover.
We recommend technical clarification prior to ordering. Why is a hollow tube more stable than a solid tube. Very similar to most direct driven horizontal motors. Removing the core of a solid shaft shifts the shear stress distribution, thus, to get the same maximum shear stress on the outside, a hollow shaft will need to be of greater. Hollow shaft solid shaft speed changers and reducers miki. You can get better strength with a hollow shaft due to the polar moment of inertia j14 pi r4, this with the same weight hollow vs. If speed feedback is a crucial factor, a hollow shaft encoder is the best choice. The bending stress fs developed in a solid shaft is given by.
The fraunhofer iwu has become a leader in the production of rotary parts by forming. Compare solid shaft with the hollow shaft, by strength and their weight. Rwm models these are hollow shaft geared motors for motor outputs of 0. Electric motors, solid or hollow shaft engines with right angle gear drives steam turbines separate axial thrust bearing assembly standard and iso 709api 610 vs1, latest. Hollow shafts are cheaper than solid and having more flexibility and light weight in compared to solid shaft. Rwm models these are hollowshaft geared motors for motor outputs of 0. Bending strength in this case is proportional to the moment of inertia which for a constant mass is higher if the mass is distributed further away from the center.
I recall being told once that hollow rodsshafts tend to resist torsion more than solid rodsshafts. Hollow or solid which one is better tdiclub forums. Large hollow shaft design allows cables, shafts or lasers to pass through the axis of rotation. Gear tooth forming by means of gear tooth rolling and the manufacturing of the hollow shafts by means of spin extrusion are two technologies that have been engineered and can be employed to optimise production engineering process in terms of resource efficiency. Eppinger develops and manufactures cycloidal gear boxes to round off the product portfolio. The hollow shaft can be used to pass cables or conduct laser beams through it in order to save space. These are hollow shaft geared motors for motor outputs of 0. Nanotec offers stepper motors with hollow shaft in the sizes nema 17 42 mm and nema 23 56 mm. Novotechnik hollow shaft angle sensors offer high quality construction, precision and accept various shaft sizes and configurations. Assume that both the shaft has same length, material, and same weight and hence the same maximums shear stress. The strength of the hollow shaft is more than the solid shaft with same weight. Its extraordinarily broad hydraulic coverage is well complemented by its versatility. Shafts hollow shafts misumi features this shaft facilitates customers to arrange wiring, because the wire can be pierced into the inside of the shaft and contributes to weight saving of equipment, because the shaft is hollow. Advantage of hollow shaft over the solid shaft answer parth hollow shafts are cheaper than solid and having more flexibility and light weight in compared to solid shaft.
Power transmission in solid and hollow shaft exergic. The torsion of solid or hollow shafts polar moment of inertia of area. The stiffness of the hollow shaft is more than the solid shaft with same weight. The oem hollow shaft will be tortionally stiffer and with less vibration in the drivetrain, will allow all drivetrain components to have longer lives. Convert solid shaft to hollow shaft physics forums. The main technical characteristics of hollow shaft stepper motor are as follows. Determine the maximum shear stress developed in the shaft. What is the minimum diameter, d, of the solid shaft. Round hollow shaft mechanical properties minimum yield strength. Figure 1 shows a typical 2286 frame hollow shaft motor and figure 2 shows the 324405 frame construction. In the case of a shafted encoder, there is typically a flexible coupling between the encoder shaft and the motor shaft. Solid square shaft mechanical properties minimum yield strength.
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