1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232 
A New Worm Gear of High Efficiency
Page 135
If you've noticed an error in this article please click here to report it so we can fix it.
(\NE would have thought that everykJ thing possible regarding worm gearing had been discovered, but, apparently, this is not the case, for much experimental work by John Holnyd and Co., Ltd., Milnrow, Lancashire, has resulted in the perfecting of a new worm gear known as the Holroyd-Walker, which embodies a new form of worm thread which is claimed to give a larger contact than that of any other gear of this type. The thread design is such that it automatically forces the oil between the two surfaces, thus maintaining a permanent oil film, even under extremely heavy loads.
That these claims can be 'substantiated is shown by the remarkable results obtained during tests at the National Physical Laboratory, where the Daimler-Lanchester worm-gear testing machine was brought into service.
The particular pair of gears tested was a standard product, not run in or bedded down in any way before assembly in the testing machine, and after about two hours' running the worldrecord efficiency of 97.6 per cent, was obtained, this being sustained over a series of readings both at maximum and lighter loads and at various speeds. It is a remarkable fact that the highest efficiency was obtained under the maximum load, whereas in the previous world's record the figure of 97.3 was an isolated result obtained under the lightest load and at only one speed.
The worst conditions of the test in
volved a load of 86 b.h.p. at 2,000 Limn. The average power lost in the new gear is about 2.6 per cent, of the, input, whereas in the previous best results the loss was about 4.5 per cent., or about 75 per cent. greater. The temperature rise is directly proportional to the frictional loss ; consequently, it is in the ratio of 2.6 to 4.5, and it follows that the load capacity of the new gear should be 75 per cent, more than that of former types. If this proves to be the case in practice, it will enable smaller and more compact gears to be employed, thus effecting a saving in the weight and size of casings.
The worm-wheel used for the test was made from centrifugally east Super Holfos bronze,