FCGear: Listwa zębata ewolwentowa
FCGear: Listwa zębata ewolwentowa |
Lokalizacja w menu |
---|
Gear → Listwa zębata ewolwentowa |
Środowisko pracy |
FCGear |
Domyślny skrót |
brak |
Wprowadzono w wersji |
v0.16 |
Zobacz także |
Koło zębate ewolwentowe |
Opis
Listwy zębate służą do przekształcania ruchu obrotowego w ruch liniowy lub odwrotnie. Poniższe przykłady pokazują różne zastosowania:
- Stojak z zamontowaną przekładnią przy jazie oporowym.
- Różne systemy zębatkowe w kolejach zębatkowych.
- Układ kierowniczy z zębatką w pojeździe.
- Wciągarka zębatkowa jako podnośnik mechaniczny (np. podnośnik samochodowy).
- Pneumatyczne napędy zębatkowe stosowane do sterowania zaworami w transporcie rurociągowym.
Od lewej do prawej: Przekładnia czołowa, przekładnia walcowa, podwójna przekładnia walcowa
Użycie
- Switch to the FCGear Workbench.
- There are several ways to invoke the command:
- Press the Involute Rack button in the toolbar.
- Select the Gear → Involute Rack option from the menu.
- Change the gear parameter to the required conditions (see Properties).
Properties
An FCGear InvoluteRack object is derived from a Part Feature object and inherits all its properties. It also has the following additional properties:
Data
base
- DANEadd_endings (
Bool
): Iftrue
(default), then the total length of the rack is teeth * pitch. Iffalse
, then the rack starts with a tooth-flank. - DANEheight (
Length
): Default is5 mm
. Value of the gear width. - DANEmodule (
Length
): Default is1 mm
. Module is the ratio of the reference diameter of the gear divided by the number of teeth (see Notes). - DANEteeth (
Integer
): Default is15
. Number of teeth. - DANEthickness (
Length
): Default is5
. Height from the tooth root to the lower side of the rod.
computed
- DANEtransverse_pitch (
Length
): (read-only) Pitch in the transverse plane (see Notes).
fillets
- DANEhead_fillet (
Float
): Default is0 mm
. - DANEroot_fillet (
Float
): Default is0 mm
.
helical
- DANEbeta (
Angle
): Default is0 °
. With the helix angle β a helical gear is created – positive value → rotation direction right, negative value → rotation direction left. - DANEdouble_helix (
Bool
): Default isfalse
,true
creates a double helix gear (see Notes). - DANEproperties_from_tool (
Bool
): Default isfalse
. Iftrue
and DANEbeta is not zero, gear parameters are recomputed internally for the rotated gear.
involute
- DANEpressure_angle (
Angle
): Default is20 °
(see Notes).
precision
- DANEsimplified (
Bool
): Default isfalse
,true
generates a simplified display (without teeth).
tolerance
- DANEclearance (
Float
): Default is0.25
(see Notes). - DANEhead (
Float
): Default is0
. This value is used to change the tooth height.
version
- DANEversion (
String
):
Notes
- transverse_pitch: The value is the result of multiplication of module * pi. This means for the standard involute rack of FCGear: 15 (teeth) * 3.14 (transverse_pitch) is 47.12 mm. See also module further below.
- clearance: At a gear pair, clearance is the distance between the tooth tip of the first gear and the tooth root of the second gear.
- double_helix: To use the double helical gearing the helix angle β (beta) for the helical gearing must first be entered.
- module: Using ISO (International Organization for Standardization) guidelines, Module size is designated as the unit representing gear tooth-sizes. Module (m): m = 1 (p = 3.1416), m = 2 (p = 6.2832), m = 4 (p = 12.566). If you multiply Module by Pi, you can obtain Pitch (p). Pitch is the distance between corresponding points on adjacent teeth. The result of the multiplication is displayed in transverse_pitch
- pressure_parameter: Only change the parameter, if sufficient knowledge of the gear geometry is available.
Useful formulas
See FCGear InvoluteGear.
Scripting
Use the power of python to automate your gear modeling:
import FreeCAD as App
import freecad.gears.commands
gear = freecad.gears.commands.CreateInvoluteRack.create()
gear.teeth = 20
gear.beta = 20
gear.height = 10
gear.double_helix = True
App.ActiveDocument.recompute()
Gui.SendMsgToActiveView("ViewFit")