10. Designing the gear speed reducer

10.1. Casing and cover wall thickness

- for single stage spur gear speed reducer  = 0.025·a_w +1 8 mm;

10.2. Flange thickness at the joint plane

b = 1.5·=1.5·8=12mm

10.3. Thickness of the flange for connection to a frame

p = 2.35·=2.35·8=18.8mm

10.4. Thickness of the rib

m =1·=8

10.5.Diameter of the anchor bolt

d₁ =0.03·a_L+12=0.03·125+12=15.75mm

d₁ =16mm

10.6. Number of anchor-bolts

z = 0.005·(L₀+B₀)=0.005(316+178)=2.47 Assume z=₄ 4,

where B₀ is thewidth of the speed reducer base; L₀ is the length of the speed reducer base.

10.7. Diameter of the tie-bolt near bearings

d₂ = 0.7·d₁=0.7·16=11.2 mm

d₂ =12mm

10.8. Diameter of tie bolts that connect the casing and the cover flanges

d₃ = 0.6·d₁=0.6·16=9.6mm

d₃=10mm

10.9. Distance between tie-bolts of diameter d₃

l = 10·d₃=100mm

11.10. Disposition of bolts on the flange

d1: x = 1·d_hole=1·19=19mmy =  + e=8+16=24mm

d1: x = 1·d_hole=1·14=14mm y =  + e=8+14=22mm

d1: x = 1·d_hole=1·11=11mm y =  + e=8+13=21mm

10.3.11. Height of the boss is determined from structural consideration taking into account the following requirement

q ³ 0.5·d₂ + d_k =0.5·12+10=16

where d_k is the diameter of the bolt, that connects the bearing cap with the casing.

The casing and the cover and to prevent their relative movement in axial direction two pins are used. They are placed along the flange diagonal. The diameter of the pin is determined as d_pin = 0.5·d₁=0.5·16=8 mm

10.11 For transition and installation the cover and the casing should be made with lifting eye-bolts or eyes and load hooks :

r = 1.5·δ=1.5·8=12mm; R = 3·δ=3·8=24mm; d = 3·δ=24mm;

a = (1.2…1.5)·δ=10.8mm; S=2.5* δ=20mm.

10.3.15. For gear inspection and lubrication an inspection hole is provided in the upper portion of the cover.

10.3.16. During operation, pressure inside a casing increases due to heating of the oil and air. As a result the lubricant is ejected outside through seals and joints. To avoid this fact air-vents are provided in the top portion of the casing for communication between the inner space and the environment.

Airvent

d1	d2	D	h	l	a	H1	H2	a1
12	20	32	40	12	5.5	29	24	13

10.3.17. For draining the oil with grit and other debris a drain hole is made in the casing bottom, which is stopped with a plug with either straight or taper thread.

10.3.18.The level of the oil contained in the speed-reducer casing is checked with oil gauges of various constructions.

Dip sticks

d	d1	d2	D	l1	l2	L
3	10	16	20	10	12	16