helical bevel gear
螺旋伞齿轮，斜齿伞齿轮

• semi-diameter
• semi-direct lighting
• semi-dull
• semiellipsoid
• semiempirical
• semifield
• semi-finished blank
• semigloss
• semiindirect lighting
• semileaky type
• semilucent
• semilustrous
• semimatrix
• semimetal
• semiopaque
• semi-permeable membrane
• semi-planar electro-optic modulator
• semi-reflecting mirror
• semi-sphere
• semi-stable state
• semi-transmitting mirror
• semitransparent
• semitransparent mirror splitter
• semitransparent thin film
• semivitreous