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pulley vs. sheave

Discussion in 'Specialized Terminology' started by amianto, Oct 14, 2011.

  1. amianto Senior Member

    Mexico - Spanish
    Los expertos en la materia me pudieran aclarar estas dos palabras.

    Encontré que sheave is a pulley but that a sheave is not always a pulley.

    El caso es que tengo estos dos términos en un documento y no se como traducir sheave

    Por ejemplo: It may also be advantageous for the pulley contact faces of the V-belt to have a first planar surface disposed
    at a first angle for enganging a sheave and a cooperating second planar surface disposed at a second angle that does not engage with a sheave surface.

    Muchas gracias por la ayuda
     
  2. k-in-sc

    k-in-sc Senior Member

    Sheave is usually "polea," but if you're just talking about the groove, maybe "roldana." See what everybody else says.
     
  3. amianto Senior Member

    Mexico - Spanish
    Gracias pero no es roldana, a ver si alguien más puede ayudar.
     
  4. rodelu2 Senior Member

    Punta Fría, R.O. del U.
    Spanish-Uruguay
    "Pulley" y "Sheave" en lenguaje corriente describen el mismo objeto. En rigor, un sheave es una "polea" y si hay varias de ellas ansambladas y unidas por un "belt" o "rope" (correa o similar), forman un "pulley" o "polipasto". La roldana es una forma de sheave, limitada a usos manuales generalmente livianos como subir el balde de un aljibe mediante una soga o abrir y cerrar las cortinas de una ventana.
     
  5. k-in-sc

    k-in-sc Senior Member

    Thanks for that explanation. So what do you call the groove of the pulley?
     
  6. amianto Senior Member

    Mexico - Spanish
    Gracias rodelu2. Entonces en el párrafo que transcribí puedo usar igualmente polea para pulley and sheave?
     
  7. k-in-sc

    k-in-sc Senior Member

    Well, they're using "pulley" as a modifier.
     
  8. amianto Senior Member

    Mexico - Spanish
    Groove of the pulley - canal o garganta de la polea
     
  9. k-in-sc

    k-in-sc Senior Member

    You could say that then.
     
  10. rodelu2 Senior Member

    Punta Fría, R.O. del U.
    Spanish-Uruguay
    Dado que el original emplea los dos vocablos, cabe suponer que se refiere a cosas diferentes al usar uno u otro; el contexto tal vez pueda ayudarte.
     
  11. pops91710

    pops91710 Senior Member

    Siempre había escuchado la ranura de la polea o rodana.
     
  12. i.sanchez

    i.sanchez Junior Member

    Spanish
    Yo no confiaría mucho en eso, porque puede estar usando sinónimos para no repetir contínuamente la misma palabra.
    El tema de los sinónimos es algo que a veces me vuelve loco, porque hasta que descubro que los términos que tengo entre manos significan lo mismo, siempre estoy pensando que me he equivocado.
     
  13. k-in-sc

    k-in-sc Senior Member

    Yes, it's pretty clear from the context that the two terms are interchangeable. I don't see why you have to use different words.
     
  14. pops91710

    pops91710 Senior Member

    K-

    At best it is arguable. I see no difference and many dictionaries don't either. But many others will argue over it. In the refrigeration industry our blowers were all sheave driven. The drive motor had a either single or double sheaves. Browning calls them sheaves yet you'll find them listed in catalogs under pulleys and sheaves! http://www.fastenal.com/web/search/...WGNT2TKphGGVFx50FQyqpFYs!1371715272!694692565

    Every one I ever took out of the carton said sheave on the Browning factory stock label, not that makes anything official.
     
  15. rodelu2 Senior Member

    Punta Fría, R.O. del U.
    Spanish-Uruguay
    Uno de los "mandamientos" para quien escribe un texto técnico (y para quien lo traduce) es la consistencia: si has asignado un nombre a una pieza la primera vez que aparece en el texto, ese nombre se vuelve mandatorio, aunque crujan los cimientos del DRAE, el lector sabrá siempre a que pieza el autor se refiere. Todo esto no quita validez a tu observación, tal vez cambiaron de nombre para no aburrir.
     
  16. pops91710

    pops91710 Senior Member

    Bien dicho!!
     
  17. dsysk New Member

    Spanish-Spain
    I think sheave refers to the rolling element and pulley to the mechanical system using the means of sheave/s and ropes. What about a snatch block? how would you translate that?

    :mad:what is this?? I had a couple of links but as a new member I am not allowed to post'em...
     
  18. amianto Senior Member

    Mexico - Spanish
    Hola a todos. En un diccionario automotriz encontré que sheave es la canaleta o garganta de la polea donde asienta la banda o correa.

    ¿Que opinan?
     
  19. k-in-sc

    k-in-sc Senior Member

    That's what I thought. At any rate, "pulley" is a normal everyday term, whereas "sheave" is technical and most people wouldn't know what it was.
     
  20. dsysk New Member

    Spanish-Spain
    if yo use google images for pulley, sheave, snatch block, polea, polipasto etc.. you may be able to withdraw your own conclusions!
     
  21. k-in-sc

    k-in-sc Senior Member

    Draw your own conclusions ;)
     
  22. rodelu2 Senior Member

    Punta Fría, R.O. del U.
    Spanish-Uruguay
    We (royal "we") don't do "normal". There's nothing we enjoy more than calling a spade a soil-inverting horticultural implement. Welcome back!
     
  23. Sethi I

    Sethi I Senior Member

    Los Ángeles-Chile
    Spanish-Chile
    Hola:
    Investigué un tanto y llegue a vuestras mismas conclusiones, salvo que:
    La diferencia radica en lo siguiente (puesto que ya se entiende de que se trata):
    Pulley(polea): corresponde a tambores motrices o no (drive pulley) con acanaladuras(canaletas) o no, por los cuales pasan cintas transportadoras(conveyors). También se refiere a las diferentes poleas que utiliza un motor por ej. de auto, en las cuales la transmision, en vez de cintas, se realiza a traves de correas en V (V-belt) o bién correas planas acanaladas.
    Sheave(polea): corresponde(genericamente), al mismo tipo de elemento o dispositivo, salvo que, al utilizar esta palabra se refieren a aquellos utilizados por ej. en las gruas móviles por donde pasan los cables de tracción, también en aquellas grúas industriales montadas bajo techo y que se deslizan a traves de estructuras fijas (montacargas) accionadas electricamente, también a los tecles pequeños, manuales o eléctricos (de todo lo anterior me estoy refiriendo exclusivamente al elemento por donde pasan los cables, cuerdas, sogas, cadenas, etc)
    See you
     
  24. raaschjt New Member

    English - United States
    I think pulley is the most general term for a simple machine that changes the direction of a force by means of a rope or cable or belt going a around a wheel and axle. Sheave is merely a technical term for the same thing. Perhaps calling something a sheave as opposed to a pulley denotes it as being a pulley designed for a specific purpose, but not necessarily.
    A block is different in that it specifies a semi-enclosed pulley or sheave. It usually hangs by its sides instead of hook, but not necessarily. The snatch block is a specific type of pulley that can be opened so that you don't need to find the end of the rope to place it on the pulley.
     
  25. k-in-sc

    k-in-sc Senior Member

  26. raaschjt New Member

    English - United States
    That's a rather dubious wikipedia article. In my work as an aerial rigger we referred to regular, plain old pulleys as both sheaves and blocks. That's how we ordered them from catalogs and rigging stores from North Dakota wind farms to Texas oil rigs. Just saying. No need for some artificial distinction.
     
  27. kuchamaa

    kuchamaa Senior Member

    San Diego, California
    USA English
    A sheave is the wheel in the pulley. A block is the housing of the pulley.

    In the days of sailing ships, pulley housings were made of blocks of wood hence the name block.
     
  28. rodelu2 Senior Member

    Punta Fría, R.O. del U.
    Spanish-Uruguay
    Last edited: Feb 4, 2013

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