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- Screw Jack Catalogue
Screw Jack Catalogue
Screw Jack Catalogue
Weingrill has been manufacturing mechanical screw jacks for over 40 years, providing reliable solutions for precise load positioning in various industrial applications. The company has been ISO 9001 certified since 1997. This document offers guidance on selecting the appropriate screw jack based on application requirements.
Screw jacks are available in capacities from 5 to 1500 kN, with various types and models offering a wide range of ratios and screw pitches. Customization is available to meet specific needs.
Screw jacks operate using a worm gear and screw system. The worm screw drives the worm gear, supported by bearings, causing the work screw to translate or rotate, depending on the jack type.
- Trapezoidal Screw Jack (TS): Made with high tensile materials, these jacks are irreversible and can support loads without additional locking systems.
- Ball Screw Jack (BS): Features a ball nut for high efficiency, with a work screw made of hardened steel.
- Stainless Steel Screw Jack (X): Suitable for corrosive environments, with special sealing to prevent contamination.
- Two Pinion Bevel Gears Jack (CC): Uses a bevel gear system for high-speed applications, requiring higher power ratings.
Screw jacks can be configured based on application needs:
- Base/Oscillating: For straight or arc movements.
- Upright/Inverted: Based on the direction of the work screw.
- Translating Screw (VT): The work screw moves axially.
- Rotating Screw (VR): The work screw rotates, moving an external nut.
Screw jacks can be equipped with anti-backlash and anti-rotation devices, and are available in various configurations such as with bases or oscillating designs. They can be driven manually or by motors, and can be combined with hydraulic cylinders for specialized applications.
1. Oscillating Jacks: Recommended for loads moving along an arc, featuring built-in clevis.
2. Upright/Inverted Units: Differ based on the work screw's extension relative to the base.
3. Translating Screw (VT): The work screw moves axially through the jack, requiring rotational constraints.
4. Rotating Screw (VR): The work screw rotates, moving a lead nut, with load applied to the nut.
- Work Screw: Options include trapezoidal or ball screws, with customizable dimensions and anti-rotation devices.
- Worm Screw: Available in various extensions with mechanical protection.
- Accessories: Include motor systems, couplings, limit switches, and manual operation tools.
- Can be operated manually or motorized, individually or in groups, ensuring synchronized movement.
- Must be protected from dust and corrosive environments during storage, with periodic lubrication and rotation.
- Ensure structural support and alignment to avoid lateral loads and uneven stress.
- Use flexible couplings for alignment errors and maintain synchronization.
- Protect work screws in dusty or wet environments.
- Verify lubrication and absence of foreign objects.
- Conduct manual idle runs before motor operation to check functionality.
- Avoid continuous testing to prevent overheating.
- Pre-lubricated with grease nipples for refilling.
- Monthly lubrication for normal use, weekly for high-duty operations.
- Regular inspection and cleaning recommended every 500 hours of operation.
- Based on load capacity (Fmax) and horsepower, ensuring capacity exceeds required load.
- Consider structural constraints and heat dissipation capabilities.
- Maximum recommended speed is 500 rpm, with adjustments for continuous service.
- Screw jacks are designed for thrust only and require an external guidance system for other loads.
- For anti-backlash screw jacks, reduce maximum load capacity to 90%.
- For continuous cycles, reduce maximum load capacity to 20%.
- Recommended maximum input speed is 500 rpm, with intermittent operation allowing up to 1500 rpm at reduced load capacity.
- High-frequency duty cycles should not exceed 10 minutes per hour to prevent overheating and reduce gearbox life.
- Formulas provided for calculating input torque and power based on load, screw pitch, and efficiency.
- Ensure calculated torque is below the maximum allowable torque.
- Static and dynamic efficiencies are provided, with reductions for anti-backlash and anti-rotation devices.
- Efficiency decreases with more jacks in the system; efficiency values are provided for different numbers of jacks.
- Overload capacity is 10% for dynamic and 25% for static loads.
- Safety factors are specified for different load types.
- Detailed example provided for selecting a screw jack based on load, speed, and efficiency requirements.
- Self-locking capabilities, mechanical stops, and stroke limitations are discussed.
- Guidance on handling side loads and critical work screw lengths is provided.
The document provides detailed specifications for various models of mechanical screw jacks, including rotating screw jacks and ball screw jacks. The models are categorized by their capacity, ranging from 5 kN to 1500 kN, and include dimensions for work screws, minimum screw lengths, and other critical measurements.
This section outlines the specifications for mechanical screw jacks with capacities from 5 kN to 1500 kN. It includes detailed dimensions for each model, such as work screw size, minimum screw length, and other relevant measurements.
Ball screw jacks are highlighted for their high efficiency, precise positioning, and uniform speed. They are available in sizes from 10 kN to 300 kN and feature a worm gear set with a ball nut for enhanced performance.
This section provides specifications for mechanical screw jacks with base, emphasizing their uniform translation speed, high speed, and efficiency. The models range from 10 kN to 300 kN, with gear ratios from 5:1 to 32:1. Both standard and stainless steel models are available, with various options for customization.
Oscillating screw jacks feature a double fork system and are noted for their uniform translation speed and high efficiency. They are available in capacities from 10 kN to 300 kN, with similar material specifications and options as the mechanical screw jacks with base.
All units are characterized by a numbered drawing that uniquely indicates the unit's dimensions and execution, making each screw jack unique and traceable. The document also includes notes on the standard models and options available for customization.
- Double clevis system ensures uniform translation speed, high speed, and high efficiency.
- Capacity ranges from 10 kN to 300 kN with gear ratios from 5:1 to 32:1.
- Standard model features a body made of nodular cast iron, a worm screw in high resistance stainless steel, a worm gear in special bronze, and a work screw in high resistance steel.
- Stainless steel model includes a body in cast stainless steel, a worm screw in high resistance stainless steel, a worm gear in special bronze, and a work screw hardened high tensile steel with an extending terminal in stainless steel.
- Mechanical stops are included for maximum extension, intended for emergency use only.
- Work screw threads are protected, and screw jacks come complete with greaser nipples and end shaft keys.
- Rotating screw version available upon request.
- Pre-loaded ball screw for zero backlash.
- Anti-rotation device and work screw protections in neoprene or with spiral spring.
- Additional guidance for the work screw and special sealing to avoid internal contamination.
- Standard models without an anti-rotation device require the end of the worm screw to be held in position to prevent rotation.
- Tables indicate overall dimensions and characteristics for standard models, with identical load capacity and dimensions for both standard and stainless steel versions.
- Models range from 01 to 30 with capacities from 10 kN to 225 kN.
- Work screw dimensions and other specifications are detailed in the tables, providing unique and traceable characteristics for each unit.
Specifications
Mechanical screw jacks are designed for use in aggressive or dusty environments. They require protection for the work screw to maintain proper lubrication and prevent contamination. Neoprene bellow boots and spiral springs are used for protection against dust, moisture, and corrosive agents.
For environments with dust and moisture, neoprene bellow boots are recommended. For protection against corrosive agents, spiral springs made of standard or stainless steel are used. The use of these protections may alter the dimensions of the screw jack compared to standard models.
Consult the Weingrill technical department for specific information regarding the dimensions and execution of the screw jacks. Recommended lubrication is with oil type EP220 or equivalent.
These are used in conjunction with couplings and connecting shafts for multiple jack arrangements. They come in three or four-way units with torque capacities up to 430 Nm and a gear ratio of 1:1. Options include stainless steel bodies and external parts.
These are suitable for slow and precise movements, with a capacity of 5 kN and a gear ratio of 40:1. They feature an anti-backlash device and are available in manual or motorized versions. Options include anti-rotation devices and stainless steel bodies.
Designed for high precision adjustments, these screws are self-locking and available in capacities ranging from 5 to 50 kN. They are made from stainless steel and special bronze, with tailored design options available.
Dimensions provided are typical for standard models. Each unit is uniquely identified by a numbered drawing, ensuring traceability and uniqueness.
Catalog excerpts
MARTINETTI MECCANICI MECHANICAL SCREW JACKS
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Indice Index Martinetti meccanici Weingrill Weingrill screw jacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 9) Arresti meccanici 9) Mechanical stops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Capacità e caratteristiche Sizes and characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 10) Corsa del martinetto 10) Screw jack stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Principi di funzionamento del martinetto vite senza fine Principles of operation of worm screw jack. . . . . . ....
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MARTINETTI MECCANICI MECHANICAL SCREW JACKS MARTINETTI MECCANICI WEINGRILL Da oltre 40 anni Weingrill produce martinetti utilizzati nelle più svariate applicazioni industriali, con ottimi risultati di funzionalità e durata. Il martinetto meccanico rappresenta la soluzione razionale ed affidabile, per movimentare carichi con precisione e mantenerli in posizione senza scorrimento per tempo indefinito. WEINGRILL SCREW JACKS Weingrill screw jacks have been used by the thousands for over 40 years in the most varied industrial applications with excellent functional and durability results. The mechanical...
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MARTINETTI MECCANICI MECHANICAL SCREW JACKS PRINCIPI DI FUNZIONAMENTO DEL MARTINETTO VITE SENZA FINE Il corpo del martinetto contiene la vite senza fine e la ruota elicoidale. La vite senza fine aziona la ruota elicoidale ed è supportata da cuscinetti a rulli conici, la ruota elicoidale è supportata da cuscinetti a sfere. La parte interna della ruota elicoidale costituisce la madrevite (chiocciola) della vite di lavoro, la sua rotazione comporta la traslazione o la rotazione della vite di lavoro in base al tipo di martinetto. PRINCIPLES OF OPERATION OF WORM SCREW JACK The jack housing contain...
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MARTINETTI MECCANICI MECHANICAL SCREW JACKS CONFIGURAZIONI I martinetti hanno diverse configurazioni a seconda della applicazione e dell’utilizzo. CONFIGURATIONS Screw jacks have different configuration in relation with the application. BASE / OSCILLANTE - B / O Nel caso in cui il carico si muova lungo una retta la configurazione tipica prevede un martinetto con base ed anello di centraggio. Per applicazioni con movimento del carico lungo un arco si consiglia l’utilizzo di martinetti oscillanti. Questi martinetti hanno le sedi per i perni ricavate direttamente nel corpo. BASE / OSCILLATING -...
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L'esperienza acquisita nel fornire martinetti costruiti secondo le necessita del cliente consente di proporre una vasta gamma di dotazioni, accessori e soluzioni. ■ Vite di lavoro trapezia o a ricircolazione di sfere. ■ Diametri, passi ed estremita con dimensioni a richiesta. ■ Dispositivo di recupero del gioco e anti-rotazione. ■ Guide aggiuntive ed arresti meccanici. ■ Protezioni flessibili o fisse, a spirale o telescopiche. Vite senza fine ■ Sporgenze doppie o semplici, ridotte o prolungate. ■ Protezione meccanica della sporgenza non utilizzata. ■ Rapporti speciali vite senza fine/ruota elicoidale...
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MARTINETTI MECCANICI MECHANICAL SCREW JACKSINSTALLAZIONE ■ Controllare che la struttura portante sia atta a sostenere il martinetto e il carico previsto. ■ Verificare la regolarita della superficie di appoggio. ■ Verificare che l'installazione sia eseguita in modo da non creare carichi laterali sulla vite di lavoro. ■ Verificare l'ortogonalita tra vite di lavoro e il piano di fissaggio del martinetto. ■ Verificare l'assialita tra il carico e la vite di lavoro. ■ Verificare che la vite senza fine non sia sottoposta a sollecitazioni anomale, dovute ad applicazione scorretta del motore e degli organi...
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■ I martinetti weingrill vengono forniti pre-lubrificati e sono dotati di ingrassatori per il ripristino in caso di necessita. ■ La lubrificazione della vite di lavoro e a cura dell'utilizzatore. ■ Per impiego normale ingrassare con frequenza mensile. ■ Per impegno gravoso ingrassare con frequenza settimanale. ■ Il corpo e riempito di lubrificante grasso minerale. In condizioni di impiego normali il corpo e lubrificato a vita. Poiche il grasso minerale decade dopo 2-3 anni, si consiglia la completa pulizia e sostituzione dopo tale periodo. ■ In caso di manovre frequenti o continue dotare i martinetti...
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MARTINETTI MECCANICI MECHANICAL SCREW JACKSSCELTA DEL MARTINETTO La scelta del martinetto e limitata da due vincoli: Capacita di carico e potenza applicata. La capacita di carico e limitata dalle caratteristiche strutturali dei suoi componenti. Il limite della potenza applicabile e il risultato della capacita del martinetto di dissipare il calore generato dagli attriti interni. ■ Selezionare un martinetto con capacita di carico (Fmax) superiore al carico richiesto. ■ La capacita indicata vale sia per martinetti in esecuzione ghisa-acciaio che in acciaio inossidabile. ■ La capacita di carico massima...
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MARTINETTI MECCANICI MECHANICAL SCREW JACKS2) Calcolo della coppia e della potenza Coppia in ingresso al martinetto per carico F: 2) Torque and power calculation Screw jack input torque for a given load F: Potenza in ingresso al martinetto per carico F: T = coppia in ingresso al martinetto [Nm] p = passo della vite di lavoro [mm] P = potenza in ingresso al martinetto [kW] V = velocita di spostamento della vite di lavoro [m/min] n = velocita in ingresso al martinetto [gir/min] Verificare che la coppia richiesta sia inferiore alia coppia massima ammissibile (Tmax ) indicata nella tab. 5/6. Se T...
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MARTINETTI MECCANICI MECHANICAL SCREW JACKS 5) Sovraccarichi II sovraccarico massimo consentito per servizio discontinue e di circa il 10% per carichi dinamici e del 25% per carichi statici. I fattori di sicurezza da considerare come riferimento, per definire il limite di rottura del martinetto rispetto alia sua capacita, sono: Overload capacity for intermittent operation is ax. 10% for dynamic load and 25% for static loads. To define the screw jack ultimate strength in relation with its capacity the following safety factors are considered: Load type Screw jacks connected: 2 Required speed 0.5...
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