According to the invention, the chamber includes radially internal walls (14) and radially external walls (12) connected by a bottom chamber wall having openings, each receiving a fuel injection system (18). Baffles (22) for protecting against heat are attached onto the bottom chamber wall (16). Bores (24) provided in the bottom chamber wall ensure the passage of cooling air on one surface upstream from each baffle (22). The inner or outer edge of a baffle (22) has a sealing wall (23f) sealing the inner or outer wall.
